wip: editor stuff

2025-03-13 17:59:50 -07:00
474 changed files with 48026 additions and 46653 deletions
@@ -1,7 +1,15 @@
 ;;; Directory Local Variables            -*- no-byte-compile: t -*-
 ;;; For more information see (info "(emacs) Directory Variables")

-((c++-mode . ((c-file-style . "filament")
+((c++-mode . ((eval . (progn
+                        (make-local-variable 'eglot-ignored-server-capabilities)
+                        (add-to-list 'eglot-ignored-server-capabilities
+                                     :documentOnTypeFormattingProvider)))
+              (c-file-style . "filament")
              (apheleia-inhibit . t)))
- (c-mode . ((c-file-style . "filament")
+ (c-mode . ((eval . (progn
+                      (make-local-variable 'eglot-ignored-server-capabilities)
+                      (add-to-list 'eglot-ignored-server-capabilities
+                                   :documentOnTypeFormattingProvider)))
+            (c-file-style . "filament")
            (apheleia-inhibit . t))))
@@ -5,7 +5,7 @@ end_of_line = lf
 insert_final_newline = true
 charset = utf-8

-[*.{c,cpp,h,inc,kt,java,js,md}]
+[*.{c,cpp,h,inc,kt,java,js,md,fs,vs}]
 indent_style = space
 indent_size = 4
 max_line_length = 100
@@ -12,7 +12,7 @@ jobs:
    name: build-android
    # We intentially use a larger runner here to enable larger disk space
    # (standard linux runner will fail on disk space and faster build time).
-    runs-on: 'ubuntu-24.04-32core'
+    runs-on: ubuntu-22.04-32core

    steps:
      - uses: actions/checkout@v4.1.6
@@ -10,7 +10,7 @@ on:
 jobs:
  build-linux:
    name: build-linux
-    runs-on: 'ubuntu-24.04-16core'
+    runs-on: ubuntu-22.04-16core

    steps:
      - uses: actions/checkout@v4.1.6
@@ -40,7 +40,7 @@ jobs:

  build-android:
    name: build-android
-    runs-on: 'ubuntu-24.04-16core'
+    runs-on: ubuntu-22.04-16core

    steps:
      - uses: actions/checkout@v4.1.6
@@ -69,7 +69,7 @@ jobs:

  build-web:
    name: build-web
-    runs-on: 'ubuntu-24.04-16core'
+    runs-on: ubuntu-22.04-16core

    steps:
      - uses: actions/checkout@v4.1.6
@@ -79,7 +79,7 @@ jobs:

  validate-docs:
    name: validate-docs
-    runs-on: 'ubuntu-24.04-4core'
+    runs-on: ubuntu-22.04-4core
    steps:
      - uses: actions/checkout@v4.1.6
        with:
@@ -92,33 +92,26 @@ jobs:

  test-renderdiff:
    name: test-renderdiff
-    runs-on: macos-14-xlarge
+    runs-on: ubuntu-22.04-16core
+
    steps:
      - uses: actions/checkout@v4.1.6
-      - name: Set up Homebrew
-        id: set-up-homebrew
-        uses: Homebrew/actions/setup-homebrew@master
-      - name: Set up Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: '3.x'
-      - name: Install python prereqs
-        run: pip install mako setuptools pyyaml
+      - uses: ./.github/actions/ubuntu-apt-add-src
      - name: Run script
        run: |
-          bash test/renderdiff/test.sh
+          source ./build/linux/ci-common.sh && bash test/renderdiff/test.sh
      - uses: actions/upload-artifact@v4
        with:
          name: presubmit-renderdiff-result
          path: ./out/renderdiff_tests

-  validate-wgsl-webgpu:
-    name: validate-wgsl-webgpu
-    runs-on: 'ubuntu-24.04-8core'
+  validate-wgsl-pipeline:
+    name: validate-wgsl-pipeline
+    runs-on: macos-14-xlarge

    steps:
      - uses: actions/checkout@v4.1.6
      - name: Run build script
-        run: source ./build/linux/ci-common.sh && ./build.sh -W debug test_filamat filament
+        run: ./build.sh -W debug test_filamat
      - name: Run test
-        run: ./out/cmake-debug/libs/filamat/test_filamat --gtest_filter=MaterialCompiler.Wgsl*
+        run: ./out/cmake-debug/libs/filamat/test_filamat --gtest_filter=MaterialCompiler.Wgsl*
@@ -70,7 +70,7 @@ jobs:

  build-web:
    name: build-web
-    runs-on: 'ubuntu-24.04-16core'
+    runs-on: ubuntu-22.04-16core
    if: github.event_name == 'release' || github.event.inputs.platform == 'web'

    steps:
@@ -103,7 +103,7 @@ jobs:

  build-android:
    name: build-android
-    runs-on: 'ubuntu-24.04-16core'
+    runs-on: ubuntu-22.04-16core
    if: github.event_name == 'release' || github.event.inputs.platform == 'android'

    steps:
@@ -10,7 +10,7 @@ on:
 jobs:
  build-web:
    name: build-web
-    runs-on: 'ubuntu-24.04-16core'
+    runs-on: ubuntu-22.04-16core

    steps:
      - uses: actions/checkout@v4.1.6
@@ -139,14 +139,14 @@ else()
    set(LINUX FALSE)
 endif()

-if (NOT FILAMENT_OSMESA_PATH STREQUAL "")
-    if (NOT EXISTS ${FILAMENT_OSMESA_PATH}/)
-        message(FATAL_ERROR "Cannot find specified OSMesa build directory: ${FILAMENT_OSMESA_PATH}")
-    endif()
-    set(FILAMENT_SUPPORTS_OSMESA TRUE)
-endif()
-
 if (LINUX)
+    if (NOT FILAMENT_OSMESA_PATH STREQUAL "")
+        if (NOT EXISTS ${FILAMENT_OSMESA_PATH}/)
+            message(FATAL_ERROR "Cannot find specified OSMesa build directory: ${FILAMENT_OSMESA_PATH}")
+        endif()
+        set(FILAMENT_SUPPORTS_OSMESA TRUE)
+    endif()
+
    if (FILAMENT_SUPPORTS_WAYLAND)
        add_definitions(-DFILAMENT_SUPPORTS_WAYLAND)
        set(FILAMENT_SUPPORTS_X11 FALSE)
@@ -184,12 +184,6 @@ if (NOT ANDROID AND NOT WEBGL AND NOT IOS AND NOT FILAMENT_LINUX_IS_MOBILE)
    set(IS_HOST_PLATFORM TRUE)
 endif()

-if (APPLE)
-    if (FILAMENT_SUPPORTS_OSMESA)
-        add_definitions(-DFILAMENT_SUPPORTS_OSMESA)
-    endif()
-endif()
-
 if (WIN32)
    # Link statically against c/c++ lib to avoid missing redistriburable such as
    # "VCRUNTIME140.dll not found. Try reinstalling the app.", but give users
@@ -607,14 +601,6 @@ if (FILAMENT_SUPPORTS_METAL)
    set(MATC_API_FLAGS ${MATC_API_FLAGS} -a metal)
 endif()

-# With WebGPU, push constants are not supported. Skinning uses them.
-# WebGPU has a proposal to add push constants at https://github.com/gpuweb/gpuweb/blob/main/proposals/push-constants.md
-# With WebGPU, Tint does not support ClipDistance which is used in Stereo.  Mentioned in comment
-# https://github.com/google/dawn/blob/855d17b08abdf02f9142bf5a8f14d0ea088810a4/src/tint/lang/spirv/reader/ast_parser/function.cc#L4434
-if (FILAMENT_SUPPORTS_WEBGPU)
-    set(MATC_API_FLAGS ${MATC_API_FLAGS} -a webgpu --variant-filter=skinning,stereo)
-endif()
-
 # Disable ESSL 1.0 code generation.
 if (NOT FILAMENT_ENABLE_FEATURE_LEVEL_0)
    set(MATC_API_FLAGS ${MATC_API_FLAGS} -1)
@@ -31,7 +31,7 @@ repositories {
 }

 dependencies {
-    implementation 'com.google.android.filament:filament-android:1.59.1'
+    implementation 'com.google.android.filament:filament-android:1.58.0'
 }
 ```

@@ -51,7 +51,7 @@ Here are all the libraries available in the group `com.google.android.filament`:
 iOS projects can use CocoaPods to install the latest release:

 ```shell
-pod 'Filament', '~> 1.59.1'
+pod 'Filament', '~> 1.58.0'
 ```

 ## Documentation
@@ -7,17 +7,6 @@ A new header is inserted each time a *tag* is created.
 Instead, if you are authoring a PR for the main branch, add your release note to
 [NEW_RELEASE_NOTES.md](./NEW_RELEASE_NOTES.md).

-## v1.59.1
-
-
-## v1.59.0
-
- materials: five custom variables (varyings) are now available on the condition that the `color` attribute is not requested (b/404930099). [⚠️ **New Material Version**]
-
-## v1.58.2
-
- engine: Generate 1D instead of 3D LUTs for color grading whenever possible.
-
 ## v1.58.1


@@ -12,12 +12,12 @@ if (FILAMENT_SUPPORTS_VULKAN)
 endif()

 if (FILAMENT_SUPPORTS_WEBGPU)
-    # See third_party/dawn/tnt/CMakeLists.txt and libs/filamat/CMakeLists.txt
-    add_library(tint STATIC IMPORTED)
-    set_target_properties(tint PROPERTIES IMPORTED_LOCATION
-            ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libtint_combined.a)
+    add_library(webgpu_dawn STATIC IMPORTED)
+    set_target_properties(webgpu_dawn PROPERTIES IMPORTED_LOCATION
+            ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libwebgpu_dawn.a)
 endif()

+
 add_library(${FILAMAT_FLAVOR} STATIC IMPORTED)
 set_target_properties(${FILAMAT_FLAVOR} PROPERTIES IMPORTED_LOCATION
        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/lib${FILAMAT_FLAVOR}.a)
@@ -57,5 +57,5 @@ target_link_libraries(filamat-jni
        utils
        log
        smol-v
-        $<$<STREQUAL:${FILAMENT_SUPPORTS_WEBGPU},ON>:tint>
+        $<$<STREQUAL:${FILAMENT_SUPPORTS_WEBGPU},ON>:webgpu_dawn> # for tint
 )
@@ -29,6 +29,10 @@ add_library(filaflat STATIC IMPORTED)
 set_target_properties(filaflat PROPERTIES IMPORTED_LOCATION
        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libfilaflat.a)

+add_library(filamat STATIC IMPORTED)
+set_target_properties(filamat PROPERTIES IMPORTED_LOCATION
+        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libfilamat.a)
+
 add_library(geometry STATIC IMPORTED)
 set_target_properties(geometry PROPERTIES IMPORTED_LOCATION
        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libgeometry.a)
@@ -55,11 +59,11 @@ add_library(smol-v STATIC IMPORTED)
 set_target_properties(smol-v PROPERTIES IMPORTED_LOCATION
        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libsmol-v.a)

-if (FILAMENT_ENABLE_FGVIEWER)
-    add_library(fgviewer STATIC IMPORTED)
-    set_target_properties(fgviewer PROPERTIES IMPORTED_LOCATION
-            ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libfgviewer.a)
-endif()
+ if (FILAMENT_ENABLE_FGVIEWER)
+     add_library(fgviewer STATIC IMPORTED)
+     set_target_properties(fgviewer PROPERTIES IMPORTED_LOCATION
+             ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libfgviewer.a)
+ endif()

 if (FILAMENT_ENABLE_MATDBG)
    add_library(matdbg STATIC IMPORTED)
@@ -68,21 +68,6 @@ Java_com_google_android_filament_Texture_nIsTextureSwizzleSupported(JNIEnv*, jcl
    return (jboolean) Texture::isTextureSwizzleSupported(*engine);
 }

-
-extern "C" JNIEXPORT jint JNICALL
-Java_com_google_android_filament_Texture_nGetMaxTextureSize(JNIEnv *, jclass,
-        jlong nativeEngine, jint sampler) {
-    Engine *engine = (Engine *) nativeEngine;
-    return Texture::getMaxTextureSize(*engine, (Texture::Sampler)sampler);
-}
-
-extern "C" JNIEXPORT jint JNICALL
-Java_com_google_android_filament_Texture_nGetMaxArrayTextureLayers(JNIEnv *, jclass,
-        jlong nativeEngine) {
-    Engine *engine = (Engine *) nativeEngine;
-    return Texture::getMaxArrayTextureLayers(*engine);
-}
-
 extern "C" JNIEXPORT jboolean JNICALL
 Java_com_google_android_filament_Texture_nValidatePixelFormatAndType(JNIEnv*, jclass,
        jint internalFormat, jint pixelDataFormat, jint pixelDataType) {
@@ -46,8 +46,9 @@ import static com.google.android.filament.Asserts.assertFloat4In;
 *
 * <h1>Performance</h1>
 *
- * Creating a new ColorGrading object may be more expensive than other Filament objects as a LUT may
- * need to be generated. The generation of this LUT, if necessary, may happen on the CPU.
+ * Creating a new ColorGrading object may be more expensive than other Filament objects as a
+ * 3D LUT may need to be generated. The generation of a 3D LUT, if necessary, may happen on
+ * the CPU.
 *
 * <h1>Ordering</h1>
 *
@@ -159,10 +160,6 @@ public class ColorGrading {
         * quality level will use a 32x32x32 10 bit LUT, a high quality will use a 32x32x32 16 bit
         * LUT, and a ultra quality will use a 64x64x64 16 bit LUT.
         *
-         * This setting has no effect if generating a 1D LUT.
-         *
-         * This overrides the values set by format() and dimensions().
-         *
         * The default quality is {@link QualityLevel#MEDIUM}.
         *
         * @param qualityLevel The desired quality of the color grading process
@@ -178,8 +175,6 @@ public class ColorGrading {
         * When color grading is implemented using a 3D LUT, this sets the texture format of
         * of the LUT. This overrides the value set by quality().
         *
-         * This setting has no effect if generating a 1D LUT.
-         *
         * The default is INTEGER
         *
         * @param format The desired format of the 3D LUT.
@@ -195,8 +190,6 @@ public class ColorGrading {
         * When color grading is implemented using a 3D LUT, this sets the dimension of the LUT.
         * This overrides the value set by quality().
         *
-         * This setting has no effect if generating a 1D LUT.
-         *
         * The default is 32
         *
         * @param dim The desired dimension of the LUT. Between 16 and 64.
@@ -623,3 +616,4 @@ public class ColorGrading {

    private static native long nBuilderBuild(long nativeBuilder, long nativeEngine);
 }
+
@@ -691,24 +691,6 @@ public class Texture {
                pixelDataType.ordinal());
    }

-    /**
-     * @param engine {@link Engine}
-     * @param type Texture sampler type
-     * @return The maximum size in texels of a texture of type \p type. At least 2048 for
-     *         2D textures, 256 for 3D textures
-     */
-    public static int getMaxTextureSize(@NonNull Engine engine, Sampler type) {
-        return nGetMaxTextureSize(engine.getNativeObject(), type.ordinal());
-    }
-
-    /**
-     * @param engine {@link Engine}
-     * @return The maximum number of layers supported by texture arrays. At least 256.
-     */
-    public static int getMaxArrayTextureLayers(@NonNull Engine engine) {
-        return nGetMaxArrayTextureLayers(engine.getNativeObject());
-    }
-
    /**
     * Use <code>Builder</code> to construct a <code>Texture</code> object instance.
     */
@@ -1307,8 +1289,6 @@ public class Texture {
    private static native boolean nIsTextureFormatSupported(long nativeEngine, int internalFormat);
    private static native boolean nIsTextureFormatMipmappable(long nativeEngine, int internalFormat);
    private static native boolean nIsTextureSwizzleSupported(long nativeEngine);
-    private static native int nGetMaxTextureSize(long nativeObject, int ordinal);
-    private static native int nGetMaxArrayTextureLayers(long nativeObject);

    private static native boolean nValidatePixelFormatAndType(int internalFormat, int pixelDataFormat,
            int pixelDataType);
@@ -31,6 +31,8 @@ package com.google.android.filament;
 *   <li>DisplayRangeToneMapper</li>
 * </ul>
 * </ul>
+ *
+ * You can create custom tone mapping operators by subclassing ToneMapper.
 */
 public class ToneMapper {
    private final long mNativeObject;
@@ -1,5 +1,5 @@
 GROUP=com.google.android.filament
-VERSION_NAME=1.59.1
+VERSION_NAME=1.58.0

 POM_DESCRIPTION=Real-time physically based rendering engine for Android.

@@ -200,9 +200,8 @@ WEBGPU_ANDROID_GRADLE_OPTION=""
 EGL_ON_LINUX_OPTION="-DFILAMENT_SUPPORTS_EGL_ON_LINUX=OFF"

 MATDBG_OPTION="-DFILAMENT_ENABLE_MATDBG=OFF"
-MATDBG_GRADLE_OPTION=""
 FGVIEWER_OPTION="-DFILAMENT_ENABLE_FGVIEWER=OFF"
-FGVIEWER_GRADLE_OPTION=""
+MATDBG_GRADLE_OPTION=""

 MATOPT_OPTION=""
 MATOPT_GRADLE_OPTION=""
@@ -534,7 +533,6 @@ function build_android {
            ${VULKAN_ANDROID_GRADLE_OPTION} \
            ${WEBGPU_ANDROID_GRADLE_OPTION} \
            ${MATDBG_GRADLE_OPTION} \
-            ${FGVIEWER_GRADLE_OPTION} \
            ${MATOPT_GRADLE_OPTION} \
            :filament-android:assembleDebug \
            :gltfio-android:assembleDebug \
@@ -586,7 +584,6 @@ function build_android {
            ${VULKAN_ANDROID_GRADLE_OPTION} \
            ${WEBGPU_ANDROID_GRADLE_OPTION} \
            ${MATDBG_GRADLE_OPTION} \
-            ${FGVIEWER_GRADLE_OPTION} \
            ${MATOPT_GRADLE_OPTION} \
            :filament-android:assembleRelease \
            :gltfio-android:assembleRelease \
@@ -30,9 +30,6 @@ if [[ "$GITHUB_WORKFLOW" ]]; then
    sudo apt-get install clang-$GITHUB_CLANG_VERSION libc++-$GITHUB_CLANG_VERSION-dev libc++abi-$GITHUB_CLANG_VERSION-dev
    sudo apt-get install mesa-common-dev libxi-dev libxxf86vm-dev

-    # For dawn
-    sudo apt-get install libxrandr-dev libxinerama-dev libxcursor-dev libxi-dev libx11-xcb-dev
-
    sudo update-alternatives --install /usr/bin/cc cc /usr/bin/clang-${GITHUB_CLANG_VERSION} 100
    sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/clang++-${GITHUB_CLANG_VERSION} 100
 fi
@@ -13,7 +13,7 @@ This document is part of the [Filament project](https://github.com/google/filame
 ## Authors

 - [Romain Guy](https://github.com/romainguy), [@romainguy](https://twitter.com/romainguy)
- [Mathias Agopian](https://github.com/pixelflinger), [@pixelflinger](https://bsky.app/profile/pixelflinger.bsky.social)
+- [Mathias Agopian](https://github.com/pixelflinger), [@darthmoosious](https://twitter.com/darthmoosious)

 # Overview

@@ -78,27 +78,26 @@ in table [standardProperties].
        Property        |      Definition
 -----------------------:|:---------------------
 **baseColor**           | Diffuse albedo for non-metallic surfaces, and specular color for metallic surfaces
-**roughness**           | Perceived smoothness (1.0) or roughness (0.0) of a surface. Smooth surfaces exhibit sharp reflections
 **metallic**            | Whether a surface appears to be dielectric (0.0) or conductor (1.0). Often used as a binary value (0 or 1)
+**roughness**           | Perceived smoothness (1.0) or roughness (0.0) of a surface. Smooth surfaces exhibit sharp reflections
 **reflectance**         | Fresnel reflectance at normal incidence for dielectric surfaces. This directly controls the strength of the reflections
-**ambientOcclusion**    | Defines how much of the ambient light is accessible to a surface point. It is a per-pixel shadowing factor between 0.0 and 1.0
-**clearCoat**           | Strength of the clear coat layer
-**clearCoatRoughness**  | Perceived smoothness or roughness of the clear coat layer
-**clearCoatNormal**     | A detail normal used to perturb the clear coat layer using _bump mapping_ (_normal mapping_)
-**anisotropy**          | Amount of anisotropy in either the tangent or bitangent direction
-**anisotropyDirection** | Local surface direction in tangent space
-**thickness**           | Thickness of the solid volume of refractive objects
 **sheenColor**          | Strength of the sheen layer
 **sheenRoughness**      | Perceived smoothness or roughness of the sheen layer
-**emissive**            | Additional diffuse albedo to simulate emissive surfaces (such as neons, etc.) This property is mostly useful in an HDR pipeline with a bloom pass
+**clearCoat**           | Strength of the clear coat layer
+**clearCoatRoughness**  | Perceived smoothness or roughness of the clear coat layer
+**anisotropy**          | Amount of anisotropy in either the tangent or bitangent direction
+**anisotropyDirection** | Local surface direction in tangent space
+**ambientOcclusion**    | Defines how much of the ambient light is accessible to a surface point. It is a per-pixel shadowing factor between 0.0 and 1.0
 **normal**              | A detail normal used to perturb the surface using _bump mapping_ (_normal mapping_)
-**postLightingColor**   | Additional color that can be blended with the result of the lighting computations. See `postLightingBlending`
-**absorption**          | Absorption factor for refractive objects
-**transmission**        | Defines how much of the diffuse light of a dielectric is transmitted through the object, in other words this defines how transparent an object is
-**ior**                 | Index of refraction, either for refractive objects or as an alternative to reflectance
-**microThickness**      | Thickness of the thin layer of refractive objects
 **bentNormal**          | A normal pointing in the average unoccluded direction. Can be used to improve indirect lighting quality
-**shadowStrength**      | Strength factor between 0 and 1 for all shadows received by this material
+**clearCoatNormal**     | A detail normal used to perturb the clear coat layer using _bump mapping_ (_normal mapping_)
+**emissive**            | Additional diffuse albedo to simulate emissive surfaces (such as neons, etc.) This property is mostly useful in an HDR pipeline with a bloom pass
+**postLightingColor**   | Additional color that can be blended with the result of the lighting computations. See `postLightingBlending`
+**ior**                 | Index of refraction, either for refractive objects or as an alternative to reflectance
+**transmission**        | Defines how much of the diffuse light of a dielectric is transmitted through the object, in other words this defines how transparent an object is
+**absorption**          | Absorption factor for refractive objects
+**microThickness**      | Thickness of the thin layer of refractive objects
+**thickness**           | Thickness of the solid volume of refractive objects
 [Table [standardProperties]: Properties of the standard model]

 The type and range of each property is described in table [standardPropertiesTypes].
@@ -1273,9 +1272,6 @@ Description
      when selecting any shading model that is not `unlit`. See the shader sections of this document
      for more information on how to access these attributes from the shaders.

-!!! Note: Interaction with custom variables
-    When the `color` attribute is specified, only four custom variables are available instead of five.
-
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ JSON
 material {
    parameters : [
@@ -1306,7 +1302,7 @@ Type
 :    array of `string`

 Value
-:     Up to 5 strings, each must be a valid GLSL identifier.
+:     Up to 4 strings, each must be a valid GLSL identifier.

 Description
 :     Defines custom interpolants (or variables) that are output by the material's vertex shader.
@@ -1322,10 +1318,6 @@ Description
      particular if `default` is specified the default precision is used is the fragment shader
      (`mediump`) and in the vertex shader (`highp`).

-!!! Warning: Interaction with required attributes
-    If the `color` attribute is specified in the `required` list, then only four variables can be used
-    instead of five.
-
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ JSON
 material {
    name : Skybox,
@@ -108,12 +108,8 @@ if (FILAMENT_SUPPORTS_OPENGL AND NOT FILAMENT_USE_EXTERNAL_GLES3)
        list(APPEND SRCS src/opengl/platforms/PlatformCocoaTouchGL.mm)
        list(APPEND SRCS src/opengl/platforms/CocoaTouchExternalImage.mm)
    elseif (APPLE)
-        if (FILAMENT_SUPPORTS_OSMESA)
-            list(APPEND SRCS src/opengl/platforms/PlatformOSMesa.cpp)
-        else()
-            list(APPEND SRCS src/opengl/platforms/PlatformCocoaGL.mm)
-            list(APPEND SRCS src/opengl/platforms/CocoaExternalImage.mm)
-        endif()
+        list(APPEND SRCS src/opengl/platforms/PlatformCocoaGL.mm)
+        list(APPEND SRCS src/opengl/platforms/CocoaExternalImage.mm)
    elseif (WEBGL)
        list(APPEND SRCS src/opengl/platforms/PlatformWebGL.cpp)
    elseif (LINUX)
@@ -177,6 +173,27 @@ endif()
 if (FILAMENT_SUPPORTS_VULKAN)
    list(APPEND SRCS
            include/backend/platforms/VulkanPlatform.h
+            src/vulkan/caching/VulkanDescriptorSetManager.cpp
+            src/vulkan/caching/VulkanDescriptorSetManager.h
+            src/vulkan/caching/VulkanPipelineLayoutCache.cpp
+            src/vulkan/caching/VulkanPipelineLayoutCache.h
+            src/vulkan/memory/ResourceManager.cpp
+            src/vulkan/memory/ResourceManager.h
+            src/vulkan/memory/ResourcePointer.h
+            src/vulkan/memory/Resource.cpp
+            src/vulkan/memory/Resource.h
+            src/vulkan/platform/VulkanPlatform.cpp
+            src/vulkan/platform/VulkanPlatformSwapChainImpl.cpp
+            src/vulkan/platform/VulkanPlatformSwapChainImpl.h
+            src/vulkan/utils/Conversion.cpp
+            src/vulkan/utils/Conversion.h
+            src/vulkan/utils/Definitions.h
+            src/vulkan/utils/Helper.h
+            src/vulkan/utils/Image.h
+            src/vulkan/utils/Image.cpp
+            src/vulkan/utils/Spirv.h
+            src/vulkan/utils/Spirv.cpp
+            src/vulkan/utils/StaticVector.h
            src/vulkan/VulkanAsyncHandles.h
            src/vulkan/VulkanBlitter.cpp
            src/vulkan/VulkanBlitter.h
@@ -187,56 +204,29 @@ if (FILAMENT_SUPPORTS_VULKAN)
            src/vulkan/VulkanConstants.h
            src/vulkan/VulkanContext.cpp
            src/vulkan/VulkanContext.h
-            src/vulkan/VulkanDescriptorSetCache.cpp
-            src/vulkan/VulkanDescriptorSetCache.h
-            src/vulkan/VulkanDescriptorSetLayoutCache.cpp
-            src/vulkan/VulkanDescriptorSetLayoutCache.h
            src/vulkan/VulkanDriver.cpp
            src/vulkan/VulkanDriver.h
            src/vulkan/VulkanDriverFactory.h
-            src/vulkan/VulkanExternalImageManager.cpp
-            src/vulkan/VulkanExternalImageManager.h
            src/vulkan/VulkanFboCache.cpp
            src/vulkan/VulkanFboCache.h
            src/vulkan/VulkanHandles.cpp
            src/vulkan/VulkanHandles.h
-            src/vulkan/VulkanMemory.cpp
            src/vulkan/VulkanMemory.h
+            src/vulkan/VulkanMemory.cpp
            src/vulkan/VulkanPipelineCache.cpp
            src/vulkan/VulkanPipelineCache.h
-            src/vulkan/VulkanPipelineLayoutCache.cpp
-            src/vulkan/VulkanPipelineLayoutCache.h
            src/vulkan/VulkanQueryManager.cpp
            src/vulkan/VulkanQueryManager.h
-            src/vulkan/VulkanReadPixels.cpp
-            src/vulkan/VulkanReadPixels.h
            src/vulkan/VulkanSamplerCache.cpp
            src/vulkan/VulkanSamplerCache.h
            src/vulkan/VulkanStagePool.cpp
            src/vulkan/VulkanStagePool.h
            src/vulkan/VulkanSwapChain.cpp
            src/vulkan/VulkanSwapChain.h
+            src/vulkan/VulkanReadPixels.cpp
+            src/vulkan/VulkanReadPixels.h
            src/vulkan/VulkanTexture.cpp
            src/vulkan/VulkanTexture.h
-            src/vulkan/VulkanYcbcrConversionCache.cpp
-            src/vulkan/VulkanYcbcrConversionCache.h
-            src/vulkan/memory/Resource.cpp
-            src/vulkan/memory/Resource.h
-            src/vulkan/memory/ResourceManager.cpp
-            src/vulkan/memory/ResourceManager.h
-            src/vulkan/memory/ResourcePointer.h
-            src/vulkan/platform/VulkanPlatform.cpp
-            src/vulkan/platform/VulkanPlatformSwapChainImpl.cpp
-            src/vulkan/platform/VulkanPlatformSwapChainImpl.h
-            src/vulkan/utils/Conversion.cpp
-            src/vulkan/utils/Conversion.h
-            src/vulkan/utils/Definitions.h
-            src/vulkan/utils/Helper.h
-            src/vulkan/utils/Image.cpp
-            src/vulkan/utils/Image.h
-            src/vulkan/utils/Spirv.cpp
-            src/vulkan/utils/Spirv.h
-            src/vulkan/utils/StaticVector.h
    )
    if (LINUX OR WIN32)
        list(APPEND SRCS src/vulkan/platform/VulkanPlatformLinuxWindows.cpp)
@@ -252,31 +242,11 @@ endif()

 if (FILAMENT_SUPPORTS_WEBGPU)
    list(APPEND SRCS
-            include/backend/platforms/WebGPUPlatform.h
-            src/webgpu/platform/WebGPUPlatform.cpp
-            src/webgpu/WebGPUConstants.h
            src/webgpu/WebGPUDriver.cpp
            src/webgpu/WebGPUDriver.h
+            src/webgpu/WebGPUPlatform.cpp
+            src/webgpu/WebGPUPlatform.h
    )
-    if (WIN32)
-        list(APPEND SRCS src/webgpu/platform/WebGPUPlatformWindows.cpp)
-    elseif (LINUX)
-        list(APPEND SRCS src/webgpu/platform/WebGPUPlatformLinux.cpp)
-    elseif (APPLE OR IOS)
-        list(APPEND SRCS src/webgpu/platform/WebGPUPlatformApple.mm)
-    elseif (ANDROID)
-        list(APPEND SRCS src/webgpu/platform/WebGPUPlatformAndroid.cpp)
-    endif()
-
-    if (TNT_DEV)
-        set(FILAMENT_WEBGPU_IMMEDIATE_ERROR_HANDLING_DEFAULT ON)
-    else()
-        set(FILAMENT_WEBGPU_IMMEDIATE_ERROR_HANDLING_DEFAULT OFF)
-    endif()
-
-    option(FILAMENT_WEBGPU_IMMEDIATE_ERROR_HANDLING
-            "Enable immediate_error_handling for the WebGPU backend Dawn implementation"
-            ${FILAMENT_WEBGPU_IMMEDIATE_ERROR_HANDLING_DEFAULT})
 endif()

 if (ANDROID)
@@ -426,12 +396,9 @@ set(LINUX_LINKER_OPTIMIZATION_FLAGS
        -Wl,--exclude-libs,bluegl
 )

-if (FILAMENT_SUPPORTS_OSMESA)
-    if (LINUX)
-        set(OSMESA_COMPILE_FLAGS -I${FILAMENT_OSMESA_PATH}/include/GL)
-    elseif (APPLE)
-        set(OSMESA_COMPILE_FLAGS -I${FILAMENT_OSMESA_PATH}/include)
-    endif()
+if (LINUX AND FILAMENT_SUPPORTS_OSMESA)
+    set(OSMESA_COMPILE_FLAGS
+        -I${FILAMENT_OSMESA_PATH}/include/GL)
 endif()

 if (MSVC)
@@ -466,10 +433,6 @@ if (FILAMENT_SUPPORTS_METAL)
    target_compile_definitions(${TARGET} PRIVATE $<$<BOOL:${FILAMENT_METAL_PROFILING}>:FILAMENT_METAL_PROFILING>)
 endif()

-if (FILAMENT_SUPPORTS_WEBGPU)
-    target_compile_definitions(${TARGET} PRIVATE $<$<BOOL:${FILAMENT_WEBGPU_IMMEDIATE_ERROR_HANDLING}>:FILAMENT_WEBGPU_IMMEDIATE_ERROR_HANDLING>)
-endif()
-
 target_link_libraries(${TARGET} PRIVATE
        ${OSMESA_LINKER_FLAGS}
        $<$<AND:$<PLATFORM_ID:Linux>,$<CONFIG:Release>>:${LINUX_LINKER_OPTIMIZATION_FLAGS}>
@@ -498,9 +461,7 @@ if (APPLE OR LINUX)
        test/ShaderGenerator.cpp
        test/TrianglePrimitive.cpp
        test/Arguments.cpp
-        test/ImageExpectations.cpp
        test/Lifetimes.cpp
-        test/Shader.cpp
        test/test_FeedbackLoops.cpp
        test/test_Blit.cpp
        test/test_MissingRequiredAttributes.cpp
@@ -516,7 +477,6 @@ if (APPLE OR LINUX)
        test/test_Handles.cpp
    )
    set(BACKEND_TEST_LIBS
-        absl::str_format
        backend
        getopt
        gtest
@@ -532,7 +492,7 @@ if (APPLE AND NOT IOS)
    list(APPEND BACKEND_TEST_SRC
         test/test_RenderExternalImage.cpp)
    add_library(backend_test STATIC ${BACKEND_TEST_SRC})
-    target_link_libraries(backend_test PUBLIC ${BACKEND_TEST_LIBS})
+    target_link_libraries(backend_test PRIVATE ${BACKEND_TEST_LIBS})

    set(BACKEND_TEST_DEPS
            OSDependent
@@ -126,10 +126,6 @@ static_assert(MAX_VERTEX_BUFFER_COUNT <= MAX_VERTEX_ATTRIBUTE_COUNT,
 static constexpr size_t CONFIG_UNIFORM_BINDING_COUNT = 9;   // This is guaranteed by OpenGL ES.
 static constexpr size_t CONFIG_SAMPLER_BINDING_COUNT = 4;   // This is guaranteed by OpenGL ES.

-static constexpr uint8_t EXTERNAL_SAMPLER_DATA_INDEX_UNUSED =
-        uint8_t(-1);// Case where the descriptor set binding isnt using any external sampler state
-                     // and therefore doesn't have a valid entry.
-
 /**
 * Defines the backend's feature levels.
 */
@@ -256,21 +252,21 @@ struct DescriptorSetLayoutBinding {
    DescriptorFlags flags = DescriptorFlags::NONE;
    uint16_t count = 0;

-    //  TODO: uncomment when needed.  Note that this class is used as hash key.  We need to ensure
-    //  no uninitialized padding bytes.
-    //    uint8_t externalSamplerDataIndex = EXTERNAL_SAMPLER_DATA_INDEX_UNUSED;
-
-    friend inline bool operator==(DescriptorSetLayoutBinding const& lhs,
+    friend inline bool operator==(
+            DescriptorSetLayoutBinding const& lhs,
            DescriptorSetLayoutBinding const& rhs) noexcept {
        return lhs.type == rhs.type &&
               lhs.flags == rhs.flags &&
               lhs.count == rhs.count &&
               lhs.stageFlags == rhs.stageFlags;
-//               lhs.stageFlags == rhs.stageFlags &&
-//               lhs.externalSamplerDataIndex == rhs.externalSamplerDataIndex;
    }
 };

+struct DescriptorSetLayout {
+    utils::FixedCapacityVector<DescriptorSetLayoutBinding> bindings;
+};
+
+
 /**
 * Bitmask for selecting render buffers
 */
@@ -972,28 +968,8 @@ enum class SamplerCompareFunc : uint8_t {
    N           //!< Never. The depth / stencil test always fails.
 };

-//! this API is copied from (and only applies to) the Vulkan spec.
-//! These specify YUV to RGB conversions.
-enum class SamplerYcbcrModelConversion : uint8_t {
-    RGB_IDENTITY = 0,
-    YCBCR_IDENTITY = 1,
-    YCBCR_709 = 2,
-    YCBCR_601 = 3,
-    YCBCR_2020 = 4,
-};
-
-enum class SamplerYcbcrRange : uint8_t {
-    ITU_FULL = 0,
-    ITU_NARROW = 1,
-};
-
-enum class ChromaLocation : uint8_t {
-    COSITED_EVEN = 0,
-    MIDPOINT = 1,
-};
-
 //! Sampler parameters
-struct SamplerParams {             // NOLINT
+struct SamplerParams { // NOLINT
    SamplerMagFilter filterMag      : 1;    //!< magnification filter (NEAREST)
    SamplerMinFilter filterMin      : 3;    //!< minification filter  (NEAREST)
    SamplerWrapMode wrapS           : 2;    //!< s-coordinate wrap mode (CLAMP_TO_EDGE)
@@ -1048,7 +1024,6 @@ private:
        return SamplerParams::LessThan{}(lhs, rhs);
    }
 };
-
 static_assert(sizeof(SamplerParams) == 4);

 // The limitation to 64-bits max comes from how we store a SamplerParams in our JNI code
@@ -1056,95 +1031,6 @@ static_assert(sizeof(SamplerParams) == 4);
 static_assert(sizeof(SamplerParams) <= sizeof(uint64_t),
        "SamplerParams must be no more than 64 bits");

-//! Sampler parameters
-struct SamplerYcbcrConversion {// NOLINT
-    SamplerYcbcrModelConversion ycbcrModel : 4;
-    TextureSwizzle r : 4;
-    TextureSwizzle g : 4;
-    TextureSwizzle b : 4;
-    TextureSwizzle a : 4;
-    SamplerYcbcrRange ycbcrRange : 1;
-    ChromaLocation xChromaOffset : 1;
-    ChromaLocation yChromaOffset : 1;
-    SamplerMagFilter chromaFilter : 1;
-    uint8_t padding;
-
-    struct Hasher {
-        size_t operator()(const SamplerYcbcrConversion p) const noexcept {
-            // we don't use std::hash<> here, so we don't have to include <functional>
-            return *reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&p));
-        }
-    };
-
-    struct EqualTo {
-        bool operator()(SamplerYcbcrConversion lhs, SamplerYcbcrConversion rhs) const noexcept {
-            assert_invariant(lhs.padding == 0);
-            auto* pLhs = reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&lhs));
-            auto* pRhs = reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&rhs));
-            return *pLhs == *pRhs;
-        }
-    };
-
-    struct LessThan {
-        bool operator()(SamplerYcbcrConversion lhs, SamplerYcbcrConversion rhs) const noexcept {
-            assert_invariant(lhs.padding == 0);
-            auto* pLhs = reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&lhs));
-            auto* pRhs = reinterpret_cast<uint32_t const*>(reinterpret_cast<char const*>(&rhs));
-            return *pLhs < *pRhs;
-        }
-    };
-
-private:
-    friend inline bool operator == (SamplerYcbcrConversion lhs, SamplerYcbcrConversion rhs)
-            noexcept {
-        return SamplerYcbcrConversion::EqualTo{}(lhs, rhs);
-    }
-    friend inline bool operator != (SamplerYcbcrConversion lhs, SamplerYcbcrConversion rhs)
-            noexcept {
-        return  !SamplerYcbcrConversion::EqualTo{}(lhs, rhs);
-    }
-    friend inline bool operator < (SamplerYcbcrConversion lhs, SamplerYcbcrConversion rhs)
-            noexcept {
-        return SamplerYcbcrConversion::LessThan{}(lhs, rhs);
-    }
-};
-
-static_assert(sizeof(SamplerYcbcrConversion) == 4);
-
-static_assert(sizeof(SamplerYcbcrConversion) <= sizeof(uint64_t),
-        "SamplerYcbcrConversion must be no more than 64 bits");
-
-struct ExternalSamplerDatum {
-    ExternalSamplerDatum(SamplerYcbcrConversion ycbcr, SamplerParams spm, uint32_t extFmt)
-        : YcbcrConversion(ycbcr),
-          samplerParams(spm),
-          externalFormat(extFmt) {}
-    bool operator==(ExternalSamplerDatum const& rhs) const {
-        return (YcbcrConversion == rhs.YcbcrConversion && samplerParams == rhs.samplerParams &&
-                externalFormat == rhs.externalFormat);
-    }
-    struct EqualTo {
-        bool operator()(const ExternalSamplerDatum& lhs,
-                const ExternalSamplerDatum& rhs) const noexcept {
-            return (lhs.YcbcrConversion == rhs.YcbcrConversion &&
-                lhs.samplerParams == rhs.samplerParams &&
-                lhs.externalFormat == rhs.externalFormat);
-        }
-    };
-    SamplerYcbcrConversion YcbcrConversion;
-    SamplerParams samplerParams;
-    uint32_t externalFormat;
-};
-// No implicit padding allowed due to it being a hash key.
-static_assert(sizeof(ExternalSamplerDatum) == 12);
-
-struct DescriptorSetLayout {
-    utils::FixedCapacityVector<DescriptorSetLayoutBinding> bindings;
-
-//  TODO: uncomment when needed
-//    utils::FixedCapacityVector<ExternalSamplerDatum> externalSamplerData;
-};
-
 //! blending equation function
 enum class BlendEquation : uint8_t {
    ADD,                    //!< the fragment is added to the color buffer
@@ -33,7 +33,7 @@ public:
    PlatformCocoaGL();
    ~PlatformCocoaGL() noexcept override;

-    ExternalImageHandle UTILS_PUBLIC createExternalImage(void* cvPixelBuffer) noexcept;
+    ExternalImageHandle createExternalImage(void* cvPixelBuffer) noexcept;

 protected:
    // --------------------------------------------------------------------------------------------
@@ -32,7 +32,7 @@ public:
    PlatformCocoaTouchGL();
    ~PlatformCocoaTouchGL() noexcept override;

-    ExternalImageHandle UTILS_PUBLIC createExternalImage(void* cvPixelBuffer) noexcept;
+    ExternalImageHandle createExternalImage(void* cvPixelBuffer) noexcept;

    // --------------------------------------------------------------------------------------------
    // Platform Interface
@@ -50,7 +50,7 @@ public:
    /**
     * Creates an ExternalImage from a EGLImageKHR
     */
-    ExternalImageHandle UTILS_PUBLIC createExternalImage(EGLImageKHR eglImage) noexcept;
+    ExternalImageHandle createExternalImage(EGLImageKHR eglImage) noexcept;

 protected:
    // --------------------------------------------------------------------------------------------
@@ -23,7 +23,6 @@
 #include <backend/platforms/PlatformEGL.h>

 #include <utils/android/PerformanceHintManager.h>
-#include <utils/compiler.h>

 #include <chrono>

@@ -44,21 +43,8 @@ public:
    PlatformEGLAndroid() noexcept;
    ~PlatformEGLAndroid() noexcept override;

-    /**
-     * Creates an ExternalImage from a EGLImageKHR
-     */
-    ExternalImageHandle UTILS_PUBLIC createExternalImage(AHardwareBuffer const* buffer, bool sRGB) noexcept;
-
-    struct UTILS_PUBLIC ExternalImageDescAndroid {
-        uint32_t width;      // Texture width
-        uint32_t height;     // Texture height
-        TextureFormat format;// Texture format
-        TextureUsage usage;  // Texture usage flags
-    };
-
-    ExternalImageDescAndroid UTILS_PUBLIC getExternalImageDesc(ExternalImageHandle externalImage) noexcept;
-
 protected:
+
    // --------------------------------------------------------------------------------------------
    // Platform Interface

@@ -71,6 +57,11 @@ protected:
    Driver* createDriver(void* sharedContext,
            const Platform::DriverConfig& driverConfig) noexcept override;

+    /**
+     * Creates an ExternalImage from a EGLImageKHR
+     */
+    ExternalImageHandle createExternalImage(AHardwareBuffer const *buffer, bool sRGB) noexcept;
+
    // --------------------------------------------------------------------------------------------
    // OpenGLPlatform Interface

@@ -104,26 +95,15 @@ protected:
     */
    AcquiredImage transformAcquiredImage(AcquiredImage source) noexcept override;

-    OpenGLPlatform::ExternalTexture* createExternalImageTexture() noexcept override;
-    void destroyExternalImageTexture(ExternalTexture* texture) noexcept override;
+    bool setExternalImage(ExternalImageHandleRef externalImage, ExternalTexture* texture) noexcept override;

    struct ExternalImageEGLAndroid : public ExternalImageEGL {
        AHardwareBuffer* aHardwareBuffer = nullptr;
-        uint32_t width;      // Texture width
-        uint32_t height;     // Texture height
-        TextureFormat format;// Texture format
-        TextureUsage usage;  // Texture usage flags
        bool sRGB = false;
-
    protected:
        ~ExternalImageEGLAndroid() override;
    };

-    bool setExternalImage(ExternalImageHandleRef externalImage,
-            ExternalTexture* texture) noexcept override;
-    bool setImage(ExternalImageEGLAndroid const* eglExternalImage,
-            ExternalTexture* texture) noexcept;
-
 protected:
    bool makeCurrent(ContextType type,
            SwapChain* drawSwapChain,
@@ -21,12 +21,7 @@

 #include "bluegl/BlueGL.h"

-#if defined(__linux__)
 #include <osmesa.h>
-#elif defined(__APPLE__)
-#undef GLAPI
-#include <GL/osmesa.h>
-#endif

 #include <backend/platforms/OpenGLPlatform.h>
 #include <backend/DriverEnums.h>
@@ -18,7 +18,6 @@
 #define TNT_FILAMENT_BACKEND_PLATFORMS_VULKANPLATFORM_H

 #include <backend/Platform.h>
-#include <backend/DriverEnums.h>

 #include <bluevk/BlueVK.h>

@@ -298,16 +297,6 @@ public:
    VkQueue getProtectedGraphicsQueue() const noexcept;

    struct ExternalImageMetadata {
-        /**
-         * The Filament texture format.
-         */
-        TextureFormat filamentFormat;
-
-        /**
-         * The Filament texture usage.
-         */
-        TextureUsage filamentUsage;
-
        /**
         * The width of the external image
         */
@@ -318,21 +307,26 @@ public:
         */
        uint32_t height;

+        /**
+         * The layerCount of the external image
+         */
+        uint32_t layerCount;
+
        /**
         * The layer count of the external image
         */
        uint32_t layers;

-        /**
-         * The numbers of samples per texel
-         */
-        VkSampleCountFlagBits samples;
-
        /**
         * The format of the external image
         */
        VkFormat format;

+        /**
+         * An external buffer can be protected. This tells you if it is.
+         */
+        bool isProtected;
+
        /**
         * The type of external format (opaque int) if used.
         */
@@ -352,58 +346,25 @@ public:
         * Heap information
         */
        uint32_t memoryTypeBits;
-
-        /**
-         * Ycbcr conversion components
-         */
-        VkComponentMapping ycbcrConversionComponents;
-
-        /**
-         * Ycbcr model
-         */
-        VkSamplerYcbcrModelConversion ycbcrModel;
-
-        /**
-         * Ycbcr range
-         */
-        VkSamplerYcbcrRange ycbcrRange;
-
-        /**
-         * Ycbcr x chroma offset
-         */
-        VkChromaLocation xChromaOffset;
-
-        /**
-         * Ycbcr y chroma offset
-         */
-        VkChromaLocation yChromaOffset;
    };
-
-
-    // Note that the image metadata might change per-frame, hence we need a method for extracting
-    // it.
-    virtual ExternalImageMetadata extractExternalImageMetadata(ExternalImageHandleRef image) const {
-        return {};
-    }
+    virtual ExternalImageMetadata getExternalImageMetadata(ExternalImageHandleRef externalImage);

    using ImageData = std::pair<VkImage, VkDeviceMemory>;
-    virtual ImageData createVkImageFromExternal(ExternalImageHandleRef image) const {
-        return { VK_NULL_HANDLE, VK_NULL_HANDLE };
-    }
-
-protected:
-    virtual ExtensionSet getSwapchainInstanceExtensions() const;
-
-    using SurfaceBundle = std::tuple<VkSurfaceKHR, VkExtent2D>;
-    virtual SurfaceBundle createVkSurfaceKHR(void* nativeWindow, VkInstance instance,
-            uint64_t flags) const noexcept;
+    virtual ImageData createExternalImageData(ExternalImageHandleRef externalImage,
+            const ExternalImageMetadata& metadata);

 private:
-    // Platform dependent helper methods
-    static ExtensionSet getSwapchainInstanceExtensionsImpl();
+    static ExtensionSet getSwapchainInstanceExtensions();
+
+    static ExternalImageMetadata getExternalImageMetadataImpl(ExternalImageHandleRef externalImage,
+            VkDevice device);
+
+    static ImageData createExternalImageDataImpl(ExternalImageHandleRef externalImage,
+            VkDevice device, const ExternalImageMetadata& metadata);

    // Platform dependent helper methods
-    static SurfaceBundle createVkSurfaceKHRImpl(void* nativeWindow, VkInstance instance,
+    using SurfaceBundle = std::tuple<VkSurfaceKHR, VkExtent2D>;
+    static SurfaceBundle createVkSurfaceKHR(void* nativeWindow, VkInstance instance,
            uint64_t flags) noexcept;

    friend struct VulkanPlatformPrivate;
@@ -17,50 +17,27 @@
 #ifndef TNT_FILAMENT_BACKEND_PLATFORMS_VULKAN_PLATFORM_ANDROID_H
 #define TNT_FILAMENT_BACKEND_PLATFORMS_VULKAN_PLATFORM_ANDROID_H

-#include <backend/DriverEnums.h>
-#include <backend/platforms/VulkanPlatform.h>
+#include <backend/Platform.h>

 #include <android/hardware_buffer.h>

-namespace filament::backend {
+namespace filament::backend::fvkandroid {

-class VulkanPlatformAndroid : public VulkanPlatform {
-public:
-    ExternalImageHandle UTILS_PUBLIC createExternalImage(AHardwareBuffer const* buffer,
-            bool sRGB) noexcept;
-
-    struct UTILS_PUBLIC ExternalImageDescAndroid {
-        uint32_t width;      // Texture width
-        uint32_t height;     // Texture height
-        TextureFormat format;// Texture format
-        TextureUsage usage;  // Texture usage flags
-    };
-
-    ExternalImageDescAndroid UTILS_PUBLIC getExternalImageDesc(
-            ExternalImageHandleRef externalImage) const noexcept;
-
-    virtual ExternalImageMetadata extractExternalImageMetadata(
-            ExternalImageHandleRef image) const override;
-
-    virtual ImageData createVkImageFromExternal(ExternalImageHandleRef image) const override;
+struct ExternalImageVulkanAndroid : public Platform::ExternalImage {
+    AHardwareBuffer* aHardwareBuffer = nullptr;
+    bool sRGB = false;
+    unsigned int width;   // Texture width
+    unsigned int height;  // Texture height
+    TextureFormat format; // Texture format
+    TextureUsage usage;   // Texture usage flags

 protected:
-    virtual ExtensionSet getSwapchainInstanceExtensions() const override;
-
-    using SurfaceBundle = VulkanPlatform::SurfaceBundle;
-    virtual SurfaceBundle createVkSurfaceKHR(void* nativeWindow, VkInstance instance,
-            uint64_t flags) const noexcept override;
-
-private:
-    struct ExternalImageVulkanAndroid : public Platform::ExternalImage {
-        AHardwareBuffer* aHardwareBuffer = nullptr;
-        bool sRGB = false;
-
-    protected:
-        ~ExternalImageVulkanAndroid() override;
-    };
+    ~ExternalImageVulkanAndroid() override;
 };

-}// namespace filament::backend
+Platform::ExternalImageHandle createExternalImage(AHardwareBuffer const* buffer,
+        bool sRGB) noexcept;

-#endif// TNT_FILAMENT_BACKEND_PLATFORMS_VULKAN_PLATFORM_ANDROID_H
+} // namespace filament::backend::fvkandroid
+
+#endif // TNT_FILAMENT_BACKEND_PLATFORMS_VULKAN_PLATFORM_ANDROID_H
@@ -1,59 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef TNT_FILAMENT_BACKEND_PLATFORMS_WEBGPUPLATFORM_H
-#define TNT_FILAMENT_BACKEND_PLATFORMS_WEBGPUPLATFORM_H
-
-#include <backend/Platform.h>
-
-#include <webgpu/webgpu_cpp.h>
-
-#include <cstdint>
-
-namespace filament::backend {
-
-/**
- * A Platform interface, handling the environment-specific concerns, e.g. OS, for creating a WebGPU
- * driver (backend).
- */
-class WebGPUPlatform final : public Platform {
-public:
-    WebGPUPlatform();
-    ~WebGPUPlatform() override = default;
-
-    [[nodiscard]] int getOSVersion() const noexcept final { return 0; }
-
-    [[nodiscard]] wgpu::Instance& getInstance() noexcept { return mInstance; }
-
-    // either returns a valid surface or panics
-    [[nodiscard]] wgpu::Surface createSurface(void* nativeWindow, uint64_t flags);
-    // either returns a valid adapter or panics
-    [[nodiscard]] wgpu::Adapter requestAdapter(wgpu::Surface const& surface);
-    // either returns a valid device or panics
-    [[nodiscard]] wgpu::Device requestDevice(wgpu::Adapter const& adapter);
-
-protected:
-    [[nodiscard]] Driver* createDriver(void* sharedContext,
-            const Platform::DriverConfig& driverConfig) noexcept override;
-
-private:
-    // we may consider having the driver own this in the future
-    wgpu::Instance mInstance;
-};
-
-}// namespace filament::backend
-
-#endif// TNT_FILAMENT_BACKEND_PLATFORMS_WEBGPUPLATFORM_H
@@ -362,8 +362,6 @@ DECL_DRIVER_API_SYNCHRONOUS_0(bool, isProtectedTexturesSupported)
 DECL_DRIVER_API_SYNCHRONOUS_0(bool, isDepthClampSupported)
 DECL_DRIVER_API_SYNCHRONOUS_0(uint8_t, getMaxDrawBuffers)
 DECL_DRIVER_API_SYNCHRONOUS_0(size_t, getMaxUniformBufferSize)
-DECL_DRIVER_API_SYNCHRONOUS_N(size_t, getMaxTextureSize, backend::SamplerType, target)
-DECL_DRIVER_API_SYNCHRONOUS_0(size_t, getMaxArrayTextureLayers)
 DECL_DRIVER_API_SYNCHRONOUS_0(math::float2, getClipSpaceParams)
 DECL_DRIVER_API_SYNCHRONOUS_N(void, setupExternalImage2, backend::Platform::ExternalImageHandleRef, image)
 DECL_DRIVER_API_SYNCHRONOUS_N(void, setupExternalImage, void*, image)
@@ -40,11 +40,9 @@
 #include <stddef.h>
 #include <stdint.h>

-#define HandleAllocatorGL   HandleAllocator<32,  96, 184>    // ~4520 / pool / MiB
-#define HandleAllocatorVK   HandleAllocator<64, 160, 312>    // ~1820 / pool / MiB
-#define HandleAllocatorMTL  HandleAllocator<32,  64, 552>    // ~1660 / pool / MiB
-// TODO WebGPU examine right size of handles
-#define HandleAllocatorWGPU HandleAllocator<64, 160, 552>    // ~1820 / pool / MiB
+#define HandleAllocatorGL  HandleAllocator<32,  96, 184>    // ~4520 / pool / MiB
+#define HandleAllocatorVK  HandleAllocator<64, 160, 312>    // ~1820 / pool / MiB
+#define HandleAllocatorMTL HandleAllocator<32,  64, 552>    // ~1660 / pool / MiB

 namespace filament::backend {

@@ -211,8 +211,4 @@ template class HandleAllocatorVK;
 template class HandleAllocatorMTL;
 #endif

-#if defined (FILAMENT_SUPPORTS_WEBGPU)
-template class HandleAllocatorWGPU;
-#endif
-
 } // namespace filament::backend
@@ -19,11 +19,6 @@
 #include <utils/Systrace.h>
 #include <utils/debug.h>

-// We need to keep this up top for the linux (X11) name collisions.
-#if defined(FILAMENT_SUPPORTS_WEBGPU)
-    #include "backend/platforms/WebGPUPlatform.h"
-#endif
-
 #if defined(__ANDROID__)
    #include <sys/system_properties.h>
    #if defined(FILAMENT_SUPPORTS_OPENGL) && !defined(FILAMENT_USE_EXTERNAL_GLES3)
@@ -35,11 +30,7 @@
    #endif
 #elif defined(__APPLE__)
    #if defined(FILAMENT_SUPPORTS_OPENGL) && !defined(FILAMENT_USE_EXTERNAL_GLES3)
-        #if defined(FILAMENT_SUPPORTS_OSMESA)
-            #include <backend/platforms/PlatformOSMesa.h>
-        #else
-            #include <backend/platforms/PlatformCocoaGL.h>
-        #endif
+        #include <backend/platforms/PlatformCocoaGL.h>
    #endif
 #elif defined(__linux__)
    #if defined(FILAMENT_SUPPORTS_X11)
@@ -64,11 +55,7 @@
 #endif

 #if defined(FILAMENT_DRIVER_SUPPORTS_VULKAN)
-    #if defined(__ANDROID__)
-        #include "backend/platforms/VulkanPlatformAndroid.h"
-    #else
-        #include "backend/platforms/VulkanPlatform.h"
-    #endif
+    #include "backend/platforms/VulkanPlatform.h"
 #endif

 #if defined (FILAMENT_SUPPORTS_METAL)
@@ -78,6 +65,9 @@ filament::backend::Platform* createDefaultMetalPlatform();
 #endif

 #include "noop/PlatformNoop.h"
+#if defined(FILAMENT_SUPPORTS_WEBGPU)
+    #include "webgpu/WebGPUPlatform.h"
+#endif

 namespace filament::backend {

@@ -114,11 +104,7 @@ Platform* PlatformFactory::create(Backend* backend) noexcept {
    }
    if (*backend == Backend::VULKAN) {
        #if defined(FILAMENT_DRIVER_SUPPORTS_VULKAN)
-            #if defined(__ANDROID__)
-                return new VulkanPlatformAndroid();
-            #else
-                return new VulkanPlatform();
-            #endif
+            return new VulkanPlatform();
        #else
            return nullptr;
        #endif
@@ -146,11 +132,7 @@ Platform* PlatformFactory::create(Backend* backend) noexcept {
        #elif defined(FILAMENT_IOS)
            return new PlatformCocoaTouchGL();
        #elif defined(__APPLE__)
-            #if defined(FILAMENT_SUPPORTS_OSMESA)
-                return new PlatformOSMesa();
-            #else
-                return new PlatformCocoaGL();
-            #endif
+            return new PlatformCocoaGL();
        #elif defined(__linux__)
            #if defined(FILAMENT_SUPPORTS_X11)
                return new PlatformGLX();
@@ -1177,24 +1177,6 @@ size_t MetalDriver::getMaxUniformBufferSize() {
    return 256 * 1024 * 1024;   // TODO: return the actual size instead of hardcoding the minspec
 }

-size_t MetalDriver::getMaxTextureSize(SamplerType type) {
-    if (type == SamplerType::SAMPLER_3D) {
-        return 2048;
-    }
-    if (mContext->highestSupportedGpuFamily.apple >= 3 ||
-            mContext->highestSupportedGpuFamily.mac >= 2) {
-        return 16384;
-    } else if (mContext->highestSupportedGpuFamily.apple >= 2) {
-        return 8192;
-    }
-    return 4096;
-}
-
-size_t MetalDriver::getMaxArrayTextureLayers() {
-    // TODO: return the actual size instead of hardcoding the minspec
-    return 256;
-}
-
 void MetalDriver::updateIndexBuffer(Handle<HwIndexBuffer> ibh, BufferDescriptor&& data,
        uint32_t byteOffset) {
    FILAMENT_CHECK_PRECONDITION(data.buffer)
@@ -240,16 +240,6 @@ size_t NoopDriver::getMaxUniformBufferSize() {
    return 16384u;
 }

-size_t NoopDriver::getMaxTextureSize(SamplerType target) {
-    // NoopDriver is being actively used for other purposes.  This needs to be resolved before we
-    // can change it to 2048. b/406832484
-    return 16384u;
-}
-
-size_t NoopDriver::getMaxArrayTextureLayers() {
-    return 256u;
-}
-
 void NoopDriver::updateIndexBuffer(Handle<HwIndexBuffer> ibh, BufferDescriptor&& p,
        uint32_t byteOffset) {
    scheduleDestroy(std::move(p));
@@ -20,7 +20,7 @@

 namespace filament::backend {

-Driver* PlatformNoop::createDriver(void* sharedGLContext, const Platform::DriverConfig& driverConfig) noexcept {
+Driver* PlatformNoop::createDriver(void* const sharedGLContext, const Platform::DriverConfig& driverConfig) noexcept {
    return NoopDriver::create();
 }

@@ -94,22 +94,18 @@ OpenGLContext::OpenGLContext(OpenGLPlatform& platform,
    }
    #endif

-    initExtensions(&ext, state.major, state.minor);
+    OpenGLContext::initExtensions(&ext, state.major, state.minor);

-    initProcs(&procs, ext, state.major, state.minor);
+    OpenGLContext::initProcs(&procs, ext, state.major, state.minor);

-    initBugs(&bugs, ext, state.major, state.minor,
+    OpenGLContext::initBugs(&bugs, ext, state.major, state.minor,
            state.vendor, state.renderer, state.version, state.shader);

    glGetIntegerv(GL_MAX_RENDERBUFFER_SIZE,             &gets.max_renderbuffer_size);
    glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS,           &gets.max_texture_image_units);
    glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS,  &gets.max_combined_texture_image_units);
-    glGetIntegerv(GL_MAX_TEXTURE_SIZE,                  &gets.max_texture_size);
-    glGetIntegerv(GL_MAX_CUBE_MAP_TEXTURE_SIZE,         &gets.max_cubemap_texture_size);
-    glGetIntegerv(GL_MAX_3D_TEXTURE_SIZE,               &gets.max_3d_texture_size);
-    glGetIntegerv(GL_MAX_ARRAY_TEXTURE_LAYERS,          &gets.max_array_texture_layers);

-    mFeatureLevel = resolveFeatureLevel(state.major, state.minor, ext, gets, bugs);
+    mFeatureLevel = OpenGLContext::resolveFeatureLevel(state.major, state.minor, ext, gets, bugs);

 #ifdef BACKEND_OPENGL_VERSION_GLES
    mShaderModel = ShaderModel::MOBILE;
@@ -181,14 +177,6 @@ OpenGLContext::OpenGLContext(OpenGLPlatform& platform,
                    << gets.max_anisotropy << '\n'
            << "GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS = "
                    << gets.max_combined_texture_image_units << '\n'
-            << "GL_MAX_TEXTURE_SIZE = "
-                    << gets.max_texture_size << '\n'
-            << "GL_MAX_CUBE_MAP_TEXTURE_SIZE = "
-                    << gets.max_cubemap_texture_size << '\n'
-            << "GL_MAX_3D_TEXTURE_SIZE = "
-                    << gets.max_3d_texture_size << '\n'
-            << "GL_MAX_ARRAY_TEXTURE_LAYERS = "
-                    << gets.max_array_texture_layers << '\n'
            << "GL_MAX_DRAW_BUFFERS = "
                    << gets.max_draw_buffers << '\n'
            << "GL_MAX_RENDERBUFFER_SIZE = "
@@ -566,11 +554,7 @@ void OpenGLContext::initBugs(Bugs* bugs, Extensions const& exts,
        } else if (strstr(renderer, "AMD") ||
                   strstr(renderer, "ATI")) {
            // AMD/ATI GPU
-        } else if (strstr(renderer, "Mozilla")) {
-            bugs->disable_invalidate_framebuffer = true;
-        }
-
-        if (strstr(vendor, "Mesa")) {
+        } else if (strstr(vendor, "Mesa")) {
            // Seen on
            //  [Mesa],
            //  [llvmpipe (LLVM 17.0.6, 256 bits)],
@@ -578,6 +562,8 @@ void OpenGLContext::initBugs(Bugs* bugs, Extensions const& exts,
            //  [4.50]
            // not known which version are affected
            bugs->rebind_buffer_after_deletion = true;
+        } else if (strstr(renderer, "Mozilla")) {
+            bugs->disable_invalidate_framebuffer = true;
        }
    } else {
        // When running under ANGLE, it's a different set of workaround that we need.
@@ -589,19 +575,6 @@ void OpenGLContext::initBugs(Bugs* bugs, Extensions const& exts,
        }
    }

-    if (strstr(vendor, "Mozilla")) {
-        // Seen on
-        //  [Mozilla],
-        //  [GeForce GTX 980, or similar]
-        //    or [ANGLE (NVIDIA, NVIDIA GeForce GTX 980 Direct3D11 vs_5_0 ps_5_0), or similar]
-        //    or anything else,
-        //  [OpenGL ES 3.0 (WebGL 2.0)],
-        //  [OpenGL ES GLSL ES 3.00 (WebGL GLSL ES 3.00)]
-        // For Mozilla, the issue appears to be observed regardless of whether the renderer is
-        // ANGLE or not. (b/376125497)
-        bugs->rebind_buffer_after_deletion = true;
-    }
-
 #ifdef BACKEND_OPENGL_VERSION_GLES
 #   ifndef FILAMENT_IOS // FILAMENT_IOS is guaranteed to have ES3.x
    if (UTILS_UNLIKELY(major == 2)) {
@@ -203,10 +203,6 @@ public:
        GLint max_renderbuffer_size;
        GLint max_samples;
        GLint max_texture_image_units;
-        GLint max_texture_size;
-        GLint max_cubemap_texture_size;
-        GLint max_3d_texture_size;
-        GLint max_array_texture_layers;
        GLint max_transform_feedback_separate_attribs;
        GLint max_uniform_block_size;
        GLint max_uniform_buffer_bindings;
@@ -320,8 +316,8 @@ public:
        // a glFinish. So we must delay the destruction until we know the GPU is finished.
        bool delay_fbo_destruction;

-        // Mesa and Mozilla(web) sometimes clear the generic buffer binding when *another* buffer
-        // is destroyed, if that other buffer is bound on an *indexed* buffer binding.
+        // Mesa sometimes clears the generic buffer binding when *another* buffer is destroyed,
+        // if that other buffer is bound on an *indexed* buffer binding.
        bool rebind_buffer_after_deletion;

        // Force feature level 0. Typically used for low end ES3 devices with significant driver
@@ -148,8 +148,8 @@ using namespace utils;
 namespace filament::backend {

 Driver* OpenGLDriverFactory::create(
-        OpenGLPlatform* platform,
-        void* sharedGLContext,
+        OpenGLPlatform* const platform,
+        void* const sharedGLContext,
        const Platform::DriverConfig& driverConfig) noexcept {
    return OpenGLDriver::create(platform, sharedGLContext, driverConfig);
 }
@@ -159,10 +159,10 @@ using namespace GLUtils;
 // ------------------------------------------------------------------------------------------------

 UTILS_NOINLINE
-OpenGLDriver* OpenGLDriver::create(OpenGLPlatform* platform,
-        void* /*sharedGLContext*/, const Platform::DriverConfig& driverConfig) noexcept {
+OpenGLDriver* OpenGLDriver::create(OpenGLPlatform* const platform,
+        void* const /*sharedGLContext*/, const Platform::DriverConfig& driverConfig) noexcept {
    assert_invariant(platform);
-    OpenGLPlatform* ec = platform;
+    OpenGLPlatform* const ec = platform;

 #if 0
    // this is useful for development, but too verbose even for debug builds
@@ -230,7 +230,7 @@ OpenGLDriver* OpenGLDriver::create(OpenGLPlatform* platform,
    constexpr size_t defaultSize = FILAMENT_OPENGL_HANDLE_ARENA_SIZE_IN_MB * 1024U * 1024U;
    Platform::DriverConfig validConfig{ driverConfig };
    validConfig.handleArenaSize = std::max(driverConfig.handleArenaSize, defaultSize);
-    OpenGLDriver* driver = new(std::nothrow) OpenGLDriver(ec, validConfig);
+    OpenGLDriver* const driver = new(std::nothrow) OpenGLDriver(ec, validConfig);
    return driver;
 }

@@ -2460,26 +2460,6 @@ size_t OpenGLDriver::getMaxUniformBufferSize() {
    return mContext.gets.max_uniform_block_size;
 }

-size_t OpenGLDriver::getMaxTextureSize(SamplerType target) {
-    switch (target) {
-        case SamplerType::SAMPLER_2D:
-        case SamplerType::SAMPLER_2D_ARRAY:
-        case SamplerType::SAMPLER_EXTERNAL:
-            return mContext.gets.max_texture_size;
-        case SamplerType::SAMPLER_CUBEMAP:
-            return mContext.gets.max_cubemap_texture_size;
-        case SamplerType::SAMPLER_3D:
-            return mContext.gets.max_3d_texture_size;
-        case SamplerType::SAMPLER_CUBEMAP_ARRAY:
-            return mContext.gets.max_cubemap_texture_size;
-    }
-    return 0;
-}
-
-size_t OpenGLDriver::getMaxArrayTextureLayers() {
-    return mContext.gets.max_array_texture_layers;
-}
-
 // ------------------------------------------------------------------------------------------------
 // Swap chains
 // ------------------------------------------------------------------------------------------------
@@ -64,7 +64,7 @@ PlatformCocoaTouchGL::~PlatformCocoaTouchGL() noexcept {
    delete pImpl;
 }

-Driver* PlatformCocoaTouchGL::createDriver(void* sharedGLContext, const Platform::DriverConfig& driverConfig) noexcept {
+Driver* PlatformCocoaTouchGL::createDriver(void* const sharedGLContext, const Platform::DriverConfig& driverConfig) noexcept {
    EAGLSharegroup* sharegroup = (__bridge EAGLSharegroup*) sharedGLContext;

    EAGLContext *context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3 sharegroup:sharegroup];
@@ -19,7 +19,6 @@
 #include <backend/platforms/PlatformEGL.h>
 #include <backend/platforms/PlatformEGLAndroid.h>

-#include <private/backend/BackendUtilsAndroid.h>
 #include <private/backend/VirtualMachineEnv.h>

 #include "opengl/GLUtils.h"
@@ -35,8 +34,6 @@
 #include <utils/ostream.h>
 #include <utils/Panic.h>
 #include <utils/Log.h>
-#include <utils/compiler.h>
-#include <utils/ostream.h>

 #include <EGL/egl.h>
 #include <EGL/eglext.h>
@@ -234,133 +231,26 @@ Driver* PlatformEGLAndroid::createDriver(void* sharedContext,
    return driver;
 }

-PlatformEGLAndroid::ExternalImageEGLAndroid::~ExternalImageEGLAndroid() {
-    if (__builtin_available(android 26, *)) {
-        if (aHardwareBuffer) {
-            AHardwareBuffer_release(aHardwareBuffer);
-        }
-    }
-}
+PlatformEGLAndroid::ExternalImageEGLAndroid::~ExternalImageEGLAndroid() = default;

-Platform::ExternalImageHandle PlatformEGLAndroid::createExternalImage(AHardwareBuffer const* buffer,
-        bool sRGB) noexcept {
-    if (__builtin_available(android 26, *)) {
-        auto* const p = new (std::nothrow) ExternalImageEGLAndroid;
-        auto hardwareBuffer = const_cast<AHardwareBuffer*>(buffer);
-        AHardwareBuffer_acquire(hardwareBuffer);
-        p->aHardwareBuffer = hardwareBuffer;
-        p->sRGB = sRGB;
-        AHardwareBuffer_Desc hardwareBufferDescription = {};
-        AHardwareBuffer_describe(hardwareBuffer, &hardwareBufferDescription);
-        p->height = hardwareBufferDescription.height;
-        p->width = hardwareBufferDescription.width;
-        auto textureFormat = mapToFilamentFormat(hardwareBufferDescription.format, sRGB);
-        p->usage = mapToFilamentUsage(hardwareBufferDescription.usage, textureFormat);
-        return ExternalImageHandle{ p };
-    }
-
-    return Platform::ExternalImageHandle{};
-}
-
-PlatformEGLAndroid::ExternalImageDescAndroid PlatformEGLAndroid::getExternalImageDesc(
-        ExternalImageHandle externalImage) noexcept {
-    auto const* const eglExternalImage =
-            static_cast<ExternalImageEGLAndroid const*>(externalImage.get());
-    ExternalImageDescAndroid metadata = {};
-    if (!eglExternalImage) {
-        return metadata;
-    }
-    metadata.height = eglExternalImage->height;
-    metadata.width = eglExternalImage->width;
-    metadata.format = eglExternalImage->format;
-    metadata.usage = eglExternalImage->usage;
-    return metadata;
+Platform::ExternalImageHandle PlatformEGLAndroid::createExternalImage(AHardwareBuffer const* buffer, bool sRGB) noexcept {
+    auto* const p = new(std::nothrow) ExternalImageEGLAndroid;
+    p->aHardwareBuffer = const_cast<AHardwareBuffer*>(buffer);
+    p->sRGB = sRGB;
+    return ExternalImageHandle{ p };
 }

 bool PlatformEGLAndroid::setExternalImage(ExternalImageHandleRef externalImage,
        UTILS_UNUSED_IN_RELEASE ExternalTexture* texture) noexcept {
-    auto const* const eglExternalImage =
-            static_cast<ExternalImageEGLAndroid const*>(externalImage.get());
+    auto const* const eglExternalImage = static_cast<ExternalImageEGLAndroid const*>(externalImage.get());
    if (eglExternalImage->aHardwareBuffer) {
-        return PlatformEGLAndroid::setImage(eglExternalImage, texture);
+        // TODO: implement PlatformEGLAndroid::setExternalImage w/ AHardwareBuffer
+        return true;
    }
    // not a AHardwareBuffer, fallback to the inherited version
    return PlatformEGL::setExternalImage(externalImage, texture);
 }

-OpenGLPlatform::ExternalTexture* PlatformEGLAndroid::createExternalImageTexture() noexcept {
-    ExternalTexture* outTexture = new (std::nothrow) ExternalTexture{};
-    glGenTextures(1, &outTexture->id);
-    return outTexture;
-}
-
-void PlatformEGLAndroid::destroyExternalImageTexture(ExternalTexture* texture) noexcept {
-    glDeleteTextures(1, &texture->id);
-    delete texture;
-}
-
-bool PlatformEGLAndroid::setImage(ExternalImageEGLAndroid const* eglExternalImage,
-        UTILS_UNUSED_IN_RELEASE ExternalTexture* texture) noexcept {
-    AHardwareBuffer* hardwareBuffer = eglExternalImage->aHardwareBuffer;
-
-    // Get the EGL client buffer from AHardwareBuffer
-    EGLClientBuffer clientBuffer = eglGetNativeClientBufferANDROID(hardwareBuffer);
-    EGLint imageAttrs[] = {
-        EGL_IMAGE_PRESERVED_KHR, EGL_TRUE,
-        EGL_NONE, EGL_NONE,  // Reserve space
-        EGL_NONE, EGL_NONE,  // Reserve space
-        EGL_NONE             // Ensure the list always ends with EGL_NONE
-    };
-    int attrIndex = 2;
-    if (eglExternalImage->sRGB) {
-        imageAttrs[attrIndex++] = EGL_GL_COLORSPACE;
-        imageAttrs[attrIndex++] = EGL_GL_COLORSPACE_SRGB;
-    }
-
-    if (static_cast<bool>(eglExternalImage->usage & TextureUsage::PROTECTED)) {
-        imageAttrs[attrIndex++] = EGL_PROTECTED_CONTENT_EXT;
-        imageAttrs[attrIndex++] = EGL_TRUE;
-    }
-    // Create an EGLImage from the client buffer
-    EGLImageKHR eglImage = eglCreateImageKHR(eglGetCurrentDisplay(), EGL_NO_CONTEXT,
-            EGL_NATIVE_BUFFER_ANDROID, clientBuffer, imageAttrs);
-    if (eglImage == EGL_NO_IMAGE_KHR) {
-        // Handle error
-        slog.e << "Failed to create EGL image" << io::endl;
-        glDeleteTextures(1, &texture->id);
-        return false;
-    }
-
-    // Create and bind the OpenGL texture
-    GLint prevActiveTexture, prevTexture;
-    glGetIntegerv(GL_ACTIVE_TEXTURE, &prevActiveTexture);
-    glGetIntegerv(GL_TEXTURE_BINDING_2D, &prevTexture);
-    glActiveTexture(GL_TEXTURE0);
-    glBindTexture(texture->target, texture->id);
-    GLenum error = glGetError();
-    if (UTILS_UNLIKELY(error != GL_NO_ERROR)) {
-        slog.e << "Error after glBindTexture: " << error << io::endl;
-        glDeleteTextures(1, &texture->id);
-        eglDestroyImageKHR(eglGetCurrentDisplay(), eglImage);
-        glActiveTexture(prevActiveTexture);
-        glBindTexture(GL_TEXTURE_2D, prevTexture);
-        return false;
-    }
-    glEGLImageTargetTexture2DOES(texture->target, static_cast<GLeglImageOES>(eglImage));
-    error = glGetError();
-    if (UTILS_UNLIKELY(error != GL_NO_ERROR)) {
-        slog.e << "Error after glEGLImageTargetTexture2DOES: " << error << io::endl;
-        glDeleteTextures(1, &texture->id);
-        eglDestroyImageKHR(eglGetCurrentDisplay(), eglImage);
-        glActiveTexture(prevActiveTexture);
-        glBindTexture(GL_TEXTURE_2D, prevTexture);
-        return false;
-    }
-    glActiveTexture(prevActiveTexture);
-    glBindTexture(GL_TEXTURE_2D, prevTexture);
-    return true;
-}
-
 void PlatformEGLAndroid::setPresentationTime(int64_t presentationTimeInNanosecond) noexcept {
    EGLSurface currentDrawSurface = eglGetCurrentSurface(EGL_DRAW);
    if (currentDrawSurface != EGL_NO_SURFACE) {
@@ -128,7 +128,7 @@ namespace filament::backend {

 using namespace backend;

-Driver* PlatformGLX::createDriver(void* sharedGLContext,
+Driver* PlatformGLX::createDriver(void* const sharedGLContext,
        const DriverConfig& driverConfig) noexcept {
    loadLibraries();
    // Get the display device
@@ -22,11 +22,9 @@
 #include <dlfcn.h>
 #include <memory>

-#if defined(__linux__)
 // This is to ensure that linking during compilation will not fail even if
 // OSMesaGetProcAddress is not linked.
 __attribute__((weak)) OSMESAproc OSMesaGetProcAddress(char const*);
-#endif

 namespace filament::backend {

@@ -50,27 +48,20 @@ struct OSMesaSwapchain {

 struct OSMesaAPI {
 private:
-    using CreateContextAttribsFunc = OSMesaContext (*)(const int *, OSMesaContext);
+    using CreateContextFunc = OSMesaContext (*)(GLenum format, OSMesaContext);
    using DestroyContextFunc = GLboolean (*)(OSMesaContext);
    using MakeCurrentFunc = GLboolean (*)(OSMesaContext ctx, void* buffer, GLenum type,
            GLsizei width, GLsizei height);
    using GetProcAddressFunc = OSMESAproc (*)(const char* funcName);

 public:
-    CreateContextAttribsFunc fOSMesaCreateContextAttribs;
+    CreateContextFunc fOSMesaCreateContext;
    DestroyContextFunc fOSMesaDestroyContext;
    MakeCurrentFunc fOSMesaMakeCurrent;
    GetProcAddressFunc fOSMesaGetProcAddress;

    OSMesaAPI() {
-        static constexpr char const* libraryNames[] = {
-#if defined(__linux__)
-            "libOSMesa.so",
-            "libosmesa.so",
-#elif defined(__APPLE__)
-            "libOSMesa.dylib",
-#endif
-        };
+        constexpr char const* libraryNames[] = {"libOSMesa.so", "libosmesa.so"};
        for (char const* libName: libraryNames) {
            mLib = dlopen(libName, RTLD_GLOBAL | RTLD_NOW);
            if (mLib) {
@@ -80,24 +71,22 @@ public:
        if (mLib) {
            // Loading from a libosmesa.os
            fOSMesaGetProcAddress = (GetProcAddressFunc) dlsym(mLib, "OSMesaGetProcAddress");
-        }
-#if defined(__linux__)
-        else {
+        } else {
            // Filament is built into a .so
            fOSMesaGetProcAddress = (GetProcAddressFunc) dlsym(RTLD_LOCAL, "OSMesaGetProcAddress");
        }
+
        if (!fOSMesaGetProcAddress) {
            // Statically linking osmesa
            fOSMesaGetProcAddress = OSMesaGetProcAddress;
        }
-#endif // __linux__

        FILAMENT_CHECK_PRECONDITION(fOSMesaGetProcAddress)
                << "Unable to link against libOSMesa to create a software GL context";

-        fOSMesaCreateContextAttribs =
-                (CreateContextAttribsFunc) fOSMesaGetProcAddress("OSMesaCreateContextAttribs");
-        fOSMesaDestroyContext = (DestroyContextFunc) fOSMesaGetProcAddress("OSMesaDestroyContext");
+        fOSMesaCreateContext = (CreateContextFunc) fOSMesaGetProcAddress("OSMesaCreateContext");
+        fOSMesaDestroyContext =
+                (DestroyContextFunc) fOSMesaGetProcAddress("OSMesaDestroyContext");
        fOSMesaMakeCurrent = (MakeCurrentFunc) fOSMesaGetProcAddress("OSMesaMakeCurrent");
    }

@@ -112,24 +101,14 @@ private:

 }// anonymous namespace

-Driver* PlatformOSMesa::createDriver(void* sharedGLContext,
+Driver* PlatformOSMesa::createDriver(void* const sharedGLContext,
        const DriverConfig& driverConfig) noexcept {
-
    OSMesaAPI* api = new OSMesaAPI();
    mOsMesaApi = api;

-    static constexpr int attribs[] = {
-        OSMESA_FORMAT, GL_RGBA,
-        OSMESA_DEPTH_BITS, 24,
-        OSMESA_STENCIL_BITS, 8,
-        OSMESA_ACCUM_BITS, 0,
-        OSMESA_PROFILE, OSMESA_CORE_PROFILE,
-        0,
-    };
-
    FILAMENT_CHECK_PRECONDITION(sharedGLContext == nullptr)
            << "shared GL context is not supported with PlatformOSMesa";
-    mContext = api->fOSMesaCreateContextAttribs(attribs, NULL);
+    mContext = api->fOSMesaCreateContext(GL_RGBA, NULL);

    // We need to do a no-op makecurrent here so that the context will be in a correct state before
    // any GL calls.
@@ -75,7 +75,7 @@ struct WGLSwapChain {

 static PFNWGLCREATECONTEXTATTRIBSARBPROC wglCreateContextAttribs = nullptr;

-Driver* PlatformWGL::createDriver(void* sharedGLContext,
+Driver* PlatformWGL::createDriver(void* const sharedGLContext,
        const Platform::DriverConfig& driverConfig) noexcept {
    int result = 0;
    int pixelFormat = 0;
@@ -20,7 +20,7 @@ namespace filament::backend {

 using namespace backend;

-Driver* PlatformWebGL::createDriver(void* sharedGLContext,
+Driver* PlatformWebGL::createDriver(void* const sharedGLContext,
        const Platform::DriverConfig& driverConfig) noexcept {
    return OpenGLPlatform::createDefaultDriver(this, sharedGLContext, driverConfig);
 }
@@ -17,6 +17,9 @@
 #include "VulkanBlitter.h"
 #include "VulkanCommands.h"
 #include "VulkanContext.h"
+#include "VulkanFboCache.h"
+#include "VulkanHandles.h"
+#include "VulkanSamplerCache.h"
 #include "VulkanTexture.h"
 #include "vulkan/utils/Image.h"

@@ -24,6 +24,13 @@

 namespace filament::backend {

+class VulkanBuffer;
+class VulkanFboCache;
+class VulkanPipelineCache;
+class VulkanSamplerCache;
+
+struct VulkanProgram;
+
 class VulkanBlitter {
 public:
    VulkanBlitter(VkPhysicalDevice physicalDevice, VulkanCommands* commands) noexcept;
@@ -56,9 +56,9 @@ VkImageView VulkanAttachment::getImageView() {
    assert_invariant(texture);
    VkImageSubresourceRange range = getSubresourceRange();
    if (range.layerCount > 1) {
-        return texture->getAttachmentView(range, VK_IMAGE_VIEW_TYPE_2D_ARRAY);
+        return texture->getMultiviewAttachmentView(range);
    }
-    return texture->getAttachmentView(range, VK_IMAGE_VIEW_TYPE_2D);
+    return texture->getAttachmentView(range);
 }

 bool VulkanAttachment::isDepth() const {
@@ -68,11 +68,11 @@ bool VulkanAttachment::isDepth() const {
 VkImageSubresourceRange VulkanAttachment::getSubresourceRange() const {
    assert_invariant(texture);
    return {
-        .aspectMask = texture->getImageAspect(),
-        .baseMipLevel = uint32_t(level),
-        .levelCount = 1,
-        .baseArrayLayer = uint32_t(layer),
-        .layerCount = layerCount,
+            .aspectMask = texture->getImageAspect(),
+            .baseMipLevel = uint32_t(level),
+            .levelCount = 1,
+            .baseArrayLayer = uint32_t(layer),
+            .layerCount = layerCount,
    };
 }

@@ -17,6 +17,7 @@
 #ifndef TNT_FILAMENT_BACKEND_VULKANCONTEXT_H
 #define TNT_FILAMENT_BACKEND_VULKANCONTEXT_H

+#include "VulkanConstants.h"
 #include "vulkan/utils/Image.h"
 #include "vulkan/utils/Definitions.h"

@@ -29,6 +30,8 @@

 #include <bluevk/BlueVK.h>

+#include <memory>
+
 VK_DEFINE_HANDLE(VmaAllocator)
 VK_DEFINE_HANDLE(VmaPool)

@@ -70,11 +73,13 @@ struct VulkanRenderPass {
 // context are stored in VulkanPlatform.
 struct VulkanContext {
 public:
-    static uint32_t selectMemoryType(VkPhysicalDeviceMemoryProperties const& memoryProperties,
-            uint32_t flags, VkFlags reqs) {
+    inline uint32_t selectMemoryType(uint32_t flags, VkFlags reqs) const {
+        if ((reqs & VK_MEMORY_PROPERTY_PROTECTED_BIT) != 0) {
+            assert_invariant(isProtectedMemorySupported() == true);
+        }
        for (uint32_t i = 0; i < VK_MAX_MEMORY_TYPES; i++) {
            if (flags & 1) {
-                if ((memoryProperties.memoryTypes[i].propertyFlags & reqs) == reqs) {
+                if ((mMemoryProperties.memoryTypes[i].propertyFlags & reqs) == reqs) {
                    return i;
                }
            }
@@ -83,13 +88,6 @@ public:
        return (uint32_t) VK_MAX_MEMORY_TYPES;
    }

-    inline uint32_t selectMemoryType(uint32_t flags, VkFlags reqs) const {
-        if ((reqs & VK_MEMORY_PROPERTY_PROTECTED_BIT) != 0) {
-            assert_invariant(isProtectedMemorySupported());
-        }
-        return selectMemoryType(mMemoryProperties, flags, reqs);
-    }
-
    inline fvkutils::VkFormatList const& getAttachmentDepthStencilFormats() const {
        return mDepthStencilFormats;
    }
@@ -123,7 +121,7 @@ public:
    }

    inline bool isMultiviewEnabled() const noexcept {
-        return mPhysicalDeviceVk11Features.multiview == VK_TRUE;
+        return mMultiviewEnabled;
    }

    inline bool isClipDistanceSupported() const noexcept {
@@ -147,9 +145,6 @@ private:
    VkPhysicalDeviceProperties2 mPhysicalDeviceProperties = {
        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROPERTIES_2,
    };
-    VkPhysicalDeviceVulkan11Features mPhysicalDeviceVk11Features = {
-        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_1_FEATURES,
-    };
    VkPhysicalDeviceFeatures2 mPhysicalDeviceFeatures = {
        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2,
    };
@@ -162,6 +157,7 @@ private:
    };
    bool mDebugMarkersSupported = false;
    bool mDebugUtilsSupported = false;
+    bool mMultiviewEnabled = false;
    bool mLazilyAllocatedMemorySupported = false;
    bool mProtectedMemorySupported = false;

@@ -1,169 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "VulkanDescriptorSetLayoutCache.h"
-
-#include "VulkanHandles.h"
-
-#include <utils/Hash.h>
-
-namespace filament::backend {
-
-namespace {
-
-using BitmaskGroup = VulkanDescriptorSetLayout::Bitmask;
-
-template<typename Bitmask>
-uint32_t appendBindings(VkDescriptorSetLayoutBinding* toBind, VkDescriptorType type,
-        Bitmask const& mask) {
-    uint32_t count = 0;
-    Bitmask alreadySeen;
-    mask.forEachSetBit([&](size_t index) {
-        VkShaderStageFlags stages = 0;
-        uint32_t binding = 0;
-        if (index < fvkutils::getFragmentStageShift<Bitmask>()) {
-            binding = (uint32_t) index;
-            stages |= VK_SHADER_STAGE_VERTEX_BIT;
-            auto fragIndex = index + fvkutils::getFragmentStageShift<Bitmask>();
-            if (mask.test(fragIndex)) {
-                stages |= VK_SHADER_STAGE_FRAGMENT_BIT;
-                alreadySeen.set(fragIndex);
-            }
-        } else if (!alreadySeen.test(index)) {
-            // We are in fragment stage bits
-            binding = (uint32_t) (index - fvkutils::getFragmentStageShift<Bitmask>());
-            stages |= VK_SHADER_STAGE_FRAGMENT_BIT;
-        }
-
-        if (stages) {
-            toBind[count++] = {
-                .binding = binding,
-                .descriptorType = type,
-                .descriptorCount = 1,
-                .stageFlags = stages,
-            };
-        }
-    });
-    return count;
-}
-
-uint32_t appendSamplerBindings(VkDescriptorSetLayoutBinding* toBind,
-        fvkutils::SamplerBitmask const& mask, fvkutils::SamplerBitmask const& external,
-        utils::FixedCapacityVector<VkSampler> const& immutableSamplers) {
-    using Bitmask = fvkutils::SamplerBitmask;
-    uint32_t count = 0;
-    Bitmask alreadySeen;
-    uint8_t immutableIndex = 0;
-    size_t const immutableSamplerCount = immutableSamplers.size();
-    mask.forEachSetBit([&](size_t index) {
-        VkShaderStageFlags stages = 0;
-        uint32_t binding = 0;
-        if (index < fvkutils::getFragmentStageShift<Bitmask>()) {
-            binding = (uint32_t) index;
-            stages |= VK_SHADER_STAGE_VERTEX_BIT;
-            auto fragIndex = index + fvkutils::getFragmentStageShift<Bitmask>();
-            if (mask.test(fragIndex)) {
-                stages |= VK_SHADER_STAGE_FRAGMENT_BIT;
-                alreadySeen.set(fragIndex);
-            }
-        } else if (!alreadySeen.test(index)) {
-            // We are in fragment stage bits
-            binding = (uint32_t) (index - fvkutils::getFragmentStageShift<Bitmask>());
-            stages |= VK_SHADER_STAGE_FRAGMENT_BIT;
-        }
-
-        if (stages) {
-            toBind[count++] = {
-                .binding = binding,
-                .descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
-                .descriptorCount = 1,
-                .stageFlags = stages,
-                .pImmutableSamplers = external[index] && immutableSamplerCount > immutableIndex
-                                              ? &immutableSamplers[immutableIndex++]
-                                              : nullptr,
-            };
-        }
-    });
-    return count;
-}
-
-uint64_t computeImmutableSamplerHash(utils::FixedCapacityVector<VkSampler> const& samplers) {
-    size_t const size = samplers.size();
-    if (size == 0) {
-        return 0;
-    } else if (size == 1) {
-        return (uint64_t) samplers[0];
-    }
-    return utils::hash::murmur3((uint32_t*) samplers.data(), samplers.size() * 2, 0);
-}
-
-} // anonymous namespace
-
-VulkanDescriptorSetLayoutCache::VulkanDescriptorSetLayoutCache(VkDevice device,
-        fvkmemory::ResourceManager* resourceManager)
-    : mDevice(device),
-      mResourceManager(resourceManager) {}
-
-VulkanDescriptorSetLayoutCache::~VulkanDescriptorSetLayoutCache() = default;
-
-void VulkanDescriptorSetLayoutCache::terminate() noexcept {
-    for (auto& itr: mVkLayouts) {
-        vkDestroyDescriptorSetLayout(mDevice, itr.second, VKALLOC);
-    }
-}
-
-VkDescriptorSetLayout VulkanDescriptorSetLayoutCache::getVkLayout(
-        VulkanDescriptorSetLayout::Bitmask const& bitmasks,
-        utils::FixedCapacityVector<VkSampler> immutableSamplers) {
-    LayoutKey key = {
-        .bitmask = bitmasks,
-        .immutableSamplerHash = computeImmutableSamplerHash(immutableSamplers),
-    };
-    if (auto itr = mVkLayouts.find(key); itr != mVkLayouts.end()) {
-        return itr->second;
-    }
-
-    VkDescriptorSetLayoutBinding toBind[VulkanDescriptorSetLayout::MAX_BINDINGS];
-    uint32_t count = 0;
-    count += appendBindings(&toBind[count], VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC,
-            bitmasks.dynamicUbo);
-    count += appendBindings(&toBind[count], VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, bitmasks.ubo);
-    count += appendSamplerBindings(&toBind[count], bitmasks.sampler, bitmasks.externalSampler,
-            immutableSamplers);
-    count += appendBindings(&toBind[count], VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT,
-            bitmasks.inputAttachment);
-
-    assert_invariant(count != 0 && "Need at least one binding for descriptor set layout.");
-    VkDescriptorSetLayoutCreateInfo dlinfo = {
-        .sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO,
-        .bindingCount = count,
-        .pBindings = toBind,
-    };
-    VkDescriptorSetLayout vklayout;
-    vkCreateDescriptorSetLayout(mDevice, &dlinfo, VKALLOC, &vklayout);
-    mVkLayouts[key] = vklayout;
-    return vklayout;
-}
-
-fvkmemory::resource_ptr<VulkanDescriptorSetLayout> VulkanDescriptorSetLayoutCache::createLayout(
-        Handle<HwDescriptorSetLayout> handle, backend::DescriptorSetLayout&& info) {
-    auto layout = fvkmemory::resource_ptr<VulkanDescriptorSetLayout>::make(mResourceManager, handle,
-            info);
-    layout->setVkLayout(getVkLayout(layout->bitmask));
-    return layout;
-}
-
-} // namespace filament::backend
@@ -1,75 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef TNT_FILAMENT_BACKEND_CACHING_VULKANDESCRIPTORSETLAYOUTCACHE_H
-#define TNT_FILAMENT_BACKEND_CACHING_VULKANDESCRIPTORSETLAYOUTCACHE_H
-
-#include "VulkanHandles.h"
-
-#include "vulkan/memory/ResourcePointer.h"
-
-#include <backend/DriverEnums.h>
-#include <backend/Program.h>
-#include <backend/TargetBufferInfo.h>
-
-#include <utils/bitset.h>
-#include <utils/FixedCapacityVector.h>
-
-#include <bluevk/BlueVK.h>
-#include <tsl/robin_map.h>
-
-namespace filament::backend {
-
-class VulkanDescriptorSetLayoutCache {
-public:
-    VulkanDescriptorSetLayoutCache(VkDevice device, fvkmemory::ResourceManager* resourceManager);
-    ~VulkanDescriptorSetLayoutCache();
-
-    void terminate() noexcept;
-
-    // Just a wrapper around getVkLayout()
-    fvkmemory::resource_ptr<VulkanDescriptorSetLayout> createLayout(
-            Handle<HwDescriptorSetLayout> handle, backend::DescriptorSetLayout&& info);
-
-    // This method is meant to be used with external samplers
-    VkDescriptorSetLayout getVkLayout(VulkanDescriptorSetLayout::Bitmask const& bitmasks,
-            utils::FixedCapacityVector<VkSampler> immutableSamplers = {});
-
-private:
-    VkDevice mDevice;
-    fvkmemory::ResourceManager* mResourceManager;
-
-    struct LayoutKey {
-        // this describes the layout using bitset.
-        VulkanDescriptorSetLayout::Bitmask bitmask = {};
-        // number of immutable samplers can be arbitrary; so we hash them into 64-bit.
-        uint64_t immutableSamplerHash = 0;
-    };
-    static_assert(sizeof(LayoutKey) == 48);
-
-    using LayoutKeyHashFn = utils::hash::MurmurHashFn<LayoutKey>;
-    struct LayoutKeyEqual {
-        bool operator()(LayoutKey const& k1, LayoutKey const& k2) const {
-            return k1.bitmask == k2.bitmask && k1.immutableSamplerHash == k2.immutableSamplerHash;
-        }
-    };
-
-    tsl::robin_map<LayoutKey, VkDescriptorSetLayout, LayoutKeyHashFn, LayoutKeyEqual> mVkLayouts;
-};
-
-} // namespace filament::backend
-
-#endif// TNT_FILAMENT_BACKEND_CACHING_VULKANDESCRIPTORSETLAYOUTCACHE_H
@@ -17,6 +17,7 @@
 #include "VulkanDriver.h"

 #include "CommandStreamDispatcher.h"
+#include "DataReshaper.h"
 #include "SystraceProfile.h"
 #include "VulkanAsyncHandles.h"
 #include "VulkanBuffer.h"
@@ -25,17 +26,16 @@
 #include "VulkanHandles.h"
 #include "VulkanMemory.h"
 #include "VulkanTexture.h"
-#include "vulkan/VulkanSamplerCache.h"
 #include "vulkan/memory/ResourceManager.h"
 #include "vulkan/memory/ResourcePointer.h"
 #include "vulkan/utils/Conversion.h"
 #include "vulkan/utils/Definitions.h"
-#include "vulkan/vulkan_core.h"

 #include <backend/DriverEnums.h>
 #include <backend/platforms/VulkanPlatform.h>

 #include <utils/CString.h>
+#include <utils/FixedCapacityVector.h>
 #include <utils/Panic.h>

 #ifndef NDEBUG
@@ -44,6 +44,8 @@

 using namespace bluevk;

+using utils::FixedCapacityVector;
+
 #if defined(__clang__)
 // Vulkan functions often immediately dereference pointers, so it's fine to pass in a pointer
 // to a stack-allocated variable.
@@ -200,7 +202,9 @@ Dispatcher VulkanDriver::getDispatcher() const noexcept {
 VulkanDriver::VulkanDriver(VulkanPlatform* platform, VulkanContext const& context,
        Platform::DriverConfig const& driverConfig) noexcept
    : mPlatform(platform),
-      mResourceManager(driverConfig.handleArenaSize, driverConfig.disableHandleUseAfterFreeCheck,
+      mResourceManager(
+              driverConfig.handleArenaSize,
+              driverConfig.disableHandleUseAfterFreeCheck,
              driverConfig.disableHeapHandleTags),
      mAllocator(createAllocator(mPlatform->getInstance(), mPlatform->getPhysicalDevice(),
              mPlatform->getDevice())),
@@ -212,15 +216,11 @@ VulkanDriver::VulkanDriver(VulkanPlatform* platform, VulkanContext const& contex
      mPipelineCache(mPlatform->getDevice()),
      mStagePool(mAllocator, &mCommands),
      mFramebufferCache(mPlatform->getDevice()),
-      mYcbcrConversionCache(mPlatform->getDevice()),
      mSamplerCache(mPlatform->getDevice()),
      mBlitter(mPlatform->getPhysicalDevice(), &mCommands),
      mReadPixels(mPlatform->getDevice()),
-      mDescriptorSetLayoutCache(mPlatform->getDevice(), &mResourceManager),
-      mDescriptorSetCache(mPlatform->getDevice(), &mResourceManager),
+      mDescriptorSetManager(mPlatform->getDevice(), &mResourceManager),
      mQueryManager(mPlatform->getDevice()),
-      mExternalImageManager(platform, &mSamplerCache, &mYcbcrConversionCache, &mDescriptorSetCache,
-              &mDescriptorSetLayoutCache),
      mIsSRGBSwapChainSupported(mPlatform->getCustomization().isSRGBSwapChainSupported),
      mStereoscopicType(driverConfig.stereoscopicType) {

@@ -313,7 +313,7 @@ void VulkanDriver::terminate() {

    mCurrentSwapChain = {};
    mDefaultRenderTarget = {};
-    mPipelineState = {};
+    mBoundPipeline = {};

    mQueryManager.terminate();

@@ -325,16 +325,11 @@ void VulkanDriver::terminate() {

    mCommands.terminate();

-    // Must come before samplerCache, ycbcrConversionCache, descriptorSetCache,
-    // descriptorSetLayoutCache
-    mExternalImageManager.terminate();
-
    mStagePool.terminate();
    mPipelineCache.terminate();
    mFramebufferCache.reset();
    mSamplerCache.terminate();
-    mDescriptorSetLayoutCache.terminate();
-    mDescriptorSetCache.terminate();
+    mDescriptorSetManager.terminate();
    mPipelineLayoutCache.terminate();

    // Before terminating ResourceManager, we must make sure all of the resource_ptrs have been unset.
@@ -370,7 +365,7 @@ void VulkanDriver::collectGarbage() {
    FVK_SYSTRACE_SCOPE();
    // Command buffers need to be submitted and completed before other resources can be gc'd.
    mCommands.gc();
-    mDescriptorSetCache.gc();
+    mDescriptorSetManager.clearHistory();
    mStagePool.gc();
    mFramebufferCache.gc();
    mPipelineCache.gc();
@@ -385,10 +380,6 @@ void VulkanDriver::beginFrame(int64_t monotonic_clock_ns,
        int64_t refreshIntervalNs, uint32_t frameId) {
    FVK_PROFILE_MARKER(PROFILE_NAME_BEGINFRAME);
    // Do nothing.
-
-    if (mAppState.hasExternalSamplers()) {
-        mExternalImageManager.onBeginFrame();
-    }
 }

 void VulkanDriver::setFrameScheduledCallback(Handle<HwSwapChain> sch, CallbackHandler* handler,
@@ -417,7 +408,7 @@ void VulkanDriver::updateDescriptorSetBuffer(
    FVK_SYSTRACE_SCOPE();
    auto set = resource_ptr<VulkanDescriptorSet>::cast(&mResourceManager, dsh);
    auto buffer = resource_ptr<VulkanBufferObject>::cast(&mResourceManager, boh);
-    mDescriptorSetCache.updateBuffer(set, binding, buffer, offset, size);
+    mDescriptorSetManager.updateBuffer(set, binding, buffer, offset, size);
 }

 void VulkanDriver::updateDescriptorSetTexture(
@@ -429,16 +420,8 @@ void VulkanDriver::updateDescriptorSetTexture(
    auto set = resource_ptr<VulkanDescriptorSet>::cast(&mResourceManager, dsh);
    auto texture = resource_ptr<VulkanTexture>::cast(&mResourceManager, th);

-    if (mExternalImageManager.isExternallySampledTexture(texture)) {
-        mExternalImageManager.bindExternallySampledTexture(set, binding, texture, params);
-        mAppState.hasBoundExternalImages = true;
-    } else {
-        VulkanSamplerCache::Params cacheParams = {
-            .sampler = params,
-        };
-        VkSampler const vksampler = mSamplerCache.getSampler(cacheParams);
-        mDescriptorSetCache.updateSampler(set, binding, texture, vksampler);
-    }
+    VkSampler const vksampler = mSamplerCache.getSampler(params);
+    mDescriptorSetManager.updateSampler(set, binding, texture, vksampler);
 }

 void VulkanDriver::flush(int) {
@@ -571,39 +554,26 @@ void VulkanDriver::createTextureViewSwizzleR(Handle<HwTexture> th, Handle<HwText
   texture.inc();
 }

-void VulkanDriver::createTextureExternalImage2R(Handle<HwTexture> th, backend::SamplerType target,
-        backend::TextureFormat format, uint32_t width, uint32_t height, backend::TextureUsage usage,
+void VulkanDriver::createTextureExternalImage2R(Handle<HwTexture> th,
+        backend::SamplerType target,  backend::TextureFormat format,
+        uint32_t width, uint32_t height, backend::TextureUsage usage,
        Platform::ExternalImageHandleRef externalImage) {
    FVK_SYSTRACE_SCOPE();
-    auto const& metadata = mPlatform->extractExternalImageMetadata(externalImage);

-    // In theory the following are reasonable expectations, but in practice it's hard for client's
-    // to match up the dimensions of the texture with that of the AHB.
-    // assert_invariant(width == metadata.width);
-    // assert_invariant(height == metadata.height);
-    // assert_invariant(format == metadata.filamentFormat);
-    // assert_invariant(fvkutils::getVkFormat(format) == metadata.format);
-
-    VkImage vkimg;
-    VkDeviceMemory deviceMemory;
-    std::tie(vkimg, deviceMemory) = mPlatform->createVkImageFromExternal(externalImage);
-
-    VkSamplerYcbcrConversion conversion =
-            mExternalImageManager.getVkSamplerYcbcrConversion(metadata);
-
-    auto texture = resource_ptr<VulkanTexture>::make(&mResourceManager, th, mContext,
-            mPlatform->getDevice(), mAllocator, &mResourceManager, &mCommands, vkimg, deviceMemory,
-            metadata.format, conversion, metadata.samples, metadata.width, metadata.height,
-            metadata.layers, usage, mStagePool);
-
-    if (conversion != VK_NULL_HANDLE) {
-        mExternalImageManager.addExternallySampledTexture(texture, externalImage);
+    const auto& metadata = mPlatform->getExternalImageMetadata(externalImage);
+    if (metadata.isProtected) {
+        usage |= backend::TextureUsage::PROTECTED;
    }

-    // Unlike uploaded textures or swapchains, we need to explicit transition this
-    // texture into the read layout.
-    auto& commands = mCommands.get();
-    texture->transitionLayout(&commands, texture->getPrimaryViewRange(), VulkanLayout::READ_ONLY);
+    assert_invariant(width == metadata.width);
+    assert_invariant(height == metadata.height);
+    assert_invariant(fvkutils::getVkFormat(format) == metadata.format);
+
+    const auto& data = mPlatform->createExternalImageData(externalImage, metadata);
+
+    auto texture = resource_ptr<VulkanTexture>::make(&mResourceManager, th,
+            mPlatform->getDevice(), mAllocator, &mResourceManager, &mCommands, data.first, data.second, metadata.format,
+            1, metadata.width, metadata.height, /*depth=*/1, usage, mStagePool);

    texture.inc();
 }
@@ -612,14 +582,13 @@ void VulkanDriver::createTextureExternalImageR(Handle<HwTexture> th, backend::Sa
        backend::TextureFormat format, uint32_t width, uint32_t height, backend::TextureUsage usage,
        void* externalImage) {
    FVK_SYSTRACE_SCOPE();
-    assert_invariant(false && "Not supported in Vulkan backend");
+
    // not supported in this backend
 }

 void VulkanDriver::createTextureExternalImagePlaneR(Handle<HwTexture> th,
        backend::TextureFormat format, uint32_t width, uint32_t height, backend::TextureUsage usage,
        void* image, uint32_t plane) {
-    assert_invariant(false && "Not supported in Vulkan backend");
 }

 void VulkanDriver::importTextureR(Handle<HwTexture> th, intptr_t id,
@@ -627,7 +596,6 @@ void VulkanDriver::importTextureR(Handle<HwTexture> th, intptr_t id,
        TextureFormat format, uint8_t samples, uint32_t w, uint32_t h, uint32_t depth,
        TextureUsage usage) {
    // not supported in this backend
-    assert_invariant(false && "Not supported in Vulkan backend");
 }

 void VulkanDriver::destroyTexture(Handle<HwTexture> th) {
@@ -636,8 +604,6 @@ void VulkanDriver::destroyTexture(Handle<HwTexture> th) {
    }
    auto texture = resource_ptr<VulkanTexture>::cast(&mResourceManager, th);
    texture.dec();
-
-    mExternalImageManager.removeExternallySampledTexture(texture);
 }

 void VulkanDriver::createProgramR(Handle<HwProgram> ph, Program&& program) {
@@ -795,7 +761,8 @@ void VulkanDriver::createTimerQueryR(Handle<HwTimerQuery> tqh, int) {

 void VulkanDriver::createDescriptorSetLayoutR(Handle<HwDescriptorSetLayout> dslh,
        backend::DescriptorSetLayout&& info) {
-    auto layout = mDescriptorSetLayoutCache.createLayout(dslh, std::move(info));
+    auto layout = resource_ptr<VulkanDescriptorSetLayout>::make(&mResourceManager, dslh, info);
+    mDescriptorSetManager.initVkLayout(layout);
    layout.inc();
 }

@@ -804,13 +771,8 @@ void VulkanDriver::createDescriptorSetR(Handle<HwDescriptorSet> dsh,
    FVK_SYSTRACE_SCOPE();
    fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout =
            fvkmemory::resource_ptr<VulkanDescriptorSetLayout>::cast(&mResourceManager, dslh);
-    auto set = mDescriptorSetCache.createSet(dsh, layout);
+    auto set = mDescriptorSetManager.createSet(dsh, layout);
    set.inc();
-
-    if (layout->hasExternalSamplers()) {
-        mAppState.hasExternalSamplerLayouts = true;
-        mExternalImageManager.addDescriptorSet(layout, set);
-    }
 }

 Handle<HwVertexBufferInfo> VulkanDriver::createVertexBufferInfoS() noexcept {
@@ -930,19 +892,11 @@ void VulkanDriver::destroyTimerQuery(Handle<HwTimerQuery> tqh) {
 void VulkanDriver::destroyDescriptorSetLayout(Handle<HwDescriptorSetLayout> dslh) {
    auto layout = resource_ptr<VulkanDescriptorSetLayout>::cast(&mResourceManager, dslh);
    layout.dec();
-
-    if (layout->hasExternalSamplers()) {
-        mExternalImageManager.removeDescriptorSetLayout(layout);
-    }
 }

 void VulkanDriver::destroyDescriptorSet(Handle<HwDescriptorSet> dsh) {
    auto set = resource_ptr<VulkanDescriptorSet>::cast(&mResourceManager, dsh);
    set.dec();
-
-    if (mAppState.hasExternalSamplers()) {
-        mExternalImageManager.removeDescriptorSet(set);
-    }
 }

 Handle<HwStream> VulkanDriver::createStreamNative(void* nativeStream) {
@@ -1089,7 +1043,7 @@ bool VulkanDriver::isDepthStencilBlitSupported(TextureFormat format) {
           formats.end();
 }

-bool VulkanDriver::isProtectedTexturesSupported() { return isProtectedContentSupported(); }
+bool VulkanDriver::isProtectedTexturesSupported() { return false; }

 bool VulkanDriver::isDepthClampSupported() {
    return mContext.isDepthClampSupported();
@@ -1166,28 +1120,14 @@ math::float2 VulkanDriver::getClipSpaceParams() {
 }

 uint8_t VulkanDriver::getMaxDrawBuffers() {
-    return mContext.getPhysicalDeviceLimits().maxColorAttachments;
+    return MRT::MIN_SUPPORTED_RENDER_TARGET_COUNT; // TODO: query real value
 }

 size_t VulkanDriver::getMaxUniformBufferSize() {
-    return mContext.getPhysicalDeviceLimits().maxUniformBufferRange;
-}
-
-size_t VulkanDriver::getMaxTextureSize(SamplerType type) {
-    switch (type) {
-        case SamplerType::SAMPLER_2D:
-            return mContext.getPhysicalDeviceLimits().maxImageDimension2D;
-        case SamplerType::SAMPLER_3D:
-            return mContext.getPhysicalDeviceLimits().maxImageDimension3D;
-        case SamplerType::SAMPLER_CUBEMAP:
-            return mContext.getPhysicalDeviceLimits().maxImageDimensionCube;
-        default:
-            return mContext.getPhysicalDeviceLimits().maxImageDimension1D;
-    }
-}
-
-size_t VulkanDriver::getMaxArrayTextureLayers() {
-    return mContext.getPhysicalDeviceLimits().maxImageArrayLayers;
+    // TODO: return the actual size instead of hardcoded value
+    // TODO: devices that return less than 32768 should be rejected. This represents only 3%
+    //       of android devices.
+    return 32768;
 }

 void VulkanDriver::setVertexBufferObject(Handle<HwVertexBuffer> vbh, uint32_t index,
@@ -1503,6 +1443,7 @@ void VulkanDriver::endRenderPass(int) {
    // pipeline barrier between framebuffer writes and shader reads.
    rt->emitBarriersEndRenderPass(*mCurrentRenderPass.commandBuffer);

+    mRenderPassFboInfo = {};
    mCurrentRenderPass.renderTarget = {};
    mCurrentRenderPass.renderPass = VK_NULL_HANDLE;

@@ -1525,7 +1466,7 @@ void VulkanDriver::nextSubpass(int) {

    if (mCurrentRenderPass.params.subpassMask & 0x1) {
        VulkanAttachment& subpassInput = renderTarget->getColor0();
-        mDescriptorSetCache.updateInputAttachment({}, subpassInput);
+        mDescriptorSetManager.updateInputAttachment({}, subpassInput);
    }
 }

@@ -1562,10 +1503,10 @@ void VulkanDriver::commit(Handle<HwSwapChain> sch) {

 void VulkanDriver::setPushConstant(backend::ShaderStage stage, uint8_t index,
        backend::PushConstantVariant value) {
-    assert_invariant(mPipelineState.program && "Expect a program when writing to push constants");
+    assert_invariant(mBoundPipeline.program && "Expect a program when writing to push constants");
    assert_invariant(mCurrentRenderPass.commandBuffer && "Should be called within a renderpass");
-    mPipelineState.program->writePushConstant(mCurrentRenderPass.commandBuffer->buffer(),
-            mPipelineState.pipelineLayout, stage, index, value);
+    mBoundPipeline.program->writePushConstant(mCurrentRenderPass.commandBuffer->buffer(),
+            mBoundPipeline.pipelineLayout, stage, index, value);
 }

 void VulkanDriver::insertEventMarker(char const* string) {
@@ -1744,27 +1685,6 @@ void VulkanDriver::blitDEPRECATED(TargetBufferFlags buffers,
 }

 void VulkanDriver::bindPipeline(PipelineState const& pipelineState) {
-    // We need to determine whether to delay bindning until draw().
-    mPipelineState.bindInDraw.first = false;
-    if (mAppState.hasExternalSamplers()) {
-        auto& layouts = pipelineState.pipelineLayout.setLayout;
-        auto haveExternalSamplers = [&](auto hwHandle) {
-            if (!hwHandle) {
-                return false;
-            }
-            auto layout =
-                    resource_ptr<VulkanDescriptorSetLayout>::cast(&mResourceManager, hwHandle);
-            return layout->hasExternalSamplers();
-        };
-        if (std::any_of(layouts.begin(), layouts.end(), haveExternalSamplers)) {
-            mPipelineState.bindInDraw = { true, pipelineState };
-            return;
-        }
-    }
-    bindPipelineImpl(pipelineState);
-}
-
-void VulkanDriver::bindPipelineImpl(PipelineState const& pipelineState) {
    FVK_SYSTRACE_SCOPE();
    auto commands = mCurrentRenderPass.commandBuffer;
    auto vbi = resource_ptr<VulkanVertexBufferInfo>::cast(&mResourceManager,
@@ -1833,11 +1753,10 @@ void VulkanDriver::bindPipelineImpl(PipelineState const& pipelineState) {

    constexpr uint8_t descriptorSetMaskTable[4] = {0x1, 0x3, 0x7, 0xF};

-    mPipelineState = {
+    mBoundPipeline = {
        .program = program,
        .pipelineLayout = pipelineLayout,
        .descriptorSetMask = fvkutils::DescriptorSetMask(descriptorSetMaskTable[layoutCount]),
-        .bindInDraw = {false, {}},
    };

    mPipelineCache.bindLayout(pipelineLayout);
@@ -1874,9 +1793,9 @@ void VulkanDriver::bindDescriptorSet(
        backend::DescriptorSetOffsetArray&& offsets) {
    if (dsh) {
        auto set = resource_ptr<VulkanDescriptorSet>::cast(&mResourceManager, dsh);
-        mDescriptorSetCache.bind(setIndex, set, std::move(offsets));
+        mDescriptorSetManager.bind(setIndex, set, std::move(offsets));
    } else {
-        mDescriptorSetCache.unbind(setIndex);
+        mDescriptorSetManager.unbind(setIndex);
    }
 }

@@ -1884,24 +1803,14 @@ void VulkanDriver::draw2(uint32_t indexOffset, uint32_t indexCount, uint32_t ins
    FVK_SYSTRACE_SCOPE();
    VkCommandBuffer cmdbuffer = mCurrentRenderPass.commandBuffer->buffer();

-    if (mAppState.hasExternalSamplers()) {
-        auto const& [bindInDraw, pipelineSt] = mPipelineState.bindInDraw;
-        bool const hasUpdated =
-                mExternalImageManager.prepareBindSets(mDescriptorSetCache.getBoundSets());
-        if (bindInDraw || hasUpdated) {
-            bindPipelineImpl(pipelineSt);
-        }
-        mPipelineState.bindInDraw.first = false;
-    }
-
-    mDescriptorSetCache.commit(mCurrentRenderPass.commandBuffer,
-            mPipelineState.pipelineLayout,
-            mPipelineState.descriptorSetMask);
+    mDescriptorSetManager.commit(mCurrentRenderPass.commandBuffer,
+            mBoundPipeline.pipelineLayout,
+            mBoundPipeline.descriptorSetMask);

    // Finally, make the actual draw call. TODO: support subranges
-    uint32_t const firstIndex = indexOffset;
-    constexpr int32_t vertexOffset = 0;
-    constexpr uint32_t firstInstId = 0;
+    const uint32_t firstIndex = indexOffset;
+    const int32_t vertexOffset = 0;
+    const uint32_t firstInstId = 0;

    vkCmdDrawIndexed(cmdbuffer, indexCount, instanceCount, firstIndex, vertexOffset, firstInstId);
 }
@@ -27,11 +27,8 @@
 #include "VulkanSamplerCache.h"
 #include "VulkanStagePool.h"
 #include "VulkanQueryManager.h"
-#include "VulkanYcbcrConversionCache.h"
-#include "vulkan/VulkanDescriptorSetCache.h"
-#include "vulkan/VulkanDescriptorSetLayoutCache.h"
-#include "vulkan/VulkanExternalImageManager.h"
-#include "vulkan/VulkanPipelineLayoutCache.h"
+#include "vulkan/caching/VulkanDescriptorSetManager.h"
+#include "vulkan/caching/VulkanPipelineLayoutCache.h"
 #include "vulkan/memory/ResourceManager.h"
 #include "vulkan/memory/ResourcePointer.h"
 #include "vulkan/utils/Definitions.h"
@@ -120,7 +117,6 @@ private:

 private:
    void collectGarbage();
-    void bindPipelineImpl(PipelineState const& pipelineState);

    VulkanPlatform* mPlatform = nullptr;
    fvkmemory::ResourceManager mResourceManager;
@@ -138,36 +134,26 @@ private:
    VulkanPipelineCache mPipelineCache;
    VulkanStagePool mStagePool;
    VulkanFboCache mFramebufferCache;
-    VulkanYcbcrConversionCache mYcbcrConversionCache;
    VulkanSamplerCache mSamplerCache;
    VulkanBlitter mBlitter;
    VulkanReadPixels mReadPixels;
-    VulkanDescriptorSetLayoutCache mDescriptorSetLayoutCache;
-    VulkanDescriptorSetCache mDescriptorSetCache;
+    VulkanDescriptorSetManager mDescriptorSetManager;
    VulkanQueryManager mQueryManager;
-    VulkanExternalImageManager mExternalImageManager;

    // This is necessary for us to write to push constants after binding a pipeline.
    struct {
-        // For push constant
        resource_ptr<VulkanProgram> program;
-        // For push commiting dynamic ubos in draw()
        VkPipelineLayout pipelineLayout;
        fvkutils::DescriptorSetMask descriptorSetMask;
+    } mBoundPipeline = {};

-        std::pair<bool, PipelineState> bindInDraw = {false, {}};
-    } mPipelineState = {};
-
+    // We need to store information about a render pass to enable better barriers at the end of a
+    // renderpass.
    struct {
-        // This tracks whether the app has seen external samplers bound to a the descriptor set.
-        // This will force bindPipeline to take a slow path.
-        bool hasExternalSamplerLayouts = false;
-        bool hasBoundExternalImages = false;
-
-        bool hasExternalSamplers() const noexcept {
-            return hasExternalSamplerLayouts && hasBoundExternalImages;
-        }
-    } mAppState;
+        using AttachmentArray =
+                fvkutils::StaticVector<VulkanAttachment, MAX_RENDERTARGET_ATTACHMENT_TEXTURES>;
+        AttachmentArray attachments;
+    } mRenderPassFboInfo = {};

    bool const mIsSRGBSwapChainSupported;
    backend::StereoscopicType const mStereoscopicType;
@@ -1,280 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "VulkanExternalImageManager.h"
-
-#include "VulkanDescriptorSetCache.h"
-#include "VulkanDescriptorSetLayoutCache.h"
-#include "VulkanSamplerCache.h"
-#include "VulkanYcbcrConversionCache.h"
-#include "vulkan/memory/ResourcePointer.h"
-#include "vulkan/utils/Conversion.h"
-
-#include <backend/platforms/VulkanPlatform.h>
-
-#include <algorithm>
-
-namespace filament::backend {
-
-namespace {
-
-template<typename T>
-void erasep(std::vector<T>& v, std::function<bool(T const&)> f) {
-    auto newEnd = std::remove_if(v.begin(), v.end(), f);
-    v.erase(newEnd, v.end());
-}
-
-} // anonymous
-
-VulkanExternalImageManager::VulkanExternalImageManager(VulkanPlatform* platform,
-        VulkanSamplerCache* samplerCache, VulkanYcbcrConversionCache* ycbcrConversionCache,
-        VulkanDescriptorSetCache* setCache, VulkanDescriptorSetLayoutCache* layoutCache)
-    : mPlatform(platform),
-      mSamplerCache(samplerCache),
-      mYcbcrConversionCache(ycbcrConversionCache),
-      mDescriptorSetCache(setCache),
-      mDescriptorSetLayoutCache(layoutCache) {
-}
-
-VulkanExternalImageManager::~VulkanExternalImageManager() = default;
-
-void VulkanExternalImageManager::terminate() {
-    mSetAndLayouts.clear();
-    mSetBindings.clear();
-    mImages.clear();
-}
-
-void VulkanExternalImageManager::onBeginFrame() {
-    std::for_each(mImages.begin(), mImages.end(), [](ImageData& image) {
-        image.hasBeenValidated = false;
-    });
-}
-
-bool VulkanExternalImageManager::prepareBindSets(SetArray const& sets) {
-    bool hasUpdated = false;
-    for (auto set: sets) {
-        if (!set) {
-            continue;
-        }
-        if (auto itr = std::find_if(mSetAndLayouts.begin(), mSetAndLayouts.end(),
-                    [&](auto const& setAndLayout) { return setAndLayout.first == set; });
-                itr != mSetAndLayouts.end()) {
-            hasUpdated = updateSetAndLayout(itr->first, itr->second) || hasUpdated;
-        }
-    }
-    return hasUpdated;
-}
-
-bool VulkanExternalImageManager::updateSetAndLayout(
-        fvkmemory::resource_ptr<VulkanDescriptorSet> set,
-        fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout) {
-    auto findImage = [&](fvkmemory::resource_ptr<VulkanTexture> texture) -> ImageData* {
-        auto itr = std::find_if(mImages.begin(), mImages.end(), [&](ImageData const& data) {
-            return data.ptr == texture;
-        });
-        assert_invariant(itr != mImages.end());
-        return &(*itr);
-    };
-
-    //std::vector<std::pair<uint8_t, ImageData*>> externalImages;
-    utils::FixedCapacityVector<std::pair<uint8_t, VkSampler>> samplerAndBindings;
-    samplerAndBindings.reserve(MAX_SAMPLER_COUNT);
-
-    bool hasImageUpdates = false;
-    for (auto& bindingInfo : mSetBindings) {
-        if (bindingInfo.set != set) {
-            continue;
-        }
-        auto imageData = findImage(bindingInfo.image);
-        hasImageUpdates = updateImage(imageData) || hasImageUpdates;
-
-        auto samplerParams = bindingInfo.samplerParams;
-        // according to spec, these must match chromaFilter
-        // https://registry.khronos.org/vulkan/specs/latest/man/html/VkSamplerCreateInfo.html#VUID-VkSamplerCreateInfo-minFilter-01645
-        samplerParams.filterMag = SamplerMagFilter::NEAREST;
-        samplerParams.filterMin = SamplerMinFilter::NEAREST;
-
-        auto sampler = mSamplerCache->getSampler({
-            .sampler = samplerParams,
-            .conversion = imageData->conversion,
-        });
-        samplerAndBindings.push_back({ bindingInfo.binding, sampler });
-    }
-
-    // We need to sort by binding number
-    std::sort(samplerAndBindings.begin(), samplerAndBindings.end());
-
-    utils::FixedCapacityVector<VkSampler> outSamplers;
-    outSamplers.reserve(MAX_SAMPLER_COUNT);
-    std::for_each(samplerAndBindings.begin(), samplerAndBindings.end(),
-            [&](auto const& b) { outSamplers.push_back(b.second); });
-
-    VkDescriptorSetLayout const oldLayout = layout->getVkLayout();
-    VkDescriptorSetLayout const newLayout =
-            mDescriptorSetLayoutCache->getVkLayout(layout->bitmask, outSamplers);
-    bool const hasLayoutUpdate = oldLayout != newLayout;
-    layout->setVkLayout(newLayout);
-
-    assert_invariant(
-            (!hasImageUpdates && !hasLayoutUpdate) ||
-            (hasImageUpdates && hasLayoutUpdate));
-
-    if (!hasLayoutUpdate) {
-        return false;
-    }
-
-    auto foldBitsInHalf = [](auto bitset) {
-        constexpr size_t BITMASK_LOWER_BITS_LEN = sizeof(bitset) * 4;
-        decltype(bitset) outBitset;
-        bitset.forEachSetBit([&](size_t index) { outBitset.set(index % BITMASK_LOWER_BITS_LEN); });
-        return outBitset;
-    };
-    // We need to build a new descriptor set from the new layout
-    VkDescriptorSet oldSet = set->getVkSet();
-    VkDescriptorSet newSet = mDescriptorSetCache->getVkSet(layout);
-
-    using Bitmask = fvkutils::UniformBufferBitmask;
-    static_assert(sizeof(Bitmask) * 8 == fvkutils::MAX_DESCRIPTOR_SET_BITMASK_BITS);
-
-    auto const ubo = layout->bitmask.ubo | layout->bitmask.dynamicUbo;
-    auto const samplers = layout->bitmask.sampler & (~layout->bitmask.externalSampler);
-
-    // each bitmask denotes a binding index, and separated into two stages - vertex and buffer
-    // We fold the two stages into just the lower half of the bits to denote a combined set of
-    // bindings.
-    Bitmask const copyBindings = foldBitsInHalf(ubo | samplers);
-
-    // TODO: fix the size for better memory
-    std::vector<VkCopyDescriptorSet> copies;
-    copyBindings.forEachSetBit([&](size_t index) {
-        copies.push_back({
-            .sType = VK_STRUCTURE_TYPE_COPY_DESCRIPTOR_SET,
-            .srcSet = oldSet,
-            .srcBinding = (uint32_t) index,
-            .dstSet = newSet,
-            .dstBinding = (uint32_t) index,
-            .descriptorCount = 1,
-        });
-    });
-    vkUpdateDescriptorSets(mPlatform->getDevice(), 0, nullptr, copies.size(), copies.data());
-
-    set->setVkSet(newSet);
-
-    // We need to release the vkset, which is no longer used, back into the pool.
-    mDescriptorSetCache->manualRecyle(layout->count, oldLayout, oldSet);
-
-    // We need to update the external samplers in the set
-    for (auto& bindingInfo: mSetBindings) {
-        if (bindingInfo.set != set) {
-            continue;
-        }
-        mDescriptorSetCache->updateSampler(set, bindingInfo.binding, bindingInfo.image,
-                VK_NULL_HANDLE);
-    }
-    return true;
-}
-
-VkSamplerYcbcrConversion VulkanExternalImageManager::getVkSamplerYcbcrConversion(
-        VulkanPlatform::ExternalImageMetadata const& metadata) {
-    // This external image does not require external sampler (YUV conversion).
-    if (metadata.externalFormat == 0) {
-        return VK_NULL_HANDLE;
-    }
-    VulkanYcbcrConversionCache::Params ycbcrParams = {
-        .conversion = {
-            .ycbcrModel = fvkutils::getYcbcrModelConversionFilament(metadata.ycbcrModel),
-            .r = fvkutils::getSwizzleFilament(metadata.ycbcrConversionComponents.r, 0),
-            .g = fvkutils::getSwizzleFilament(metadata.ycbcrConversionComponents.g, 1),
-            .b = fvkutils::getSwizzleFilament(metadata.ycbcrConversionComponents.b, 2),
-            .a = fvkutils::getSwizzleFilament(metadata.ycbcrConversionComponents.a, 3),
-            .ycbcrRange = fvkutils::getYcbcrRangeFilament(metadata.ycbcrRange),
-            .xChromaOffset = fvkutils::getChromaLocationFilament(metadata.xChromaOffset),
-            .yChromaOffset = fvkutils::getChromaLocationFilament(metadata.yChromaOffset),
-
-            // Unclear where to get the chromaFilter, we just assume it's nearest.
-            .chromaFilter = SamplerMagFilter::NEAREST,
-        },
-        .format = metadata.filamentFormat,
-        .externalFormat = metadata.externalFormat,
-    };
-    return mYcbcrConversionCache->getConversion(ycbcrParams);
-}
-
-bool VulkanExternalImageManager::updateImage(ImageData* image) {
-    if (image->hasBeenValidated) {
-        return false;
-    }
-    image->hasBeenValidated = true;
-
-    auto metadata = mPlatform->extractExternalImageMetadata(image->platformHandle);
-    auto vkYcbcr = getVkSamplerYcbcrConversion(metadata);
-    if (vkYcbcr == image->conversion) {
-        return false;
-    }
-
-    image->ptr->setYcbcrConversion(vkYcbcr, metadata.externalFormat != 0);
-    image->conversion = vkYcbcr;
-    return true;
-}
-
-void VulkanExternalImageManager::addDescriptorSet(
-        fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout,
-        fvkmemory::resource_ptr<VulkanDescriptorSet> set) {
-    mSetAndLayouts.push_back({set, layout});
-}
-
-void VulkanExternalImageManager::removeDescriptorSet(
-        fvkmemory::resource_ptr<VulkanDescriptorSet> inSet) {
-    erasep<SetAndLayout>(mSetAndLayouts,
-            [&](auto const& setLayout) { return (setLayout.first == inSet); });
-    erasep<SetBindingInfo>(mSetBindings,
-            [&](auto const& bindingInfo) { return (bindingInfo.set == inSet); });
-}
-
-void VulkanExternalImageManager::removeDescriptorSetLayout(
-        fvkmemory::resource_ptr<VulkanDescriptorSetLayout> inLayout) {
-    erasep<SetAndLayout>(mSetAndLayouts,
-            [&](auto const& setLayout) { return (setLayout.second == inLayout); });
-}
-
-void VulkanExternalImageManager::bindExternallySampledTexture(
-        fvkmemory::resource_ptr<VulkanDescriptorSet> set, uint8_t bindingPoint,
-        fvkmemory::resource_ptr<VulkanTexture> image, SamplerParams samplerParams) {
-    // Should we do duplicate validation here?
-    mSetBindings.push_back({ bindingPoint, image, set, samplerParams });
-}
-
-void VulkanExternalImageManager::addExternallySampledTexture(
-        fvkmemory::resource_ptr<VulkanTexture> image,
-        Platform::ExternalImageHandleRef platformHandleRef) {
-    mImages.push_back({ image, platformHandleRef, false });
-}
-
-void VulkanExternalImageManager::removeExternallySampledTexture(
-        fvkmemory::resource_ptr<VulkanTexture> image) {
-    erasep<SetBindingInfo>(mSetBindings,
-            [&](auto const& bindingInfo) { return (bindingInfo.image == image); });
-    erasep<ImageData>(mImages, [&](auto const& imageData) { return imageData.ptr == image; });
-}
-
-bool VulkanExternalImageManager::isExternallySampledTexture(
-        fvkmemory::resource_ptr<VulkanTexture> image) const {
-    return std::find_if(mImages.begin(), mImages.end(),
-                   [&](auto const& imageData) { return imageData.ptr == image; }) != mImages.end();
-}
-
-
-} // namesapce filament::backend
@@ -1,115 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef TNT_FILAMENT_BACKEND_CACHING_VULKANEXTERNALIMAGEMANAGER_H
-#define TNT_FILAMENT_BACKEND_CACHING_VULKANEXTERNALIMAGEMANAGER_H
-
-#include "VulkanHandles.h"
-
-#include <backend/DriverEnums.h>
-
-#include <array>
-#include <vector>
-
-namespace filament::backend {
-
-class VulkanYcbcrConversionCache;
-class VulkanSamplerCache;
-class VulkanDescriptorSetLayoutCache;
-class VulkanDescriptorSetCache;
-
-// Manages the logic of external images and their quirks wrt Vulikan.
-class VulkanExternalImageManager {
-public:
-
-    VulkanExternalImageManager(
-            VulkanPlatform* platform,
-            VulkanSamplerCache* samplerCache,
-            VulkanYcbcrConversionCache* ycbcrConversionCache,
-            VulkanDescriptorSetCache* setCache,
-            VulkanDescriptorSetLayoutCache* layoutCache);
-
-    ~VulkanExternalImageManager();
-
-    void terminate();
-
-    void onBeginFrame();
-
-    using SetArray = std::array<fvkmemory::resource_ptr<VulkanDescriptorSet>,
-            VulkanDescriptorSetLayout::UNIQUE_DESCRIPTOR_SET_COUNT>;
-
-    // This sets the currently bound layouts objects for the pipeline
-    bool prepareBindSets(SetArray const& layouts);
-
-    void addDescriptorSet(fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout,
-            fvkmemory::resource_ptr<VulkanDescriptorSet> set);
-
-    void removeDescriptorSetLayout(fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);
-
-    void removeDescriptorSet(fvkmemory::resource_ptr<VulkanDescriptorSet> set);
-
-    void bindExternallySampledTexture(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
-            uint8_t bindingPoint, fvkmemory::resource_ptr<VulkanTexture> image,
-            SamplerParams samplerParams);
-
-    void addExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> image,
-            Platform::ExternalImageHandleRef platformHandleRef);
-
-    void removeExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> image);
-
-    bool isExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> image) const;
-
-    VkSamplerYcbcrConversion getVkSamplerYcbcrConversion(
-            VulkanPlatform::ExternalImageMetadata const& metadata);
-
-private:
-
-    struct ImageData {
-        fvkmemory::resource_ptr<VulkanTexture> ptr;
-        Platform::ExternalImageHandle platformHandle;
-        bool hasBeenValidated = false; // indicates whether the image has been validated *this frame*
-        VkSamplerYcbcrConversion conversion = VK_NULL_HANDLE;
-    };
-
-    bool updateSetAndLayout(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
-            fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);
-    bool updateImage(ImageData* imageData);
-
-    VulkanPlatform* mPlatform;
-    VulkanSamplerCache* mSamplerCache;
-    VulkanYcbcrConversionCache* mYcbcrConversionCache;
-    VulkanDescriptorSetCache* mDescriptorSetCache;
-    VulkanDescriptorSetLayoutCache* mDescriptorSetLayoutCache;
-
-    using SetAndLayout = std::pair<fvkmemory::resource_ptr<VulkanDescriptorSet>,
-            fvkmemory::resource_ptr<VulkanDescriptorSetLayout>>;
-
-    struct SetBindingInfo {
-        uint8_t binding = 0;
-        fvkmemory::resource_ptr<VulkanTexture> image;
-        fvkmemory::resource_ptr<VulkanDescriptorSet> set;
-        SamplerParams samplerParams;
-    };
-
-    // Use vectors instead of hash maps because we only expect small number of entries.
-    std::vector<SetAndLayout> mSetAndLayouts;
-    std::vector<SetBindingInfo> mSetBindings;
-    std::vector<ImageData> mImages;
-};
-
-} // filament::backend
-
-#endif // TNT_FILAMENT_BACKEND_CACHING_VULKANEXTERNALIMAGEMANAGER_H
@@ -30,7 +30,6 @@

 #include <backend/platforms/VulkanPlatform.h>

-#include <utils/compiler.h> // UTILS_FALLTHROUGH
 #include <utils/Panic.h>    // ASSERT_POSTCONDITION

 using namespace bluevk;
@@ -90,9 +89,8 @@ BitmaskGroup fromBackendLayout(DescriptorSetLayout const& layout) {
                }
                break;
            }
+            // TODO: properly handle external sampler
            case DescriptorType::SAMPLER_EXTERNAL:
-                fromStageFlags(binding.stageFlags, binding.binding, mask.externalSampler);
-                UTILS_FALLTHROUGH;
            case DescriptorType::SAMPLER: {
                fromStageFlags(binding.stageFlags, binding.binding, mask.sampler);
                break;
@@ -66,21 +66,18 @@ struct VulkanDescriptorSetLayout : public HwDescriptorSetLayout, fvkmemory::Reso

    // The bitmask representation of a set layout.
    struct Bitmask {
+        // TODO: better utiltize the space below and use bitset instead.
        fvkutils::UniformBufferBitmask ubo;         // 8 bytes
        fvkutils::UniformBufferBitmask dynamicUbo;  // 8 bytes
        fvkutils::SamplerBitmask sampler;           // 8 bytes
        fvkutils::InputAttachmentBitmask inputAttachment; // 8 bytes

-        // This is a subset of the bitmask.sampler field.
-        fvkutils::SamplerBitmask externalSampler; // 8 bytes
-
        bool operator==(Bitmask const& right) const {
            return ubo == right.ubo && dynamicUbo == right.dynamicUbo && sampler == right.sampler &&
-                   inputAttachment == right.inputAttachment &&
-                   externalSampler == right.externalSampler;
+                   inputAttachment == right.inputAttachment;
        }
    };
-    static_assert(sizeof(Bitmask) == 40);
+    static_assert(sizeof(Bitmask) == 32);

    // This is a convenience struct to quickly check layout compatibility in terms of descriptor set
    // pools.
@@ -122,16 +119,10 @@ struct VulkanDescriptorSetLayout : public HwDescriptorSetLayout, fvkmemory::Reso

    VulkanDescriptorSetLayout(DescriptorSetLayout const& layout);

-    // Note that we don't destroy the vklayout. This is done by the layout cache.
    ~VulkanDescriptorSetLayout() = default;

-    VkDescriptorSetLayout const& getVkLayout() const noexcept { return mVkLayout; }
-
-    // It is possible to have the layout switch out due to AHardwarebuffer (external image) format
-    // changes.
-    void setVkLayout(VkDescriptorSetLayout vklayout) noexcept { mVkLayout = vklayout; }
-
-    bool hasExternalSamplers() const noexcept { return bitmask.externalSampler.count() > 0; }
+    VkDescriptorSetLayout getVkLayout() const { return mVkLayout; }
+    void setVkLayout(VkDescriptorSetLayout vklayout) { mVkLayout = vklayout; }

    Bitmask const bitmask;
    Count const count;
@@ -146,11 +137,12 @@ public:
    // can use to repackage the vk handle.
    using OnRecycle = std::function<void(VulkanDescriptorSet*)>;

-    VulkanDescriptorSet(
+    VulkanDescriptorSet(VkDescriptorSet rawSet,
            fvkutils::UniformBufferBitmask const& dynamicUboMask,
            uint8_t uniqueDynamicUboCount,
            OnRecycle&& onRecycleFn)
-        : dynamicUboMask(dynamicUboMask),
+        : vkSet(rawSet),
+          dynamicUboMask(dynamicUboMask),
          uniqueDynamicUboCount(uniqueDynamicUboCount),
          mOnRecycleFn(std::move(onRecycleFn)) {}

@@ -160,13 +152,6 @@ public:
        }
    }

-    VkDescriptorSet const& getVkSet() const noexcept {
-        return mVkSet;
-    }
-
-    // Note that the only case where you'd set it more than once is with external images/samplers.
-    void setVkSet(VkDescriptorSet vkset) noexcept { mVkSet = vkset; }
-
    void setOffsets(backend::DescriptorSetOffsetArray&& offsets) noexcept {
        mOffsets = std::move(offsets);
    }
@@ -178,11 +163,11 @@ public:
    void acquire(fvkmemory::resource_ptr<VulkanTexture> texture);
    void acquire(fvkmemory::resource_ptr<VulkanBufferObject> buffer);

+    VkDescriptorSet const vkSet;
    fvkutils::UniformBufferBitmask const dynamicUboMask;
    uint8_t const uniqueDynamicUboCount;

 private:
-    VkDescriptorSet mVkSet = VK_NULL_HANDLE;
    backend::DescriptorSetOffsetArray mOffsets;
    std::vector<fvkmemory::resource_ptr<fvkmemory::Resource>> mResources;
    OnRecycle mOnRecycleFn;
@@ -15,12 +15,15 @@
 */

 #include "VulkanPipelineCache.h"
+#include "VulkanMemory.h"
+#include "caching/VulkanDescriptorSetManager.h"

 #include <utils/Log.h>
 #include <utils/Panic.h>

 #include "VulkanConstants.h"
 #include "VulkanHandles.h"
+#include "VulkanTexture.h"
 #include "vulkan/utils/Conversion.h"

 #if defined(__clang__)
@@ -18,18 +18,24 @@
 #define TNT_FILAMENT_BACKEND_VULKANPIPELINECACHE_H

 #include "VulkanCommands.h"
+#include "VulkanMemory.h"

 #include <backend/DriverEnums.h>
 #include <backend/TargetBufferInfo.h>

+#include "backend/Program.h"
+
 #include <bluevk/BlueVK.h>

 #include <utils/bitset.h>
 #include <utils/compiler.h>
 #include <utils/Hash.h>

+#include <list>
 #include <tsl/robin_map.h>
 #include <type_traits>
+#include <vector>
+#include <unordered_map>

 namespace filament::backend {

@@ -14,11 +14,8 @@
 * limitations under the License.
 */

-#include "VulkanSamplerCache.h"
-
-#include "VulkanConstants.h"
+#include "vulkan/VulkanSamplerCache.h"
 #include "vulkan/utils/Conversion.h"
-#include "vulkan/vulkan_core.h"

 #include <utils/Panic.h>

@@ -26,51 +23,117 @@ using namespace bluevk;

 namespace filament::backend {

+constexpr inline VkSamplerAddressMode getWrapMode(SamplerWrapMode mode) noexcept {
+    switch (mode) {
+        case SamplerWrapMode::REPEAT:
+            return VK_SAMPLER_ADDRESS_MODE_REPEAT;
+        case SamplerWrapMode::CLAMP_TO_EDGE:
+            return VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
+        case SamplerWrapMode::MIRRORED_REPEAT:
+            return VK_SAMPLER_ADDRESS_MODE_MIRRORED_REPEAT;
+    }
+}
+
+constexpr inline VkFilter getFilter(SamplerMinFilter filter) noexcept {
+    switch (filter) {
+        case SamplerMinFilter::NEAREST:
+            return VK_FILTER_NEAREST;
+        case SamplerMinFilter::LINEAR:
+            return VK_FILTER_LINEAR;
+        case SamplerMinFilter::NEAREST_MIPMAP_NEAREST:
+            return VK_FILTER_NEAREST;
+        case SamplerMinFilter::LINEAR_MIPMAP_NEAREST:
+            return VK_FILTER_LINEAR;
+        case SamplerMinFilter::NEAREST_MIPMAP_LINEAR:
+            return VK_FILTER_NEAREST;
+        case SamplerMinFilter::LINEAR_MIPMAP_LINEAR:
+            return VK_FILTER_LINEAR;
+    }
+}
+
+constexpr inline VkFilter getFilter(SamplerMagFilter filter) noexcept {
+    switch (filter) {
+        case SamplerMagFilter::NEAREST:
+            return VK_FILTER_NEAREST;
+        case SamplerMagFilter::LINEAR:
+            return VK_FILTER_LINEAR;
+    }
+}
+
+constexpr inline VkSamplerMipmapMode getMipmapMode(SamplerMinFilter filter) noexcept {
+    switch (filter) {
+        case SamplerMinFilter::NEAREST:
+            return VK_SAMPLER_MIPMAP_MODE_NEAREST;
+        case SamplerMinFilter::LINEAR:
+            return VK_SAMPLER_MIPMAP_MODE_NEAREST;
+        case SamplerMinFilter::NEAREST_MIPMAP_NEAREST:
+            return VK_SAMPLER_MIPMAP_MODE_NEAREST;
+        case SamplerMinFilter::LINEAR_MIPMAP_NEAREST:
+            return VK_SAMPLER_MIPMAP_MODE_NEAREST;
+        case SamplerMinFilter::NEAREST_MIPMAP_LINEAR:
+            return VK_SAMPLER_MIPMAP_MODE_LINEAR;
+        case SamplerMinFilter::LINEAR_MIPMAP_LINEAR:
+            return VK_SAMPLER_MIPMAP_MODE_LINEAR;
+    }
+}
+
+constexpr inline float getMaxLod(SamplerMinFilter filter) noexcept {
+    switch (filter) {
+        case SamplerMinFilter::NEAREST:
+        case SamplerMinFilter::LINEAR:
+            // The Vulkan spec recommends a max LOD of 0.25 to "disable" mipmapping.
+            // See "Mapping of OpenGL to Vulkan filter modes" in the VK Spec.
+            return 0.25f;
+        case SamplerMinFilter::NEAREST_MIPMAP_NEAREST:
+        case SamplerMinFilter::LINEAR_MIPMAP_NEAREST:
+        case SamplerMinFilter::NEAREST_MIPMAP_LINEAR:
+        case SamplerMinFilter::LINEAR_MIPMAP_LINEAR:
+            return VK_LOD_CLAMP_NONE;
+    }
+}
+
+constexpr inline VkBool32 getCompareEnable(SamplerCompareMode mode) noexcept {
+    return mode == SamplerCompareMode::NONE ? VK_FALSE : VK_TRUE;
+}
+
 VulkanSamplerCache::VulkanSamplerCache(VkDevice device)
    : mDevice(device) {}

-VkSampler VulkanSamplerCache::getSampler(Params params) noexcept {
+VkSampler VulkanSamplerCache::getSampler(SamplerParams params) noexcept {
    auto iter = mCache.find(params);
    if (UTILS_LIKELY(iter != mCache.end())) {
        return iter->second;
    }
-    VkSamplerYcbcrConversionInfo ycbcrConversion = {
-        .sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_INFO,
-        .conversion = params.conversion,
-    };
-
-    auto const& samplerParams = params.sampler;
-    VkSamplerCreateInfo samplerInfo{
+    VkSamplerCreateInfo samplerInfo {
        .sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO,
-        .pNext = params.conversion != VK_NULL_HANDLE ? &ycbcrConversion : VK_NULL_HANDLE,
-        .magFilter = fvkutils::getFilter(samplerParams.filterMag),
-        .minFilter = fvkutils::getFilter(samplerParams.filterMin),
-        .mipmapMode = fvkutils::getMipmapMode(samplerParams.filterMin),
-        .addressModeU = fvkutils::getWrapMode(samplerParams.wrapS),
-        .addressModeV = fvkutils::getWrapMode(samplerParams.wrapT),
-        .addressModeW = fvkutils::getWrapMode(samplerParams.wrapR),
-        .anisotropyEnable = samplerParams.anisotropyLog2 == 0 ? VK_FALSE : VK_TRUE,
-        .maxAnisotropy = (float) (1u << samplerParams.anisotropyLog2),
-        .compareEnable = fvkutils::getCompareEnable(samplerParams.compareMode),
-        .compareOp = fvkutils::getCompareOp(samplerParams.compareFunc),
+        .magFilter = getFilter(params.filterMag),
+        .minFilter = getFilter(params.filterMin),
+        .mipmapMode = getMipmapMode(params.filterMin),
+        .addressModeU = getWrapMode(params.wrapS),
+        .addressModeV = getWrapMode(params.wrapT),
+        .addressModeW = getWrapMode(params.wrapR),
+        .anisotropyEnable = params.anisotropyLog2 == 0 ? 0u : 1u,
+        .maxAnisotropy = (float)(1u << params.anisotropyLog2),
+        .compareEnable = getCompareEnable(params.compareMode),
+        .compareOp = fvkutils::getCompareOp(params.compareFunc),
        .minLod = 0.0f,
-        .maxLod = fvkutils::getMaxLod(samplerParams.filterMin),
+        .maxLod = getMaxLod(params.filterMin),
        .borderColor = VK_BORDER_COLOR_INT_OPAQUE_BLACK,
-        .unnormalizedCoordinates = VK_FALSE,
+        .unnormalizedCoordinates = VK_FALSE
    };
    VkSampler sampler;
    VkResult result = vkCreateSampler(mDevice, &samplerInfo, VKALLOC, &sampler);
    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS) << "Unable to create sampler."
                                                       << " error=" << static_cast<int32_t>(result);
-    mCache.insert({ params, sampler });
+    mCache.insert({params, sampler});
    return sampler;
 }

 void VulkanSamplerCache::terminate() noexcept {
-    for (auto pair: mCache) {
+    for (auto pair : mCache) {
        vkDestroySampler(mDevice, pair.second, VKALLOC);
    }
    mCache.clear();
 }

-}// namespace filament::backend
+} // namespace filament::backend
@@ -17,11 +17,8 @@
 #ifndef TNT_FILAMENT_BACKEND_VULKANSAMPLERCACHE_H
 #define TNT_FILAMENT_BACKEND_VULKANSAMPLERCACHE_H

-#include <backend/DriverEnums.h>
+#include "VulkanContext.h"

-#include <utils/Hash.h>
-
-#include <bluevk/BlueVK.h>
 #include <tsl/robin_map.h>

 namespace filament::backend {
@@ -29,28 +26,12 @@ namespace filament::backend {
 // Simple manager for VkSampler objects.
 class VulkanSamplerCache {
 public:
-    struct Params {
-        SamplerParams sampler = {};
-        uint32_t padding = 0;
-        VkSamplerYcbcrConversion conversion = VK_NULL_HANDLE;
-    };
-
-    static_assert(sizeof(Params) == 16);
-
    explicit VulkanSamplerCache(VkDevice device);
-    VkSampler getSampler(Params params) noexcept;
+    VkSampler getSampler(SamplerParams params) noexcept;
    void terminate() noexcept;
 private:
    VkDevice mDevice;
-
-    struct SamplerEqualTo {
-        bool operator()(Params lhs, Params rhs) const noexcept {
-            SamplerParams::EqualTo equal;
-            return equal(lhs.sampler, rhs.sampler) && lhs.conversion == rhs.conversion;
-        }
-    };
-    using SamplerHashFn = utils::hash::MurmurHashFn<Params>;
-    tsl::robin_map<Params, VkSampler, SamplerHashFn, SamplerEqualTo> mCache;
+    tsl::robin_map<SamplerParams, VkSampler, SamplerParams::Hasher, SamplerParams::EqualTo> mCache;
 };

 } // namespace filament::backend
@@ -32,7 +32,6 @@ VulkanSwapChain::VulkanSwapChain(VulkanPlatform* platform, VulkanContext const&
        VulkanCommands* commands, VulkanStagePool& stagePool, void* nativeWindow, uint64_t flags,
        VkExtent2D extent)
    : mPlatform(platform),
-      mContext(context),
      mResourceManager(resourceManager),
      mCommands(commands),
      mAllocator(allocator),
@@ -78,16 +77,16 @@ void VulkanSwapChain::update() {
    }
    for (auto const color: bundle.colors) {
        auto colorTexture = fvkmemory::resource_ptr<VulkanTexture>::construct(mResourceManager,
-                mContext, device, mAllocator, mResourceManager, mCommands, color, VK_NULL_HANDLE,
-                bundle.colorFormat, VK_NULL_HANDLE /*ycrcb */, 1, bundle.extent.width,
-                bundle.extent.height, bundle.layerCount, colorUsage, mStagePool);
+                device, mAllocator, mResourceManager, mCommands, color, VK_NULL_HANDLE,
+                bundle.colorFormat, 1, bundle.extent.width, bundle.extent.height, bundle.layerCount, colorUsage,
+                mStagePool);
        mColors.push_back(colorTexture);
    }

-    mDepth = fvkmemory::resource_ptr<VulkanTexture>::construct(mResourceManager, mContext, device,
-            mAllocator, mResourceManager, mCommands, bundle.depth, VK_NULL_HANDLE,
-            bundle.depthFormat, VK_NULL_HANDLE /*ycrcb */, 1, bundle.extent.width,
-            bundle.extent.height, bundle.layerCount, depthUsage, mStagePool);
+    mDepth = fvkmemory::resource_ptr<VulkanTexture>::construct(mResourceManager, device,
+        mAllocator, mResourceManager, mCommands, bundle.depth, VK_NULL_HANDLE,
+        bundle.depthFormat, 1, bundle.extent.width, bundle.extent.height, bundle.layerCount, depthUsage,
+        mStagePool);

    mExtent = bundle.extent;
    mLayerCount = bundle.layerCount;
@@ -19,7 +19,6 @@

 #include "DriverBase.h"

-#include "VulkanConstants.h"
 #include "VulkanContext.h"
 #include "VulkanTexture.h"
 #include "vulkan/memory/Resource.h"
@@ -29,6 +28,7 @@
 #include <bluevk/BlueVK.h>
 #include <utils/FixedCapacityVector.h>

+#include <memory>

 using namespace bluevk;

@@ -83,7 +83,6 @@ private:
    void update();

    VulkanPlatform* mPlatform;
-    VulkanContext const& mContext;
    fvkmemory::ResourceManager* mResourceManager;
    VulkanCommands* mCommands;
    VmaAllocator mAllocator;
@@ -15,7 +15,6 @@
 */

 #include "VulkanCommands.h"
-#include "VulkanContext.h"
 #include "VulkanMemory.h"
 #include "VulkanTexture.h"
 #include "vulkan/memory/ResourcePointer.h"
@@ -55,61 +54,64 @@ VkComponentMapping composeSwizzle(VkComponentMapping const& prev, VkComponentMap
        VK_COMPONENT_SWIZZLE_B,
        VK_COMPONENT_SWIZZLE_A,
    };
-    auto const compose = [](VkComponentMapping const& prev,
-                                 VkComponentMapping const& next) -> VkComponentMapping {
-        VkComponentSwizzle vals[4] = { next.r, next.g, next.b, next.a };
-        for (auto& out: vals) {
-            switch (out) {
-                case VK_COMPONENT_SWIZZLE_R:
-                    out = prev.r;
-                    break;
-                case VK_COMPONENT_SWIZZLE_G:
-                    out = prev.g;
-                    break;
-                case VK_COMPONENT_SWIZZLE_B:
-                    out = prev.b;
-                    break;
-                case VK_COMPONENT_SWIZZLE_A:
-                    out = prev.a;
-                    break;
-                // Do not modify the value
-                case VK_COMPONENT_SWIZZLE_IDENTITY:
-                case VK_COMPONENT_SWIZZLE_ZERO:
-                case VK_COMPONENT_SWIZZLE_ONE:
-                // Below is not exposed in Vulkan's API, but needs to be there for compilation.
-                case VK_COMPONENT_SWIZZLE_MAX_ENUM:
-                    break;
-            }
+
+    auto const compose = [](VkComponentSwizzle out, VkComponentMapping const& prev,
+                                 uint8_t channelIndex) {
+        // We need to first change all identities to its equivalent channel.
+        if (out == VK_COMPONENT_SWIZZLE_IDENTITY) {
+            out = IDENTITY[channelIndex];
        }
-        return { vals[0], vals[1], vals[2], vals[3] };
+        switch (out) {
+            case VK_COMPONENT_SWIZZLE_R:
+                out = prev.r;
+                break;
+            case VK_COMPONENT_SWIZZLE_G:
+                out = prev.g;
+                break;
+            case VK_COMPONENT_SWIZZLE_B:
+                out = prev.b;
+                break;
+            case VK_COMPONENT_SWIZZLE_A:
+                out = prev.a;
+                break;
+            case VK_COMPONENT_SWIZZLE_IDENTITY:
+            case VK_COMPONENT_SWIZZLE_ZERO:
+            case VK_COMPONENT_SWIZZLE_ONE:
+                return out;
+            // Below is not exposed in Vulkan's API, but needs to be there for compilation.
+            case VK_COMPONENT_SWIZZLE_MAX_ENUM:
+                break;
+        }
+        // If the result correctly corresponds to the identity, just return identity.
+        if (IDENTITY[channelIndex] == out) {
+            return VK_COMPONENT_SWIZZLE_IDENTITY;
+        }
+        return out;
    };

-    auto const identityToChannel = [](VkComponentMapping const& mapping) -> VkComponentMapping {
-        VkComponentSwizzle vals[4] = { mapping.r, mapping.g, mapping.b, mapping.a };
-        for (uint8_t i = 0; i < 4; i++) {
-            if (vals[i] != VK_COMPONENT_SWIZZLE_IDENTITY) {
-                continue;
-            }
-            vals[i] = IDENTITY[i];
+    auto const identityToChannel = [](VkComponentSwizzle val, uint8_t channelIndex) {
+        if (val != VK_COMPONENT_SWIZZLE_IDENTITY) {
+            return val;
        }
-        return { vals[0], vals[1], vals[2], vals[3] };
-    };
-    auto const channelToIdentity = [](VkComponentMapping const& mapping) -> VkComponentMapping {
-        VkComponentSwizzle vals[4] = { mapping.r, mapping.g, mapping.b, mapping.a };
-        for (uint8_t i = 0; i < 4; i++) {
-            if (IDENTITY[i] != vals[i]) {
-                continue;
-            }
-            vals[i] = VK_COMPONENT_SWIZZLE_IDENTITY;
-        }
-        return { vals[0], vals[1], vals[2], vals[3] };
+        return IDENTITY[channelIndex];
    };

    // We make sure all all identities are mapped into respective channels so that actual channel
    // mapping will be passed onto the output.
-    VkComponentMapping const prevExplicit = identityToChannel(prev);
-    VkComponentMapping const nextExplicit = identityToChannel(next);
-    return channelToIdentity(compose(prevExplicit, nextExplicit));
+    VkComponentMapping const prevExplicit = {
+            identityToChannel(prev.r, 0),
+            identityToChannel(prev.g, 1),
+            identityToChannel(prev.b, 2),
+            identityToChannel(prev.a, 3),
+    };
+
+    // Note that the channel index corresponds to the VkComponentMapping struct layout.
+    return {
+        compose(next.r, prevExplicit, 0),
+        compose(next.g, prevExplicit, 1),
+        compose(next.b, prevExplicit, 2),
+        compose(next.a, prevExplicit, 3),
+    };
 }

 inline VulkanLayout getDefaultLayoutImpl(TextureUsage usage) {
@@ -151,152 +153,36 @@ uint8_t getLayerCountFromDepth(uint32_t const depth) {
    return getLayerCount(getSamplerTypeFromDepth(depth), depth);
 }

-VkImageUsageFlags getUsage(VulkanContext const& context, uint8_t samples,
-        VkPhysicalDevice physicalDevice, VkFormat vkFormat, TextureUsage tusage) {
-    VkImageUsageFlags usage = {};
-    if (any(tusage & TextureUsage::BLIT_SRC)) {
-        usage |= VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
-    }
-    if (any(tusage & TextureUsage::BLIT_DST)) {
-        usage |= VK_IMAGE_USAGE_TRANSFER_DST_BIT;
-    }
-
-    // Determine if we can use the transient usage flag combined with lazily allocated memory.
-    const bool useTransientAttachment =
-            // Lazily allocated memory is available.
-            context.isLazilyAllocatedMemorySupported() &&
-            // Usage consists of attachment flags only.
-            none(tusage & ~TextureUsage::ALL_ATTACHMENTS) &&
-            // Usage contains at least one attachment flag.
-            any(tusage & TextureUsage::ALL_ATTACHMENTS) &&
-            // Depth resolve cannot use transient attachment because it uses a custom shader.
-            // TODO: see VulkanDriver::isDepthStencilResolveSupported() to know when to remove this
-            // restriction.
-            // Note that the custom shader does not resolve stencil. We do need to move to vk 1.2
-            // and above to be able to support stencil resolve (along with depth).
-            !(any(tusage & TextureUsage::DEPTH_ATTACHMENT) && samples > 1);
-
-    const VkImageUsageFlags transientFlag =
-       useTransientAttachment ? VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BIT : 0U;
-
-    if (any(tusage & TextureUsage::SAMPLEABLE)) {
-
-#if FVK_ENABLED(FVK_DEBUG_TEXTURE)
-        if (physicalDevice != VK_NULL_HANDLE) {
-            // Validate that the format is actually sampleable.
-            VkFormatProperties props;
-            vkGetPhysicalDeviceFormatProperties(physicalDevice, vkFormat, &props);
-            if (!(props.optimalTilingFeatures & VK_FORMAT_FEATURE_SAMPLED_IMAGE_BIT)) {
-                FVK_LOGW << "Texture usage is SAMPLEABLE but format " << mState->mVkFormat << " is not "
-                        "sampleable with optimal tiling." << utils::io::endl;
-            }
-        }
-#endif
-
-        usage |= VK_IMAGE_USAGE_SAMPLED_BIT;
-    }
-    if (any(tusage & TextureUsage::COLOR_ATTACHMENT)) {
-        usage |= VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | transientFlag;
-        if (any(tusage & TextureUsage::SUBPASS_INPUT)) {
-            usage |= VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT;
-        }
-    }
-    if (any(tusage & TextureUsage::STENCIL_ATTACHMENT)) {
-        usage |= VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | transientFlag;
-    }
-    if (any(tusage & TextureUsage::UPLOADABLE)) {
-        usage |= VK_IMAGE_USAGE_TRANSFER_DST_BIT;
-    }
-    if (any(tusage & TextureUsage::DEPTH_ATTACHMENT)) {
-        usage |= VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | transientFlag;
-
-        // Depth resolves uses a custom shader and therefore needs to be sampleable.
-        if (samples > 1) {
-            usage |= VK_IMAGE_USAGE_SAMPLED_BIT;
-        }
-    }
-    return usage;
-}

 } // anonymous namespace

-VulkanTextureState::VulkanTextureState(VulkanStagePool& stagePool, VulkanCommands* commands,
-        VmaAllocator allocator, VkDevice device, VkImage image, VkDeviceMemory deviceMemory,
-        VkFormat format, VkImageViewType viewType, uint8_t levels, uint8_t layerCount,
-        VkSamplerYcbcrConversion ycbcrConversion, bool isExternalFormat, VkImageUsageFlags usage,
+VulkanTextureState::VulkanTextureState(VkDevice device, VmaAllocator allocator,
+        VulkanCommands* commands, VulkanStagePool& stagePool, VkFormat format,
+        VkImageViewType viewType, uint8_t levels, uint8_t layerCount, VulkanLayout defaultLayout,
        bool isProtected)
-    : mStagePool(stagePool),
-      mCommands(commands),
-      mAllocator(allocator),
-      mDevice(device),
-      mTextureImage(image),
-      mTextureImageMemory(deviceMemory),
-      mVkFormat(format),
+    : mVkFormat(format),
      mViewType(viewType),
-      mFullViewRange{ fvkutils::getImageAspect(format), 0, levels, 0, layerCount },
-      mYcbcr{ ycbcrConversion, isExternalFormat },
-      mDefaultLayout(getDefaultLayoutImpl(usage)),
-      mUsage(usage),
-      mIsProtected(isProtected) {}
+      mFullViewRange{fvkutils::getImageAspect(format), 0, levels, 0, layerCount},
+      mDefaultLayout(defaultLayout),
+      mIsProtected(isProtected),
+      mStagePool(stagePool),
+      mDevice(device),
+      mAllocator(allocator),
+      mCommands(commands),
+      mIsTransientAttachment(false) {}

-VulkanTextureState::~VulkanTextureState() {
-    if (mTextureImageMemory != VK_NULL_HANDLE) {
-        vkDestroyImage(mDevice, mTextureImage, VKALLOC);
-        vkFreeMemory(mDevice, mTextureImageMemory, VKALLOC);
-    }
-    clearCachedImageViews();
-}
-
-void VulkanTextureState::clearCachedImageViews() noexcept {
-    for (auto entry: mCachedImageViews) {
-        vkDestroyImageView(mDevice, entry.second, VKALLOC);
-    }
-    mCachedImageViews.clear();
-}
-
-VkImageView VulkanTextureState::getImageView(VkImageSubresourceRange range, VkImageViewType viewType,
-        VkComponentMapping swizzle) {
-    ImageViewKey const key{ range, viewType, swizzle };
-    if (auto iter = mCachedImageViews.find(key); iter != mCachedImageViews.end()) {
-        return iter->second;
-    }
-
-    VkSamplerYcbcrConversionInfo conversionInfo = {
-        .sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_INFO,
-        .conversion = mYcbcr.conversion,
-    };
-
-    VkImageViewCreateInfo viewInfo = {
-        .sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO,
-        .pNext = mYcbcr.conversion != VK_NULL_HANDLE ? &conversionInfo : nullptr,
-        .flags = 0,
-        .image = mTextureImage,
-        .viewType = viewType,
-        .format = mYcbcr.isExternalFormat ? VK_FORMAT_UNDEFINED : mVkFormat,
-        .components = swizzle,
-        .subresourceRange = range,
-    };
-    VkImageView imageView;
-    vkCreateImageView(mDevice, &viewInfo, VKALLOC, &imageView);
-    mCachedImageViews.emplace(key, imageView);
-    return imageView;
-}
-
-// Constructor for internally passed VkImage - including swapchain images and external images.
-VulkanTexture::VulkanTexture(VulkanContext const& context, VkDevice device, VmaAllocator allocator,
+// Constructor for internally passed VkImage
+VulkanTexture::VulkanTexture(VkDevice device, VmaAllocator allocator,
        fvkmemory::ResourceManager* resourceManager, VulkanCommands* commands, VkImage image,
-        VkDeviceMemory memory, VkFormat format, VkSamplerYcbcrConversion conversion,
-        uint8_t samples, uint32_t width, uint32_t height, uint32_t depth, TextureUsage tusage,
-        VulkanStagePool& stagePool)
-    : HwTexture(getSamplerTypeFromDepth(depth), 1, samples, width, height, depth,
-              TextureFormat::UNUSED, tusage),
-      mState(fvkmemory::resource_ptr<VulkanTextureState>::construct(resourceManager, stagePool,
-              commands, allocator, device, image, memory, format,
-              fvkutils::getViewType(SamplerType::SAMPLER_2D),
-              /*mipLevels=*/1, getLayerCountFromDepth(depth), conversion,
-              /*isExternalFormat=*/false,
-              getUsage(context, samples, VK_NULL_HANDLE, format, tusage),
-              any(usage & TextureUsage::PROTECTED))) {
+        VkDeviceMemory memory, VkFormat format, uint8_t samples, uint32_t width,
+        uint32_t height, uint32_t depth, TextureUsage tusage, VulkanStagePool& stagePool)
+    : HwTexture(getSamplerTypeFromDepth(depth), 1, samples, width, height, depth, TextureFormat::UNUSED,
+              tusage),
+      mState(fvkmemory::resource_ptr<VulkanTextureState>::construct(resourceManager, device,
+              allocator, commands, stagePool, format, fvkutils::getViewType(SamplerType::SAMPLER_2D),
+              /*mipLevels=*/1, getLayerCountFromDepth(depth), getDefaultLayoutImpl(tusage), any(usage & TextureUsage::PROTECTED))) {
+    mState->mTextureImage = image;
+    mState->mTextureImageMemory = memory;
    mPrimaryViewRange = mState->mFullViewRange;
 }

@@ -306,19 +192,21 @@ VulkanTexture::VulkanTexture(VkDevice device, VkPhysicalDevice physicalDevice,
        fvkmemory::ResourceManager* resourceManager, VulkanCommands* commands, SamplerType target,
        uint8_t levels, TextureFormat tformat, uint8_t samples, uint32_t w, uint32_t h,
        uint32_t depth, TextureUsage tusage, VulkanStagePool& stagePool)
-     : HwTexture(target, levels, samples, w, h, depth, tformat, tusage) {
+    : HwTexture(target, levels, samples, w, h, depth, tformat, tusage),
+      mState(fvkmemory::resource_ptr<VulkanTextureState>::construct(resourceManager, device,
+              allocator, commands, stagePool, fvkutils::getVkFormat(tformat),
+              fvkutils::getViewType(target), levels, getLayerCount(target, depth),
+              VulkanLayout::UNDEFINED, any(usage & TextureUsage::PROTECTED))) {
    // Create an appropriately-sized device-only VkImage, but do not fill it yet.
-    VkFormat const vkFormat = fvkutils::getVkFormat(tformat);
-    bool const isProtected = any(tusage & TextureUsage::PROTECTED);
    VkImageCreateInfo imageInfo{
        .sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,
        .imageType = target == SamplerType::SAMPLER_3D ? VK_IMAGE_TYPE_3D : VK_IMAGE_TYPE_2D,
-        .format = vkFormat,
+        .format = mState->mVkFormat,
        .extent = {w, h, depth},
        .mipLevels = levels,
        .arrayLayers = 1,
        .tiling = VK_IMAGE_TILING_OPTIMAL,
-        .usage = getUsage(context, samples, physicalDevice, vkFormat, tusage),
+        .usage = 0,
    };
    if (target == SamplerType::SAMPLER_3D && any(tusage & TextureUsage::ALL_ATTACHMENTS)) {
        if (context.isImageView2DOn3DImageSupported()) {
@@ -348,17 +236,72 @@ VulkanTexture::VulkanTexture(VkDevice device, VkPhysicalDevice physicalDevice,
        imageInfo.arrayLayers = depth * 6;
        imageInfo.extent.depth = 1;
    }
-    if (isProtected) {
+    if (any(usage & TextureUsage::PROTECTED)) {
        imageInfo.flags |= VK_IMAGE_CREATE_PROTECTED_BIT;
    }

+    if (any(usage & TextureUsage::BLIT_SRC)) {
+        imageInfo.usage |= VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
+    }
+    if (any(usage & TextureUsage::BLIT_DST)) {
+        imageInfo.usage |= VK_IMAGE_USAGE_TRANSFER_DST_BIT;
+    }
+
+    // Determine if we can use the transient usage flag combined with lazily allocated memory.
+    const bool useTransientAttachment =
+        // Lazily allocated memory is available.
+        context.isLazilyAllocatedMemorySupported() &&
+        // Usage consists of attachment flags only.
+        none(tusage & ~TextureUsage::ALL_ATTACHMENTS) &&
+        // Usage contains at least one attachment flag.
+        any(tusage & TextureUsage::ALL_ATTACHMENTS);
+    mState->mIsTransientAttachment = useTransientAttachment;
+
+    const VkImageUsageFlags transientFlag =
+       useTransientAttachment ? VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BIT : 0U;
+
+    if (any(usage & TextureUsage::SAMPLEABLE)) {
+
+#if FVK_ENABLED(FVK_DEBUG_TEXTURE)
+        // Validate that the format is actually sampleable.
+        VkFormatProperties props;
+        vkGetPhysicalDeviceFormatProperties(physicalDevice, mState->mVkFormat, &props);
+        if (!(props.optimalTilingFeatures & VK_FORMAT_FEATURE_SAMPLED_IMAGE_BIT)) {
+            FVK_LOGW << "Texture usage is SAMPLEABLE but format " << mState->mVkFormat << " is not "
+                    "sampleable with optimal tiling." << utils::io::endl;
+        }
+#endif
+
+        imageInfo.usage |= VK_IMAGE_USAGE_SAMPLED_BIT;
+    }
+    if (any(usage & TextureUsage::COLOR_ATTACHMENT)) {
+        imageInfo.usage |= VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | transientFlag;
+        if (any(usage & TextureUsage::SUBPASS_INPUT)) {
+            imageInfo.usage |= VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT;
+        }
+    }
+    if (any(usage & TextureUsage::STENCIL_ATTACHMENT)) {
+        imageInfo.usage |= VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | transientFlag;
+    }
+    if (any(usage & TextureUsage::UPLOADABLE)) {
+        imageInfo.usage |= VK_IMAGE_USAGE_TRANSFER_DST_BIT;
+    }
+    if (any(usage & TextureUsage::DEPTH_ATTACHMENT)) {
+        imageInfo.usage |= VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | transientFlag;
+
+        // Depth resolves uses a custom shader and therefore needs to be sampleable.
+        if (samples > 1) {
+            imageInfo.usage |= VK_IMAGE_USAGE_SAMPLED_BIT;
+        }
+    }
+
    // Constrain the sample count according to the sample count masks in VkPhysicalDeviceProperties.
    // Note that VulkanRenderTarget holds a single MSAA count, so we play it safe if this is used as
    // any kind of attachment (color or depth).
-    auto const& limits = context.getPhysicalDeviceLimits();
+    const auto& limits = context.getPhysicalDeviceLimits();
    if (imageInfo.usage & VK_IMAGE_USAGE_SAMPLED_BIT) {
        samples = fvkutils::reduceSampleCount(samples,
-                fvkutils::isVkDepthFormat(vkFormat)
+                fvkutils::isVkDepthFormat(mState->mVkFormat)
                        ? limits.sampledImageDepthSampleCounts
                        : limits.sampledImageColorSampleCounts);
    }
@@ -372,36 +315,33 @@ VulkanTexture::VulkanTexture(VkDevice device, VkPhysicalDevice physicalDevice,
    this->samples = samples;
    imageInfo.samples = (VkSampleCountFlagBits) samples;

-    VkImage textureImage;
-    VkResult result = vkCreateImage(device, &imageInfo, VKALLOC, &textureImage);
+    VkResult result = vkCreateImage(mState->mDevice, &imageInfo, VKALLOC, &mState->mTextureImage);
    if (result != VK_SUCCESS || FVK_ENABLED(FVK_DEBUG_TEXTURE)) {
        FVK_LOGD << "vkCreateImage: "
-            << "image = " << textureImage << ", "
+            << "image = " << mState->mTextureImage << ", "
            << "result = " << result << ", "
-            << "handle = " << utils::io::hex << textureImage << utils::io::dec << ", "
+            << "handle = " << utils::io::hex << mState->mTextureImage << utils::io::dec << ", "
            << "extent = " << w << "x" << h << "x"<< depth << ", "
            << "mipLevels = " << int(levels) << ", "
-            << "TextureUsage = " << static_cast<int>(tusage) << ", "
+            << "TextureUsage = " << static_cast<int>(usage) << ", "
            << "usage = " << imageInfo.usage << ", "
            << "samples = " << imageInfo.samples << ", "
            << "type = " << imageInfo.imageType << ", "
            << "flags = " << imageInfo.flags << ", "
            << "target = " << static_cast<int>(target) <<", "
-            << "format = " << vkFormat << utils::io::endl;
+            << "format = " << mState->mVkFormat << utils::io::endl;
    }
    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS) << "Unable to create image."
                                                       << " error=" << static_cast<int32_t>(result);

    // Allocate memory for the VkImage and bind it.
-    VkMemoryRequirements memReqs;
-    vkGetImageMemoryRequirements(device, textureImage, &memReqs);
+    VkMemoryRequirements memReqs = {};
+    vkGetImageMemoryRequirements(mState->mDevice, mState->mTextureImage, &memReqs);

-    bool const useTransientAttachment = imageInfo.usage & VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BIT;
-
-    VkFlags const requiredMemoryFlags =
+    const VkFlags requiredMemoryFlags =
        VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT |
        (useTransientAttachment ? VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT : 0U) |
-        (isProtected ? VK_MEMORY_PROPERTY_PROTECTED_BIT : 0U);
+        (mState->mIsProtected ? VK_MEMORY_PROPERTY_PROTECTED_BIT : 0U);
    uint32_t memoryTypeIndex
            = context.selectMemoryType(memReqs.memoryTypeBits, requiredMemoryFlags);

@@ -413,22 +353,21 @@ VulkanTexture::VulkanTexture(VkDevice device, VkPhysicalDevice physicalDevice,
        .allocationSize = memReqs.size,
        .memoryTypeIndex = memoryTypeIndex,
    };
-    VkDeviceMemory textureImageMemory;
-    result = vkAllocateMemory(device, &allocInfo, nullptr, &textureImageMemory);
+    result = vkAllocateMemory(mState->mDevice, &allocInfo, nullptr, &mState->mTextureImageMemory);
    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS) << "Unable to allocate image memory."
                                                       << " error=" << static_cast<int32_t>(result);
-    result = vkBindImageMemory(device, textureImage, textureImageMemory, 0);
+    result = vkBindImageMemory(mState->mDevice, mState->mTextureImage, mState->mTextureImageMemory,
+            0);
    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS) << "Unable to bind image."
                                                       << " error=" << static_cast<int32_t>(result);

-    mState = fvkmemory::resource_ptr<VulkanTextureState>::construct(resourceManager, stagePool,
-            commands, allocator, device, textureImage, textureImageMemory, vkFormat,
-            fvkutils::getViewType(target), levels, getLayerCount(target, depth),
-            VK_NULL_HANDLE /* ycbcrConversion */, false /*isExternalFormat*/, imageInfo.usage,
-            isProtected);
-
    // Spec out the "primary" VkImageView that shaders use to sample from the image.
    mPrimaryViewRange = mState->mFullViewRange;
+
+    // Go ahead and create the primary image view.
+    getImageView(mPrimaryViewRange, mState->mViewType, mSwizzle);
+
+    mState->mDefaultLayout = getDefaultLayoutImpl(imageInfo.usage);
 }

 // Constructor for creating a texture view
@@ -437,8 +376,8 @@ VulkanTexture::VulkanTexture(VkDevice device, VkPhysicalDevice physicalDevice,
        fvkmemory::resource_ptr<VulkanTexture> src, uint8_t baseLevel,
        uint8_t levelCount)
    : HwTexture(src->target, src->levels, src->samples, src->width, src->height, src->depth,
-            src->format, src->usage),
-      mState(src->mState) {
+            src->format, src->usage) {
+    mState = src->mState;
    mPrimaryViewRange = src->mPrimaryViewRange;
    mPrimaryViewRange.baseMipLevel = src->mPrimaryViewRange.baseMipLevel + baseLevel;
    mPrimaryViewRange.levelCount = levelCount;
@@ -449,10 +388,21 @@ VulkanTexture::VulkanTexture(VkDevice device, VkPhysicalDevice physicalDevice,
        VulkanContext const& context, VmaAllocator allocator, VulkanCommands* commands,
        fvkmemory::resource_ptr<VulkanTexture> src, VkComponentMapping swizzle)
    : HwTexture(src->target, src->levels, src->samples, src->width, src->height, src->depth,
-              src->format, src->usage),
-      mState(src->mState),
-      mPrimaryViewRange(src->mPrimaryViewRange),
-      mSwizzle(composeSwizzle(src->mSwizzle, swizzle)) {}
+              src->format, src->usage) {
+    mState = src->mState;
+    mPrimaryViewRange = src->mPrimaryViewRange;
+    mSwizzle = composeSwizzle(src->mSwizzle, swizzle);
+}
+
+VulkanTextureState::~VulkanTextureState() {
+    if (mTextureImageMemory != VK_NULL_HANDLE) {
+        vkDestroyImage(mDevice, mTextureImage, VKALLOC);
+        vkFreeMemory(mDevice, mTextureImageMemory, VKALLOC);
+    }
+    for (auto entry: mCachedImageViews) {
+        vkDestroyImageView(mDevice, entry.second, VKALLOC);
+    }
+}

 void VulkanTexture::updateImage(const PixelBufferDescriptor& data, uint32_t width, uint32_t height,
        uint32_t depth, uint32_t xoffset, uint32_t yoffset, uint32_t zoffset, uint32_t miplevel) {
@@ -559,20 +509,20 @@ void VulkanTexture::updateImageWithBlit(const PixelBufferDescriptor& hostData, u
    commands.acquire(fvkmemory::resource_ptr<VulkanTexture>::cast(this));

    // TODO: support blit-based format conversion for 3D images and cubemaps.
-    constexpr int layer = 0;
+    const int layer = 0;

-    VkOffset3D const rect[2] { {0, 0, 0}, {int32_t(width), int32_t(height), 1} };
+    const VkOffset3D rect[2] { {0, 0, 0}, {int32_t(width), int32_t(height), 1} };

-    VkImageAspectFlags const aspect = getImageAspect();
+    const VkImageAspectFlags aspect = getImageAspect();

-    VkImageBlit const blitRegions[1] = {{
+    const VkImageBlit blitRegions[1] = {{
        .srcSubresource = { aspect, 0, 0, 1 },
        .srcOffsets = { rect[0], rect[1] },
        .dstSubresource = { aspect, uint32_t(miplevel), layer, 1 },
        .dstOffsets = { rect[0], rect[1] }
    }};

-    VkImageSubresourceRange const range = { aspect, miplevel, 1, layer, 1 };
+    const VkImageSubresourceRange range = { aspect, miplevel, 1, layer, 1 };

    VulkanLayout const newLayout = VulkanLayout::TRANSFER_DST;
    VulkanLayout const oldLayout = getLayout(layer, miplevel);
@@ -588,21 +538,41 @@ VulkanLayout VulkanTexture::getDefaultLayout() const {
    return mState->mDefaultLayout;
 }

-VkImageView VulkanTexture::getAttachmentView(VkImageSubresourceRange const& range, VkImageViewType type) {
-    assert_invariant(mState->mYcbcr.conversion == VK_NULL_HANDLE &&
-                     "We are not yet supporting external image as attachments.");
-    if (type == VK_IMAGE_VIEW_TYPE_2D) {
-        VkImageSubresourceRange copy = range;
-        copy.levelCount = 1;
-        copy.layerCount = 1;
-        return mState->getImageView(copy, type, {});
-    } else {
-        return mState->getImageView(range, type, {});
-    }
+VkImageView VulkanTexture::getAttachmentView(VkImageSubresourceRange range) {
+    range.levelCount = 1;
+    range.layerCount = 1;
+    return getImageView(range, VK_IMAGE_VIEW_TYPE_2D, {});
 }

-VkImageView VulkanTexture::getView(VkImageSubresourceRange const& range) {
-    return mState->getImageView(range, mState->mViewType, mSwizzle);
+VkImageView VulkanTexture::getMultiviewAttachmentView(VkImageSubresourceRange range) {
+    return getImageView(range, VK_IMAGE_VIEW_TYPE_2D_ARRAY, {});
+}
+
+VkImageView VulkanTexture::getViewForType(VkImageSubresourceRange const& range, VkImageViewType type) {
+    return getImageView(range, type, mSwizzle);
+}
+
+VkImageView VulkanTexture::getImageView(VkImageSubresourceRange range, VkImageViewType viewType,
+        VkComponentMapping swizzle) {
+    VulkanTextureState::ImageViewKey const key{ range, viewType, swizzle };
+    auto iter = mState->mCachedImageViews.find(key);
+    if (iter != mState->mCachedImageViews.end()) {
+        return iter->second;
+    }
+    VkImageViewCreateInfo viewInfo = {
+        .sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO,
+        .pNext = nullptr,
+        .flags = 0,
+        .image = mState->mTextureImage,
+        .viewType = viewType,
+        .format = mState->mVkFormat,
+        .components = swizzle,
+        .subresourceRange = range,
+    };
+    VkImageView imageView;
+    vkCreateImageView(mState->mDevice, &viewInfo, VKALLOC, &imageView);
+    mState->mCachedImageViews.emplace(key, imageView);
+    return imageView;
 }

 VkImageAspectFlags VulkanTexture::getImageAspect() const {
@@ -764,21 +734,6 @@ void VulkanTexture::setLayout(VkImageSubresourceRange const& range, VulkanLayout
    }
 }

-void VulkanTexture::setYcbcrConversion(VkSamplerYcbcrConversion conversion, bool isExternalFormat) {
-    // Note that this comparison is valid because we only ever create VkSamplerYcbcrConversion from
-    // a cache.  So for each set of parameters, there is exactly one conversion (similar to
-    // samplers).
-    VulkanTextureState::Ycbcr ycbcr = {
-        .conversion = conversion,
-        .isExternalFormat = isExternalFormat,
-    };
-
-    if (mState->mYcbcr != ycbcr) {
-        mState->mYcbcr = ycbcr;
-        mState->clearCachedImageViews();
-    }
-}
-
 VulkanLayout VulkanTexture::getLayout(uint32_t layer, uint32_t level) const {
    assert_invariant(level <= 0xffff && layer <= 0xffff);
    const uint32_t key = (layer << 16) | level;
@@ -19,10 +19,7 @@

 #include "DriverBase.h"

-#include "VulkanCommands.h"
-#include "VulkanConstants.h"
-#include "VulkanMemory.h"
-#include "VulkanStagePool.h"
+#include "VulkanBuffer.h"
 #include "vulkan/memory/Resource.h"
 #include "vulkan/memory/ResourcePointer.h"
 #include "vulkan/utils/Image.h"
@@ -34,14 +31,10 @@

 namespace filament::backend {

-struct VulkanTexture;
-
 struct VulkanTextureState : public fvkmemory::Resource {
-    VulkanTextureState(VulkanStagePool& stagePool, VulkanCommands* commands, VmaAllocator allocator,
-            VkDevice device, VkImage image, VkDeviceMemory deviceMemory, VkFormat format,
-            VkImageViewType viewType, uint8_t levels, uint8_t layerCount,
-            VkSamplerYcbcrConversion ycbcrConversion, bool isExternalFormat,
-            VkImageUsageFlags usage, bool isProtected);
+    VulkanTextureState(VkDevice device, VmaAllocator allocator, VulkanCommands* commands,
+            VulkanStagePool& stagePool, VkFormat format, VkImageViewType viewType, uint8_t levels,
+            uint8_t layerCount, VulkanLayout defaultLayout, bool isProtected);

    ~VulkanTextureState();

@@ -64,50 +57,29 @@ struct VulkanTextureState : public fvkmemory::Resource {
    // No implicit padding allowed due to it being a hash key.
    static_assert(sizeof(ImageViewKey) == 40);

-    VkImageView getImageView(VkImageSubresourceRange range, VkImageViewType viewType,
-            VkComponentMapping swizzle);
-private:
-    void clearCachedImageViews() noexcept;
-    VulkanStagePool& mStagePool;
-    VulkanCommands* const mCommands;
-    VmaAllocator const mAllocator;
-    VkDevice const mDevice;
+    using ImageViewHash = utils::hash::MurmurHashFn<ImageViewKey>;

    // The texture with the sidecar owns the sidecar.
    fvkmemory::resource_ptr<VulkanTexture> mSidecarMSAA;
+    VkDeviceMemory mTextureImageMemory = VK_NULL_HANDLE;

-    VkImage const mTextureImage;
-    VkDeviceMemory const mTextureImageMemory;
    VkFormat const mVkFormat;
    VkImageViewType const mViewType;
    VkImageSubresourceRange const mFullViewRange;
+    VkImage mTextureImage = VK_NULL_HANDLE;
+    VulkanLayout mDefaultLayout;

-    // Note that this parameter is not constant due to the fact that AHB can force a change in the
-    // conversion matrix per-frame.
-    struct Ycbcr {
-        VkSamplerYcbcrConversion conversion;
-        bool isExternalFormat;
-
-        bool operator==(Ycbcr const& other) const {
-            return conversion == other.conversion && isExternalFormat == other.isExternalFormat;
-        }
-
-        bool operator!=(Ycbcr const& other) const {
-            return !((*this) == other);
-        }
-
-    } mYcbcr;
-
-    VulkanLayout const mDefaultLayout;
-    VkImageUsageFlags const mUsage;
-    bool const mIsProtected;
+    bool mIsProtected = false;

    // Track the image layout of each subresource using a sparse range map.
    utils::RangeMap<uint32_t, VulkanLayout> mSubresourceLayouts;
-    using ImageViewHash = utils::hash::MurmurHashFn<ImageViewKey>;
-    std::unordered_map<ImageViewKey, VkImageView, ImageViewHash> mCachedImageViews;

-    friend struct VulkanTexture;
+    std::unordered_map<ImageViewKey, VkImageView, ImageViewHash> mCachedImageViews;
+    VulkanStagePool& mStagePool;
+    VkDevice mDevice;
+    VmaAllocator mAllocator;
+    VulkanCommands* mCommands;
+    bool mIsTransientAttachment;
 };

 struct VulkanTexture : public HwTexture, fvkmemory::Resource {
@@ -119,10 +91,10 @@ struct VulkanTexture : public HwTexture, fvkmemory::Resource {
            VulkanStagePool& stagePool);

    // Specialized constructor for internally created textures (e.g. from a swap chain)
-    VulkanTexture(VulkanContext const& context, VkDevice device, VmaAllocator allocator,
+    // The texture will never destroy the given VkImage, but it does manages its subresources.
+    VulkanTexture(VkDevice device, VmaAllocator allocator,
            fvkmemory::ResourceManager* resourceManager, VulkanCommands* commands, VkImage image,
-            VkDeviceMemory memory, VkFormat format, VkSamplerYcbcrConversion conversion,
-            uint8_t samples, uint32_t width, uint32_t height, uint32_t depth,
+            VkDeviceMemory memory, VkFormat format, uint8_t samples, uint32_t width, uint32_t height, uint32_t depth,
            TextureUsage tusage, VulkanStagePool& stagePool);

    // Constructor for creating a texture view for wrt specific mip range
@@ -141,6 +113,11 @@ struct VulkanTexture : public HwTexture, fvkmemory::Resource {
    void updateImage(const PixelBufferDescriptor& data, uint32_t width, uint32_t height,
            uint32_t depth, uint32_t xoffset, uint32_t yoffset, uint32_t zoffset, uint32_t miplevel);

+    // Returns the primary image view, which is used for shader sampling.
+    VkImageView getPrimaryImageView() {
+        return getImageView(mPrimaryViewRange, mState->mViewType, mSwizzle);
+    }
+
    VkImageViewType getViewType() const {
        return mState->mViewType;
    }
@@ -155,11 +132,20 @@ struct VulkanTexture : public HwTexture, fvkmemory::Resource {
    // time of the call.
    VulkanLayout getDefaultLayout() const;

-    // Gets or creates a cached VkImageView for a subresource that can be used as a render
-    // target attachment.  Unlike the primary image view, this always the identity swizzle.
-    VkImageView getAttachmentView(VkImageSubresourceRange const& range, VkImageViewType type);
+    // Gets or creates a cached VkImageView for a single subresource that can be used as a render
+    // target attachment.  Unlike the primary image view, this always has type VK_IMAGE_VIEW_TYPE_2D
+    // and the identity swizzle.
+    VkImageView getAttachmentView(VkImageSubresourceRange range);

-    VkImageView getView(VkImageSubresourceRange const& range);
+    // Gets or creates a cached VkImageView for a single subresource that can be used as a render
+    // target attachment when rendering with multiview.
+    VkImageView getMultiviewAttachmentView(VkImageSubresourceRange range);
+
+    // This is a workaround for the first few frames where we're waiting for the texture to actually
+    // be uploaded.  In that case, we bind the sampler to an empty texture, but the corresponding
+    // imageView needs to be of the right type. Hence, we provide an option to indicate the
+    // view type. Swizzle option does not matter in this case.
+    VkImageView getViewForType(VkImageSubresourceRange const& range, VkImageViewType type);

    VkFormat getVkFormat() const {
        return mState->mVkFormat;
@@ -179,7 +165,7 @@ struct VulkanTexture : public HwTexture, fvkmemory::Resource {
    }

    bool isTransientAttachment() const {
-        return mState->mUsage & VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BIT;
+        return mState->mIsTransientAttachment;
    }

    bool getIsProtected() const {
@@ -206,11 +192,6 @@ struct VulkanTexture : public HwTexture, fvkmemory::Resource {
    // manually (outside of calls to transitionLayout).
    void setLayout(VkImageSubresourceRange const& range, VulkanLayout newLayout);

-    // This is used in the case of external images and external samplers. AHB might update the
-    // conversion per-frame. This implies that we need to invalidate the view cache when that
-    // happens.
-    void setYcbcrConversion(VkSamplerYcbcrConversion conversion, bool isExternal);
-
 #if FVK_ENABLED(FVK_DEBUG_TEXTURE)
    void print() const;
 #endif
@@ -1,84 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "VulkanYcbcrConversionCache.h"
-
-#include "vulkan/VulkanConstants.h"
-#include "vulkan/utils/Conversion.h"
-
-#include <utils/Panic.h>
-
-#if defined(__ANDROID__)
-#include <vulkan/vulkan_android.h>  // for VkExternalFormatANDROID
-#endif
-
-using namespace bluevk;
-
-namespace filament::backend {
-
-VulkanYcbcrConversionCache::VulkanYcbcrConversionCache(VkDevice device)
-    : mDevice(device) {}
-
-VkSamplerYcbcrConversion VulkanYcbcrConversionCache::getConversion(
-        VulkanYcbcrConversionCache::Params params) noexcept {
-    auto iter = mCache.find(params);
-    if (UTILS_LIKELY(iter != mCache.end())) {
-        return iter->second;
-    }
-
-    auto const& chroma = params.conversion;
-    TextureSwizzle const swizzleArray[] = { chroma.r, chroma.g, chroma.b, chroma.a };
-    VkSamplerYcbcrConversionCreateInfo conversionInfo = {
-        .sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_CREATE_INFO,
-        .format = fvkutils::getVkFormat(params.format),
-        .ycbcrModel = fvkutils::getYcbcrModelConversion(chroma.ycbcrModel),
-        .ycbcrRange = fvkutils::getYcbcrRange(chroma.ycbcrRange),
-        .components = fvkutils::getSwizzleMap(swizzleArray),
-        .xChromaOffset = fvkutils::getChromaLocation(chroma.xChromaOffset),
-        .yChromaOffset = fvkutils::getChromaLocation(chroma.yChromaOffset),
-        .chromaFilter = fvkutils::getFilter(chroma.chromaFilter),
-    };
-
-    // We could put this in the platform class, but that seems like a bit of an overkill
-#if defined(__ANDROID__)
-    VkExternalFormatANDROID externalFormat = {
-        .sType = VK_STRUCTURE_TYPE_EXTERNAL_FORMAT_ANDROID,
-        .externalFormat = params.externalFormat,
-    };
-    if (params.externalFormat) {
-        conversionInfo.pNext = &externalFormat;
-        conversionInfo.format = VK_FORMAT_UNDEFINED;
-    }
-#endif
-
-    VkSamplerYcbcrConversion conversion;
-    VkResult result =
-            vkCreateSamplerYcbcrConversion(mDevice, &conversionInfo, nullptr, &conversion);
-    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS) << "Unable to create Ycbcr Conversion."
-                                                       << " error=" << static_cast<int32_t>(result);
-
-    mCache.insert({ params, conversion });
-    return conversion;
-}
-
-void VulkanYcbcrConversionCache::terminate() noexcept {
-    for (auto& [param, conv]: mCache) {
-        vkDestroySamplerYcbcrConversion(mDevice, conv, VKALLOC);
-    }
-    mCache.clear();
-}
-
-} // namespace filament::backend
@@ -1,60 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef TNT_FILAMENT_BACKEND_VULKANYCBCRCONVERSIONCACHE_H
-#define TNT_FILAMENT_BACKEND_VULKANYCBCRCONVERSIONCACHE_H
-
-#include <backend/DriverEnums.h>
-
-#include <utils/Hash.h>
-
-#include <bluevk/BlueVK.h>
-#include <tsl/robin_map.h>
-
-namespace filament::backend {
-
-// Simple manager for VkSamplerYcbcrConversion objects.
-class VulkanYcbcrConversionCache {
-public:
-    struct Params {
-        SamplerYcbcrConversion conversion = {};
-        TextureFormat format = {};
-        uint16_t padding = 0;
-        uint64_t externalFormat = 0;
-    };
-    static_assert(sizeof(Params) == 16);
-
-    explicit VulkanYcbcrConversionCache(VkDevice device);
-    VkSamplerYcbcrConversion getConversion(Params params) noexcept;
-    void terminate() noexcept;
-
-private:
-    VkDevice mDevice;
-
-    struct ConversionEqualTo {
-        bool operator()(Params lhs, Params rhs) const noexcept {
-            SamplerYcbcrConversion::EqualTo equal;
-            return equal(lhs.conversion, rhs.conversion) &&
-                   lhs.externalFormat == rhs.externalFormat;
-        }
-    };
-    using ConversionHashFn = utils::hash::MurmurHashFn<Params>;
-    tsl::robin_map<Params, VkSamplerYcbcrConversion, ConversionHashFn, ConversionEqualTo> mCache;
-};
-
-}// namespace filament::backend
-
-#endif// TNT_FILAMENT_BACKEND_VULKANYCBCRCONVERSIONCACHE_H
@@ -14,25 +14,35 @@
 * limitations under the License.
 */

-#include "VulkanDescriptorSetCache.h"
+#include "VulkanDescriptorSetManager.h"

-#include "VulkanCommands.h"
-#include "VulkanHandles.h"
-#include "VulkanConstants.h"
+#include "vulkan/VulkanCommands.h"
+#include "vulkan/VulkanHandles.h"
+#include "vulkan/VulkanConstants.h"

 #include <utils/FixedCapacityVector.h>
 #include <utils/Panic.h>

+#include <math.h>
+
 #include <algorithm>
 #include <memory>
+#include <type_traits>
 #include <vector>

 namespace filament::backend {

 namespace {

+using BitmaskGroup = VulkanDescriptorSetLayout::Bitmask;
 using DescriptorCount = VulkanDescriptorSetLayout::Count;
-using DescriptorSetLayoutArray = VulkanDescriptorSetCache::DescriptorSetLayoutArray;
+using DescriptorSetLayoutArray = VulkanDescriptorSetManager::DescriptorSetLayoutArray;
+using BitmaskGroupHashFn = utils::hash::MurmurHashFn<BitmaskGroup>;
+struct BitmaskGroupEqual {
+    bool operator()(BitmaskGroup const& k1, BitmaskGroup const& k2) const {
+        return k1 == k2;
+    }
+};

 // We create a pool for each layout as defined by the number of descriptors of each type. For
 // example, a layout of
@@ -189,12 +199,72 @@ struct Equal {
    }
 };

+template<typename Bitmask>
+uint32_t createBindings(VkDescriptorSetLayoutBinding* toBind, uint32_t count, VkDescriptorType type,
+        Bitmask const& mask) {
+    Bitmask alreadySeen;
+    mask.forEachSetBit([&](size_t index) {
+        VkShaderStageFlags stages = 0;
+        uint32_t binding = 0;
+        if (index < fvkutils::getFragmentStageShift<Bitmask>()) {
+            binding = (uint32_t) index;
+            stages |= VK_SHADER_STAGE_VERTEX_BIT;
+            auto fragIndex = index + fvkutils::getFragmentStageShift<Bitmask>();
+            if (mask.test(fragIndex)) {
+                stages |= VK_SHADER_STAGE_FRAGMENT_BIT;
+                alreadySeen.set(fragIndex);
+            }
+        } else if (!alreadySeen.test(index)) {
+            // We are in fragment stage bits
+            binding = (uint32_t) (index - fvkutils::getFragmentStageShift<Bitmask>());
+            stages |= VK_SHADER_STAGE_FRAGMENT_BIT;
+        }
+
+        if (stages) {
+            toBind[count++] = {
+                .binding = binding,
+                .descriptorType = type,
+                .descriptorCount = 1,
+                .stageFlags = stages,
+            };
+        }
+    });
+    return count;
+}
+
+inline VkDescriptorSetLayout createLayout(VkDevice device, BitmaskGroup const& bitmaskGroup) {
+    // Note that the following *needs* to be static so that VkDescriptorSetLayoutCreateInfo will not
+    // refer to stack memory.
+    VkDescriptorSetLayoutBinding toBind[VulkanDescriptorSetLayout::MAX_BINDINGS];
+    uint32_t count = 0;
+
+    count = createBindings(toBind, count, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC,
+            bitmaskGroup.dynamicUbo);
+    count = createBindings(toBind, count, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, bitmaskGroup.ubo);
+    count = createBindings(toBind, count, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
+            bitmaskGroup.sampler);
+    count = createBindings(toBind, count, VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT,
+            bitmaskGroup.inputAttachment);
+
+    assert_invariant(count != 0 && "Need at least one binding for descriptor set layout.");
+    VkDescriptorSetLayoutCreateInfo dlinfo = {
+            .sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO,
+            .pNext = nullptr,
+            .bindingCount = count,
+            .pBindings = toBind,
+    };
+
+    VkDescriptorSetLayout layout;
+    vkCreateDescriptorSetLayout(device, &dlinfo, VKALLOC, &layout);
+    return layout;
+}
+
 } // anonymous namespace

 // This is an ever-expanding pool of sets where it
 //    1. Keeps a list of smaller pools of different layout-dimensions.
 //    2. Will add a pool if existing pool are not compatible with the requested layout o runs out.
-class VulkanDescriptorSetCache::DescriptorInfinitePool {
+class VulkanDescriptorSetManager::DescriptorInfinitePool {
 private:
    static constexpr uint16_t EXPECTED_SET_COUNT = 10;
    static constexpr float SET_COUNT_GROWTH_FACTOR = 1.5;
@@ -249,58 +319,79 @@ private:
    std::vector<std::unique_ptr<DescriptorPool>> mPools;
 };

+class VulkanDescriptorSetManager::DescriptorSetLayoutManager {
+public:
+    DescriptorSetLayoutManager(VkDevice device)
+        : mDevice(device) {}

-VulkanDescriptorSetCache::VulkanDescriptorSetCache(VkDevice device,
+    VkDescriptorSetLayout getVkLayout(VulkanDescriptorSetLayout::Bitmask const& bitmasks) {
+        if (auto itr = mVkLayouts.find(bitmasks); itr != mVkLayouts.end()) {
+            return itr->second;
+        }
+        auto vklayout = createLayout(mDevice, bitmasks);
+        mVkLayouts[bitmasks] = vklayout;
+        return vklayout;
+    }
+
+    ~DescriptorSetLayoutManager() {
+        for (auto& itr: mVkLayouts) {
+            vkDestroyDescriptorSetLayout(mDevice, itr.second, VKALLOC);
+        }
+    }
+
+private:
+    VkDevice mDevice;
+    tsl::robin_map<BitmaskGroup, VkDescriptorSetLayout, BitmaskGroupHashFn, BitmaskGroupEqual>
+            mVkLayouts;
+};
+
+VulkanDescriptorSetManager::VulkanDescriptorSetManager(VkDevice device,
        fvkmemory::ResourceManager* resourceManager)
    : mDevice(device),
      mResourceManager(resourceManager),
+      mLayoutManager(std::make_unique<DescriptorSetLayoutManager>(device)),
      mDescriptorPool(std::make_unique<DescriptorInfinitePool>(device)) {}

-VulkanDescriptorSetCache::~VulkanDescriptorSetCache() = default;
+VulkanDescriptorSetManager::~VulkanDescriptorSetManager() = default;

-void VulkanDescriptorSetCache::terminate() noexcept{
+void VulkanDescriptorSetManager::terminate() noexcept{
+    mLayoutManager.reset();
    mDescriptorPool.reset();
+    clearHistory();
 }

 // bind() is not really binding the set but just stashing until we have all the info
 // (pipelinelayout).
-void VulkanDescriptorSetCache::bind(uint8_t setIndex,
+void VulkanDescriptorSetManager::bind(uint8_t setIndex,
        fvkmemory::resource_ptr<VulkanDescriptorSet> set,
        backend::DescriptorSetOffsetArray&& offsets) {
    set->setOffsets(std::move(offsets));
    mStashedSets[setIndex] = set;
 }

-void VulkanDescriptorSetCache::unbind(uint8_t setIndex) {
+void VulkanDescriptorSetManager::unbind(uint8_t setIndex) {
    mStashedSets[setIndex] = {};
 }

-void VulkanDescriptorSetCache::commit(VulkanCommandBuffer* commands,
+void VulkanDescriptorSetManager::commit(VulkanCommandBuffer* commands,
        VkPipelineLayout pipelineLayout, fvkutils::DescriptorSetMask const& setMask) {
    // setMask indicates the set of descriptor sets the driver wants to bind, curMask is the
    // actual set of sets that *needs* to be bound.
    fvkutils::DescriptorSetMask curMask = setMask;

    auto& updateSets = mStashedSets;
-    bool const pipelineLayoutIsSame = mLastBoundInfo.pipelineLayout == pipelineLayout;
+    auto& lastBoundSets = mLastBoundInfo.boundSets;

-    if (pipelineLayoutIsSame) {
-        auto& lastBoundSets = mLastBoundInfo.boundSets;
-        setMask.forEachSetBit([&](size_t index) {
-            if (!updateSets[index] || updateSets[index] == lastBoundSets[index]) {
-                curMask.unset(index);
-            }
-        });
-        if (curMask.none() &&
-                mLastBoundInfo.setMask == setMask && mLastBoundInfo.boundSets == updateSets) {
-            return;
+    setMask.forEachSetBit([&](size_t index) {
+        if (!updateSets[index] || updateSets[index] == lastBoundSets[index]) {
+            curMask.unset(index);
        }
-    } else {
-        setMask.forEachSetBit([&](size_t index) {
-            if (!updateSets[index]) {
-                curMask.unset(index);
-            }
-        });
+    });
+
+    if (curMask.none() &&
+            (mLastBoundInfo.pipelineLayout == pipelineLayout && mLastBoundInfo.setMask == setMask &&
+                    mLastBoundInfo.boundSets == updateSets)) {
+        return;
    }

    curMask.forEachSetBit([&updateSets, commands, pipelineLayout](size_t index) {
@@ -308,7 +399,7 @@ void VulkanDescriptorSetCache::commit(VulkanCommandBuffer* commands,
        auto set = updateSets[index];
        VkCommandBuffer const cmdbuffer = commands->buffer();
        vkCmdBindDescriptorSets(cmdbuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, index,
-                1, &set->getVkSet(), set->uniqueDynamicUboCount, set->getOffsets()->data());
+                1, &set->vkSet, set->uniqueDynamicUboCount, set->getOffsets()->data());
        commands->acquire(set);
    });

@@ -321,7 +412,7 @@ void VulkanDescriptorSetCache::commit(VulkanCommandBuffer* commands,
    };
 }

-void VulkanDescriptorSetCache::updateBuffer(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
+void VulkanDescriptorSetManager::updateBuffer(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
        uint8_t binding, fvkmemory::resource_ptr<VulkanBufferObject> bufferObject,
        VkDeviceSize offset, VkDeviceSize size) noexcept {
    VkDescriptorBufferInfo const info = {
@@ -336,7 +427,8 @@ void VulkanDescriptorSetCache::updateBuffer(fvkmemory::resource_ptr<VulkanDescri
    }
    VkWriteDescriptorSet const descriptorWrite = {
        .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
-        .dstSet = set->getVkSet(),
+        .pNext = nullptr,
+        .dstSet = set->vkSet,
        .dstBinding = binding,
        .descriptorCount = 1,
        .descriptorType = type,
@@ -346,28 +438,29 @@ void VulkanDescriptorSetCache::updateBuffer(fvkmemory::resource_ptr<VulkanDescri
    set->acquire(bufferObject);
 }

-void VulkanDescriptorSetCache::updateSampler(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
+void VulkanDescriptorSetManager::updateSampler(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
        uint8_t binding, fvkmemory::resource_ptr<VulkanTexture> texture,
        VkSampler sampler) noexcept {
-    VkImageSubresourceRange range = texture->getPrimaryViewRange();
+    VkDescriptorImageInfo info{
+        .sampler = sampler,
+    };
+    VkImageSubresourceRange const range = texture->getPrimaryViewRange();
    VkImageViewType const expectedType = texture->getViewType();
    if (any(texture->usage & TextureUsage::DEPTH_ATTACHMENT) &&
            expectedType == VK_IMAGE_VIEW_TYPE_2D) {
        // If the sampler is part of a mipmapped depth texture, where one of the level *can* be
-        // an attachment, then the range for this view has exactly one level and one layer.
-        range.levelCount = 1;
-        range.layerCount = 1;
+        // an attachment, then the sampler for this texture has the same view properties as a
+        // view for an attachment. Therefore, we can use getAttachmentView to get a
+        // corresponding VkImageView.
+        info.imageView = texture->getAttachmentView(range);
+    } else {
+        info.imageView = texture->getViewForType(range, expectedType);
    }
-    VkDescriptorImageInfo info{
-        .sampler = sampler,
-        .imageView = texture->getView(range),
-        .imageLayout = fvkutils::getVkLayout(texture->getDefaultLayout()),
-    };
-
+    info.imageLayout = fvkutils::getVkLayout(texture->getDefaultLayout());
    VkWriteDescriptorSet const descriptorWrite = {
        .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
        .pNext = nullptr,
-        .dstSet = set->getVkSet(),
+        .dstSet = set->vkSet,
        .dstBinding = binding,
        .descriptorCount = 1,
        .descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
@@ -377,18 +470,18 @@ void VulkanDescriptorSetCache::updateSampler(fvkmemory::resource_ptr<VulkanDescr
    set->acquire(texture);
 }

-void VulkanDescriptorSetCache::updateInputAttachment(
+void VulkanDescriptorSetManager::updateInputAttachment(
        fvkmemory::resource_ptr<VulkanDescriptorSet> set,
        VulkanAttachment const& attachment) noexcept {
-    // TOOD: fill this in.
+    // TOOD: fill-in this region
 }

-fvkmemory::resource_ptr<VulkanDescriptorSet> VulkanDescriptorSetCache::createSet(
+fvkmemory::resource_ptr<VulkanDescriptorSet> VulkanDescriptorSetManager::createSet(
        Handle<HwDescriptorSet> handle, fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout) {
-    auto const vkSet = getVkSet(layout);
+    auto const vkSet = mDescriptorPool->obtainSet(layout);
    auto const& count = layout->count;
    auto const vklayout = layout->getVkLayout();
-    auto set = fvkmemory::resource_ptr<VulkanDescriptorSet>::make(mResourceManager, handle,
+    return fvkmemory::resource_ptr<VulkanDescriptorSet>::make(mResourceManager, handle, vkSet,
            layout->bitmask.dynamicUbo, layout->count.dynamicUbo,
            [vkSet, count, vklayout, this](VulkanDescriptorSet*) {
                // Note that mDescriptorPool could be gone due to terminate (when the backend shuts
@@ -397,20 +490,15 @@ fvkmemory::resource_ptr<VulkanDescriptorSet> VulkanDescriptorSetCache::createSet
                    mDescriptorPool->recycle(count, vklayout, vkSet);
                }
            });
-    set->setVkSet(vkSet);
-    return set;
 }

-VkDescriptorSet VulkanDescriptorSetCache::getVkSet(
+void VulkanDescriptorSetManager::initVkLayout(
        fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout) {
-    return mDescriptorPool->obtainSet(layout);
+    layout->setVkLayout(mLayoutManager->getVkLayout(layout->bitmask));
 }

-void VulkanDescriptorSetCache::manualRecyle(VulkanDescriptorSetLayout::Count const& count,
-        VkDescriptorSetLayout vklayout, VkDescriptorSet vkSet) {
-    mDescriptorPool->recycle(count, vklayout, vkSet);
+void VulkanDescriptorSetManager::clearHistory() {
+    mStashedSets = {};
 }

-void VulkanDescriptorSetCache::gc() { mStashedSets = {}; }
-
 } // namespace filament::backend
@@ -14,10 +14,10 @@
 * limitations under the License.
 */

-#ifndef TNT_FILAMENT_BACKEND_CACHING_VULKANDESCRIPTORSETCACHE_H
-#define TNT_FILAMENT_BACKEND_CACHING_VULKANDESCRIPTORSETCACHE_H
+#ifndef TNT_FILAMENT_BACKEND_CACHING_VULKANDESCRIPTORSETMANAGER_H
+#define TNT_FILAMENT_BACKEND_CACHING_VULKANDESCRIPTORSETMANAGER_H

-#include "VulkanHandles.h"
+#include "vulkan/VulkanHandles.h"
 #include "vulkan/memory/ResourcePointer.h"
 #include "vulkan/utils/Definitions.h"  // For DescriptorSetMask

@@ -34,18 +34,20 @@

 namespace filament::backend {

-// Abstraction over the descriptor set pool.
-class VulkanDescriptorSetCache {
+// [GDSR]: Great-Descriptor-Set-Refactor: As of 03/20/24, the Filament frontend is planning to
+// introduce descriptor set. This PR will arrive before that change is complete. As such, some of
+// the methods introduced here will be obsolete, and certain logic will be generalized.
+
+// Abstraction over the pool and the layout cache.
+class VulkanDescriptorSetManager {
 public:
    static constexpr uint8_t UNIQUE_DESCRIPTOR_SET_COUNT =
            VulkanDescriptorSetLayout::UNIQUE_DESCRIPTOR_SET_COUNT;

    using DescriptorSetLayoutArray = VulkanDescriptorSetLayout::DescriptorSetLayoutArray;
-    using DescriptorSetArray =
-            std::array<fvkmemory::resource_ptr<VulkanDescriptorSet>, UNIQUE_DESCRIPTOR_SET_COUNT>;

-    VulkanDescriptorSetCache(VkDevice device, fvkmemory::ResourceManager* resourceManager);
-    ~VulkanDescriptorSetCache();
+    VulkanDescriptorSetManager(VkDevice device, fvkmemory::ResourceManager* resourceManager);
+    ~VulkanDescriptorSetManager();

    void terminate() noexcept;

@@ -70,23 +72,20 @@ public:
    fvkmemory::resource_ptr<VulkanDescriptorSet> createSet(Handle<HwDescriptorSet> handle,
            fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);

-    // This method is only meant to be used with external samplers (or internally within this
-    // class).
-    VkDescriptorSet getVkSet(fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);
+    void initVkLayout(fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);

-    // This method is only meant to be used with external samplers.
-    void manualRecyle(VulkanDescriptorSetLayout::Count const& count, VkDescriptorSetLayout vklayout,
-            VkDescriptorSet vkSet);
-
-    DescriptorSetArray const& getBoundSets() const { return mStashedSets; }
-
-    void gc();
+    void clearHistory();

 private:
+    class DescriptorSetLayoutManager;
    class DescriptorInfinitePool;

+    using DescriptorSetArray =
+            std::array<fvkmemory::resource_ptr<VulkanDescriptorSet>, UNIQUE_DESCRIPTOR_SET_COUNT>;
+
    VkDevice mDevice;
    fvkmemory::ResourceManager* mResourceManager;
+    std::unique_ptr<DescriptorSetLayoutManager> mLayoutManager;
    std::unique_ptr<DescriptorInfinitePool> mDescriptorPool;
    std::pair<VulkanAttachment, VkDescriptorImageInfo> mInputAttachment;
    DescriptorSetArray mStashedSets = {};
@@ -100,4 +99,4 @@ private:

 }// namespace filament::backend

-#endif// TNT_FILAMENT_BACKEND_CACHING_VULKANDESCRIPTORSETCACHE_H
+#endif// TNT_FILAMENT_BACKEND_CACHING_VULKANDESCRIPTORSETMANAGER_H
@@ -17,8 +17,7 @@
 #ifndef TNT_FILAMENT_BACKEND_VULKANPIPELINELAYOUTCACHE_H
 #define TNT_FILAMENT_BACKEND_VULKANPIPELINELAYOUTCACHE_H

-#include "VulkanHandles.h"
-
+#include <vulkan/VulkanHandles.h>
 #include <bluevk/BlueVK.h>

 #include <utils/Hash.h>
@@ -132,10 +132,6 @@ public:
        return id() == other.id() && type() == other.type();
    }

-    inline bool operator!=(resource_ptr<D> const& other) const {
-        return !((*this) == other);
-    }
-
    inline explicit operator bool() const {
        return bool(mRef);
    }
@@ -211,7 +211,6 @@ ExtensionSet getDeviceExtensions(VkPhysicalDevice device) {
        VK_KHR_DEDICATED_ALLOCATION_EXTENSION_NAME,
        VK_KHR_SAMPLER_YCBCR_CONVERSION_EXTENSION_NAME,
        VK_ANDROID_EXTERNAL_MEMORY_ANDROID_HARDWARE_BUFFER_EXTENSION_NAME,
-        VK_EXT_QUEUE_FAMILY_FOREIGN_EXTENSION_NAME,
 #endif
        // MoltenVk is the only non-conformant implementation we're interested in.
 #if defined(__APPLE__)
@@ -327,9 +326,7 @@ VkInstance createInstance(ExtensionSet const& requiredExts) {
 }

 VkDevice createLogicalDevice(VkPhysicalDevice physicalDevice,
-        VkPhysicalDeviceFeatures2 const& features,
-        VkPhysicalDeviceVulkan11Features const& vk11Features,
-        uint32_t graphicsQueueFamilyIndex,
+        VkPhysicalDeviceFeatures2 const& features, uint32_t graphicsQueueFamilyIndex,
        uint32_t protectedGraphicsQueueFamilyIndex, ExtensionSet const& deviceExtensions,
        bool requestImageView2DOn3DImage) {
    VkDevice device;
@@ -362,28 +359,14 @@ VkDevice createLogicalDevice(VkPhysicalDevice physicalDevice,

    // We could simply enable all supported features, but since that may have performance
    // consequences let's just enable the features we need.
-    VkPhysicalDeviceFeatures enabledFeatures = {
+    VkPhysicalDeviceFeatures enabledFeatures{
        .depthClamp = features.features.depthClamp,
        .samplerAnisotropy = features.features.samplerAnisotropy,
        .textureCompressionETC2 = features.features.textureCompressionETC2,
        .textureCompressionBC = features.features.textureCompressionBC,
        .shaderClipDistance = features.features.shaderClipDistance,
    };
-
-    VkPhysicalDeviceFeatures2 enabledFeatures2 = {
-        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2,
-        .features = enabledFeatures,
-    };
-    chainStruct(&deviceCreateInfo, &enabledFeatures2);
-
-    VkPhysicalDeviceVulkan11Features enabledVk11Features = {
-        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_1_FEATURES,
-        .multiview = vk11Features.multiview,
-#if defined(__ANDROID__)
-        .samplerYcbcrConversion = vk11Features.samplerYcbcrConversion,
-#endif
-    };
-    chainStruct(&deviceCreateInfo, &enabledVk11Features);
+    deviceCreateInfo.pEnabledFeatures = &enabledFeatures;

    deviceCreateInfo.enabledExtensionCount = (uint32_t) requestExtensions.size();
    deviceCreateInfo.ppEnabledExtensionNames = requestExtensions.data();
@@ -400,7 +383,7 @@ VkDevice createLogicalDevice(VkPhysicalDevice physicalDevice,

    VkPhysicalDeviceMultiviewFeaturesKHR multiview = {
        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MULTIVIEW_FEATURES_KHR,
-        .multiview = vk11Features.multiview,
+        .multiview = VK_TRUE,
        .multiviewGeometryShader = VK_FALSE,
        .multiviewTessellationShader = VK_FALSE,
    };
@@ -751,9 +734,12 @@ Driver* VulkanPlatform::createDriver(void* sharedContext,
        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROTECTED_MEMORY_PROPERTIES,
    };
    chainStruct(&context.mPhysicalDeviceFeatures, &queryProtectedMemoryFeatures);
-    chainStruct(&context.mPhysicalDeviceFeatures, &context.mPhysicalDeviceVk11Features);
    chainStruct(&context.mPhysicalDeviceProperties, &protectedMemoryProperties);

+    // We know we need to allocate the protected version of the VK objects
+    context.mProtectedMemorySupported =
+            static_cast<bool>(queryProtectedMemoryFeatures.protectedMemory);
+
    // Initialize the following fields: physicalDeviceProperties, memoryProperties,
    // physicalDeviceFeatures, graphicsQueueFamilyIndex.
    vkGetPhysicalDeviceProperties2(mImpl->mPhysicalDevice, &context.mPhysicalDeviceProperties);
@@ -773,10 +759,6 @@ Driver* VulkanPlatform::createDriver(void* sharedContext,
        mImpl->mGraphicsQueueIndex = 0;
    }

-    // We know we need to allocate the protected version of the VK objects
-    context.mProtectedMemorySupported =
-            static_cast<bool>(queryProtectedMemoryFeatures.protectedMemory);
-
    if (context.mProtectedMemorySupported) {
        mImpl->mProtectedGraphicsQueueFamilyIndex = identifyGraphicsQueueFamilyIndex(
                mImpl->mPhysicalDevice, (VK_QUEUE_GRAPHICS_BIT | VK_QUEUE_PROTECTED_BIT));
@@ -813,10 +795,10 @@ Driver* VulkanPlatform::createDriver(void* sharedContext,
    }

    if (mImpl->mDevice == VK_NULL_HANDLE) {
-        mImpl->mDevice = createLogicalDevice(mImpl->mPhysicalDevice,
-                context.mPhysicalDeviceFeatures, context.mPhysicalDeviceVk11Features,
-                mImpl->mGraphicsQueueFamilyIndex, mImpl->mProtectedGraphicsQueueFamilyIndex,
-                deviceExts, requestPortabilitySubsetImageView2DOn3DImage);
+        mImpl->mDevice =
+                createLogicalDevice(mImpl->mPhysicalDevice, context.mPhysicalDeviceFeatures,
+                        mImpl->mGraphicsQueueFamilyIndex, mImpl->mProtectedGraphicsQueueFamilyIndex,
+                        deviceExts, requestPortabilitySubsetImageView2DOn3DImage);
    }

    assert_invariant(mImpl->mDevice != VK_NULL_HANDLE);
@@ -844,10 +826,12 @@ Driver* VulkanPlatform::createDriver(void* sharedContext,
    if (!mImpl->mSharedContext) {
        context.mDebugUtilsSupported = setContains(instExts, VK_EXT_DEBUG_UTILS_EXTENSION_NAME);
        context.mDebugMarkersSupported = setContains(deviceExts, VK_EXT_DEBUG_MARKER_EXTENSION_NAME);
+        context.mMultiviewEnabled = setContains(deviceExts, VK_KHR_MULTIVIEW_EXTENSION_NAME);
    } else {
        VulkanSharedContext const* scontext = (VulkanSharedContext const*) sharedContext;
        context.mDebugUtilsSupported = scontext->debugUtilsSupported;
        context.mDebugMarkersSupported = scontext->debugMarkersSupported;
+        context.mMultiviewEnabled = scontext->multiviewSupported;
    }

    // Check the availability of lazily allocated memory
@@ -993,14 +977,16 @@ VkQueue VulkanPlatform::getProtectedGraphicsQueue() const noexcept {
    return mImpl->mProtectedGraphicsQueue;
 }

-ExtensionSet VulkanPlatform::getSwapchainInstanceExtensions() const {
-    return getSwapchainInstanceExtensionsImpl();
+VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadata(
+        ExternalImageHandleRef externalImage) {
+    return getExternalImageMetadataImpl(externalImage, mImpl->mDevice);
 }

-VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHR(void* nativeWindow,
-        VkInstance instance, uint64_t flags) const noexcept {
-    return createVkSurfaceKHRImpl(nativeWindow, instance, flags);
+VulkanPlatform::ImageData VulkanPlatform::createExternalImageData(
+        ExternalImageHandleRef externalImage, const ExternalImageMetadata& metadata) {
+    return createExternalImageDataImpl(externalImage, mImpl->mDevice, metadata);
 }
+
 #undef SWAPCHAIN_RET_FUNC

 }// namespace filament::backend
@@ -13,15 +13,14 @@
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
-#include <backend/platforms/VulkanPlatformAndroid.h>
-
-#include "vulkan/VulkanConstants.h"
-#include "vulkan/VulkanContext.h"
-#include "vulkan/vulkan_core.h"
+#include <backend/platforms/VulkanPlatform.h>

 #include <backend/DriverEnums.h>
+#include <backend/platforms/VulkanPlatformAndroid.h>
 #include <private/backend/BackendUtilsAndroid.h>

+#include "vulkan/VulkanConstants.h"
+
 #include <utils/Panic.h>

 #include <bluevk/BlueVK.h>
@@ -57,7 +56,7 @@ VkFormat transformVkFormat(VkFormat format, bool sRGB) {
 }

 bool isProtectedFromUsage(uint64_t usage) {
-    return usage & AHARDWAREBUFFER_USAGE_PROTECTED_CONTENT;
+    return (usage & AHARDWAREBUFFER_USAGE_PROTECTED_CONTENT) ? true : false;
 }

 std::pair<VkFormat, VkImageUsageFlags> getVKFormatAndUsage(const AHardwareBuffer_Desc& desc,
@@ -120,9 +119,7 @@ std::pair<VkFormat, VkImageUsageFlags> getVKFormatAndUsage(const AHardwareBuffer
    usage = 0;
    if (desc.usage & AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE) {
        usage |= VK_IMAGE_USAGE_SAMPLED_BIT;
-
-        // We shouldn't be using external samplers as input attachments
-        // usage |= VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT;
+        usage |= VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT;
    }
    if (desc.usage & AHARDWAREBUFFER_USAGE_GPU_FRAMEBUFFER) {
        if (isDepthFormat) {
@@ -138,60 +135,102 @@ std::pair<VkFormat, VkImageUsageFlags> getVKFormatAndUsage(const AHardwareBuffer
    return { format, usage };
 }

-std::pair<TextureFormat, TextureUsage> getFilamentFormatAndUsage(const AHardwareBuffer_Desc& desc,
-        bool sRGB) {
-    auto const format = mapToFilamentFormat(desc.format, sRGB);
-    return {
-        format,
-        mapToFilamentUsage(desc.usage, format),
+VulkanPlatform::ImageData allocateExternalImage(AHardwareBuffer* buffer, VkDevice device,
+        VulkanPlatform::ExternalImageMetadata const& metadata) {
+    VulkanPlatform::ImageData data;
+
+    // if external format we need to specifiy it in the allocation
+    const bool useExternalFormat = metadata.format == VK_FORMAT_UNDEFINED;
+
+    const VkExternalFormatANDROID externalFormat = {
+        .sType = VK_STRUCTURE_TYPE_EXTERNAL_FORMAT_ANDROID,
+        .pNext = nullptr,
+        .externalFormat = metadata
+                .externalFormat,// pass down the format (external means we don't have it VK defined)
    };
+    const VkExternalMemoryImageCreateInfo externalCreateInfo = {
+        .sType = VK_STRUCTURE_TYPE_EXTERNAL_MEMORY_IMAGE_CREATE_INFO,
+        .pNext = useExternalFormat ? &externalFormat : nullptr,
+        .handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID,
+    };
+
+    VkImageCreateInfo imageInfo{.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO};
+    imageInfo.pNext = &externalCreateInfo;
+    imageInfo.format = metadata.format;
+    imageInfo.imageType = VK_IMAGE_TYPE_2D;
+    imageInfo.extent = {
+        metadata.width,
+        metadata.height,
+        1u,
+    };
+    imageInfo.mipLevels = 1;
+    imageInfo.arrayLayers = metadata.layers;
+    imageInfo.usage = metadata.usage;
+    // In the unprotected case add R/W capabilities
+    if (metadata.isProtected == false)
+        imageInfo.usage |= VK_IMAGE_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
+
+    VkResult result = vkCreateImage(device, &imageInfo, VKALLOC, &data.first);
+    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+            << "vkCreateImage failed with error=" << static_cast<int32_t>(result);
+
+    // Allocate the memory
+    VkImportAndroidHardwareBufferInfoANDROID androidHardwareBufferInfo = {
+        .sType = VK_STRUCTURE_TYPE_IMPORT_ANDROID_HARDWARE_BUFFER_INFO_ANDROID,
+        .pNext = nullptr,
+        .buffer = buffer,
+    };
+    VkMemoryDedicatedAllocateInfo memoryDedicatedAllocateInfo = {
+        .sType = VK_STRUCTURE_TYPE_MEMORY_DEDICATED_ALLOCATE_INFO,
+        .pNext = &androidHardwareBufferInfo,
+        .image = data.first,
+        .buffer = VK_NULL_HANDLE,
+    };
+    VkMemoryAllocateInfo allocInfo = {.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
+        .pNext = &memoryDedicatedAllocateInfo,
+        .allocationSize = metadata.allocationSize,
+        .memoryTypeIndex = metadata.memoryTypeBits};
+    result = vkAllocateMemory(device, &allocInfo, VKALLOC, &data.second);
+    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+            << "vkAllocateMemory failed with error=" << static_cast<int32_t>(result);
+
+    return data;
 }

+} // namespace

-}// namespace
+namespace fvkandroid {

-VulkanPlatformAndroid::ExternalImageVulkanAndroid::~ExternalImageVulkanAndroid() {
+ExternalImageVulkanAndroid::~ExternalImageVulkanAndroid() = default;
+
+Platform::ExternalImageHandle createExternalImage(AHardwareBuffer const* buffer,
+        bool sRGB) noexcept {
    if (__builtin_available(android 26, *)) {
-        if (aHardwareBuffer) {
-            AHardwareBuffer_release(aHardwareBuffer);
-        }
-    }
-}
-
-Platform::ExternalImageHandle VulkanPlatformAndroid::createExternalImage(
-        AHardwareBuffer const* buffer, bool sRGB) noexcept {
-    if (__builtin_available(android 26, *)) {
-        auto bufferImpl = const_cast<AHardwareBuffer*>(buffer);
-        AHardwareBuffer_acquire(bufferImpl);
-
        AHardwareBuffer_Desc hardwareBufferDescription = {};
        AHardwareBuffer_describe(buffer, &hardwareBufferDescription);

        auto* const p = new (std::nothrow) ExternalImageVulkanAndroid;
        p->aHardwareBuffer = const_cast<AHardwareBuffer*>(buffer);
        p->sRGB = sRGB;
+        p->height = hardwareBufferDescription.height;
+        p->width = hardwareBufferDescription.width;
+        TextureFormat textureFormat = mapToFilamentFormat(hardwareBufferDescription.format, sRGB);
+        p->format = textureFormat;
+        p->usage = mapToFilamentUsage(hardwareBufferDescription.usage, textureFormat);
        return Platform::ExternalImageHandle{ p };
    }

    return Platform::ExternalImageHandle{};
 }

-VulkanPlatformAndroid::ExternalImageDescAndroid VulkanPlatformAndroid::getExternalImageDesc(
-        ExternalImageHandleRef externalImage) const noexcept {
-    auto metadata = extractExternalImageMetadata(externalImage);
-    return {
-        .width = metadata.width,
-        .height = metadata.height,
-        .format = metadata.filamentFormat,
-        .usage = metadata.filamentUsage,
-    };
-}
+} // namespace fvkandroid

-VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::extractExternalImageMetadata(
-        ExternalImageHandleRef image) const {
-    auto const* fvkExternalImage = static_cast<ExternalImageVulkanAndroid const*>(image.get());
+VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device) {
+    auto const* fvkExternalImage =
+            static_cast<fvkandroid::ExternalImageVulkanAndroid const*>(externalImage.get());

-    ExternalImageMetadata metadata = {};
+    ExternalImageMetadata metadata;
    AHardwareBuffer* buffer = fvkExternalImage->aHardwareBuffer;
    if (__builtin_available(android 26, *)) {
        AHardwareBuffer_Desc bufferDesc;
@@ -199,159 +238,58 @@ VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::extractExternalImag
        metadata.width = bufferDesc.width;
        metadata.height = bufferDesc.height;
        metadata.layers = bufferDesc.layers;
+        metadata.isProtected = isProtectedFromUsage(bufferDesc.usage);
        std::tie(metadata.format, metadata.usage) =
                getVKFormatAndUsage(bufferDesc, fvkExternalImage->sRGB);
-        std::tie(metadata.filamentFormat, metadata.filamentUsage) =
-                getFilamentFormatAndUsage(bufferDesc, fvkExternalImage->sRGB);
-
-        if (isProtectedFromUsage(bufferDesc.usage)) {
-            metadata.filamentUsage |= TextureUsage::PROTECTED;
-        }
-
-        // TODO: The following seems unnecessary. we should be able to discern directly from the
-        // bufferDesc.
-        if (any(metadata.filamentUsage & TextureUsage::BLIT_SRC)) {
-            metadata.usage |= VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
-        }
-
-        if (any(metadata.filamentUsage & (TextureUsage::BLIT_DST | TextureUsage::UPLOADABLE))) {
-            metadata.usage |= VK_IMAGE_USAGE_TRANSFER_DST_BIT;
-        }
    }
-    metadata.samples = VK_SAMPLE_COUNT_1_BIT;
-
+    // In the unprotected case add R/W capabilities
+    if (metadata.isProtected == false) {
+        metadata.usage |= VK_IMAGE_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
+    }

    VkAndroidHardwareBufferFormatPropertiesANDROID formatInfo = {
        .sType = VK_STRUCTURE_TYPE_ANDROID_HARDWARE_BUFFER_FORMAT_PROPERTIES_ANDROID,
+        .pNext = nullptr,
    };
    VkAndroidHardwareBufferPropertiesANDROID properties = {
        .sType = VK_STRUCTURE_TYPE_ANDROID_HARDWARE_BUFFER_PROPERTIES_ANDROID,
        .pNext = &formatInfo,
    };
-    VkResult result = vkGetAndroidHardwareBufferPropertiesANDROID(getDevice(), buffer, &properties);
+    VkResult result = vkGetAndroidHardwareBufferPropertiesANDROID(device, buffer, &properties);
    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
-            << "vkGetAndroidHardwareBufferProperties failed with error="
-            << static_cast<int32_t>(result);
+        << "vkGetAndroidHardwareBufferProperties failed with error="
+        << static_cast<int32_t>(result);
+                            
    VkFormat bufferPropertiesFormat = transformVkFormat(formatInfo.format, fvkExternalImage->sRGB);
    FILAMENT_CHECK_POSTCONDITION(metadata.format == bufferPropertiesFormat)
            << "mismatched image format( " << metadata.format << ") and queried format("
            << bufferPropertiesFormat << ") for external image (AHB)";
    metadata.externalFormat = formatInfo.externalFormat;
-
-    // Choose either externalFormat > 0 or metadata.format and prefer the latter.
-    if (metadata.externalFormat > 0 &&  metadata.format != VK_FORMAT_UNDEFINED) {
-        // See VUID-VkImageCreateInfo-pNext-09457
-        metadata.usage = VK_IMAGE_USAGE_SAMPLED_BIT;
-        metadata.externalFormat = 0;
-    }
-
    metadata.allocationSize = properties.allocationSize;
    metadata.memoryTypeBits = properties.memoryTypeBits;
-
-    metadata.ycbcrConversionComponents = formatInfo.samplerYcbcrConversionComponents;
-    metadata.ycbcrModel = formatInfo.suggestedYcbcrModel;
-    metadata.ycbcrRange = formatInfo.suggestedYcbcrRange;
-    metadata.xChromaOffset = formatInfo.suggestedXChromaOffset;
-    metadata.yChromaOffset = formatInfo.suggestedYChromaOffset;
-
    return metadata;
 }

-VulkanPlatformAndroid::ImageData VulkanPlatformAndroid::createVkImageFromExternal(
-        ExternalImageHandleRef externalImage) const {
-    auto const& metadata = extractExternalImageMetadata(externalImage);
-
+VulkanPlatform::ImageData VulkanPlatform::createExternalImageDataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device,
+        const ExternalImageMetadata& metadata) {
    auto const* fvkExternalImage =
-            static_cast<ExternalImageVulkanAndroid const*>(externalImage.get());
-    AHardwareBuffer* buffer = fvkExternalImage->aHardwareBuffer;
-
-    // if external format we need to specifiy it in the allocation
-    bool const useExternalFormat = metadata.format == VK_FORMAT_UNDEFINED;
-
-    VkExternalFormatANDROID const externalFormat = {
-        .sType = VK_STRUCTURE_TYPE_EXTERNAL_FORMAT_ANDROID,
-        .pNext = nullptr,
-        .externalFormat = metadata.externalFormat,
-    };
-    VkExternalMemoryImageCreateInfo const externalCreateInfo = {
-        .sType = VK_STRUCTURE_TYPE_EXTERNAL_MEMORY_IMAGE_CREATE_INFO,
-        .pNext = useExternalFormat ? &externalFormat : nullptr,
-        .handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID,
-    };
-
-    VkImageCreateInfo const imageInfo{
-        .sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,
-        .pNext = &externalCreateInfo,
-        .flags = useExternalFormat ? VK_IMAGE_CREATE_ALIAS_BIT : 0u,
-        .imageType = VK_IMAGE_TYPE_2D,
-        .format = metadata.format,
-        .extent = {
-            metadata.width,
-            metadata.height,
-            1u,
-        },
-        .mipLevels = 1,
-        .arrayLayers = metadata.layers,
-        .samples = metadata.samples,
-        .usage = metadata.usage,
-    };
-
-    VkDevice const device = getDevice();
-
-    VkImage image;
-    VkResult result = vkCreateImage(device, &imageInfo, VKALLOC, &image);
-    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
-            << "vkCreateImage failed with error=" << static_cast<int32_t>(result);
-
-    // Allocate the memory
-    VkImportAndroidHardwareBufferInfoANDROID const androidHardwareBufferInfo = {
-        .sType = VK_STRUCTURE_TYPE_IMPORT_ANDROID_HARDWARE_BUFFER_INFO_ANDROID,
-        .buffer = buffer,
-    };
-    VkMemoryDedicatedAllocateInfo const memoryDedicatedAllocateInfo = {
-        .sType = VK_STRUCTURE_TYPE_MEMORY_DEDICATED_ALLOCATE_INFO,
-        .pNext = &androidHardwareBufferInfo,
-        .image = image,
-        .buffer = VK_NULL_HANDLE,
-    };
-
-    VkPhysicalDeviceMemoryProperties memoryProperties;
-    vkGetPhysicalDeviceMemoryProperties(getPhysicalDevice(), &memoryProperties);
-
-
-    VkMemoryPropertyFlags const requiredMemoryFlags =
-            any(metadata.filamentUsage & TextureUsage::UPLOADABLE)
-                    ? VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
-                    : VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;
-
-    uint32_t const memoryTypeIndex = VulkanContext::selectMemoryType(memoryProperties,
-            metadata.memoryTypeBits, requiredMemoryFlags);
-
-    VkMemoryAllocateInfo const allocInfo = {
-        .sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
-        .pNext = &memoryDedicatedAllocateInfo,
-        .allocationSize = metadata.allocationSize,
-        .memoryTypeIndex = memoryTypeIndex,
-    };
-    VkDeviceMemory memory;
-    result = vkAllocateMemory(device, &allocInfo, VKALLOC, &memory);
-    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
-            << "vkAllocateMemory failed with error=" << static_cast<int32_t>(result);
-
-    result = vkBindImageMemory(getDevice(), image, memory, 0);
+            static_cast<fvkandroid::ExternalImageVulkanAndroid const*>(externalImage.get());
+    ImageData data = allocateExternalImage(fvkExternalImage->aHardwareBuffer, device, metadata);
+    VkResult result = vkBindImageMemory(device, data.first, data.second, 0);
    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
            << "vkBindImageMemory error=" << static_cast<int32_t>(result);
-    return { image, memory };
+    return data;
 }

-VulkanPlatform::ExtensionSet VulkanPlatformAndroid::getSwapchainInstanceExtensions() const {
+VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensions() {
    return {
        VK_KHR_ANDROID_SURFACE_EXTENSION_NAME,
    };
 }

-VulkanPlatform::SurfaceBundle VulkanPlatformAndroid::createVkSurfaceKHR(void* nativeWindow,
-        VkInstance instance, uint64_t flags) const noexcept {
+VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHR(void* nativeWindow,
+    VkInstance instance, uint64_t flags) noexcept {
    VkSurfaceKHR surface;
    VkExtent2D extent;

@@ -363,15 +301,6 @@ VulkanPlatform::SurfaceBundle VulkanPlatformAndroid::createVkSurfaceKHR(void* na
            vkCreateAndroidSurfaceKHR(instance, &createInfo, VKALLOC, (VkSurfaceKHR*) &surface);
    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
            << "vkCreateAndroidSurfaceKHR with error=" << static_cast<int32_t>(result);
-    return { surface, extent };
+    return {surface, extent};
 }
-
-// Deprecated platform dependent helper methods
-VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensionsImpl() { return {}; }
-
-VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHRImpl(void* nativeWindow,
-        VkInstance instance, uint64_t flags) noexcept {
-    return SurfaceBundle{};
 }
-
-} // namespace filament::backend
@@ -52,7 +52,7 @@ using namespace bluevk;

 namespace filament::backend {

-VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensionsImpl() {
+VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensions() {
    ExtensionSet const ret = {
    #if defined(__APPLE__)
        VK_MVK_MACOS_SURFACE_EXTENSION_NAME,  // TODO: replace with VK_EXT_metal_surface
@@ -63,7 +63,18 @@ VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensionsImpl(
    return ret;
 }

-VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHRImpl(void* nativeWindow,
+VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device) {
+    return {};
+}
+
+VulkanPlatform::ImageData VulkanPlatform::createExternalImageDataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device,
+        const ExternalImageMetadata& metadata) {
+    return {};
+}
+
+VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHR(void* nativeWindow,
        VkInstance instance, uint64_t flags) noexcept {
    VkSurfaceKHR surface;
    #if defined(__APPLE__)
@@ -84,7 +84,18 @@ using namespace bluevk;

 namespace filament::backend {

-VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensionsImpl() {
+VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device) {
+    return {};
+}
+
+VulkanPlatform::ImageData VulkanPlatform::createExternalImageDataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device,
+        const ExternalImageMetadata& metadata) {
+    return {};
+}
+
+VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensions() {
    VulkanPlatform::ExtensionSet const ret = {
 #if defined(__linux__) && defined(FILAMENT_SUPPORTS_WAYLAND)
        VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME,
@@ -102,7 +113,7 @@ VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensionsImpl(
    return ret;
 }

-VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHRImpl(void* nativeWindow,
+VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHR(void* nativeWindow,
        VkInstance instance, uint64_t flags) noexcept {
    VkSurfaceKHR surface;

@@ -18,12 +18,12 @@
 #define TNT_FILAMENT_BACKEND_VULKANSWAPCHAIN_IMPL_H

 #include "vulkan/VulkanContext.h"
-#include "vulkan/VulkanConstants.h"

 #include <backend/platforms/VulkanPlatform.h>

 #include <bluevk/BlueVK.h>

+#include <tuple>
 #include <unordered_map>

 using namespace bluevk;
@@ -588,79 +588,6 @@ VkComponentMapping getSwizzleMap(TextureSwizzle const swizzle[4]) {
    return map;
 }

-VkFilter getFilter(SamplerMinFilter filter) {
-    switch (filter) {
-    case SamplerMinFilter::NEAREST:
-        return VK_FILTER_NEAREST;
-    case SamplerMinFilter::LINEAR:
-        return VK_FILTER_LINEAR;
-    case SamplerMinFilter::NEAREST_MIPMAP_NEAREST:
-        return VK_FILTER_NEAREST;
-    case SamplerMinFilter::LINEAR_MIPMAP_NEAREST:
-        return VK_FILTER_LINEAR;
-    case SamplerMinFilter::NEAREST_MIPMAP_LINEAR:
-        return VK_FILTER_NEAREST;
-    case SamplerMinFilter::LINEAR_MIPMAP_LINEAR:
-        return VK_FILTER_LINEAR;
-    }
-}
-
-VkFilter getFilter(SamplerMagFilter filter) {
-    switch (filter) {
-    case SamplerMagFilter::NEAREST:
-        return VK_FILTER_NEAREST;
-    case SamplerMagFilter::LINEAR:
-        return VK_FILTER_LINEAR;
-    }
-}
-
-VkSamplerMipmapMode getMipmapMode(SamplerMinFilter filter) {
-    switch (filter) {
-    case SamplerMinFilter::NEAREST:
-        return VK_SAMPLER_MIPMAP_MODE_NEAREST;
-    case SamplerMinFilter::LINEAR:
-        return VK_SAMPLER_MIPMAP_MODE_NEAREST;
-    case SamplerMinFilter::NEAREST_MIPMAP_NEAREST:
-        return VK_SAMPLER_MIPMAP_MODE_NEAREST;
-    case SamplerMinFilter::LINEAR_MIPMAP_NEAREST:
-        return VK_SAMPLER_MIPMAP_MODE_NEAREST;
-    case SamplerMinFilter::NEAREST_MIPMAP_LINEAR:
-        return VK_SAMPLER_MIPMAP_MODE_LINEAR;
-    case SamplerMinFilter::LINEAR_MIPMAP_LINEAR:
-        return VK_SAMPLER_MIPMAP_MODE_LINEAR;
-    }
-}
-
-VkSamplerAddressMode getWrapMode(SamplerWrapMode mode) {
-    switch (mode) {
-    case SamplerWrapMode::REPEAT:
-        return VK_SAMPLER_ADDRESS_MODE_REPEAT;
-    case SamplerWrapMode::CLAMP_TO_EDGE:
-        return VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
-    case SamplerWrapMode::MIRRORED_REPEAT:
-        return VK_SAMPLER_ADDRESS_MODE_MIRRORED_REPEAT;
-    }
-}
-
-VkBool32 getCompareEnable(SamplerCompareMode mode) {
-    return mode == SamplerCompareMode::NONE ? VK_FALSE : VK_TRUE;
-}
-
-float getMaxLod(SamplerMinFilter filter) {
-    switch (filter) {
-    case SamplerMinFilter::NEAREST:
-    case SamplerMinFilter::LINEAR:
-        // The Vulkan spec recommends a max LOD of 0.25 to "disable" mipmapping.
-        // See "Mapping of OpenGL to Vulkan filter modes" in the VK Spec.
-        return 0.25f;
-    case SamplerMinFilter::NEAREST_MIPMAP_NEAREST:
-    case SamplerMinFilter::LINEAR_MIPMAP_NEAREST:
-    case SamplerMinFilter::NEAREST_MIPMAP_LINEAR:
-    case SamplerMinFilter::LINEAR_MIPMAP_LINEAR:
-        return VK_LOD_CLAMP_NONE;
-    }
-}
-
 VkShaderStageFlags getShaderStageFlags(ShaderStageFlags stageFlags) {
    VkShaderStageFlags flags = 0x0;
    if (any(stageFlags & ShaderStageFlags::VERTEX))     flags |= VK_SHADER_STAGE_VERTEX_BIT;
@@ -668,111 +595,4 @@ VkShaderStageFlags getShaderStageFlags(ShaderStageFlags stageFlags) {
    return flags;
 }

-VkSamplerYcbcrModelConversion getYcbcrModelConversion(
-    SamplerYcbcrModelConversion model) {
-    switch (model) {
-    case SamplerYcbcrModelConversion::RGB_IDENTITY:
-        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY;
-    case SamplerYcbcrModelConversion::YCBCR_IDENTITY:
-        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY;
-    case SamplerYcbcrModelConversion::YCBCR_709:
-        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709;
-    case SamplerYcbcrModelConversion::YCBCR_601:
-        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601;
-    case SamplerYcbcrModelConversion::YCBCR_2020:
-        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020;
-    default:
-        assert_invariant(false &&
-            "Unknown data type, conversion is not supported.");
-    }
-}
-
-VkSamplerYcbcrRange getYcbcrRange(SamplerYcbcrRange range) {
-    switch (range) {
-    case SamplerYcbcrRange::ITU_FULL:
-        return VK_SAMPLER_YCBCR_RANGE_ITU_FULL;
-    case SamplerYcbcrRange::ITU_NARROW:
-        return VK_SAMPLER_YCBCR_RANGE_ITU_NARROW;
-    default:
-        assert_invariant(false &&
-            "Unknown data type, conversion is not supported.");
-    }
-}
-
-VkChromaLocation getChromaLocation(ChromaLocation loc) {
-    switch (loc) {
-    case ChromaLocation::COSITED_EVEN:
-        return VK_CHROMA_LOCATION_COSITED_EVEN;
-    case ChromaLocation::MIDPOINT:
-        return VK_CHROMA_LOCATION_MIDPOINT;
-    default:
-        assert_invariant(false &&
-            "Unknown data type, conversion is not supported.");
-    }
-}
-
-SamplerYcbcrModelConversion getYcbcrModelConversionFilament(VkSamplerYcbcrModelConversion model) {
-    switch (model) {
-        case VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY:
-            return SamplerYcbcrModelConversion::RGB_IDENTITY;
-        case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY:
-            return SamplerYcbcrModelConversion::YCBCR_IDENTITY;
-        case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709:
-            return SamplerYcbcrModelConversion::YCBCR_709;
-        case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601:
-            return SamplerYcbcrModelConversion::YCBCR_601;
-        case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020:
-            return SamplerYcbcrModelConversion::YCBCR_2020;
-        default:
-            assert_invariant(false && "Unknown data type, conversion is not supported.");
-            return {};
-    }
-}
-
-SamplerYcbcrRange getYcbcrRangeFilament(VkSamplerYcbcrRange range) {
-    switch (range) {
-        case VK_SAMPLER_YCBCR_RANGE_ITU_FULL:
-            return SamplerYcbcrRange::ITU_FULL;
-        case VK_SAMPLER_YCBCR_RANGE_ITU_NARROW:
-            return SamplerYcbcrRange::ITU_NARROW;
-        default:
-            assert_invariant(false && "Unknown data type, conversion is not supported.");
-            return {};
-    }
-}
-
-ChromaLocation getChromaLocationFilament(VkChromaLocation loc) {
-    switch (loc) {
-        case VK_CHROMA_LOCATION_COSITED_EVEN:
-            return ChromaLocation::COSITED_EVEN;
-        case VK_CHROMA_LOCATION_MIDPOINT:
-            return ChromaLocation::MIDPOINT;
-        default:
-            assert_invariant(false && "Unknown data type, conversion is not supported.");
-            return {};
-    }
-}
-
-TextureSwizzle getSwizzleFilament(VkComponentSwizzle c, uint8_t rgbaIndex) {
-    switch (c) {
-        case VK_COMPONENT_SWIZZLE_ZERO:
-            return TextureSwizzle::SUBSTITUTE_ZERO;
-        case VK_COMPONENT_SWIZZLE_ONE:
-            return TextureSwizzle::SUBSTITUTE_ONE;
-        case VK_COMPONENT_SWIZZLE_IDENTITY:
-            return (TextureSwizzle) (((uint8_t) TextureSwizzle::CHANNEL_0) + rgbaIndex);
-        case VK_COMPONENT_SWIZZLE_R:
-            return TextureSwizzle::CHANNEL_0;
-        case VK_COMPONENT_SWIZZLE_G:
-            return TextureSwizzle::CHANNEL_1;
-        case VK_COMPONENT_SWIZZLE_B:
-            return TextureSwizzle::CHANNEL_2;
-        case VK_COMPONENT_SWIZZLE_A:
-            return TextureSwizzle::CHANNEL_3;
-        default:
-            assert_invariant(false && "Unknown data type, conversion is not supported.");
-            return {};
-    }
-}
-
 } // namespace filament::backend::fvkutils
@@ -56,25 +56,6 @@ uint32_t getComponentCount(VkFormat format);
 VkComponentMapping getSwizzleMap(TextureSwizzle const swizzle[4]);
 VkShaderStageFlags getShaderStageFlags(ShaderStageFlags stageFlags);

-// Needed by the Platform for external sampler creation
-VkFilter getFilter(SamplerMinFilter filter);
-VkFilter getFilter(SamplerMagFilter filter);
-VkSamplerMipmapMode getMipmapMode(SamplerMinFilter filter);
-VkSamplerAddressMode getWrapMode(SamplerWrapMode mode);
-VkBool32 getCompareEnable(SamplerCompareMode mode);
-float getMaxLod(SamplerMinFilter filter);
-
-// Ycbcr related functions
-VkSamplerYcbcrModelConversion getYcbcrModelConversion(SamplerYcbcrModelConversion model);
-VkSamplerYcbcrRange getYcbcrRange(SamplerYcbcrRange range);
-VkChromaLocation getChromaLocation(ChromaLocation loc);
-
-// Ycbcr related functions
-SamplerYcbcrModelConversion getYcbcrModelConversionFilament(VkSamplerYcbcrModelConversion model);
-SamplerYcbcrRange getYcbcrRangeFilament(VkSamplerYcbcrRange range);
-ChromaLocation getChromaLocationFilament(VkChromaLocation loc);
-TextureSwizzle getSwizzleFilament(VkComponentSwizzle c, uint8_t rgbaIndex);
-
 inline VkImageViewType getViewType(SamplerType target) {
    switch (target) {
        case SamplerType::SAMPLER_CUBEMAP:
@@ -348,10 +348,6 @@ using SamplerBitmask = utils::bitset64;
 // general.
 using InputAttachmentBitmask = utils::bitset64;

-constexpr uint8_t MAX_DESCRIPTOR_SET_BITMASK_BITS =
-        std::max(std::max(sizeof(UniformBufferBitmask), sizeof(SamplerBitmask)),
-                sizeof(InputAttachmentBitmask)) * 8;
-
 template<typename Bitmask>
 static constexpr uint8_t getVertexStageShift() noexcept {
    // We assume the bottom half of bits are for vertex stages.
@@ -1,66 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef TNT_FILAMENT_BACKEND_WEBGPUCONSTANTS_H
-#define TNT_FILAMENT_BACKEND_WEBGPUCONSTANTS_H
-
-#include <utils/Log.h>
-
-#include <cstdint>
-
-// FWGPU is short for Filament WebGPU
-
-// turn on runtime validation, namely for debugging, that would normally not run (for release)
-#define FWGPU_DEBUG_VALIDATION     0x00000001
-// print/log system component details to the console, e.g. about the
-// instance, surface, adapter, device, etc.
-#define FWGPU_PRINT_SYSTEM         0x00000002
-
-// Set this to enable logging "only" to one output stream. This is useful in the case where we want
-// to debug with print statements and want ordered logging (e.g slog.i and slog.e will not appear in
-// order of calls).
-#define FWGPU_DEBUG_FORCE_LOG_TO_I 0x00000004
-
-// Useful default combinations
-#define FWGPU_DEBUG_EVERYTHING     0xFFFFFFFF
-
-#if defined(FILAMENT_BACKEND_DEBUG_FLAG)
-    #define FWGPU_DEBUG_FORWARDED_FLAG (FILAMENT_BACKEND_DEBUG_FLAG & FWGPU_DEBUG_EVERYTHING)
-#else
-    #define FWGPU_DEBUG_FORWARDED_FLAG 0
-#endif
-
-#ifndef NDEBUG
-    #define FWGPU_DEBUG_FLAGS FWGPU_DEBUG_FORWARDED_FLAG
-#else
-    #define FWGPU_DEBUG_FLAGS 0
-#endif
-
-#define FWGPU_ENABLED(flags) (((FWGPU_DEBUG_FLAGS) & (flags)) == (flags))
-
-#if FWGPU_ENABLED(FWGPU_DEBUG_FORCE_LOG_TO_I)
-    #define FWGPU_LOGI (utils::slog.i)
-    #define FWGPU_LOGD FWGPU_LOGI
-    #define FWGPU_LOGE FWGPU_LOGI
-    #define FWGPU_LOGW FWGPU_LOGI
-#else
-    #define FWGPU_LOGE (utils::slog.e)
-    #define FWGPU_LOGW (utils::slog.w)
-    #define FWGPU_LOGD (utils::slog.d)
-    #define FWGPU_LOGI (utils::slog.i)
-#endif
-
-#endif// TNT_FILAMENT_BACKEND_WEBGPUCONSTANTS_H
@@ -14,261 +14,21 @@
 * limitations under the License.
 */

-#include "webgpu/WebGPUDriver.h"
-
-#include "webgpu/WebGPUConstants.h"
-#include <backend/platforms/WebGPUPlatform.h>
-
-#include "CommandStreamDispatcher.h"
-#include "DriverBase.h"
-#include "private/backend/Dispatcher.h"
 #include <backend/DriverEnums.h>
 #include <backend/Handle.h>

-#include <math/mat3.h>
-#include <utils/CString.h>
-#include <utils/ostream.h>
+#include "webgpu/WebGPUDriver.h"
+#include "CommandStreamDispatcher.h"

-#include <dawn/webgpu_cpp_print.h>
-#include <webgpu/webgpu_cpp.h>
-
-#include <algorithm>
-#include <cstddef>
-#include <cstdint>
-#include <sstream>
-#include <string_view>
-#include <utility>
-#include <variant>
+#include <stdint.h>

 namespace filament::backend {

-namespace {
-
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-void printInstanceDetails(wgpu::Instance const& instance) {
-    wgpu::SupportedWGSLLanguageFeatures supportedWGSLLanguageFeatures{};
-    if (!instance.GetWGSLLanguageFeatures(&supportedWGSLLanguageFeatures)) {
-        FWGPU_LOGW << "Failed to get WebGPU instance supported WGSL language features"
-                   << utils::io::endl;
-    } else {
-        FWGPU_LOGI << "WebGPU instance supported WGSL language features ("
-                   << supportedWGSLLanguageFeatures.featureCount << "):" << utils::io::endl;
-        if (supportedWGSLLanguageFeatures.featureCount > 0 &&
-                supportedWGSLLanguageFeatures.features != nullptr) {
-            std::for_each(supportedWGSLLanguageFeatures.features,
-                    supportedWGSLLanguageFeatures.features +
-                            supportedWGSLLanguageFeatures.featureCount,
-                    [](wgpu::WGSLLanguageFeatureName const featureName) {
-                        std::stringstream nameStream{};
-                        nameStream << featureName;
-                        FWGPU_LOGI << "  " << nameStream.str() << utils::io::endl;
-                    });
-        }
-    }
-}
-#endif
-
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-void printLimit(std::string_view name, const std::variant<uint32_t, uint64_t> value) {
-    FWGPU_LOGI << "  " << name.data() << ": ";
-    bool undefined = true;
-    if (std::holds_alternative<uint32_t>(value)) {
-        if (std::get<uint32_t>(value) != WGPU_LIMIT_U32_UNDEFINED) {
-            undefined = false;
-            FWGPU_LOGI << std::get<uint32_t>(value);
-        }
-    } else if (std::holds_alternative<uint64_t>(value)) {
-        if (std::get<uint64_t>(value) != WGPU_LIMIT_U64_UNDEFINED) {
-            undefined = false;
-            FWGPU_LOGI << std::get<uint64_t>(value);
-        }
-    }
-    if (undefined) {
-        FWGPU_LOGI << "UNDEFINED";
-    }
-    FWGPU_LOGI << utils::io::endl;
-}
-#endif
-
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-void printLimits(wgpu::Limits const& limits) {
-    printLimit("maxTextureDimension1D", limits.maxTextureDimension1D);
-    printLimit("maxTextureDimension2D", limits.maxTextureDimension2D);
-    printLimit("maxTextureDimension3D", limits.maxTextureDimension3D);
-    printLimit("maxTextureArrayLayers", limits.maxTextureArrayLayers);
-    printLimit("maxBindGroups", limits.maxBindGroups);
-    printLimit("maxBindGroupsPlusVertexBuffers", limits.maxBindGroupsPlusVertexBuffers);
-    printLimit("maxBindingsPerBindGroup", limits.maxBindingsPerBindGroup);
-    printLimit("maxDynamicUniformBuffersPerPipelineLayout",
-            limits.maxDynamicUniformBuffersPerPipelineLayout);
-    printLimit("maxDynamicStorageBuffersPerPipelineLayout",
-            limits.maxDynamicStorageBuffersPerPipelineLayout);
-    printLimit("maxSampledTexturesPerShaderStage", limits.maxSampledTexturesPerShaderStage);
-    printLimit("maxSamplersPerShaderStage", limits.maxSamplersPerShaderStage);
-    printLimit("maxStorageBuffersPerShaderStage", limits.maxStorageBuffersPerShaderStage);
-    printLimit("maxStorageTexturesPerShaderStage", limits.maxStorageTexturesPerShaderStage);
-    printLimit("maxUniformBuffersPerShaderStage", limits.maxUniformBuffersPerShaderStage);
-    printLimit("maxUniformBufferBindingSize", limits.maxUniformBufferBindingSize);
-    printLimit("maxStorageBufferBindingSize", limits.maxStorageBufferBindingSize);
-    printLimit("minUniformBufferOffsetAlignment", limits.minUniformBufferOffsetAlignment);
-    printLimit("minStorageBufferOffsetAlignment", limits.minStorageBufferOffsetAlignment);
-    printLimit("maxVertexBuffers", limits.maxVertexBuffers);
-    printLimit("maxBufferSize", limits.maxBufferSize);
-    printLimit("maxVertexAttributes", limits.maxVertexAttributes);
-    printLimit("maxVertexBufferArrayStride", limits.maxVertexBufferArrayStride);
-    printLimit("maxInterStageShaderComponents", limits.maxInterStageShaderComponents);
-    printLimit("maxInterStageShaderVariables", limits.maxInterStageShaderVariables);
-    printLimit("maxColorAttachments", limits.maxColorAttachments);
-    printLimit("maxColorAttachmentBytesPerSample", limits.maxColorAttachmentBytesPerSample);
-    printLimit("maxComputeWorkgroupStorageSize", limits.maxComputeWorkgroupStorageSize);
-    printLimit("maxComputeInvocationsPerWorkgroup", limits.maxComputeInvocationsPerWorkgroup);
-    printLimit("maxComputeWorkgroupSizeX", limits.maxComputeWorkgroupSizeX);
-    printLimit("maxComputeWorkgroupSizeY", limits.maxComputeWorkgroupSizeY);
-    printLimit("maxComputeWorkgroupSizeZ", limits.maxComputeWorkgroupSizeZ);
-    printLimit("maxComputeWorkgroupsPerDimension", limits.maxComputeWorkgroupsPerDimension);
-    printLimit("maxStorageBuffersInVertexStage", limits.maxStorageBuffersInVertexStage);
-    printLimit("maxStorageTexturesInVertexStage", limits.maxStorageTexturesInVertexStage);
-    printLimit("maxStorageBuffersInFragmentStage", limits.maxStorageBuffersInFragmentStage);
-    printLimit("maxStorageTexturesInFragmentStage", limits.maxStorageTexturesInFragmentStage);
-}
-#endif
-
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-void printAdapterDetails(wgpu::Adapter const& adapter) {
-    wgpu::DawnAdapterPropertiesPowerPreference powerPreferenceProperties{};
-    wgpu::AdapterInfo adapterInfo{};
-    adapterInfo.nextInChain = &powerPreferenceProperties;
-    if (!adapter.GetInfo(&adapterInfo)) {
-        FWGPU_LOGW << "Failed to get WebGPU adapter info" << utils::io::endl;
-    } else {
-        std::stringstream backendTypeStream{};
-        backendTypeStream << adapterInfo.backendType;
-        std::stringstream adapterTypeStream{};
-        adapterTypeStream << adapterInfo.adapterType;
-        std::stringstream powerPreferenceStream{};
-        powerPreferenceStream << powerPreferenceProperties.powerPreference;
-        FWGPU_LOGI << "WebGPU adapter info:" << utils::io::endl;
-        FWGPU_LOGI << "  vendor: " << adapterInfo.vendor.data << utils::io::endl;
-        FWGPU_LOGI << "  architecture: " << adapterInfo.architecture.data << utils::io::endl;
-        FWGPU_LOGI << "  device: " << adapterInfo.device.data << utils::io::endl;
-        FWGPU_LOGI << "  description: " << adapterInfo.description.data << utils::io::endl;
-        FWGPU_LOGI << "  backend type: " << backendTypeStream.str().data() << utils::io::endl;
-        FWGPU_LOGI << "  adapter type: " << adapterTypeStream.str().data() << utils::io::endl;
-        FWGPU_LOGI << "  device ID: " << adapterInfo.deviceID << utils::io::endl;
-        FWGPU_LOGI << "  vendor ID: " << adapterInfo.vendorID << utils::io::endl;
-        FWGPU_LOGI << "  subgroup min size: " << adapterInfo.subgroupMinSize << utils::io::endl;
-        FWGPU_LOGI << "  subgroup max size: " << adapterInfo.subgroupMaxSize << utils::io::endl;
-        FWGPU_LOGI << "  compatibility mode: " << bool(adapterInfo.compatibilityMode)
-                   << utils::io::endl;
-        FWGPU_LOGI << "  power preference: " << powerPreferenceStream.str() << utils::io::endl;
-    }
-    wgpu::SupportedFeatures supportedFeatures{};
-    adapter.GetFeatures(&supportedFeatures);
-    FWGPU_LOGI << "WebGPU adapter supported features (" << supportedFeatures.featureCount
-               << "):" << utils::io::endl;
-    if (supportedFeatures.featureCount > 0 && supportedFeatures.features != nullptr) {
-        std::for_each(supportedFeatures.features,
-                supportedFeatures.features + supportedFeatures.featureCount,
-                [](wgpu::FeatureName const name) {
-                    std::stringstream nameStream{};
-                    nameStream << name;
-                    FWGPU_LOGI << "  " << nameStream.str().data() << utils::io::endl;
-                });
-    }
-    wgpu::SupportedLimits supportedLimits{};
-    if (!adapter.GetLimits(&supportedLimits)) {
-        FWGPU_LOGW << "Failed to get WebGPU adapter supported limits" << utils::io::endl;
-    } else {
-        FWGPU_LOGI << "WebGPU adapter supported limits:" << utils::io::endl;
-        printLimits(supportedLimits.limits);
-    }
-}
-#endif
-
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-void printSurfaceCapabilitiesDetails(wgpu::SurfaceCapabilities const& capabilities) {
-    std::stringstream usages_stream{};
-    usages_stream << capabilities.usages;
-    FWGPU_LOGI << "WebGPU surface capabilities:" << utils::io::endl;
-    FWGPU_LOGI << "  surface usages: " << usages_stream.str().data() << utils::io::endl;
-    FWGPU_LOGI << "  surface formats (" << capabilities.formatCount << "):" << utils::io::endl;
-    if (capabilities.formatCount > 0 && capabilities.formats != nullptr) {
-        std::for_each(capabilities.formats, capabilities.formats + capabilities.formatCount,
-                [](wgpu::TextureFormat const format) {
-                    std::stringstream format_stream{};
-                    format_stream << format;
-                    FWGPU_LOGI << "    " << format_stream.str().data() << utils::io::endl;
-                });
-    }
-    FWGPU_LOGI << "  surface present modes (" << capabilities.presentModeCount
-               << "):" << utils::io::endl;
-    if (capabilities.presentModeCount > 0 && capabilities.presentModes != nullptr) {
-        std::for_each(capabilities.presentModes,
-                capabilities.presentModes + capabilities.presentModeCount,
-                [](wgpu::PresentMode const presentMode) {
-                    std::stringstream present_mode_stream{};
-                    present_mode_stream << presentMode;
-                    FWGPU_LOGI << "    " << present_mode_stream.str().data() << utils::io::endl;
-                });
-    }
-    FWGPU_LOGI << "  surface alpha modes (" << capabilities.alphaModeCount
-               << "):" << utils::io::endl;
-    if (capabilities.alphaModeCount > 0 && capabilities.alphaModes != nullptr) {
-        std::for_each(capabilities.alphaModes,
-                capabilities.alphaModes + capabilities.alphaModeCount,
-                [](wgpu::CompositeAlphaMode const alphaMode) {
-                    std::stringstream alpha_mode_stream{};
-                    alpha_mode_stream << alphaMode;
-                    FWGPU_LOGI << "    " << alpha_mode_stream.str().data() << utils::io::endl;
-                });
-    }
-}
-#endif
-
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-void printDeviceDetails(wgpu::Device const& device) {
-    wgpu::SupportedFeatures supportedFeatures{};
-    device.GetFeatures(&supportedFeatures);
-    FWGPU_LOGI << "WebGPU device supported features (" << supportedFeatures.featureCount
-               << "):" << utils::io::endl;
-    if (supportedFeatures.featureCount > 0 && supportedFeatures.features != nullptr) {
-        std::for_each(supportedFeatures.features,
-                supportedFeatures.features + supportedFeatures.featureCount,
-                [](wgpu::FeatureName const name) {
-                    std::stringstream nameStream{};
-                    nameStream << name;
-                    FWGPU_LOGI << "  " << nameStream.str().data() << utils::io::endl;
-                });
-    }
-    wgpu::SupportedLimits supportedLimits{};
-    if (!device.GetLimits(&supportedLimits)) {
-        FWGPU_LOGW << "Failed to get WebGPU supported device limits" << utils::io::endl;
-    } else {
-        FWGPU_LOGI << "WebGPU device supported limits:" << utils::io::endl;
-        printLimits(supportedLimits.limits);
-    }
-}
-#endif
-
-}// namespace
-
-Driver* WebGPUDriver::create(WebGPUPlatform& platform, const Platform::DriverConfig& driverConfig) noexcept {
-    constexpr size_t defaultSize = FILAMENT_WEBGPU_HANDLE_ARENA_SIZE_IN_MB * 1024U * 1024U;
-    Platform::DriverConfig validConfig {driverConfig};
-    validConfig.handleArenaSize = std::max(driverConfig.handleArenaSize, defaultSize);
-    return new WebGPUDriver(platform, validConfig);
+Driver* WebGPUDriver::create() {
+    return new WebGPUDriver();
 }

-WebGPUDriver::WebGPUDriver(WebGPUPlatform& platform, const Platform::DriverConfig& driverConfig) noexcept
-    : mPlatform(platform),
-      mHandleAllocator("Handles",
-              driverConfig.handleArenaSize,
-              driverConfig.disableHandleUseAfterFreeCheck,
-              driverConfig.disableHeapHandleTags) {
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-    printInstanceDetails(mPlatform.getInstance());
-#endif
-}
+WebGPUDriver::WebGPUDriver() noexcept = default;

 WebGPUDriver::~WebGPUDriver() noexcept = default;

@@ -363,188 +123,6 @@ void WebGPUDriver::destroyDescriptorSetLayout(Handle<HwDescriptorSetLayout> tqh)
 void WebGPUDriver::destroyDescriptorSet(Handle<HwDescriptorSet> tqh) {
 }

-Handle<HwSwapChain> WebGPUDriver::createSwapChainS() noexcept {
-    return Handle<HwSwapChain>((Handle<HwSwapChain>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwSwapChain> WebGPUDriver::createSwapChainHeadlessS() noexcept {
-    return Handle<HwSwapChain>((Handle<HwSwapChain>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwTexture> WebGPUDriver::createTextureS() noexcept {
-    return Handle<HwTexture>((Handle<HwTexture>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwTexture> WebGPUDriver::importTextureS() noexcept {
-    return Handle<HwTexture>((Handle<HwTexture>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwProgram> WebGPUDriver::createProgramS() noexcept {
-    return Handle<HwProgram>((Handle<HwProgram>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwFence> WebGPUDriver::createFenceS() noexcept {
-    return Handle<HwFence>((Handle<HwFence>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwTimerQuery> WebGPUDriver::createTimerQueryS() noexcept {
-    return Handle<HwTimerQuery>((Handle<HwTimerQuery>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwIndexBuffer> WebGPUDriver::createIndexBufferS() noexcept {
-    return allocHandle<HwIndexBuffer>();
-}
-
-Handle<HwTexture> WebGPUDriver::createTextureViewS() noexcept {
-    return Handle<HwTexture>((Handle<HwTexture>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwBufferObject> WebGPUDriver::createBufferObjectS() noexcept {
-    return Handle<HwBufferObject>((Handle<HwBufferObject>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwRenderTarget> WebGPUDriver::createRenderTargetS() noexcept {
-    return Handle<HwRenderTarget>((Handle<HwRenderTarget>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwVertexBuffer> WebGPUDriver::createVertexBufferS() noexcept {
-    return Handle<HwVertexBuffer>((Handle<HwVertexBuffer>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwDescriptorSet> WebGPUDriver::createDescriptorSetS() noexcept {
-    return Handle<HwDescriptorSet>((Handle<HwDescriptorSet>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwRenderPrimitive> WebGPUDriver::createRenderPrimitiveS() noexcept {
-    return Handle<HwRenderPrimitive>((Handle<HwRenderPrimitive>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwVertexBufferInfo> WebGPUDriver::createVertexBufferInfoS() noexcept {
-    return Handle<HwVertexBufferInfo>((Handle<HwVertexBufferInfo>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwTexture> WebGPUDriver::createTextureViewSwizzleS() noexcept {
-    return Handle<HwTexture>((Handle<HwTexture>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwRenderTarget> WebGPUDriver::createDefaultRenderTargetS() noexcept {
-    return Handle<HwRenderTarget>((Handle<HwRenderTarget>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwDescriptorSetLayout> WebGPUDriver::createDescriptorSetLayoutS() noexcept {
-    return Handle<HwDescriptorSetLayout>(
-            (Handle<HwDescriptorSetLayout>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwTexture> WebGPUDriver::createTextureExternalImageS() noexcept {
-    return Handle<HwTexture>((Handle<HwTexture>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwTexture> WebGPUDriver::createTextureExternalImage2S() noexcept {
-    return Handle<HwTexture>((Handle<HwTexture>::HandleId) mNextFakeHandle++);
-}
-
-Handle<HwTexture> WebGPUDriver::createTextureExternalImagePlaneS() noexcept {
-    return Handle<HwTexture>((Handle<HwTexture>::HandleId) mNextFakeHandle++);
-}
-
-void WebGPUDriver::createSwapChainR(Handle<HwSwapChain> sch, void* nativeWindow, uint64_t flags) {
-    mSurface= mPlatform.createSurface(nativeWindow, flags);
-    mAdapter = mPlatform.requestAdapter(mSurface);
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-    printAdapterDetails(mAdapter);
-    wgpu::SurfaceCapabilities surfaceCapabilities{};
-    if (!mSurface.GetCapabilities(mAdapter, &surfaceCapabilities)) {
-        FWGPU_LOGW << "Failed to get WebGPU surface capabilities" << utils::io::endl;
-    } else {
-        printSurfaceCapabilitiesDetails(surfaceCapabilities);
-    }
-#endif
-    mDevice = mPlatform.requestDevice(mAdapter);
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-    printDeviceDetails(mDevice);
-#endif
-    mQueue = mDevice.GetQueue();
-    // TODO configure the surface (maybe before or after creating the swapchain?
-    //                             how do we get the surface extent?)
-    // TODO actually create the swapchain
-    FWGPU_LOGW << "WebGPU support is still essentially a no-op at this point in development (only "
-                  "background components have been instantiated/selected, such as surface/screen, "
-                  "graphics device/GPU, etc.), thus nothing is being drawn to the screen."
-               << utils::io::endl;
-#if !FWGPU_ENABLED(FWGPU_PRINT_SYSTEM) && !defined(NDEBUG)
-    FWGPU_LOGI << "If the FILAMENT_BACKEND_DEBUG_FLAG variable were set with the " << utils::io::hex
-               << FWGPU_PRINT_SYSTEM << utils::io::dec
-               << " bit flag on during build time the application would print system details "
-                  "about the selected graphics device, surface, etc. To see this try "
-                  "rebuilding Filament with that flag, e.g. ./build.sh -x "
-               << FWGPU_PRINT_SYSTEM << " ..." << utils::io::endl;
-#endif
-}
-
-void WebGPUDriver::createSwapChainHeadlessR(Handle<HwSwapChain> sch, uint32_t width,
-        uint32_t height, uint64_t flags) {}
-
-void WebGPUDriver::createVertexBufferInfoR(Handle<HwVertexBufferInfo> vbih, uint8_t bufferCount,
-        uint8_t attributeCount, AttributeArray attributes) {}
-
-void WebGPUDriver::createVertexBufferR(Handle<HwVertexBuffer> vbh, uint32_t vertexCount,
-        Handle<HwVertexBufferInfo> vbih) {}
-
-void WebGPUDriver::createIndexBufferR(Handle<HwIndexBuffer> ibh, ElementType elementType,
-        uint32_t indexCount, BufferUsage usage) {}
-
-void WebGPUDriver::createBufferObjectR(Handle<HwBufferObject> boh, uint32_t byteCount,
-        BufferObjectBinding bindingType, BufferUsage usage) {}
-
-void WebGPUDriver::createTextureR(Handle<HwTexture> th, SamplerType target, uint8_t levels,
-        TextureFormat format, uint8_t samples, uint32_t w, uint32_t h, uint32_t depth,
-        TextureUsage usage) {}
-
-void WebGPUDriver::createTextureViewR(Handle<HwTexture> th, Handle<HwTexture> srch,
-        uint8_t baseLevel, uint8_t levelCount) {}
-
-void WebGPUDriver::createTextureViewSwizzleR(Handle<HwTexture> th, Handle<HwTexture> srch,
-        backend::TextureSwizzle r, backend::TextureSwizzle g, backend::TextureSwizzle b,
-        backend::TextureSwizzle a) {}
-
-void WebGPUDriver::createTextureExternalImage2R(Handle<HwTexture> th, backend::SamplerType target,
-        backend::TextureFormat format, uint32_t width, uint32_t height, backend::TextureUsage usage,
-        Platform::ExternalImageHandleRef externalImage) {}
-
-void WebGPUDriver::createTextureExternalImageR(Handle<HwTexture> th, backend::SamplerType target,
-        backend::TextureFormat format, uint32_t width, uint32_t height, backend::TextureUsage usage,
-        void* externalImage) {}
-
-void WebGPUDriver::createTextureExternalImagePlaneR(Handle<HwTexture> th,
-        backend::TextureFormat format, uint32_t width, uint32_t height, backend::TextureUsage usage,
-        void* image, uint32_t plane) {}
-
-void WebGPUDriver::importTextureR(Handle<HwTexture> th, intptr_t id, SamplerType target,
-        uint8_t levels, TextureFormat format, uint8_t samples, uint32_t w, uint32_t h,
-        uint32_t depth, TextureUsage usage) {}
-
-void WebGPUDriver::createRenderPrimitiveR(Handle<HwRenderPrimitive> rph, Handle<HwVertexBuffer> vbh,
-        Handle<HwIndexBuffer> ibh, PrimitiveType pt) {}
-
-void WebGPUDriver::createProgramR(Handle<HwProgram> ph, Program&& program) {}
-
-void WebGPUDriver::createDefaultRenderTargetR(Handle<HwRenderTarget> rth, int) {}
-
-void WebGPUDriver::createRenderTargetR(Handle<HwRenderTarget> rth, TargetBufferFlags targets,
-        uint32_t width, uint32_t height, uint8_t samples, uint8_t layerCount, MRT color,
-        TargetBufferInfo depth, TargetBufferInfo stencil) {}
-
-void WebGPUDriver::createFenceR(Handle<HwFence> fh, int) {}
-
-void WebGPUDriver::createTimerQueryR(Handle<HwTimerQuery> tqh, int) {}
-
-void WebGPUDriver::createDescriptorSetLayoutR(Handle<HwDescriptorSetLayout> dslh,
-        backend::DescriptorSetLayout&& info) {}
-
-void WebGPUDriver::createDescriptorSetR(Handle<HwDescriptorSet> dsh,
-        Handle<HwDescriptorSetLayout> dslh) {}
-
 Handle<HwStream> WebGPUDriver::createStreamNative(void* nativeStream) {
    return {};
 }
@@ -662,14 +240,6 @@ size_t WebGPUDriver::getMaxUniformBufferSize() {
    return 16384u;
 }

-size_t WebGPUDriver::getMaxTextureSize(SamplerType target) {
-    return 2048u;
-}
-
-size_t WebGPUDriver::getMaxArrayTextureLayers() {
-    return 256u;
-}
-
 void WebGPUDriver::updateIndexBuffer(Handle<HwIndexBuffer> ibh, BufferDescriptor&& p,
        uint32_t byteOffset) {
    scheduleDestroy(std::move(p));
@@ -17,49 +17,26 @@
 #ifndef TNT_FILAMENT_BACKEND_WEBGPUDRIVER_H
 #define TNT_FILAMENT_BACKEND_WEBGPUDRIVER_H

-#include <backend/platforms/WebGPUPlatform.h>
-
-#include "DriverBase.h"
-#include "private/backend/Dispatcher.h"
 #include "private/backend/Driver.h"
-#include "private/backend/HandleAllocator.h"
-#include <backend/DriverEnums.h>
+#include "DriverBase.h"

 #include <utils/compiler.h>

-#include <webgpu/webgpu_cpp.h>
-
-#include <cstdint>
-
-#ifndef FILAMENT_WEBGPU_HANDLE_ARENA_SIZE_IN_MB
-#    define FILAMENT_WEBGPU_HANDLE_ARENA_SIZE_IN_MB 8
-#endif
-
 namespace filament::backend {

-/**
- * WebGPU backend (driver) implementation
- */
 class WebGPUDriver final : public DriverBase {
-public:
+    WebGPUDriver() noexcept;
    ~WebGPUDriver() noexcept override;
+    Dispatcher getDispatcher() const noexcept final;

-    [[nodiscard]] Dispatcher getDispatcher() const noexcept final;
-    [[nodiscard]] static Driver* create(WebGPUPlatform& platform, const Platform::DriverConfig& driverConfig) noexcept;
+public:
+    static Driver* create();

 private:
-    explicit WebGPUDriver(WebGPUPlatform& platform, const Platform::DriverConfig& driverConfig) noexcept;
-    [[nodiscard]] ShaderModel getShaderModel() const noexcept final;
-    [[nodiscard]] ShaderLanguage getShaderLanguage() const noexcept final;
+    ShaderModel getShaderModel() const noexcept final;
+    ShaderLanguage getShaderLanguage() const noexcept final;

-    // the platform (e.g. OS) specific aspects of the WebGPU backend are strictly only
-    // handled in the WebGPUPlatform
-    WebGPUPlatform& mPlatform;
-    wgpu::Surface mSurface = nullptr;
-    wgpu::Adapter mAdapter = nullptr;
-    wgpu::Device mDevice = nullptr;
-    wgpu::Queue mQueue = nullptr;
-    uint64_t mNextFakeHandle = 1;
+    uint64_t nextFakeHandle = 1;

    /*
     * Driver interface
@@ -68,31 +45,20 @@ private:
    template<typename T>
    friend class ConcreteDispatcher;

-#define DECL_DRIVER_API(methodName, paramsDecl, params)                                            \
+#define DECL_DRIVER_API(methodName, paramsDecl, params) \
    UTILS_ALWAYS_INLINE inline void methodName(paramsDecl);

-#define DECL_DRIVER_API_SYNCHRONOUS(RetType, methodName, paramsDecl, params)                       \
+#define DECL_DRIVER_API_SYNCHRONOUS(RetType, methodName, paramsDecl, params) \
    RetType methodName(paramsDecl) override;

-#define DECL_DRIVER_API_RETURN(RetType, methodName, paramsDecl, params)                            \
-    RetType methodName##S() noexcept override;                                                     \
-    UTILS_ALWAYS_INLINE inline void methodName##R(RetType, paramsDecl);
+#define DECL_DRIVER_API_RETURN(RetType, methodName, paramsDecl, params) \
+    RetType methodName##S() noexcept override { \
+        return RetType((RetType::HandleId)nextFakeHandle++); } \
+    UTILS_ALWAYS_INLINE inline void methodName##R(RetType, paramsDecl) { }

 #include "private/backend/DriverAPI.inc"
-
-    /*
-     * Memory management
-     */
-
-    HandleAllocatorWGPU mHandleAllocator;
-
-    template<typename D>
-    Handle<D> allocHandle() {
-        return mHandleAllocator.allocate<D>();
-    }
-
 };

-}// namespace filament::backend
+} // namespace filament

 #endif // TNT_FILAMENT_BACKEND_WEBGPUDRIVER_H
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2025 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "webgpu/WebGPUPlatform.h"
+#include "webgpu/WebGPUDriver.h"
+
+#include "utils/Log.h"
+
+namespace filament::backend {
+
+Driver* WebGPUPlatform::createDriver(void* const sharedContext , const Platform::DriverConfig& driverConfig) noexcept {
+    wgpu::InstanceDescriptor instance_descriptor {};
+    wgpu::Instance instance = wgpu::CreateInstance(&instance_descriptor);
+    if (instance) {
+        utils::slog.i << " WebGPU instance created\n";
+    } else {
+        utils::slog.e << " WebGPU instance failed to create\n";
+        return nullptr;
+    }
+    return WebGPUDriver::create();
+}
+
+} // namespace filament
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2025 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_WEBGPUPLATFORM_H
+#define TNT_FILAMENT_BACKEND_WEBGPUPLATFORM_H
+
+#include <backend/DriverEnums.h>
+#include <backend/Platform.h>
+
+#include "webgpu/webgpu_cpp.h"
+
+namespace filament::backend {
+
+class WebGPUPlatform
+    final : public Platform {
+public:
+
+    int getOSVersion() const noexcept final { return 0; }
+
+    ~WebGPUPlatform() noexcept override = default;
+
+protected:
+
+    Driver* createDriver(void* sharedContext, const Platform::DriverConfig& driverConfig) noexcept override;
+};
+
+} // namespace filament
+
+#endif // TNT_FILAMENT_BACKEND_WEBGPUPLATFORM_H
@@ -1,159 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <backend/platforms/WebGPUPlatform.h>
-
-#include "webgpu/WebGPUConstants.h"
-#include "webgpu/WebGPUDriver.h"
-
-#include <backend/Platform.h>
-#include <utils/Panic.h>
-#include <utils/ostream.h>
-
-#include <dawn/webgpu_cpp_print.h>
-#include <webgpu/webgpu_cpp.h>
-
-#include <cstdint>
-#include <sstream>
-
-/**
- * WebGPU Backend implementation common across platforms or operating systems (at least for now).
- * Some of these functions may likely be refactored to platform/OS-specific implementations
- * over time as needed. The caller of the WebGPUPlatform doesn't need to care which is the case.
- */
-
-namespace filament::backend {
-
-namespace {
-
-//either returns a valid instance or panics
-[[nodiscard]] wgpu::Instance createInstance() {
-    wgpu::DawnTogglesDescriptor dawnTogglesDescriptor{};
-#if defined(FILAMENT_WEBGPU_IMMEDIATE_ERROR_HANDLING)
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-    FWGPU_LOGI << "setting on toggle enable_immediate_error_handling" << utils::io::endl;
-#endif
-    /**
-     * Have the un-captured error callback invoked immediately when an error occurs, rather than
-     * waiting for the next Tick. This enables using the stack trace in which the un-captured error
-     * occurred when breaking into the un-captured error callback.
-     * https://crbug.com/dawn/1789
-     */
-    static const char* toggleName = "enable_immediate_error_handling";
-    dawnTogglesDescriptor.enabledToggleCount = 1;
-    dawnTogglesDescriptor.enabledToggles = &toggleName;
-#endif
-    wgpu::InstanceDescriptor instanceDescriptor{
-        .nextInChain = &dawnTogglesDescriptor,
-        .capabilities = {
-            .timedWaitAnyEnable = true// TODO consider using pure async instead
-        }
-    };
-    wgpu::Instance instance = wgpu::CreateInstance(&instanceDescriptor);
-    FILAMENT_CHECK_POSTCONDITION(instance != nullptr) << "Unable to create webgpu instance.";
-    return instance;
-}
-
-}// namespace
-
-wgpu::Adapter WebGPUPlatform::requestAdapter(wgpu::Surface const& surface) {
-    // TODO consider power preference etc. (can be custom preferences passed to the platform or
-    //                                      based on whether this is a Mobile or Desktop system,
-    //                                      etc...)
-    wgpu::RequestAdapterOptions adaptorOptions{ .compatibleSurface = surface };
-    // note this just gets the first adapter
-    wgpu::Adapter adapter = nullptr;
-    wgpu::WaitStatus status = mInstance.WaitAny(
-            mInstance.RequestAdapter(&adaptorOptions, wgpu::CallbackMode::WaitAnyOnly,
-                    [&adapter](wgpu::RequestAdapterStatus const status,
-                            wgpu::Adapter const& readyAdapter, wgpu::StringView const message) {
-                        // TODO consider more robust error handling
-                        FILAMENT_CHECK_POSTCONDITION(status == wgpu::RequestAdapterStatus::Success)
-                                << "Unable to request a WebGPU adapter. Status "
-                                << static_cast<uint32_t>(status)
-                                << " with message: " << message.data;
-                        adapter = readyAdapter;
-                    }),
-            UINT16_MAX);// TODO define reasonable timeout (or do this asynchronously)
-    FILAMENT_CHECK_POSTCONDITION(status == wgpu::WaitStatus::Success)
-            << "Non-successful wait status requesting a WebGPU adapter "
-            << static_cast<uint32_t>(status);
-    FILAMENT_CHECK_POSTCONDITION(adapter != nullptr)
-            << "Failed to get a WebGPU adapter for the platform";
-    // TODO consider validating adapter has required features and/or limits
-    return adapter;
-}
-
-wgpu::Device WebGPUPlatform::requestDevice(wgpu::Adapter const& adapter) {
-    // TODO consider passing required features and/or limits
-    wgpu::DeviceDescriptor deviceDescriptor{};
-    deviceDescriptor.label = "graphics_device";
-    deviceDescriptor.defaultQueue.label = "default_queue";
-    deviceDescriptor.SetDeviceLostCallback(wgpu::CallbackMode::AllowSpontaneous,
-            [](wgpu::Device const&, wgpu::DeviceLostReason const& reason,
-                    wgpu::StringView message) {
-                if (reason == wgpu::DeviceLostReason::Destroyed) {
-                    FWGPU_LOGD << "WebGPU device lost due to being destroyed (expected)"
-                               << utils::io::endl;
-                    return;
-                }
-                // TODO try recreating the device instead of just panicking
-                std::stringstream reasonStream{};
-                reasonStream << reason;
-                FILAMENT_CHECK_POSTCONDITION(reason != wgpu::DeviceLostReason::Destroyed)
-                        << "WebGPU device lost: " << reasonStream.str() << " " << message.data;
-            });
-    deviceDescriptor.SetUncapturedErrorCallback(
-            [](wgpu::Device const&, wgpu::ErrorType errorType, wgpu::StringView message) {
-                std::stringstream typeStream{};
-                typeStream << errorType;
-                FWGPU_LOGE << "WebGPU device error: " << typeStream.str() << " " << message.data
-                           << utils::io::endl;
-            });
-    wgpu::Device device = nullptr;
-    wgpu::WaitStatus status = mInstance.WaitAny(
-            adapter.RequestDevice(&deviceDescriptor, wgpu::CallbackMode::WaitAnyOnly,
-                    [&device](wgpu::RequestDeviceStatus const status,
-                            wgpu::Device const& readyDevice, wgpu::StringView const message) {
-                        FILAMENT_CHECK_POSTCONDITION(status == wgpu::RequestDeviceStatus::Success)
-                                << "Unable to request a WebGPU device. Status: "
-                                << static_cast<uint32_t>(status)
-                                << " with message: " << message.data;
-                        device = readyDevice;
-                    }),
-            UINT64_MAX);// TODO define reasonable timeout (or do this asynchronously)
-    FILAMENT_CHECK_POSTCONDITION(status == wgpu::WaitStatus::Success)
-            << "Non-successful wait status requesting a WebGPU device "
-            << static_cast<uint32_t>(status);
-    FILAMENT_CHECK_POSTCONDITION(device != nullptr)
-            << "Failed to get a WebGPU device for the platform.";
-    return device;
-}
-
-Driver* WebGPUPlatform::createDriver(void* sharedContext,
-        const Platform::DriverConfig& driverConfig) noexcept {
-    if (sharedContext) {
-        FWGPU_LOGW << "sharedContext is ignored/unused in the WebGPU backend. A non-null "
-                      "sharedContext was provided, but it will be ignored."
-                   << utils::io::endl;
-    }
-    return WebGPUDriver::create(*this, driverConfig);
-}
-
-WebGPUPlatform::WebGPUPlatform()
-    : mInstance(createInstance()) {}
-
-}// namespace filament::backend
@@ -1,43 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <backend/platforms/WebGPUPlatform.h>
-
-#include <utils/Panic.h>
-
-#include <webgpu/webgpu_cpp.h>
-
-#include <cstdint>
-
-/**
- * Android OS specific implementation aspects of the WebGPU backend
- */
-
-namespace filament::backend {
-
-wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t /*flags*/) {
-    wgpu::SurfaceSourceAndroidNativeWindow surfaceSourceAndroidWindow{};
-    surfaceSourceAndroidWindow.window = nativeWindow;
-    wgpu::SurfaceDescriptor surfaceDescriptor{
-        .nextInChain = &surfaceSourceAndroidWindow,
-        .label = "android_surface"
-    };
-    wgpu::Surface surface = mInstance.CreateSurface(&surfaceDescriptor);
-    FILAMENT_CHECK_POSTCONDITION(surface != nullptr) << "Unable to create Android-backed surface.";
-    return surface;
-}
-
-}// namespace filament::backend
@@ -1,81 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <backend/platforms/WebGPUPlatform.h>
-
-#include <utils/Panic.h>
-#include <utils/ostream.h>
-
-#include <webgpu/webgpu_cpp.h>
-
-#include <cstdint>
-
-// Platform specific includes and defines
-#if defined(__APPLE__)
-    #include <Cocoa/Cocoa.h>
-    #import <QuartzCore/CAMetalLayer.h>
-#elif defined(FILAMENT_IOS)
-    // Metal is not available when building for the iOS simulator on Desktop.
-    #define METAL_AVAILABLE __has_include(<QuartzCore/CAMetalLayer.h>)
-    #if METAL_AVAILABLE
-        #import <Metal/Metal.h>
-        #import <QuartzCore/CAMetalLayer.h>
-    #endif
-    // is this needed?
-    #define METALVIEW_TAG 255
-#else
-    #error Not a supported Apple + WebGPU platform
-#endif
-
-/**
- * Apple (Mac OS and IOS) specific implementation aspects of the WebGPU backend
- */
-
-namespace filament::backend {
-
-wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t /*flags*/) {
-    wgpu::Surface surface = nullptr;
-#if defined(__APPLE__)
-    auto nsView = (__bridge NSView*) nativeWindow;
-    FILAMENT_CHECK_POSTCONDITION(nsView) << "Unable to obtain Metal-backed NSView.";
-    [nsView setWantsLayer:YES];
-    id metalLayer = [CAMetalLayer layer];
-    [nsView setLayer:metalLayer];
-    wgpu::SurfaceSourceMetalLayer surfaceSourceMetalLayer{};
-    surfaceSourceMetalLayer.layer = (__bridge void*) metalLayer;
-    wgpu::SurfaceDescriptor surfaceDescriptor = {
-        .nextInChain = &surfaceSourceMetalLayer,
-        .label = "metal_surface",
-    };
-    surface = mInstance.CreateSurface(&surfaceDescriptor);
-    FILAMENT_CHECK_POSTCONDITION(surface != nullptr) << "Unable to create Metal-backed surface.";
-#elif defined(FILAMENT_IOS)
-    CAMetalLayer* metalLayer = (CAMetalLayer*) nativeWindow;
-    wgpu::SurfaceSourceMetalLayer surfaceSourceMetalLayer{};
-    surfaceSourceMetalLayer.layer = (__bridge void*) metalLayer;
-    wgpu::SurfaceDescriptor surfaceDescriptor = {
-        .nextInChain = &surfaceSourceMetalLayer,
-        .label = "metal_surface",
-    };
-    surface = mInstance.CreateSurface(&surfaceDescriptor);
-    FILAMENT_CHECK_POSTCONDITION(surface != nullptr) << "Unable to create Metal-backed surface.";
-#else
-    #error Not a supported Apple + WebGPU platform
-#endif
-    return surface;
-}
-
-}// namespace filament::backend
@@ -1,163 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-#include <backend/platforms/WebGPUPlatform.h>
-
-#include <backend/DriverEnums.h>
-
-#include <utils/Panic.h>
-
-#include <webgpu/webgpu_cpp.h>
-
-#include <cstddef>
-#include <cstdint>
-
-#if defined(__linux__) || defined(__FreeBSD__)
-    #define LINUX_OR_FREEBSD 1
-#endif
-
-// Platform specific includes and defines
-#if defined(__linux__) && defined(FILAMENT_SUPPORTS_WAYLAND)
-    #include <dlfcn.h>
-    namespace {
-    typedef struct _wl {
-        struct wl_display* display;
-        struct wl_surface* surface;
-        uint32_t width;
-        uint32_t height;
-    } wl;
-    }// namespace
-#elif defined(LINUX_OR_FREEBSD) && defined(FILAMENT_SUPPORTS_X11)
-    // TODO: we should allow for headless on Linux explicitly. Right now this is the headless path
-    // (with no FILAMENT_SUPPORTS_XCB or FILAMENT_SUPPORTS_XLIB).
-    #include <dlfcn.h>
-    #if defined(FILAMENT_SUPPORTS_XCB)
-        #include <xcb/xcb.h>
-        namespace {
-        typedef xcb_connection_t* (*XCB_CONNECT)(const char* displayname, int* screenp);
-        }// namespace
-    #endif
-    #if defined(FILAMENT_SUPPORTS_XLIB)
-        #include <X11/Xlib.h>
-        namespace {
-        typedef Display* (*X11_OPEN_DISPLAY)(const char*);
-        }// namespace
-    #endif
-    static constexpr const char* LIBRARY_X11 = "libX11.so.6";
-    namespace {
-    struct XEnv {
-    #if defined(FILAMENT_SUPPORTS_XCB)
-        XCB_CONNECT xcbConnect;
-        xcb_connection_t* connection;
-    #endif
-    #if defined(FILAMENT_SUPPORTS_XLIB)
-        X11_OPEN_DISPLAY openDisplay;
-        Display* display;
-    #endif
-        void* library = nullptr;
-    } g_x11;
-    }// namespace
-#else
-    #error Not a supported Linux or FeeBSD + WebGPU platform
-#endif
-
-/**
- * Linux OS specific implementation aspects of the WebGPU Backend
- */
-
-namespace filament::backend {
-
-wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t flags) {
-    wgpu::Surface surface = nullptr;
-#if defined(__linux__) && defined(FILAMENT_SUPPORTS_WAYLAND)
-    wl* ptrval = reinterpret_cast<wl*>(nativeWindow);
-    wgpu::SurfaceSourceWaylandSurface surfaceSourceWayland{};
-    surfaceSourceWayland.display = ptrval->display;
-    surfaceSourceWayland.surface = ptrval->surface;
-    wgpu::SurfaceDescriptor surfaceDescriptor{
-        .nextInChain = &surfaceSourceWayland,
-        .label = "linux_wayland_surface"
-    };
-    surface = mInstance.CreateSurface(&surfaceDescriptor);
-    FILAMENT_CHECK_POSTCONDITION(surface != nullptr)
-            << "Unable to create Linux Wayland-backed surface.";
-#elif defined(LINUX_OR_FREEBSD) && defined(FILAMENT_SUPPORTS_X11)
-    if (g_x11.library == nullptr) {
-        g_x11.library = dlopen(LIBRARY_X11, RTLD_LOCAL | RTLD_NOW);
-        FILAMENT_CHECK_PRECONDITION(g_x11.library) << "Unable to open X11 library.";
-        #if defined(FILAMENT_SUPPORTS_XCB)
-            g_x11.xcbConnect = (XCB_CONNECT) dlsym(g_x11.library, "xcb_connect");
-            int screen = 0;
-            g_x11.connection = g_x11.xcbConnect(nullptr, &screen);
-        #endif
-        #if defined(FILAMENT_SUPPORTS_XLIB)
-            g_x11.openDisplay = (X11_OPEN_DISPLAY) dlsym(g_x11.library, "XOpenDisplay");
-            g_x11.display = g_x11.openDisplay(NULL);
-            FILAMENT_CHECK_PRECONDITION(g_x11.display) << "Unable to open X11 display.";
-        #endif
-    }
-    #if defined(FILAMENT_SUPPORTS_XCB) || defined(FILAMENT_SUPPORTS_XLIB)
-        bool useXcb = false;
-    #endif
-    #if defined(FILAMENT_SUPPORTS_XCB)
-        #if defined(FILAMENT_SUPPORTS_XLIB)
-            useXcb = (flags & SWAP_CHAIN_CONFIG_ENABLE_XCB) != 0;
-        #else
-            useXcb = true;
-        #endif
-        if (useXcb) {
-            wgpu::SurfaceSourceXCBWindow surfaceSourceXcb{};
-            surfaceSourceXcb.connection = g_x11.connection;
-
-            // TODO: this looks really wrong, please fix!!
-            surfaceSourceXcb.window = *((uint32_t*) nativeWindow);
-            wgpu::SurfaceDescriptor surfaceDescriptor{
-                .nextInChain = &surfaceSourceXcb,
-                .label = "linux_xcb_surface"
-            };
-            surface = mInstance.CreateSurface(&surfaceDescriptor);
-            FILAMENT_CHECK_POSTCONDITION(surface != nullptr)
-                    << "Unable to create Linux (or FreeBSD) XCB-backed surface.";
-        }
-    #endif
-    #if defined(FILAMENT_SUPPORTS_XLIB)
-        if (!useXcb) {
-            wgpu::SurfaceSourceXlibWindow surfaceSourceXlib{};
-            surfaceSourceXlib.display = g_x11.display;
-            surfaceSourceXlib.window = reinterpret_cast<uint64_t>(nativeWindow);
-            wgpu::SurfaceDescriptor surfaceDescriptor{
-                .nextInChain = &surfaceSourceXlib,
-                .label = "linux_xlib_surface"
-            };
-            surface = mInstance.CreateSurface(&surfaceDescriptor);
-            FILAMENT_CHECK_POSTCONDITION(surface != nullptr)
-                    << "Unable to create Linux (or FreeBSD) XLib-backed surface.";
-        }
-    #endif
-    FILAMENT_CHECK_POSTCONDITION(surface != nullptr)
-            << "Cannot create WebGPU X11 surface for Linux (or FreeBSD) OS "
-               "(not built with support for XCB or XLIB?)";
-#elif defined(__linux__)
-    FILAMENT_CHECK_POSTCONDITION(surface != nullptr)
-            << "Cannot create WebGPU surface for Linux (or FreeBSD) OS "
-               "(not built with support for Wayland or X11?)";
-#else
-    FILAMENT_CHECK_POSTCONDITION(surface != nullptr)
-            << "Not a supported (Linux) OS + WebGPU platform";
-#endif
-    return surface;
-}
-
-}// namespace filament::backend
@@ -1,53 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <backend/platforms/WebGPUPlatform.h>
-
-#include <utils/Panic.h>
-
-#include <webgpu/webgpu_cpp.h>
-
-#include <cstdint>
-
-/**
- * Windows OS specific implementation aspects of the WebGPU backend
- */
-
-namespace filament::backend {
-
-wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t /*flags*/) {
-    // TODO verify this is necessary for Dawn implementation as well:
-    // On (at least) NVIDIA drivers, the Vulkan implementation (specifically the call to
-    // vkGetPhysicalDeviceSurfaceCapabilitiesKHR()) does not correctly handle the fact that
-    // each native window has its own DPI_AWARENESS_CONTEXT, and erroneously uses the context
-    // of the calling thread. As a workaround, we set the current thread's DPI_AWARENESS_CONTEXT
-    // to that of the native window we've been given. This isn't a perfect solution, because an
-    // application could create swap chains on multiple native windows with varying DPI-awareness,
-    // but even then, at least one of the windows would be guaranteed to work correctly.
-    SetThreadDpiAwarenessContext(GetWindowDpiAwarenessContext((HWND) nativeWindow));
-    wgpu::SurfaceSourceWindowsHWND surfaceSourceWin{};
-    surfaceSourceWin.hinstance = GetModuleHandle(nullptr);
-    surfaceSourceWin.hwnd = nativeWindow;
-    wgpu::SurfaceDescriptor surfaceDescriptor{
-        .nextInChain = &surfaceSourceWin,
-        .label = "windows_surface"
-    };
-    wgpu::Surface surface = mInstance.CreateSurface(&surfaceDescriptor);
-    FILAMENT_CHECK_POSTCONDITION(surface != nullptr) << "Unable to create Windows-backed surface.";
-    return surface;
-}
-
-}// namespace filament::backend
@@ -1,172 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "ImageExpectations.h"
-
-#include "gtest/gtest.h"
-#include "gmock/gmock.h"
-#include "absl/strings/str_format.h"
-#include "utils/Hash.h"
-#include <fstream>
-
-#include "backend/PixelBufferDescriptor.h"
-#include "private/backend/DriverApi.h"
-
-#ifndef FILAMENT_IOS
-
-#include <imageio/ImageEncoder.h>
-#include <image/ColorTransform.h>
-
-#endif
-
-ScreenshotParams::ScreenshotParams(int width, int height, std::string fileName,
-        uint32_t expectedPixelHash)
-        : mWidth(width), mHeight(height), mFileName(std::move(fileName)),
-          mExpectedPixelHash(expectedPixelHash) {}
-
-int ScreenshotParams::width() const {
-    return mWidth;
-}
-
-int ScreenshotParams::height() const {
-    return mHeight;
-}
-
-uint32_t ScreenshotParams::expectedHash() const {
-    return mExpectedPixelHash;
-}
-
-std::string ScreenshotParams::outputDirectoryPath() const {
-    return ".";
-}
-
-std::string ScreenshotParams::generatedActualFileName() const {
-    return absl::StrFormat("%s_actual.png", mFileName);
-}
-
-std::string ScreenshotParams::generatedActualFilePath() const {
-    return absl::StrFormat("%s/%s", outputDirectoryPath(), generatedActualFileName());
-}
-
-std::string ScreenshotParams::goldenFileName() const {
-    return absl::StrFormat("%s_golden.png", mFileName);
-}
-
-std::string ScreenshotParams::goldenFilePath() const {
-    return absl::StrFormat("%s/%s", outputDirectoryPath(), goldenFileName());
-}
-
-ImageExpectation::ImageExpectation(const char* fileName, int lineNumber,
-        filament::backend::DriverApi& api, ScreenshotParams params,
-        filament::backend::RenderTargetHandle renderTarget)
-        : mFileName(fileName), mLineNumber(lineNumber), mParams(std::move(params)),
-          mResult(api, renderTarget, mParams) {}
-
-void ImageExpectation::evaluate() {
-    // Ensure this is only evaluated once.
-    if (mEvaluated) {
-        return;
-    }
-    mEvaluated = true;
-
-    // Do the actual image comparison inside a scoped trace with the stored file and line.
-    {
-        testing::ScopedTrace trace(mFileName, mLineNumber, "");
-        compareImage();
-    }
-}
-
-void ImageExpectation::compareImage() const {
-    bool bytesFilled = mResult.bytesFilled();
-    EXPECT_THAT(bytesFilled, testing::IsTrue())
-                        << "Render target wasn't copied to the buffer for " << mFileName;
-    if (bytesFilled) {
-        uint32_t actualHash = mResult.hash();
-        EXPECT_THAT(actualHash, testing::Eq(mParams.expectedHash()));
-    }
-}
-
-ImageExpectations::ImageExpectations(filament::backend::DriverApi& api) : mApi(api) {}
-
-ImageExpectations::~ImageExpectations() {
-    // Guarantee that all expectations are evaluated when this leaves scope even if the caller
-    // forgot to manually evaluate them.
-    evaluate();
-}
-
-void ImageExpectations::addExpectation(const char* fileName, int lineNumber,
-        filament::backend::RenderTargetHandle renderTarget, ScreenshotParams params) {
-    mExpectations.emplace_back(fileName, lineNumber, mApi, std::move(params), renderTarget);
-}
-
-void ImageExpectations::evaluate() {
-    for (auto& expectation: mExpectations) {
-        expectation.evaluate();
-    }
-    mExpectations.clear();
-}
-
-RenderTargetDump::RenderTargetDump(filament::backend::DriverApi& api,
-        filament::backend::RenderTargetHandle renderTarget, const ScreenshotParams& params)
-        : mInternal(std::make_unique<RenderTargetDump::Internal>(params)) {
-#ifdef FILAMENT_IOS
-    bytesFilled_ = true;
-    bytes_.resize(size);
-    std::fill(bytes_.begin(), bytes_.end(), 0);
-#else
-    const size_t size = mInternal->params.width() * mInternal->params.height() * 4;
-    mInternal->bytes.resize(size);
-
-    auto cb = [](void* buffer, size_t size, void* user) {
-        auto* internal = static_cast<RenderTargetDump::Internal*>(user);
-        image::LinearImage image(internal->params.width(), internal->params.width(), 4);
-        image = image::toLinearWithAlpha<uint8_t>(internal->params.width(),
-                internal->params.height(),
-                internal->params.width() * 4, (uint8_t*)buffer);
-        std::string filePath = internal->params.generatedActualFilePath();
-        std::ofstream pngStream(filePath, std::ios::binary | std::ios::trunc);
-        image::ImageEncoder::encode(pngStream, image::ImageEncoder::Format::PNG, image, "",
-                filePath);
-        internal->bytesFilled = true;
-    };
-    filament::backend::PixelBufferDescriptor pb(mInternal->bytes.data(), size,
-            filament::backend::PixelDataFormat::RGBA, filament::backend::PixelDataType::UBYTE, cb,
-            (void*)mInternal.get());
-    api.readPixels(renderTarget, 0, 0, mInternal->params.width(), mInternal->params.height(),
-            std::move(pb));
-#endif
-}
-
-RenderTargetDump::~RenderTargetDump() {
-    // If the GPU callback hasn't been made yet then there's a callback elsewhere that has a copy of
-    // the internal pointer. But there's no guarantee that the callback will be ever made if the GPU
-    // pipeline wasn't run for some reason. So it is necessary to leak the memory.
-    // It would be possible to try to coordinate with the callback to have it clean up the memory,
-    // but if this condition happens there's already an issue with the test case so there's no need.
-    if (!bytesFilled()) {
-        mInternal.release();
-    }
-}
-
-uint32_t RenderTargetDump::hash() const {
-    return utils::hash::murmur3((uint32_t*)mInternal->bytes.data(), mInternal->bytes.size() / 4, 0);
-}
-
-bool RenderTargetDump::bytesFilled() const {
-    return mInternal->bytesFilled;
-}
-
-RenderTargetDump::Internal::Internal(const ScreenshotParams& params) : params(params) {}
@@ -1,136 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef TNT_IMAGE_EXPECTATIONS_H
-#define TNT_IMAGE_EXPECTATIONS_H
-
-#include <vector>
-
-#include "gtest/gtest.h"
-
-#include "backend/Handle.h"
-#include "backend/DriverApiForward.h"
-
-// Arguments are (RenderTargetHandle renderTarget, ImageExpectations& expectations,
-// ScreenshotParams screenshotParams)
-#define EXPECT_IMAGE(renderTarget, expectations, screenshotParams)  \
-do {                                                                \
-    expectations.addExpectation(                                    \
-        __FILE__,                                                   \
-        __LINE__,                                                   \
-        renderTarget,                                               \
-        screenshotParams);                                          \
-} while (0)
-
-/**
- * Stores user-provided configuration values for an image expectation
- */
-class ScreenshotParams {
-public:
-    ScreenshotParams(int width, int height, std::string fileName, uint32_t expectedPixelHash);
-
-    int width() const;
-    int height() const;
-    uint32_t expectedHash() const;
-
-    std::string outputDirectoryPath() const;
-    std::string generatedActualFileName() const;
-    std::string generatedActualFilePath() const;
-    std::string goldenFileName() const;
-    std::string goldenFilePath() const;
-
-private:
-    int mWidth;
-    int mHeight;
-    uint32_t mExpectedPixelHash;
-    std::string mFileName;
-};
-
-/**
- * When created adds a command to the GPU pipeline to copy the render target into a buffer and
- * stores the result.
- * If this object is destroyed before the GPU pipeline is flushed it will leak memory in order to
- * avoid the GPU pipeline callback being a use-after-free.
- */
-class RenderTargetDump {
-public:
-    RenderTargetDump(filament::backend::DriverApi& api,
-            filament::backend::RenderTargetHandle renderTarget, const ScreenshotParams& params);
-    RenderTargetDump(RenderTargetDump&& other) = default;
-    RenderTargetDump& operator=(RenderTargetDump&& other) = default;
-    ~RenderTargetDump();
-
-    /**
-     * Should only bue used if BytesFilled returns true.
-     * @return The hash of the stored bytes.
-     */
-    uint32_t hash() const;
-    /**
-     * Thread safe as this is backed by an atomic.
-     * Once this returns true it will never return false.
-     * @return Whether the bytes have actually been copied from the GPU to the buffer.
-     */
-    bool bytesFilled() const;
-
-private:
-    struct Internal {
-        explicit Internal(const ScreenshotParams& params);
-        ScreenshotParams params;
-        std::atomic<bool> bytesFilled = false;
-        std::vector<unsigned char> bytes;
-    };
-
-    // We need a memory location that won't be invalidated to pass to GPU callbacks as they can't
-    // be canceled during the destructor.
-    std::unique_ptr<Internal> mInternal;
-};
-
-class ImageExpectation {
-public:
-    ImageExpectation(const char* fileName, int lineNumber, filament::backend::DriverApi& api,
-            ScreenshotParams params, filament::backend::RenderTargetHandle renderTarget);
-
-    void evaluate();
-
-private:
-    void compareImage() const;
-
-    bool mEvaluated = false;
-    const char* mFileName;
-    int mLineNumber;
-    ScreenshotParams mParams;
-    RenderTargetDump mResult;
-};
-
-class ImageExpectations {
-public:
-    explicit ImageExpectations(filament::backend::DriverApi& api);
-    ~ImageExpectations();
-
-    /**
-     * Not meant to be called directly, use EXPECT_IMAGE to get the file name and line number
-     */
-    void addExpectation(const char* fileName, int lineNumber,
-            filament::backend::RenderTargetHandle renderTarget, ScreenshotParams params);
-
-    void evaluate();
-
-private:
-    filament::backend::DriverApi& mApi;
-    std::vector<ImageExpectation> mExpectations;
-};
-
-#endif //TNT_IMAGE_EXPECTATIONS_H
@@ -1,64 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "Shader.h"
-
-#include "BackendTest.h"
-#include "ShaderGenerator.h"
-
-namespace test {
-
-using namespace filament::backend;
-
-Shader::Shader(DriverApi& api, Cleanup& cleanup, ShaderConfig config) {
-    utils::FixedCapacityVector<DescriptorSetLayoutBinding> kLayouts(config.uniformNames.size());
-    for (unsigned char i = 0; i < config.uniformNames.size(); ++i) {
-        kLayouts[i] =
-                { DescriptorType::UNIFORM_BUFFER, ShaderStageFlags::ALL_SHADER_STAGE_FLAGS, i };
-    };
-
-    filamat::DescriptorSets descriptors;
-    for (unsigned char i = 0; i < config.uniformNames.size(); ++i) {
-        descriptors[i + 1] = {{ config.uniformNames[i], kLayouts[i], {}}};
-    }
-    ShaderGenerator shaderGen(
-            std::move(config.vertexShader), std::move(config.fragmentShader), BackendTest::sBackend,
-            BackendTest::sIsMobilePlatform, std::move(descriptors));
-    Program prog = shaderGen.getProgram(api);
-    for (unsigned char i = 0; i < config.uniformNames.size(); ++i) {
-        prog.descriptorBindings(1, {{ config.uniformNames[i], DescriptorType::UNIFORM_BUFFER, i }});
-    }
-    mProgram = cleanup.add(api.createProgram(std::move(prog)));
-
-    mDescriptorSetLayout = cleanup.add(
-            api.createDescriptorSetLayout(DescriptorSetLayout{ kLayouts }));
-
-    mDescriptorSet = cleanup.add(api.createDescriptorSet(mDescriptorSetLayout));
-}
-
-filament::backend::ProgramHandle Shader::getProgram() const {
-    return mProgram;
-}
-
-filament::backend::DescriptorSetLayoutHandle Shader::getDescriptorSetLayout() const {
-    return mDescriptorSetLayout;
-}
-
-filament::backend::DescriptorSetHandle Shader::getDescriptorSet() const {
-    return mDescriptorSet;
-}
-
-} // namespace test
@@ -1,143 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef TNT_SHADER_H
-#define TNT_SHADER_H
-
-#include "Lifetimes.h"
-
-namespace test {
-
-// All describing a shader that should be created.
-struct ShaderConfig {
-    std::string vertexShader;
-    std::string fragmentShader;
-    std::vector<utils::CString> uniformNames;
-};
-
-// All values describing a uniform.
-struct ResolvedUniformBindingConfig {
-    size_t dataSize;
-    size_t bufferSize;
-    uint32_t byteOffset;
-    filament::backend::descriptor_set_t set;
-    filament::backend::descriptor_binding_t binding;
-};
-
-// An equivalent to ResolvedUniformBindingConfig with all fields optional.
-// resolve can be called to create a ResolvedBindingConfig with default values
-// use in place of nullopt values.
-struct UniformBindingConfig {
-    std::optional<size_t> dataSize;
-    std::optional<size_t> bufferSize;
-    std::optional<uint32_t> byteOffset;
-    std::optional<filament::backend::descriptor_set_t> set;
-    std::optional<filament::backend::descriptor_binding_t> binding;
-
-    template<typename UniformType>
-    ResolvedUniformBindingConfig resolve();
-};
-
-class Shader {
-public:
-    // All graphics resources have their lifetime controlled by the Cleanup and not this object.
-    // Shader must not outlive either the DriverApi or the Cleanup.
-    Shader(filament::backend::DriverApi& api, Cleanup& cleanup, ShaderConfig config);
-
-    // Uploads a uniform with the default config.
-    template<typename UniformType>
-    void uploadUniform(filament::backend::DriverApi& api,
-            filament::backend::Handle<filament::backend::HwBufferObject> hwBuffer,
-            UniformType uniforms) const;
-    // Binds a uniform with the default config.
-    template<typename UniformType>
-    void bindUniform(filament::backend::DriverApi& api,
-            filament::backend::Handle<filament::backend::HwBufferObject> hwBuffer) const;
-    // Uploads a uniform, with UniformBindingConfig providing the arguments.
-    template<typename UniformType>
-    void uploadUniform(filament::backend::DriverApi& api,
-            filament::backend::Handle<filament::backend::HwBufferObject> hwBuffer,
-            UniformBindingConfig config, UniformType uniforms) const;
-    // Binds a uniform, with UniformBindingConfig providing the arguments.
-    template<typename UniformType>
-    void bindUniform(filament::backend::DriverApi& api,
-            filament::backend::Handle<filament::backend::HwBufferObject> hwBuffer,
-            UniformBindingConfig config) const;
-
-    filament::backend::ProgramHandle getProgram() const;
-    filament::backend::DescriptorSetLayoutHandle getDescriptorSetLayout() const;
-    filament::backend::DescriptorSetHandle getDescriptorSet() const;
-
-protected:
-    filament::backend::ProgramHandle mProgram;
-    filament::backend::DescriptorSetLayoutHandle mDescriptorSetLayout;
-    filament::backend::DescriptorSetHandle mDescriptorSet;
-};
-
-template<typename UniformType>
-ResolvedUniformBindingConfig UniformBindingConfig::resolve() {
-    auto resolvedDataSize = dataSize.value_or(sizeof(UniformType));
-    return ResolvedUniformBindingConfig{
-            .dataSize = resolvedDataSize,
-            .bufferSize = bufferSize.value_or(resolvedDataSize),
-            .byteOffset = byteOffset.value_or(0),
-            .set = set.value_or(1),
-            .binding = binding.value_or(0)
-    };
-}
-
-template<typename UniformType>
-void Shader::uploadUniform(filament::backend::DriverApi& api,
-        filament::backend::Handle<filament::backend::HwBufferObject> hwBuffer,
-        UniformBindingConfig config, UniformType uniforms) const {
-    auto resolvedConfig = config.resolve<UniformType>();
-
-    UniformType* tmp = new UniformType(uniforms);
-    auto cb = [](void* buffer, size_t size, void* user) {
-        UniformType* sp = (UniformType*)buffer;
-        delete sp;
-    };
-    filament::backend::BufferDescriptor bd(tmp, resolvedConfig.dataSize, cb);
-    api.updateBufferObject(hwBuffer, std::move(bd), resolvedConfig.byteOffset);
-}
-
-template<typename UniformType>
-void Shader::bindUniform(filament::backend::DriverApi& api,
-        filament::backend::Handle<filament::backend::HwBufferObject> hwBuffer,
-        UniformBindingConfig config) const {
-    auto resolvedConfig = config.resolve<UniformType>();
-
-    api.updateDescriptorSetBuffer(getDescriptorSet(), resolvedConfig.binding, hwBuffer, 0,
-            resolvedConfig.bufferSize);
-    api.bindDescriptorSet(getDescriptorSet(), resolvedConfig.set, {});
-}
-
-template<typename UniformType>
-void Shader::uploadUniform(filament::backend::DriverApi& api,
-        filament::backend::Handle<filament::backend::HwBufferObject> hwBuffer,
-        UniformType uniforms) const {
-    uploadUniform(api, hwBuffer, UniformBindingConfig{}, uniforms);
-}
-
-template<typename UniformType>
-void Shader::bindUniform(filament::backend::DriverApi& api,
-        filament::backend::Handle<filament::backend::HwBufferObject> hwBuffer) const {
-    bindUniform<UniformType>(api, hwBuffer, UniformBindingConfig{});
-}
-
-} // namespace test
-
-#endif //TNT_SHADER_H
@@ -16,9 +16,8 @@

 #include "BackendTest.h"

-#include "ImageExpectations.h"
 #include "Lifetimes.h"
-#include "Shader.h"
+#include "ShaderGenerator.h"
 #include "TrianglePrimitive.h"

 #include <utils/Hash.h>
@@ -27,10 +26,8 @@
 #include <fstream>

 #ifndef FILAMENT_IOS
-
 #include <imageio/ImageEncoder.h>
 #include <image/ColorTransform.h>
-
 #endif

 namespace test {
@@ -40,21 +37,6 @@ using namespace filament::backend;
 using namespace filament::math;
 using namespace utils;

-struct MaterialParams {
-    float4 color;
-    float4 scale;
-};
-
-class BlitTest : public BackendTest {
-public:
-    BlitTest() : mCleanup(getDriverApi()) {}
-
-protected:
-    Shader createShader();
-
-    Cleanup mCleanup;
-};
-
 static const char* const triangleVs = R"(#version 450 core
 layout(location = 0) in vec4 mesh_position;
 layout(binding = 0, set = 1) uniform Params { highp vec4 color; highp vec4 scale; } params;
@@ -74,12 +56,49 @@ void main() {
    fragColor = params.color;
 })";

-Shader BlitTest::createShader() {
-    return Shader(getDriverApi(), mCleanup, ShaderConfig{
-            .vertexShader = triangleVs,
-            .fragmentShader = triangleFs,
-            .uniformNames = { "Params" },
-    });
+struct MaterialParams {
+    float4 color;
+    float4 scale;
+};
+
+struct ScreenshotParams {
+    int width;
+    int height;
+    const char* filename;
+    uint32_t pixelHashResult;
+};
+
+#ifdef FILAMENT_IOS
+static void dumpScreenshot(DriverApi& dapi, Handle<HwRenderTarget> rt, ScreenshotParams* params) {}
+#else
+static void dumpScreenshot(DriverApi& dapi, Handle<HwRenderTarget> rt, ScreenshotParams* params) {
+    using namespace image;
+    const size_t size = params->width * params->height * 4;
+    void* buffer = calloc(1, size);
+    auto cb = [](void* buffer, size_t size, void* user) {
+        ScreenshotParams* params = (ScreenshotParams*) user;
+        int w = params->width, h = params->height;
+        const uint32_t* texels = (uint32_t*) buffer;
+        params->pixelHashResult = utils::hash::murmur3(texels, size / 4, 0);
+        LinearImage image(w, h, 4);
+        image = toLinearWithAlpha<uint8_t>(w, h, w * 4, (uint8_t*) buffer);
+        std::ofstream pngstrm(params->filename, std::ios::binary | std::ios::trunc);
+        ImageEncoder::encode(pngstrm, ImageEncoder::Format::PNG, image, "", params->filename);
+    };
+    PixelBufferDescriptor pb(buffer, size, PixelDataFormat::RGBA, PixelDataType::UBYTE, cb,
+            (void*) params);
+    dapi.readPixels(rt, 0, 0, params->width, params->height, std::move(pb));
+}
+#endif
+
+static void uploadUniforms(DriverApi& dapi, Handle<HwBufferObject> ubh, MaterialParams params) {
+    MaterialParams* tmp = new MaterialParams(params);
+    auto cb = [](void* buffer, size_t size, void* user) {
+        MaterialParams* sp = (MaterialParams*) buffer;
+        delete sp;
+    };
+    BufferDescriptor bd(tmp, sizeof(MaterialParams), cb);
+    dapi.updateBufferObject(ubh, std::move(bd), 0);
 }

 static uint32_t toUintColor(float4 color) {
@@ -97,7 +116,7 @@ static void createBitmap(DriverApi& dapi, Handle<HwTexture> texture, int baseWid
    const int width = baseWidth >> level;
    const int height = baseHeight >> level;
    const size_t size0 = height * width * 4;
-    uint8_t* buffer0 = (uint8_t*)calloc(size0, 1);
+    uint8_t* buffer0 = (uint8_t*) calloc(size0, 1);
    PixelBufferDescriptor pb(buffer0, size0, PixelDataFormat::RGBA, PixelDataType::UBYTE, cb);

    const float3 foreground = color;
@@ -121,7 +140,7 @@ static void createBitmap(DriverApi& dapi, Handle<HwTexture> texture, int baseWid
    // |   ........
    // low addresses
    // This is because OpenGL automatically flips image data when uploading into the texture.
-    uint32_t* texels = (uint32_t*)buffer0;
+    uint32_t* texels = (uint32_t*) buffer0;
    for (int row = 0; row < height; row++) {
        for (int col = 0; col < width; col++) {
            float2 uv = { (col - width / 2.0f) / width, (row - height / 2.0f) / height };
@@ -149,7 +168,7 @@ static void createFaces(DriverApi& dapi, Handle<HwTexture> texture, int baseWidt
    const int width = baseWidth >> level;
    const int height = baseHeight >> level;
    const size_t size0 = height * width * 4 * 6;
-    uint8_t* buffer0 = (uint8_t*)calloc(size0, 1);
+    uint8_t* buffer0 = (uint8_t*) calloc(size0, 1);
    PixelBufferDescriptor pb(buffer0, size0, PixelDataFormat::RGBA, PixelDataType::UBYTE, cb);

    const float3 foreground = color;
@@ -157,7 +176,7 @@ static void createFaces(DriverApi& dapi, Handle<HwTexture> texture, int baseWidt
    const float radius = 0.25f;

    // Draw a circle on a yellow background.
-    uint32_t* texels = (uint32_t*)buffer0;
+    uint32_t* texels = (uint32_t*) buffer0;
    for (int face = 0; face < 6; face++) {
        for (int row = 0; row < height; row++) {
            for (int col = 0; col < width; col++) {
@@ -175,9 +194,10 @@ static void createFaces(DriverApi& dapi, Handle<HwTexture> texture, int baseWidt
    dapi.update3DImage(texture, level, 0, 0, 0, width, height, 6, std::move(pb));
 }

-TEST_F(BlitTest, ColorMagnify) {
+TEST_F(BackendTest, ColorMagnify) {
    auto& api = getDriverApi();
-    mCleanup.addPostCall([&]() { executeCommands(); });
+    Cleanup cleanup(getDriverApi());
+    cleanup.addPostCall([&]() { executeCommands(); });

    constexpr int kSrcTexWidth = 256;
    constexpr int kSrcTexHeight = 256;
@@ -188,40 +208,37 @@ TEST_F(BlitTest, ColorMagnify) {
    constexpr int kNumLevels = 3;

    // Create a SwapChain and make it current. We don't really use it so the res doesn't matter.
-    auto swapChain = mCleanup.add(api.createSwapChainHeadless(256, 256, 0));
+    auto swapChain = cleanup.add(api.createSwapChainHeadless(256, 256, 0));
    api.makeCurrent(swapChain, swapChain);

    // Create a source texture.
-    Handle<HwTexture> const srcTexture = mCleanup.add(api.createTexture(
-            SamplerType::SAMPLER_2D, kNumLevels, kSrcTexFormat, 1, kSrcTexWidth, kSrcTexHeight, 1,
-            TextureUsage::SAMPLEABLE | TextureUsage::UPLOADABLE | TextureUsage::COLOR_ATTACHMENT));
+    Handle<HwTexture> const srcTexture = cleanup.add(api.createTexture(
+        SamplerType::SAMPLER_2D, kNumLevels, kSrcTexFormat, 1, kSrcTexWidth, kSrcTexHeight, 1,
+        TextureUsage::SAMPLEABLE | TextureUsage::UPLOADABLE | TextureUsage::COLOR_ATTACHMENT));
    const bool flipY = sBackend == Backend::OPENGL;
    createBitmap(api, srcTexture, kSrcTexWidth, kSrcTexHeight, 0, float3(0.5, 0, 0), flipY);
    createBitmap(api, srcTexture, kSrcTexWidth, kSrcTexHeight, 1, float3(0, 0, 0.5), flipY);

    // Create a destination texture.
-    Handle<HwTexture> const dstTexture = mCleanup.add(api.createTexture(
-            SamplerType::SAMPLER_2D, kNumLevels, kDstTexFormat, 1, kDstTexWidth, kDstTexHeight, 1,
-            TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT));
+    Handle<HwTexture> const dstTexture = cleanup.add(api.createTexture(
+        SamplerType::SAMPLER_2D, kNumLevels, kDstTexFormat, 1, kDstTexWidth, kDstTexHeight, 1,
+        TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT));

    // Create a RenderTarget for each texture's miplevel.
    Handle<HwRenderTarget> srcRenderTargets[kNumLevels];
    Handle<HwRenderTarget> dstRenderTargets[kNumLevels];
    for (uint8_t level = 0; level < kNumLevels; level++) {
-        srcRenderTargets[level] = mCleanup.add(api.createRenderTarget(TargetBufferFlags::COLOR,
-                kSrcTexWidth >> level, kSrcTexHeight >> level, 1, 0, { srcTexture, level, 0 }, {},
-                {}));
-        dstRenderTargets[level] = mCleanup.add(api.createRenderTarget(TargetBufferFlags::COLOR,
-                kDstTexWidth >> level, kDstTexHeight >> level, 1, 0, { dstTexture, level, 0 }, {},
-                {}));
+        srcRenderTargets[level] = cleanup.add(api.createRenderTarget( TargetBufferFlags::COLOR,
+                kSrcTexWidth >> level, kSrcTexHeight >> level, 1, 0, { srcTexture, level, 0 }, {}, {}));
+        dstRenderTargets[level] = cleanup.add(api.createRenderTarget( TargetBufferFlags::COLOR,
+                kDstTexWidth >> level, kDstTexHeight >> level, 1, 0, { dstTexture, level, 0 }, {}, {}));
    }

    // Do a "magnify" blit from level 1 of the source RT to the level 0 of the destination RT.
    const int srcLevel = 1;
    api.blitDEPRECATED(TargetBufferFlags::COLOR0, dstRenderTargets[0],
-            { 0, 0, kDstTexWidth, kDstTexHeight }, srcRenderTargets[srcLevel],
-            { 0, 0, kSrcTexWidth >> srcLevel, kSrcTexHeight >> srcLevel },
-            SamplerMagFilter::LINEAR);
+            {0, 0, kDstTexWidth, kDstTexHeight}, srcRenderTargets[srcLevel],
+            {0, 0, kSrcTexWidth >> srcLevel, kSrcTexHeight >> srcLevel}, SamplerMagFilter::LINEAR);

    // Push through an empty frame to allow the texture to upload and the blit to execute.
    {
@@ -229,23 +246,29 @@ TEST_F(BlitTest, ColorMagnify) {
        api.commit(swapChain);
    }

+    // Grab a screenshot.
+    ScreenshotParams params { kDstTexWidth, kDstTexHeight, "ColorMagnify.png" };
    {
-        ImageExpectations expectations(api);
-
-        {
-            RenderFrame frame(api);
-            EXPECT_IMAGE(dstRenderTargets[0], expectations,
-                    ScreenshotParams(kDstTexWidth, kDstTexHeight, "ColorMagnify", 0x410bdd31));
-            api.commit(swapChain);
-        }
-
-        flushAndWait();
+        RenderFrame frame(api);
+        dumpScreenshot(api, dstRenderTargets[0], &params);
+        api.commit(swapChain);
    }
+
+    // Wait for the ReadPixels result to come back.
+    api.finish();
+    executeCommands();
+    getDriver().purge();
+
+    // Check if the image matches perfectly to our golden run.
+    const uint32_t expected = 0x410bdd31;
+    printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", params.pixelHashResult, expected);
+    EXPECT_TRUE(params.pixelHashResult == expected);
 }

-TEST_F(BlitTest, ColorMinify) {
+TEST_F(BackendTest, ColorMinify) {
    auto& api = getDriverApi();
-    mCleanup.addPostCall([&]() { executeCommands(); });
+    Cleanup cleanup(getDriverApi());
+    cleanup.addPostCall([&]() { executeCommands(); });

    constexpr int kSrcTexWidth = 1024;
    constexpr int kSrcTexHeight = 1024;
@@ -256,55 +279,57 @@ TEST_F(BlitTest, ColorMinify) {
    constexpr int kNumLevels = 3;

    // Create a SwapChain and make it current. We don't really use it so the res doesn't matter.
-    auto swapChain = mCleanup.add(api.createSwapChainHeadless(256, 256, 0));
+    auto swapChain = cleanup.add(api.createSwapChainHeadless(256, 256, 0));
    api.makeCurrent(swapChain, swapChain);

    // Create a source texture.
-    Handle<HwTexture> const srcTexture = mCleanup.add(api.createTexture(
-            SamplerType::SAMPLER_2D, kNumLevels, kSrcTexFormat, 1, kSrcTexWidth, kSrcTexHeight, 1,
-            TextureUsage::SAMPLEABLE | TextureUsage::UPLOADABLE | TextureUsage::COLOR_ATTACHMENT));
+    Handle<HwTexture> const srcTexture = cleanup.add(api.createTexture(
+        SamplerType::SAMPLER_2D, kNumLevels, kSrcTexFormat, 1, kSrcTexWidth, kSrcTexHeight, 1,
+        TextureUsage::SAMPLEABLE | TextureUsage::UPLOADABLE | TextureUsage::COLOR_ATTACHMENT));
    const bool flipY = sBackend == Backend::OPENGL;
    createBitmap(api, srcTexture, kSrcTexWidth, kSrcTexHeight, 0, float3(0.5, 0, 0), flipY);
    createBitmap(api, srcTexture, kSrcTexWidth, kSrcTexHeight, 1, float3(0, 0, 0.5), flipY);

    // Create a destination texture.
-    Handle<HwTexture> const dstTexture = mCleanup.add(api.createTexture(
-            SamplerType::SAMPLER_2D, kNumLevels, kDstTexFormat, 1, kDstTexWidth, kDstTexHeight, 1,
-            TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT));
+    Handle<HwTexture> const dstTexture = cleanup.add(api.createTexture(
+        SamplerType::SAMPLER_2D, kNumLevels, kDstTexFormat, 1, kDstTexWidth, kDstTexHeight, 1,
+        TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT));

    // Create a RenderTarget for each texture's miplevel.
    Handle<HwRenderTarget> srcRenderTargets[kNumLevels];
    Handle<HwRenderTarget> dstRenderTargets[kNumLevels];
    for (uint8_t level = 0; level < kNumLevels; level++) {
-        srcRenderTargets[level] = mCleanup.add(api.createRenderTarget(TargetBufferFlags::COLOR,
-                kSrcTexWidth >> level, kSrcTexHeight >> level, 1, 0, { srcTexture, level, 0 }, {},
-                {}));
-        dstRenderTargets[level] = mCleanup.add(api.createRenderTarget(TargetBufferFlags::COLOR,
-                kDstTexWidth >> level, kDstTexHeight >> level, 1, 0, { dstTexture, level, 0 }, {},
-                {}));
+        srcRenderTargets[level] = cleanup.add(api.createRenderTarget( TargetBufferFlags::COLOR,
+                kSrcTexWidth >> level, kSrcTexHeight >> level, 1, 0, { srcTexture, level, 0 }, {}, {}));
+        dstRenderTargets[level] = cleanup.add(api.createRenderTarget( TargetBufferFlags::COLOR,
+                kDstTexWidth >> level, kDstTexHeight >> level, 1, 0, { dstTexture, level, 0 }, {}, {}));
    }

    // Do a "minify" blit from level 1 of the source RT to the level 0 of the destination RT.
    const int srcLevel = 1;

    api.blitDEPRECATED(TargetBufferFlags::COLOR0,
-            dstRenderTargets[0], { 0, 0, kDstTexWidth, kDstTexHeight },
-            srcRenderTargets[srcLevel],
-            { 0, 0, kSrcTexWidth >> srcLevel, kSrcTexHeight >> srcLevel },
+            dstRenderTargets[0], {0, 0, kDstTexWidth, kDstTexHeight},
+            srcRenderTargets[srcLevel], {0, 0, kSrcTexWidth >> srcLevel, kSrcTexHeight >> srcLevel},
            SamplerMagFilter::LINEAR);

-    {
-        ImageExpectations expectations(api);

-        EXPECT_IMAGE(dstRenderTargets[0], expectations,
-                ScreenshotParams(kDstTexWidth, kDstTexHeight, "ColorMinify", 0xf3d9c53f));
+    // Grab a screenshot.
+    ScreenshotParams params { kDstTexWidth, kDstTexHeight, "ColorMinify.png" };
+    dumpScreenshot(api, dstRenderTargets[0], &params);

-        flushAndWait();
-    }
+    // Wait for the ReadPixels result to come back.
+    flushAndWait();
+
+    // Check if the image matches perfectly to our golden run.
+    const uint32_t expected = 0xf3d9c53f;
+    printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", params.pixelHashResult, expected);
+    EXPECT_TRUE(params.pixelHashResult == expected);
 }

-TEST_F(BlitTest, ColorResolve) {
+TEST_F(BackendTest, ColorResolve) {
    auto& api = getDriverApi();
+    Cleanup cleanup(getDriverApi());

    constexpr int kSrcTexWidth = 256;
    constexpr int kSrcTexHeight = 256;
@@ -313,29 +338,49 @@ TEST_F(BlitTest, ColorResolve) {
    constexpr auto kColorTexFormat = TextureFormat::RGBA8;
    constexpr int kSampleCount = 4;

-    Shader shader = createShader();
+    // Create a program.
+    ProgramHandle program;
+    {
+        filamat::DescriptorSets descriptors;
+        descriptors[1] = { { "Params",
+                { DescriptorType::UNIFORM_BUFFER, ShaderStageFlags::ALL_SHADER_STAGE_FLAGS, 0 },
+                {} } };
+        ShaderGenerator shaderGen(
+                triangleVs, triangleFs, sBackend, sIsMobilePlatform, std::move(descriptors));
+        Program prog = shaderGen.getProgram(api);
+        prog.descriptorBindings(1, {{ "Params", DescriptorType::UNIFORM_BUFFER, 0 }});
+        program = cleanup.add(api.createProgram(std::move(prog)));
+    }
+
+    DescriptorSetLayoutHandle descriptorSetLayout = cleanup.add(api.createDescriptorSetLayout({
+            {{
+                     DescriptorType::UNIFORM_BUFFER,
+                     ShaderStageFlags::ALL_SHADER_STAGE_FLAGS, 0,
+                     DescriptorFlags::NONE, 0
+             }}}));
+
+    DescriptorSetHandle descriptorSet = cleanup.add(api.createDescriptorSet(descriptorSetLayout));

    // Create a VertexBuffer, IndexBuffer, and RenderPrimitive.
    TrianglePrimitive const triangle(api);

    // Create 4-sample texture.
-    Handle<HwTexture> const srcColorTexture = mCleanup.add(api.createTexture(
-            SamplerType::SAMPLER_2D, 1, kColorTexFormat, kSampleCount, kSrcTexWidth, kSrcTexHeight,
-            1,
-            TextureUsage::COLOR_ATTACHMENT));
+    Handle<HwTexture> const srcColorTexture = cleanup.add(api.createTexture(
+        SamplerType::SAMPLER_2D, 1, kColorTexFormat, kSampleCount, kSrcTexWidth, kSrcTexHeight, 1,
+        TextureUsage::COLOR_ATTACHMENT));

    // Create 1-sample texture.
-    Handle<HwTexture> const dstColorTexture = mCleanup.add(api.createTexture(
-            SamplerType::SAMPLER_2D, 1, kColorTexFormat, 1, kDstTexWidth, kDstTexHeight, 1,
-            TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT));
+    Handle<HwTexture> const dstColorTexture = cleanup.add(api.createTexture(
+        SamplerType::SAMPLER_2D, 1, kColorTexFormat, 1, kDstTexWidth, kDstTexHeight, 1,
+        TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT));

    // Create a 4-sample render target with the 4-sample texture.
-    Handle<HwRenderTarget> const srcRenderTarget = mCleanup.add(api.createRenderTarget(
+    Handle<HwRenderTarget> const srcRenderTarget = cleanup.add(api.createRenderTarget(
            TargetBufferFlags::COLOR, kSrcTexWidth, kSrcTexHeight, kSampleCount, 0,
            {{ srcColorTexture }}, {}, {}));

    // Create a 1-sample render target with the 1-sample texture.
-    Handle<HwRenderTarget> const dstRenderTarget = mCleanup.add(api.createRenderTarget(
+    Handle<HwRenderTarget> const dstRenderTarget = cleanup.add(api.createRenderTarget(
            TargetBufferFlags::COLOR, kDstTexWidth, kDstTexHeight, 1, 0,
            {{ dstColorTexture }}, {}, {}));

@@ -349,52 +394,58 @@ TEST_F(BlitTest, ColorResolve) {
    params.viewport.height = kSrcTexHeight;

    PipelineState state = {};
-    state.program = shader.getProgram();
-    state.pipelineLayout.setLayout[1] = { shader.getDescriptorSetLayout() };
+    state.program = program;
+    state.pipelineLayout.setLayout[1] = { descriptorSetLayout };
    state.rasterState.colorWrite = true;
    state.rasterState.depthWrite = false;
    state.rasterState.depthFunc = RasterState::DepthFunc::A;
    state.rasterState.culling = CullingMode::NONE;

-    auto ubuffer = mCleanup.add(api.createBufferObject(sizeof(MaterialParams),
+    auto ubuffer = cleanup.add(api.createBufferObject(sizeof(MaterialParams),
            BufferObjectBinding::UNIFORM, BufferUsage::STATIC));
    // Draw red triangle into srcRenderTarget.
-    shader.uploadUniform(api, ubuffer, MaterialParams{
-            .color = float4(1, 0, 0, 1),
-            .scale = float4(1, 1, 0.5, 0),
+    uploadUniforms(api, ubuffer, {
+        .color = float4(1, 0, 0, 1),
+        .scale = float4(1, 1, 0.5, 0),
    });
-    shader.bindUniform<MaterialParams>(api, ubuffer);
+
+    api.updateDescriptorSetBuffer(descriptorSet, 0, ubuffer, 0, sizeof(MaterialParams));
+    api.bindDescriptorSet(descriptorSet, 1, {});

    // FIXME: on Metal this triangle is not drawn. Can't understand why.
    {
        RenderFrame frame(api);
        api.beginRenderPass(srcRenderTarget, params);
-        api.draw(state, triangle.getRenderPrimitive(), 0, 3, 1);
+            api.draw(state, triangle.getRenderPrimitive(), 0, 3, 1);
        api.endRenderPass();
    }

    // Resolve the MSAA render target into the single-sample render target.
    api.blitDEPRECATED(TargetBufferFlags::COLOR,
-            dstRenderTarget, { 0, 0, kDstTexWidth, kDstTexHeight },
-            srcRenderTarget, { 0, 0, kSrcTexWidth, kSrcTexHeight },
+            dstRenderTarget, {0, 0, kDstTexWidth, kDstTexHeight},
+            srcRenderTarget, {0, 0, kSrcTexWidth, kSrcTexHeight},
            SamplerMagFilter::NEAREST);

-    {
-        ImageExpectations expectations(api);
+    // Grab a screenshot.
+    ScreenshotParams sparams{ kDstTexWidth, kDstTexHeight, "ColorResolve.png" };
+    dumpScreenshot(api, dstRenderTarget, &sparams);

-        EXPECT_IMAGE(dstRenderTarget, expectations,
-                ScreenshotParams(kDstTexWidth, kDstTexHeight, "ColorResolve", 0xebfac2ef));
+    // Wait for the ReadPixels result to come back.
+    flushAndWait();

-        flushAndWait();
-    }
+    // Check if the image matches perfectly to our golden run.
+    const uint32_t expected = 0xebfac2ef;
+    printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", sparams.pixelHashResult, expected);
+    EXPECT_TRUE(sparams.pixelHashResult == expected);
 }

-TEST_F(BlitTest, Blit2DTextureArray) {
+TEST_F(BackendTest, Blit2DTextureArray) {
    auto& api = getDriverApi();
-    mCleanup.addPostCall([&]() { executeCommands(); });
+    Cleanup cleanup(getDriverApi());
+    cleanup.addPostCall([&]() { executeCommands(); });

    api.startCapture(0);
-    mCleanup.addPostCall([&]() { api.stopCapture(0); });
+    cleanup.addPostCall([&]() { api.stopCapture(0); });

    constexpr int kSrcTexWidth = 256;
    constexpr int kSrcTexHeight = 256;
@@ -409,40 +460,33 @@ TEST_F(BlitTest, Blit2DTextureArray) {
    constexpr int kDstTexLayer = 0;

    // Create a SwapChain and make it current. We don't really use it so the res doesn't matter.
-    auto swapChain = mCleanup.add(api.createSwapChainHeadless(256, 256, 0));
+    auto swapChain = cleanup.add(api.createSwapChainHeadless(256, 256, 0));
    api.makeCurrent(swapChain, swapChain);

    // Create a source texture.
-    Handle<HwTexture> srcTexture = mCleanup.add(api.createTexture(
-            SamplerType::SAMPLER_2D_ARRAY, kNumLevels, kSrcTexFormat, 1, kSrcTexWidth,
-            kSrcTexHeight, kSrcTexDepth,
+    Handle<HwTexture> srcTexture = cleanup.add(api.createTexture(
+            SamplerType::SAMPLER_2D_ARRAY, kNumLevels, kSrcTexFormat, 1, kSrcTexWidth, kSrcTexHeight, kSrcTexDepth,
            TextureUsage::SAMPLEABLE | TextureUsage::UPLOADABLE | TextureUsage::COLOR_ATTACHMENT));
    const bool flipY = sBackend == Backend::OPENGL;
-    createBitmap(api, srcTexture, kSrcTexWidth, kSrcTexHeight, 0, kSrcTexLayer, float3(0.5, 0, 0),
-            flipY);
+    createBitmap(api, srcTexture, kSrcTexWidth, kSrcTexHeight, 0, kSrcTexLayer, float3(0.5, 0, 0), flipY);

    // Create a destination texture.
-    Handle<HwTexture> dstTexture = mCleanup.add(api.createTexture(
+    Handle<HwTexture> dstTexture = cleanup.add(api.createTexture(
            SamplerType::SAMPLER_2D, kNumLevels, kDstTexFormat, 1, kDstTexWidth, kDstTexHeight, 1,
            TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT));

    // Create two RenderTargets.
    const int level = 0;
-    Handle<HwRenderTarget> srcRenderTarget = mCleanup.add(
-            api.createRenderTarget(TargetBufferFlags::COLOR,
-                    kSrcTexWidth >> level, kSrcTexHeight >> level, 1, 0,
-                    { srcTexture, level, kSrcTexLayer }, {}, {}));
-    Handle<HwRenderTarget> dstRenderTarget = mCleanup.add(
-            api.createRenderTarget(TargetBufferFlags::COLOR,
-                    kDstTexWidth >> level, kDstTexHeight >> level, 1, 0,
-                    { dstTexture, level, kDstTexLayer }, {}, {}));
+    Handle<HwRenderTarget> srcRenderTarget = cleanup.add(api.createRenderTarget( TargetBufferFlags::COLOR,
+            kSrcTexWidth >> level, kSrcTexHeight >> level, 1, 0, { srcTexture, level, kSrcTexLayer }, {}, {}));
+    Handle<HwRenderTarget> dstRenderTarget = cleanup.add(api.createRenderTarget( TargetBufferFlags::COLOR,
+            kDstTexWidth >> level, kDstTexHeight >> level, 1, 0, { dstTexture, level, kDstTexLayer }, {}, {}));

    // Do a blit from kSrcTexLayer of the source RT to kDstTexLayer of the destination RT.
    const int srcLevel = 0;
    api.blitDEPRECATED(TargetBufferFlags::COLOR0, dstRenderTarget,
-            { 0, 0, kDstTexWidth, kDstTexHeight }, srcRenderTarget,
-            { 0, 0, kSrcTexWidth >> srcLevel, kSrcTexHeight >> srcLevel },
-            SamplerMagFilter::LINEAR);
+            {0, 0, kDstTexWidth, kDstTexHeight}, srcRenderTarget,
+            {0, 0, kSrcTexWidth >> srcLevel, kSrcTexHeight >> srcLevel}, SamplerMagFilter::LINEAR);

    // Push through an empty frame to allow the texture to upload and the blit to execute.
    {
@@ -450,24 +494,29 @@ TEST_F(BlitTest, Blit2DTextureArray) {
        api.commit(swapChain);
    }

+    // Grab a screenshot.
+    ScreenshotParams params { kDstTexWidth, kDstTexHeight, "Blit2DTextureArray.png" };
    {
-        ImageExpectations expectations(api);
-
-        {
-            RenderFrame frame(api);
-            EXPECT_IMAGE(dstRenderTarget, expectations,
-                    ScreenshotParams(kDstTexWidth, kDstTexHeight, "Blit2DTextureArray",
-                            0x8de7d55b));
-            api.commit(swapChain);
-        }
-
-        flushAndWait();
+        RenderFrame frame(api);
+        dumpScreenshot(api, dstRenderTarget, &params);
+        api.commit(swapChain);
    }
+
+    // Wait for the ReadPixels result to come back.
+    api.finish();
+    executeCommands();
+    getDriver().purge();
+
+    // Check if the image matches perfectly to our golden run.
+    const uint32_t expected = 0x8de7d55b;
+    printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", params.pixelHashResult, expected);
+    EXPECT_TRUE(params.pixelHashResult == expected);
 }

-TEST_F(BlitTest, BlitRegion) {
+TEST_F(BackendTest, BlitRegion) {
    auto& api = getDriverApi();
-    mCleanup.addPostCall([&]() { executeCommands(); });
+    Cleanup cleanup(getDriverApi());
+    cleanup.addPostCall([&]() { executeCommands(); });

    constexpr int kSrcTexWidth = 1024;
    constexpr int kSrcTexHeight = 1024;
@@ -480,48 +529,47 @@ TEST_F(BlitTest, BlitRegion) {
    constexpr int kDstLevel = 0;

    // Create a SwapChain and make it current. We don't really use it so the res doesn't matter.
-    auto swapChain = mCleanup.add(api.createSwapChainHeadless(256, 256, 0));
+    auto swapChain = cleanup.add(api.createSwapChainHeadless(256, 256, 0));
    api.makeCurrent(swapChain, swapChain);

    // Create a source texture.
-    Handle<HwTexture> srcTexture = mCleanup.add(api.createTexture(
-            SamplerType::SAMPLER_2D, kNumLevels, kSrcTexFormat, 1, kSrcTexWidth, kSrcTexHeight, 1,
-            TextureUsage::SAMPLEABLE | TextureUsage::UPLOADABLE | TextureUsage::COLOR_ATTACHMENT));
+    Handle<HwTexture> srcTexture = cleanup.add(api.createTexture(
+        SamplerType::SAMPLER_2D, kNumLevels, kSrcTexFormat, 1, kSrcTexWidth, kSrcTexHeight, 1,
+        TextureUsage::SAMPLEABLE | TextureUsage::UPLOADABLE | TextureUsage::COLOR_ATTACHMENT));
    const bool flipY = sBackend == Backend::OPENGL;
    createBitmap(api, srcTexture, kSrcTexWidth, kSrcTexHeight, 0, float3(0.5, 0, 0), flipY);
    createBitmap(api, srcTexture, kSrcTexWidth, kSrcTexHeight, 1, float3(0, 0, 0.5), flipY);

    // Create a destination texture.
-    Handle<HwTexture> dstTexture = mCleanup.add(api.createTexture(
-            SamplerType::SAMPLER_2D, kNumLevels, kDstTexFormat, 1, kDstTexWidth, kDstTexHeight, 1,
-            TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT));
+    Handle<HwTexture> dstTexture = cleanup.add(api.createTexture(
+        SamplerType::SAMPLER_2D, kNumLevels, kDstTexFormat, 1, kDstTexWidth, kDstTexHeight, 1,
+        TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT));

    // Blit one-quarter of src level 1 to dst level 0.
    Viewport srcRect = {
-            .left = 0,
-            .bottom = 0,
-            .width = (kSrcTexWidth >> kSrcLevel) / 2,
-            .height = (kSrcTexHeight >> kSrcLevel) / 2,
+        .left = 0,
+        .bottom = 0,
+        .width = (kSrcTexWidth >> kSrcLevel) / 2,
+        .height = (kSrcTexHeight >> kSrcLevel) / 2,
    };
    Viewport dstRect = {
-            .left = 10,
-            .bottom = 10,
-            .width = kDstTexWidth - 10,
-            .height = kDstTexHeight - 10,
+        .left = 10,
+        .bottom = 10,
+        .width = kDstTexWidth - 10,
+        .height = kDstTexHeight - 10,
    };

    // Create a RenderTarget for each texture's miplevel.
    // We purposely set the render target width and height to smaller than the texture, to check
    // that this case is handled correctly.
    Handle<HwRenderTarget> srcRenderTarget =
-            mCleanup.add(api.createRenderTarget(TargetBufferFlags::COLOR, srcRect.width,
-                    srcRect.height, 1, 0, { srcTexture, kSrcLevel, 0 }, {}, {}));
+            cleanup.add(api.createRenderTarget(TargetBufferFlags::COLOR, srcRect.width,
+                    srcRect.height, 1, 0, {srcTexture, kSrcLevel, 0}, {}, {}));
    Handle<HwRenderTarget> dstRenderTarget =
-            mCleanup.add(api.createRenderTarget(TargetBufferFlags::COLOR, kDstTexWidth >> kDstLevel,
-                    kDstTexHeight >> kDstLevel, 1, 0, { dstTexture, kDstLevel, 0 }, {}, {}));
+            cleanup.add(api.createRenderTarget(TargetBufferFlags::COLOR, kDstTexWidth >> kDstLevel,
+                    kDstTexHeight >> kDstLevel, 1, 0, {dstTexture, kDstLevel, 0}, {}, {}));

-    api.blitDEPRECATED(TargetBufferFlags::COLOR0, dstRenderTarget, dstRect, srcRenderTarget,
-            srcRect,
+    api.blitDEPRECATED(TargetBufferFlags::COLOR0, dstRenderTarget, dstRect, srcRenderTarget, srcRect,
            SamplerMagFilter::LINEAR);

    // Push through an empty frame to allow the texture to upload and the blit to execute.
@@ -530,25 +578,33 @@ TEST_F(BlitTest, BlitRegion) {
        api.commit(swapChain);
    }

+    // Grab a screenshot.
+    ScreenshotParams params { kDstTexWidth, kDstTexHeight, "BlitRegion.png" };
    {
-        ImageExpectations expectations(api);
-
-        {
-            RenderFrame frame(api);
-            // TODO: for some reason, this test has very, very slight (as in one pixel) differences
-            // between OpenGL and Metal. So disable golden checking for now.
-            // EXPECT_IMAGE(dstRenderTarget, expectations, ScreenshotParams(kDstTexWidth,
-            //         kDstTexHeight, "BlitRegion", 0x74fa34ed));
-            api.commit(swapChain);
-        }
-
-        flushAndWait();
+        RenderFrame frame(api);
+        dumpScreenshot(api, dstRenderTarget, &params);
+        api.commit(swapChain);
    }
+
+    // Wait for the ReadPixels result to come back.
+    api.finish();
+    executeCommands();
+    getDriver().purge();
+
+    // TODO: for some reason, this test has very, very slight (as in one pixel) differences between
+    // OpenGL and Metal. So disable golden checking for now.
+    // Use the compare tool from ImageMagick to see visual differences:
+    // compare -verbose -metric mae BlitRegion_Metal.png BlitRegion_OpenGL.png difference.png
+    //
+    // const uint32_t expected = 0x74fa34ed;
+    // printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", params.pixelHashResult, expected);
+    // EXPECT_TRUE(params.pixelHashResult == expected);
 }

-TEST_F(BlitTest, BlitRegionToSwapChain) {
+TEST_F(BackendTest, BlitRegionToSwapChain) {
    auto& api = getDriverApi();
-    mCleanup.addPostCall([&]() { executeCommands(); });
+    Cleanup cleanup(getDriverApi());
+    cleanup.addPostCall([&]() { executeCommands(); });

    constexpr int kSrcTexWidth = 1024;
    constexpr int kSrcTexHeight = 1024;
@@ -558,15 +614,15 @@ TEST_F(BlitTest, BlitRegionToSwapChain) {
    constexpr int kNumLevels = 3;

    // Create a SwapChain and make it current.
-    auto swapChain = mCleanup.add(createSwapChain());
+    auto swapChain = cleanup.add(createSwapChain());
    api.makeCurrent(swapChain, swapChain);

-    Handle<HwRenderTarget> dstRenderTarget = mCleanup.add(api.createDefaultRenderTarget());
+    Handle<HwRenderTarget> dstRenderTarget = cleanup.add(api.createDefaultRenderTarget());

    // Create a source texture.
-    Handle<HwTexture> srcTexture = mCleanup.add(api.createTexture(
-            SamplerType::SAMPLER_2D, kNumLevels, kSrcTexFormat, 1, kSrcTexWidth, kSrcTexHeight, 1,
-            TextureUsage::SAMPLEABLE | TextureUsage::UPLOADABLE | TextureUsage::COLOR_ATTACHMENT));
+    Handle<HwTexture> srcTexture = cleanup.add(api.createTexture(
+        SamplerType::SAMPLER_2D, kNumLevels, kSrcTexFormat, 1, kSrcTexWidth, kSrcTexHeight, 1,
+        TextureUsage::SAMPLEABLE | TextureUsage::UPLOADABLE | TextureUsage::COLOR_ATTACHMENT));
    const bool flipY = sBackend == Backend::OPENGL;
    createBitmap(api, srcTexture, kSrcTexWidth, kSrcTexHeight, 0, float3(0.5, 0, 0), flipY);
    createBitmap(api, srcTexture, kSrcTexWidth, kSrcTexHeight, 1, float3(0, 0, 0.5), flipY);
@@ -574,46 +630,42 @@ TEST_F(BlitTest, BlitRegionToSwapChain) {
    // Create a RenderTarget for each texture's miplevel.
    Handle<HwRenderTarget> srcRenderTargets[kNumLevels];
    for (uint8_t level = 0; level < kNumLevels; level++) {
-        srcRenderTargets[level] = mCleanup.add(api.createRenderTarget(TargetBufferFlags::COLOR,
-                kSrcTexWidth >> level, kSrcTexHeight >> level, 1, 0, { srcTexture, level, 0 }, {},
-                {}));
+        srcRenderTargets[level] = cleanup.add(api.createRenderTarget( TargetBufferFlags::COLOR,
+                kSrcTexWidth >> level, kSrcTexHeight >> level, 1, 0, { srcTexture, level, 0 }, {}, {}));
    }

    // Blit one-quarter of src level 1 to dst level 0.
    const int srcLevel = 1;
    Viewport srcRect = {
-            .left = (kSrcTexWidth >> srcLevel) / 2,
-            .bottom = (kSrcTexHeight >> srcLevel) / 2,
-            .width = (kSrcTexWidth >> srcLevel) / 2,
-            .height = (kSrcTexHeight >> srcLevel) / 2,
+        .left = (kSrcTexWidth >> srcLevel) / 2,
+        .bottom = (kSrcTexHeight >> srcLevel) / 2,
+        .width = (kSrcTexWidth >> srcLevel) / 2,
+        .height = (kSrcTexHeight >> srcLevel) / 2,
    };
    Viewport dstRect = {
-            .left = 10,
-            .bottom = 10,
-            .width = kDstTexWidth - 10,
-            .height = kDstTexHeight - 10,
+        .left = 10,
+        .bottom = 10,
+        .width = kDstTexWidth - 10,
+        .height = kDstTexHeight - 10,
    };

    {
-        ImageExpectations expectations(api);
-        {
-            {
-                RenderFrame frame(api);
+        RenderFrame frame(api);

-                api.blitDEPRECATED(TargetBufferFlags::COLOR0, dstRenderTarget,
-                        dstRect, srcRenderTargets[srcLevel],
-                        srcRect, SamplerMagFilter::LINEAR);
+        api.blitDEPRECATED(TargetBufferFlags::COLOR0, dstRenderTarget,
+                dstRect, srcRenderTargets[srcLevel],
+                srcRect, SamplerMagFilter::LINEAR);

-                api.commit(swapChain);
-            }
+        ScreenshotParams params { kDstTexWidth, kDstTexHeight, "BlitRegionToSwapChain.png" };
+        dumpScreenshot(api, dstRenderTarget, &params);

-            // TODO: for some reason, this test has been disabled. It needs to be tested on all
-            // machines.
-            // EXPECT_IMAGE(dstRenderTarget, expectations,
-            //         ScreenshotParams(kDstTexWidth, kDstTexHeight, "BlitRegionToSwapChain", 0x0));
-        }
-        flushAndWait();
+        api.commit(swapChain);
    }
+
+    // Wait for the ReadPixels result to come back.
+    api.finish();
+    executeCommands();
+    getDriver().purge();
 }

 } // namespace test
@@ -16,8 +16,6 @@

 #include "BackendTest.h"

-#include "Lifetimes.h"
-#include "Shader.h"
 #include "ShaderGenerator.h"
 #include "TrianglePrimitive.h"

@@ -80,28 +78,8 @@ struct MaterialParams {
    math::float4 offset;
 };
 static_assert(sizeof(MaterialParams) == 8 * sizeof(float));
-// Uniform config for writing MaterialParams to the shader uniform with 64 bytes of padding.
-const UniformBindingConfig kBindingConfig = {
-        .dataSize = sizeof(MaterialParams),
-        .bufferSize = sizeof(MaterialParams) + 64,
-        .byteOffset = 64
-};

-class BufferUpdatesTest : public BackendTest {
-public:
-    BufferUpdatesTest() : mCleanup(getDriverApi()) {}
-
-protected:
-    Shader createShader() {
-        return Shader(getDriverApi(), mCleanup, ShaderConfig{
-           vertex, fragment, {"Params"}
-        });
-    }
-
-    Cleanup mCleanup;
-};
-
-TEST_F(BufferUpdatesTest, VertexBufferUpdate) {
+TEST_F(BackendTest, VertexBufferUpdate) {
    const bool largeBuffers = false;

    // If updateIndices is true, then even-numbered triangles will have their indices set to
@@ -112,15 +90,31 @@ TEST_F(BufferUpdatesTest, VertexBufferUpdate) {
    // executeCommands().
    {
        auto& api = getDriverApi();
-        Cleanup cleanup(api);

        // Create a platform-specific SwapChain and make it current.
-        auto swapChain = cleanup.add(createSwapChain());
+        auto swapChain = createSwapChain();
        api.makeCurrent(swapChain, swapChain);

-        Shader shader = createShader();
+        // Create a program.
+        filamat::DescriptorSets descriptors;
+        descriptors[1] = { { "Params",
+                { DescriptorType::UNIFORM_BUFFER, ShaderStageFlags::FRAGMENT, 0 }, {} } };
+        ShaderGenerator shaderGen(
+                vertex, fragment, sBackend, sIsMobilePlatform, std::move(descriptors));
+        Program p = shaderGen.getProgram(api);
+        p.descriptorBindings(1, {{ "Params", DescriptorType::UNIFORM_BUFFER, 0 }});
+        auto program = api.createProgram(std::move(p));

-        auto defaultRenderTarget = cleanup.add(api.createDefaultRenderTarget(0));
+        DescriptorSetLayoutHandle descriptorSetLayout = api.createDescriptorSetLayout({
+                {{
+                         DescriptorType::UNIFORM_BUFFER,
+                         ShaderStageFlags::ALL_SHADER_STAGE_FLAGS, 0,
+                         DescriptorFlags::NONE, 0
+                 }}});
+
+        DescriptorSetHandle descriptorSet = api.createDescriptorSet(descriptorSetLayout);
+
+        auto defaultRenderTarget = api.createDefaultRenderTarget(0);

        // To test large buffers (which exercise a different code path) create an extra large
        // buffer. Only the first 3 vertices will be used.
@@ -134,29 +128,38 @@ TEST_F(BufferUpdatesTest, VertexBufferUpdate) {
        params.flags.discardEnd = TargetBufferFlags::NONE;

        PipelineState state;
-        state.program = shader.getProgram();
-        state.pipelineLayout.setLayout[1] = { shader.getDescriptorSetLayout() };
+        state.program = program;
+        state.pipelineLayout.setLayout[1] = { descriptorSetLayout };
        state.rasterState.colorWrite = true;
        state.rasterState.depthWrite = false;
        state.rasterState.depthFunc = RasterState::DepthFunc::A;
        state.rasterState.culling = CullingMode::NONE;

        // Create a uniform buffer.
-        // We use STATIC here, even though the buffer is updated, to force the Metal backend to use
-        // a GPU buffer, which is more interesting to test.
-        auto ubuffer = cleanup.add(api.createBufferObject(sizeof(MaterialParams) + 64,
-                BufferObjectBinding::UNIFORM, BufferUsage::STATIC));
+        // We use STATIC here, even though the buffer is updated, to force the Metal backend to use a
+        // GPU buffer, which is more interesting to test.
+        auto ubuffer = api.createBufferObject(sizeof(MaterialParams) + 64,
+                BufferObjectBinding::UNIFORM, BufferUsage::STATIC);

-        shader.bindUniform<MaterialParams>(api, ubuffer, kBindingConfig);
+        api.updateDescriptorSetBuffer(descriptorSet, 0, ubuffer, 0, sizeof(MaterialParams) + 64);
+        api.bindDescriptorSet(descriptorSet, 1, {});

        api.startCapture(0);

-        // Upload the uniform, but with an offset to accommodate the padding in the shader's
-        // uniform definition.
-        shader.uploadUniform(api, ubuffer, kBindingConfig, MaterialParams{
-                .color = { 1.0f, 1.0f, 1.0f, 1.0f },
-                .offset = { 0.0f, 0.0f, 0.0f, 0.0f }
-        });
+        // Upload uniforms.
+        {
+            MaterialParams params {
+                    .color = { 1.0f, 1.0f, 1.0f, 1.0f },
+                    .offset = { 0.0f, 0.0f, 0.0f, 0.0f }
+            };
+            auto* tmp = new MaterialParams(params);
+            auto cb = [](void* buffer, size_t size, void* user) {
+                auto* sp = (MaterialParams*) buffer;
+                delete sp;
+            };
+            BufferDescriptor bd(tmp, sizeof(MaterialParams), cb);
+            api.updateBufferObject(ubuffer, std::move(bd), 64);
+        }

        api.makeCurrent(swapChain, swapChain);
        api.beginFrame(0, 0, 0);
@@ -199,6 +202,13 @@ TEST_F(BufferUpdatesTest, VertexBufferUpdate) {
        api.endFrame(0);

        api.stopCapture(0);
+
+        api.destroyProgram(program);
+        api.destroySwapChain(swapChain);
+        api.destroyDescriptorSet(descriptorSet);
+        api.destroyDescriptorSetLayout(descriptorSetLayout);
+        api.destroyBufferObject(ubuffer);
+        api.destroyRenderTarget(defaultRenderTarget);
    }

    executeCommands();
@@ -206,38 +216,62 @@ TEST_F(BufferUpdatesTest, VertexBufferUpdate) {

 // This test renders two triangles in two separate draw calls. Between the draw calls, a uniform
 // buffer object is partially updated.
-TEST_F(BufferUpdatesTest, BufferObjectUpdateWithOffset) {
+TEST_F(BackendTest, BufferObjectUpdateWithOffset) {
    auto& api = getDriverApi();
-    Cleanup cleanup(api);

    // Create a platform-specific SwapChain and make it current.
-    auto swapChain = cleanup.add(createSwapChain());
+    auto swapChain = createSwapChain();
    api.makeCurrent(swapChain, swapChain);

    // Create a program.
-    Shader shader = createShader();
+    filamat::DescriptorSets descriptors;
+    descriptors[1] = { { "Params",
+            { DescriptorType::UNIFORM_BUFFER, ShaderStageFlags::FRAGMENT, 0 }, {} } };
+    ShaderGenerator shaderGen(
+            vertex, fragment, sBackend, sIsMobilePlatform, std::move(descriptors));
+    Program p = shaderGen.getProgram(api);
+    p.descriptorBindings(1, {{ "Params", DescriptorType::UNIFORM_BUFFER, 0 }});
+    auto program = api.createProgram(std::move(p));
+
+    DescriptorSetLayoutHandle descriptorSetLayout = api.createDescriptorSetLayout({
+            {{
+                     DescriptorType::UNIFORM_BUFFER,
+                     ShaderStageFlags::ALL_SHADER_STAGE_FLAGS, 0,
+                     DescriptorFlags::NONE, 0
+             }}});
+
+    DescriptorSetHandle descriptorSet = api.createDescriptorSet(descriptorSetLayout);
+

    // Create a uniform buffer.
    // We use STATIC here, even though the buffer is updated, to force the Metal backend to use a
    // GPU buffer, which is more interesting to test.
-    auto ubuffer = cleanup.add(api.createBufferObject(sizeof(MaterialParams) + 64,
-            BufferObjectBinding::UNIFORM, BufferUsage::STATIC));
+    auto ubuffer = api.createBufferObject(sizeof(MaterialParams) + 64,
+            BufferObjectBinding::UNIFORM, BufferUsage::STATIC);

-    shader.bindUniform<MaterialParams>(api, ubuffer, kBindingConfig);
+    api.updateDescriptorSetBuffer(descriptorSet, 0, ubuffer, 0, sizeof(MaterialParams) + 64);
+    api.bindDescriptorSet(descriptorSet, 1, {});

    // Create a render target.
-    auto colorTexture = cleanup.add(api.createTexture(SamplerType::SAMPLER_2D, 1,
-            TextureFormat::RGBA8, 1, 512, 512, 1, TextureUsage::COLOR_ATTACHMENT));
-    auto renderTarget = cleanup.add(api.createRenderTarget(
-            TargetBufferFlags::COLOR0, 512, 512, 1, 0, {{colorTexture}}, {}, {}));
+    auto colorTexture = api.createTexture(SamplerType::SAMPLER_2D, 1,
+            TextureFormat::RGBA8, 1, 512, 512, 1, TextureUsage::COLOR_ATTACHMENT);
+    auto renderTarget = api.createRenderTarget(
+            TargetBufferFlags::COLOR0, 512, 512, 1, 0, {{colorTexture}}, {}, {});

    // Upload uniforms for the first triangle.
-    // Upload the uniform, but with an offset to accommodate the padding in the shader's
-    // uniform definition.
-    shader.uploadUniform(api, ubuffer, kBindingConfig, MaterialParams{
+    {
+        MaterialParams params {
            .color = { 1.0f, 0.0f, 0.5f, 1.0f },
            .offset = { 0.0f, 0.0f, 0.0f, 0.0f }
-    });
+        };
+        auto* tmp = new MaterialParams(params);
+        auto cb = [](void* buffer, size_t size, void* user) {
+            auto* sp = (MaterialParams*) buffer;
+            delete sp;
+        };
+        BufferDescriptor bd(tmp, sizeof(MaterialParams), cb);
+        api.updateBufferObject(ubuffer, std::move(bd), 64);
+    }

    RenderPassParams params = {};
    params.flags.clear = TargetBufferFlags::COLOR;
@@ -246,27 +280,29 @@ TEST_F(BufferUpdatesTest, BufferObjectUpdateWithOffset) {
    params.flags.discardEnd = TargetBufferFlags::NONE;
    params.viewport.height = 512;
    params.viewport.width = 512;
-    renderTriangle({{ DescriptorSetLayoutHandle{}, shader.getDescriptorSetLayout() }},
-            renderTarget, swapChain, shader.getProgram(), params);
+    renderTriangle({{ DescriptorSetLayoutHandle{}, descriptorSetLayout }},
+            renderTarget, swapChain, program, params);

    // Upload uniforms for the second triangle. To test partial buffer updates, we'll only update
    // color.b, color.a, offset.x, and offset.y.
-    shader.uploadUniform(api, ubuffer, UniformBindingConfig{
-                    .dataSize = sizeof(std::array<float, 4>),
-                    .bufferSize = kBindingConfig.bufferSize,
-                    .byteOffset = *kBindingConfig.byteOffset + offsetof(MaterialParams, color.b),
-            },
-            std::array<float, 4>{
-                    // color.b, color.a
-                    1.0f, 1.0f,
-                    // offset.x, offset.y
-                    0.5f, 0.5f }
-    );
+    {
+        MaterialParams params {
+                .color = { 1.0f, 0.0f, 1.0f, 1.0f },
+                .offset = { 0.5f, 0.5f, 0.0f, 0.0f }
+        };
+        auto* tmp = new MaterialParams(params);
+        auto cb = [](void* buffer, size_t size, void* user) {
+            auto* sp = (MaterialParams*) ((char*)buffer - offsetof(MaterialParams, color.b));
+            delete sp;
+        };
+        BufferDescriptor bd((char*)tmp + offsetof(MaterialParams, color.b), sizeof(float) * 4, cb);
+        api.updateBufferObject(ubuffer, std::move(bd), 64 + offsetof(MaterialParams, color.b));
+    }

    params.flags.clear = TargetBufferFlags::NONE;
    params.flags.discardStart = TargetBufferFlags::NONE;
-    renderTriangle({{ DescriptorSetLayoutHandle{}, shader.getDescriptorSetLayout() }},
-            renderTarget, swapChain, shader.getProgram(), params);
+    renderTriangle({{ DescriptorSetLayoutHandle{}, descriptorSetLayout }},
+            renderTarget, swapChain, program, params);

    static const uint32_t expectedHash = 91322442;
    readPixelsAndAssertHash(
@@ -276,6 +312,14 @@ TEST_F(BufferUpdatesTest, BufferObjectUpdateWithOffset) {
    api.commit(swapChain);
    api.endFrame(0);

+    api.destroyProgram(program);
+    api.destroySwapChain(swapChain);
+    api.destroyDescriptorSet(descriptorSet);
+    api.destroyDescriptorSetLayout(descriptorSetLayout);
+    api.destroyBufferObject(ubuffer);
+    api.destroyRenderTarget(renderTarget);
+    api.destroyTexture(colorTexture);
+
    // This ensures all driver commands have finished before exiting the test.
    api.finish();

@@ -16,8 +16,6 @@

 #include "BackendTest.h"

-#include "Lifetimes.h"
-
 using namespace filament;
 using namespace filament::backend;

@@ -25,14 +23,13 @@ namespace test {

 TEST_F(BackendTest, FrameScheduledCallback) {
    auto& api = getDriverApi();
-    Cleanup cleanup(api);

    // Create a SwapChain.
    // In order for the frameScheduledCallback to be called, this must be a real SwapChain (not
    // headless) so we obtain a drawable.
-    auto swapChain = cleanup.add(createSwapChain());
+    auto swapChain = createSwapChain();

-    Handle<HwRenderTarget> renderTarget = cleanup.add(api.createDefaultRenderTarget());
+    Handle<HwRenderTarget> renderTarget = api.createDefaultRenderTarget();

    int callbackCountA = 0;
    api.setFrameScheduledCallback(swapChain, nullptr, [&callbackCountA](PresentCallable callable) {
@@ -82,10 +79,9 @@ TEST_F(BackendTest, FrameScheduledCallback) {

 TEST_F(BackendTest, FrameCompletedCallback) {
    auto& api = getDriverApi();
-    Cleanup cleanup(api);

    // Create a SwapChain.
-    auto swapChain = cleanup.add(api.createSwapChainHeadless(256, 256, 0));
+    auto swapChain = api.createSwapChainHeadless(256, 256, 0);

    int callbackCountA = 0;
    api.setFrameCompletedCallback(swapChain, nullptr,
--- a/Show More
+++ b/Show More