Merge branch 'rc/1.59.2' into release

Note that the flag is default to false while we roll out this
feature.

.github/workflows/presubmit.yml

@@ -108,21 +108,9 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: '3.x'
-      - name: Cache Mesa and deps
-        id: mesa-cache
-        uses: actions/cache@v4 # Use a specific version
-        with:
-          path: |
-            $HOME/Library/Caches/Homebrew
-            mesa
-          key: ${{ runner.os }}-mesa-deps-${{ vars.MESA_VERSION }}
-      - name: Get Mesa
-        id: mesa-prereq
-        env:
-          MESA_VERSION: ${{ vars.MESA_VERSION }}
-        run: |
-          bash test/utils/get_mesa.sh
-      - name: Run Test
+      - name: Install python prereqs
+        run: pip install mako setuptools pyyaml
+      - name: Run script
         run: |
           bash test/renderdiff/test.sh
       - uses: actions/upload-artifact@v4

CMakeLists.txt

@@ -801,7 +801,6 @@ add_subdirectory(${EXTERNAL}/draco/tnt)
 add_subdirectory(${EXTERNAL}/jsmn/tnt)
 add_subdirectory(${EXTERNAL}/stb/tnt)
 add_subdirectory(${EXTERNAL}/getopt)
-add_subdirectory(${EXTERNAL}/perfetto/tnt)
 
 # Note that this has to be placed after mikktspace in order for combine_static_libs to work.
 add_subdirectory(${LIBRARIES}/geometry)

README.md

@@ -31,7 +31,7 @@ repositories {
 }
 
 dependencies {
-    implementation 'com.google.android.filament:filament-android:1.59.3'
+    implementation 'com.google.android.filament:filament-android:1.59.2'
 }
 ```
 
@@ -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', '~> 1.59.3'
+pod 'Filament', '~> 1.59.2'
 ```
 
 ## Documentation

RELEASE_NOTES.md

@@ -7,12 +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).
 
-## v1.59.4
-
-
-## v1.59.3
-
-
 ## v1.59.2
 
 - Fix build/compile errors when upgrading to MacOS 15.4

android/filamat-android/CMakeLists.txt

@@ -26,10 +26,6 @@ add_library(utils STATIC IMPORTED)
 set_target_properties(utils PROPERTIES IMPORTED_LOCATION
         ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libutils.a)
 
-add_library(perfetto STATIC IMPORTED)
-set_target_properties(perfetto PROPERTIES IMPORTED_LOCATION
-        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libperfetto.a)
-
 add_library(filabridge STATIC IMPORTED)
 set_target_properties(filabridge PROPERTIES IMPORTED_LOCATION
         ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libfilabridge.a)
@@ -44,7 +40,6 @@ set_target_properties(shaders PROPERTIES IMPORTED_LOCATION
 
 set(FILAMAT_INCLUDE_DIRS
         ../../libs/utils/include
-        ../../third_party/perfetto
         )
 
 include_directories(${FILAMENT_DIR}/include)
@@ -60,7 +55,6 @@ target_link_libraries(filamat-jni
         filabridge
         shaders
         utils
-        perfetto
         log
         smol-v
         $<$<STREQUAL:${FILAMENT_SUPPORTS_WEBGPU},ON>:tint>

android/filament-android/CMakeLists.txt

@@ -21,10 +21,6 @@ add_library(utils STATIC IMPORTED)
 set_target_properties(utils PROPERTIES IMPORTED_LOCATION
         ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libutils.a)
 
-add_library(perfetto STATIC IMPORTED)
-set_target_properties(perfetto PROPERTIES IMPORTED_LOCATION
-        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libperfetto.a)
-
 add_library(ibl-lite STATIC IMPORTED)
 set_target_properties(ibl-lite PROPERTIES IMPORTED_LOCATION
         ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libibl-lite.a)
@@ -127,7 +123,6 @@ target_link_libraries(filament-jni
     PRIVATE android
     PRIVATE jnigraphics
     PRIVATE utils
-    PRIVATE perfetto
 
     # libgeometry is PUBLIC because gltfio uses it.
     PUBLIC geometry
@@ -146,7 +141,6 @@ target_include_directories(filament-jni PRIVATE
         ${FILAMENT_DIR}/include
         ../../filament/backend/include
         ../../third_party/robin-map
-        ../../third_party/perfetto
         ../../libs/utils/include)
 
 # Force a relink when the version script is changed:

android/gltfio-android/CMakeLists.txt

@@ -35,10 +35,6 @@ add_library(utils STATIC IMPORTED)
 set_target_properties(utils PROPERTIES IMPORTED_LOCATION
         ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libutils.a)
 
-add_library(perfetto STATIC IMPORTED)
-set_target_properties(perfetto PROPERTIES IMPORTED_LOCATION
-        ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libperfetto.a)
-
 add_library(uberzlib STATIC IMPORTED)
 set_target_properties(uberzlib PROPERTIES IMPORTED_LOCATION
         ${FILAMENT_DIR}/lib/${ANDROID_ABI}/libuberzlib.a)
@@ -125,7 +121,6 @@ set(GLTFIO_INCLUDE_DIRS
         ../../third_party/meshoptimizer/src
         ../../third_party/robin-map
         ../../third_party/stb
-        ../../third_party/perfetto
         ../../libs/utils/include
         ../../libs/ktxreader/include
 )
@@ -134,7 +129,7 @@ add_library(gltfio-jni SHARED ${GLTFIO_SRCS})
 target_include_directories(gltfio-jni PRIVATE ${GLTFIO_INCLUDE_DIRS})
 set_target_properties(gltfio-jni PROPERTIES LINK_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libgltfio-jni.symbols)
 set_target_properties(gltfio-jni PROPERTIES LINK_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libgltfio-jni.map)
-target_link_libraries(gltfio-jni filament-jni utils perfetto uberzlib log stb ktxreader basis_transcoder zstd uberarchive)
+target_link_libraries(gltfio-jni filament-jni utils uberzlib log stb ktxreader basis_transcoder zstd uberarchive)
 target_link_libraries(gltfio-jni dracodec meshoptimizer)
 target_compile_definitions(gltfio-jni PUBLIC GLTFIO_DRACO_SUPPORTED=1)
 target_include_directories(gltfio-jni PRIVATE ${DRACO_DIR}/src)

android/gradle.properties

@@ -1,5 +1,5 @@
 GROUP=com.google.android.filament
-VERSION_NAME=1.59.3
+VERSION_NAME=1.59.2
 
 POM_DESCRIPTION=Real-time physically based rendering engine for Android.
 

build/common/check-headers.sh

@@ -56,16 +56,10 @@ popd >/dev/null
 rm -rf out/check-headers
 mkdir -p out/check-headers
 
-TMP_FILE=out/check-headers/temp.cpp
 echo "Checking that public headers compile independently..."
 for include in "${includes[@]}"; do
-    rm -f ${TMP_FILE}
     echo "Checking ${include}"
-    if [[ "${include}" == "utils/Systrace.h" ]]; then
-        # A necessary define before we can include utils/Systrace.h
-        echo "#define SYSTRACE_TAG SYSTRACE_TAG_DISABLED" >> ${TMP_FILE}
-    fi
-    echo "#include <${include}>" >> ${TMP_FILE}
-    clang -std=c++17 -I "${FILAMENT_HEADERS}" ${TMP_FILE} -c -o /dev/null
+    echo "#include <${include}>" >> out/check-headers/temp.cpp
+    clang -std=c++17 -I "${FILAMENT_HEADERS}" out/check-headers/temp.cpp -c -o /dev/null
 done
 echo "Done!"

filament/backend/CMakeLists.txt

@@ -194,8 +194,6 @@ if (FILAMENT_SUPPORTS_VULKAN)
             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
@@ -261,7 +259,6 @@ if (FILAMENT_SUPPORTS_WEBGPU)
             src/webgpu/WebGPUHandles.h
             src/webgpu/WebGPUSwapChain.cpp
             src/webgpu/WebGPUSwapChain.h
-            src/webgpu/WGPUProgram.cpp
     )
     if (WIN32)
         list(APPEND SRCS src/webgpu/platform/WebGPUPlatformWindows.cpp)
@@ -510,10 +507,8 @@ if (APPLE OR LINUX)
         test/Arguments.cpp
         test/ImageExpectations.cpp
         test/Lifetimes.cpp
-        test/PlatformRunner.cpp
         test/Shader.cpp
         test/SharedShaders.cpp
-        test/Skip.cpp
         test/test_FeedbackLoops.cpp
         test/test_Blit.cpp
         test/test_MissingRequiredAttributes.cpp
@@ -537,9 +532,6 @@ if (APPLE OR LINUX)
         filamat
         SPIRV
         spirv-cross-glsl)
-    # Create input/output directories for test result images.
-    file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/images/actual_images)
-    file(COPY test/expected_images DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/images)
 endif()
 
 # TODO: Disabling IOS test due to breakage wrt glslang update

filament/backend/include/backend/BufferObjectStreamDescriptor.h

@@ -55,9 +55,4 @@ public:
 
 } // namespace filament::backend
 
-#if !defined(NDEBUG)
-utils::io::ostream& operator<<(utils::io::ostream& out,
-        const filament::backend::BufferObjectStreamDescriptor& b);
-#endif
-
 #endif // TNT_FILAMENT_BACKEND_BUFFEROBJECTSTREAMDESCRIPTOR_H

filament/backend/include/backend/Platform.h

@@ -149,6 +149,13 @@ public:
          *      - PlatformEGLAndroid
          */
         bool assertNativeWindowIsValid = false;
+
+        /**
+         * The action to take if a Drawable cannot be acquired. If true, the
+         * frame is aborted instead of panic. This is only supported for:
+         *      - PlatformMetal
+         */
+        bool metalDisablePanicOnDrawableFailure = false;
     };
 
     Platform() noexcept;

filament/backend/include/backend/platforms/VulkanPlatform.h

@@ -294,16 +294,6 @@ 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
          */
@@ -314,6 +304,11 @@ public:
          */
         uint32_t height;
 
+        /**
+         * The layerCount of the external image
+         */
+        uint32_t layerCount;
+
         /**
          * The layer count of the external image
          */
@@ -329,6 +324,11 @@ public:
          */
         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.
          */
@@ -348,61 +348,20 @@ 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;
     };
+    virtual ExternalImageMetadata getExternalImageMetadata(ExternalImageHandleRef externalImage);
 
+    using ImageData = std::pair<VkImage, VkDeviceMemory>;
+    virtual ImageData createExternalImageData(ExternalImageHandleRef externalImage,
+            const ExternalImageMetadata& metadata, uint32_t memoryTypeIndex,
+            VkImageUsageFlags usage);
 
-    // 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 VkSampler createExternalSampler(SamplerYcbcrConversion chroma,
+            SamplerParams sampler, uint32_t internalFormat);
 
-    struct ImageData {
-        struct Bundle {
-            VkImage image = VK_NULL_HANDLE;
-            VkDeviceMemory memory = VK_NULL_HANDLE;
-
-            inline bool valid() const noexcept {
-                return image != VK_NULL_HANDLE;
-            }
-        };
-        // It's possible for the external image to also have a known VK format. We need to create an
-        // image for that in case we are not looking to use an external "sampler" with this image.
-        Bundle internal;
-
-        // If we get a externalFormat in the metadata, then we should create an image with
-        // VK_FORMAT_UNDEFINED
-        Bundle external;
-    };
-
-    virtual ImageData createVkImageFromExternal(ExternalImageHandleRef image) const {
-        return {};
-    }
+    virtual VkImageView createExternalImageView(SamplerYcbcrConversion chroma,
+            uint32_t internalFormat, VkImage image, VkImageSubresourceRange range,
+            VkImageViewType viewType, VkComponentMapping swizzle);
 
 protected:
     virtual ExtensionSet getSwapchainInstanceExtensions() const;
@@ -415,6 +374,20 @@ private:
     // Platform dependent helper methods
     static ExtensionSet getSwapchainInstanceExtensionsImpl();
 
+    static ExternalImageMetadata getExternalImageMetadataImpl(ExternalImageHandleRef externalImage,
+            VkDevice device);
+
+    static ImageData createExternalImageDataImpl(ExternalImageHandleRef externalImage,
+            VkDevice device, const ExternalImageMetadata& metadata, uint32_t memoryTypeIndex,
+            VkImageUsageFlags usage);
+    static VkSampler createExternalSamplerImpl(VkDevice device,
+            SamplerYcbcrConversion chroma, SamplerParams sampler,
+            uint32_t internalFormat);
+    static VkImageView createExternalImageViewImpl(VkDevice device,
+            SamplerYcbcrConversion chroma, uint32_t internalFormat, VkImage image,
+            VkImageSubresourceRange range, VkImageViewType viewType,
+            VkComponentMapping swizzle);
+
     // Platform dependent helper methods
     static SurfaceBundle createVkSurfaceKHRImpl(void* nativeWindow, VkInstance instance,
             uint64_t flags) noexcept;

filament/backend/include/backend/platforms/VulkanPlatformAndroid.h

@@ -26,7 +26,7 @@ namespace filament::backend {
 
 class VulkanPlatformAndroid : public VulkanPlatform {
 public:
-    ExternalImageHandle UTILS_PUBLIC createExternalImage(AHardwareBuffer const* buffer,
+    Platform::ExternalImageHandle UTILS_PUBLIC createExternalImage(AHardwareBuffer const* buffer,
             bool sRGB) noexcept;
 
     struct UTILS_PUBLIC ExternalImageDescAndroid {
@@ -39,26 +39,31 @@ public:
     ExternalImageDescAndroid UTILS_PUBLIC getExternalImageDesc(
             ExternalImageHandleRef externalImage) const noexcept;
 
-    virtual ExternalImageMetadata extractExternalImageMetadata(
-            ExternalImageHandleRef image) const override;
-
-    virtual ImageData createVkImageFromExternal(ExternalImageHandleRef image) const override;
-
 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;
+        unsigned int width;  // Texture width
+        unsigned int height; // Texture height
+        TextureFormat format;// Texture format
+        TextureUsage usage;  // Texture usage flags
 
     protected:
         ~ExternalImageVulkanAndroid() override;
     };
+
+    virtual ExternalImageMetadata getExternalImageMetadata(ExternalImageHandleRef externalImage);
+
+    using ImageData = VulkanPlatform::ImageData;
+    virtual ImageData createExternalImageData(ExternalImageHandleRef externalImage,
+            const ExternalImageMetadata& metadata, uint32_t memoryTypeIndex,
+            VkImageUsageFlags usage);
+
+    virtual ExtensionSet getSwapchainInstanceExtensions() const;
+
+    using SurfaceBundle = VulkanPlatform::SurfaceBundle;
+    virtual SurfaceBundle createVkSurfaceKHR(void* nativeWindow, VkInstance instance,
+            uint64_t flags) const noexcept;
 };
 
 }// namespace filament::backend

filament/backend/include/backend/platforms/WebGPUPlatform.h

@@ -38,12 +38,6 @@ public:
 
     [[nodiscard]] wgpu::Instance& getInstance() noexcept { return mInstance; }
 
-    // TODO consider that this functionality is not WebGPU-specific, and thus could be
-    //      placed in a generic place and even reused across backends. Alternatively,
-    //      a 3rd party library could be considered. However, this was a simple and
-    //      quick change and works for now.
-    // gets the size (height and width) of the surface/window
-    [[nodiscard]] wgpu::Extent2D getSurfaceExtent(void* nativeWindow) const;
     // either returns a valid surface or panics
     [[nodiscard]] wgpu::Surface createSurface(void* nativeWindow, uint64_t flags);
     // either returns a valid adapter or panics

filament/backend/src/CommandStream.cpp

@@ -84,7 +84,7 @@ void CommandStream::execute(void* buffer) {
 
     Profiler profiler;
 
-    if constexpr (SYSTRACE_TAG) {
+    if (SYSTRACE_TAG) {
         if (UTILS_UNLIKELY(mUsePerformanceCounter)) {
             // we want to remove all this when tracing is completely disabled
             profiler.resetEvents(Profiler::EV_CPU_CYCLES  | Profiler::EV_BPU_MISSES);
@@ -100,7 +100,7 @@ void CommandStream::execute(void* buffer) {
         }
     });
 
-    if constexpr (SYSTRACE_TAG) {
+    if (SYSTRACE_TAG) {
         if (UTILS_UNLIKELY(mUsePerformanceCounter)) {
             // we want to remove all this when tracing is completely disabled
             profiler.stop();

filament/backend/src/metal/MetalDriver.mm

@@ -1408,8 +1408,8 @@ void MetalDriver::setRenderPrimitiveBuffer(Handle<HwRenderPrimitive> rph, Primit
     auto primitive = handle_cast<MetalRenderPrimitive>(rph);
     auto vertexBuffer = handle_cast<MetalVertexBuffer>(vbh);
     auto indexBuffer = handle_cast<MetalIndexBuffer>(ibh);
-    primitive->vertexBuffer = vertexBuffer;
-    primitive->indexBuffer = indexBuffer;
+    MetalVertexBufferInfo const* const vbi = handle_cast<MetalVertexBufferInfo>(vertexBuffer->vbih);
+    primitive->setBuffers(vbi, vertexBuffer, indexBuffer);
     primitive->type = pt;
 }
 

filament/backend/src/metal/MetalHandles.h

@@ -194,8 +194,12 @@ struct MetalIndexBuffer : public HwIndexBuffer {
 };
 
 struct MetalRenderPrimitive : public HwRenderPrimitive {
+    MetalRenderPrimitive();
+    void setBuffers(MetalVertexBufferInfo const* const vbi,
+            MetalVertexBuffer* vertexBuffer, MetalIndexBuffer* indexBuffer);
     // The pointers to MetalVertexBuffer and MetalIndexBuffer are "weak".
     // The MetalVertexBuffer and MetalIndexBuffer must outlive the MetalRenderPrimitive.
+
     MetalVertexBuffer* vertexBuffer = nullptr;
     MetalIndexBuffer* indexBuffer = nullptr;
 };
@@ -376,6 +380,7 @@ public:
 
     math::uint2 getAttachmentSize() noexcept;
 
+    bool isDefaultRenderTarget() const { return defaultRenderTarget; }
     uint8_t getSamples() const { return samples; }
 
     Attachment getDrawColorAttachment(size_t index);

filament/backend/src/metal/MetalHandles.mm

@@ -536,6 +536,15 @@ MetalIndexBuffer::MetalIndexBuffer(MetalContext& context, BufferUsage usage, uin
         uint32_t indexCount) : HwIndexBuffer(elementSize, indexCount),
         buffer(context, BufferObjectBinding::VERTEX, usage, elementSize * indexCount, true) { }
 
+MetalRenderPrimitive::MetalRenderPrimitive() {
+}
+
+void MetalRenderPrimitive::setBuffers(MetalVertexBufferInfo const* const vbi,
+        MetalVertexBuffer* vertexBuffer, MetalIndexBuffer* indexBuffer) {
+    this->vertexBuffer = vertexBuffer;
+    this->indexBuffer = indexBuffer;
+}
+
 MetalProgram::MetalProgram(MetalContext& context, Program&& program) noexcept
     : HwProgram(program.getName()), mContext(context) {
     mToken = context.shaderCompiler->createProgram(program.getName(), std::move(program));

filament/backend/src/metal/PlatformMetal.mm

@@ -45,6 +45,9 @@ PlatformMetal::~PlatformMetal() noexcept {
 }
 
 Driver* PlatformMetal::createDriver(void* /*sharedContext*/, const Platform::DriverConfig& driverConfig) noexcept {
+    pImpl->mDrawableFailureBehavior = driverConfig.metalDisablePanicOnDrawableFailure
+            ? DrawableFailureBehavior::ABORT_FRAME
+            : DrawableFailureBehavior::PANIC;
     return MetalDriverFactory::create(this, driverConfig);
 }
 

filament/backend/src/opengl/GLUtils.cpp

@@ -16,15 +16,9 @@
 
 #include "GLUtils.h"
 
-#include "private/backend/Driver.h"
-
-#include <utils/compiler.h>
-#include <utils/ostream.h>
 #include <utils/trap.h>
 
-#include <string_view>
-
-#include <stddef.h>
+#include "private/backend/Driver.h"
 
 namespace filament::backend {
 
@@ -34,31 +28,38 @@ using namespace utils;
 namespace GLUtils {
 
 UTILS_NOINLINE
-std::string_view getGLErrorString(GLenum error) noexcept {
+const char* getGLError(GLenum error) noexcept {
+    const char* string = "unknown";
     switch (error) {
         case GL_NO_ERROR:
-            return "GL_NO_ERROR";
+            string = "GL_NO_ERROR";
+            break;
         case GL_INVALID_ENUM:
-            return "GL_INVALID_ENUM";
+            string = "GL_INVALID_ENUM";
+            break;
         case GL_INVALID_VALUE:
-            return "GL_INVALID_VALUE";
+            string = "GL_INVALID_VALUE";
+            break;
         case GL_INVALID_OPERATION:
-            return "GL_INVALID_OPERATION";
+            string = "GL_INVALID_OPERATION";
+            break;
         case GL_INVALID_FRAMEBUFFER_OPERATION:
-            return "GL_INVALID_FRAMEBUFFER_OPERATION";
+            string = "GL_INVALID_FRAMEBUFFER_OPERATION";
+            break;
         case GL_OUT_OF_MEMORY:
-            return "GL_OUT_OF_MEMORY";
+            string = "GL_OUT_OF_MEMORY";
+            break;
         default:
             break;
     }
-    return "unknown";
+    return string;
 }
 
 UTILS_NOINLINE
 GLenum checkGLError(io::ostream& out, const char* function, size_t line) noexcept {
     GLenum const error = glGetError();
-    if (UTILS_VERY_UNLIKELY(error != GL_NO_ERROR)) {
-        auto const string = getGLErrorString(error);
+    if (error != GL_NO_ERROR) {
+        const char* string = getGLError(error);
         out << "OpenGL error " << io::hex << error << " (" << string << ") in \""
             << function << "\" at line " << io::dec << line << io::endl;
     }
@@ -68,39 +69,46 @@ GLenum checkGLError(io::ostream& out, const char* function, size_t line) noexcep
 UTILS_NOINLINE
 void assertGLError(io::ostream& out, const char* function, size_t line) noexcept {
     GLenum const err = checkGLError(out, function, line);
-    if (UTILS_VERY_UNLIKELY(err != GL_NO_ERROR)) {
+    if (err != GL_NO_ERROR) {
         debug_trap();
     }
 }
 
 UTILS_NOINLINE
-std::string_view getFramebufferStatusString(GLenum status) noexcept {
+const char* getFramebufferStatus(GLenum status) noexcept {
+    const char* string = "unknown";
     switch (status) {
         case GL_FRAMEBUFFER_COMPLETE:
-            return "GL_FRAMEBUFFER_COMPLETE";
+            string = "GL_FRAMEBUFFER_COMPLETE";
+            break;
         case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
-            return "GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT";
+            string = "GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT";
+            break;
         case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
-            return "GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT";
+            string = "GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT";
+            break;
         case GL_FRAMEBUFFER_UNSUPPORTED:
-            return "GL_FRAMEBUFFER_UNSUPPORTED";
+            string = "GL_FRAMEBUFFER_UNSUPPORTED";
+            break;
 #ifndef FILAMENT_SILENCE_NOT_SUPPORTED_BY_ES2
         case GL_FRAMEBUFFER_UNDEFINED:
-            return "GL_FRAMEBUFFER_UNDEFINED";
+            string = "GL_FRAMEBUFFER_UNDEFINED";
+            break;
         case GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE:
-            return "GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE";
+            string = "GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE";
+            break;
 #endif
         default:
             break;
     }
-    return "unknown";
+    return string;
 }
 
 UTILS_NOINLINE
 GLenum checkFramebufferStatus(io::ostream& out, GLenum target, const char* function, size_t line) noexcept {
     GLenum const status = glCheckFramebufferStatus(target);
-    if (UTILS_VERY_UNLIKELY(status != GL_FRAMEBUFFER_COMPLETE)) {
-        auto const string = getFramebufferStatusString(status);
+    if (status != GL_FRAMEBUFFER_COMPLETE) {
+        const char* string = getFramebufferStatus(status);
         out << "OpenGL framebuffer error " << io::hex << status << " (" << string << ") in \""
             << function << "\" at line " << io::dec << line << io::endl;
     }
@@ -110,7 +118,7 @@ GLenum checkFramebufferStatus(io::ostream& out, GLenum target, const char* funct
 UTILS_NOINLINE
 void assertFramebufferStatus(io::ostream& out, GLenum target, const char* function, size_t line) noexcept {
     GLenum const status = checkFramebufferStatus(out, target, function, line);
-    if (UTILS_VERY_UNLIKELY(status != GL_FRAMEBUFFER_COMPLETE)) {
+    if (status != GL_FRAMEBUFFER_COMPLETE) {
         debug_trap();
     }
 }

filament/backend/src/opengl/GLUtils.h

@@ -17,26 +17,29 @@
 #ifndef TNT_FILAMENT_BACKEND_OPENGL_GLUTILS_H
 #define TNT_FILAMENT_BACKEND_OPENGL_GLUTILS_H
 
+#include <utils/compiler.h>
 #include <utils/debug.h>
-#include <utils/ostream.h>
+#include <utils/Log.h>
 
 #include <backend/DriverEnums.h>
 
 #include <string_view>
 #include <unordered_set>
 
-#include <stddef.h>
 #include <stdint.h>
+#include <stddef.h>
+#include <string.h>
 
 #include "gl_headers.h"
 
-namespace filament::backend::GLUtils {
+namespace filament::backend {
+namespace GLUtils {
 
-std::string_view getGLErrorString(GLenum error) noexcept;
+const char* getGLError(GLenum error) noexcept;
 GLenum checkGLError(utils::io::ostream& out, const char* function, size_t line) noexcept;
 void assertGLError(utils::io::ostream& out, const char* function, size_t line) noexcept;
 
-std::string_view getFramebufferStatusString(GLenum err) noexcept;
+const char* getFramebufferStatus(GLenum err) noexcept;
 GLenum checkFramebufferStatus(utils::io::ostream& out, GLenum target, const char* function, size_t line) noexcept;
 void assertFramebufferStatus(utils::io::ostream& out, GLenum target, const char* function, size_t line) noexcept;
 
@@ -50,7 +53,7 @@ void assertFramebufferStatus(utils::io::ostream& out, GLenum target, const char*
 #   define CHECK_GL_FRAMEBUFFER_STATUS(out, target) { GLUtils::checkFramebufferStatus(out, target, __func__, __LINE__); }
 #endif
 
-constexpr GLuint getComponentCount(ElementType const type) noexcept {
+constexpr GLuint getComponentCount(ElementType type) noexcept {
     using ElementType = ElementType;
     switch (type) {
         case ElementType::BYTE:
@@ -84,29 +87,27 @@ constexpr GLuint getComponentCount(ElementType const type) noexcept {
         case ElementType::USHORT4:
             return 4;
     }
-    // should never happen
-    return 1;
 }
 
 // ------------------------------------------------------------------------------------------------
 // Our enums to GLenum conversions
 // ------------------------------------------------------------------------------------------------
 
-constexpr GLbitfield getAttachmentBitfield(TargetBufferFlags const flags) noexcept {
+constexpr GLbitfield getAttachmentBitfield(TargetBufferFlags flags) noexcept {
     GLbitfield mask = 0;
     if (any(flags & TargetBufferFlags::COLOR_ALL)) {
-        mask |= GLbitfield(GL_COLOR_BUFFER_BIT);
+        mask |= (GLbitfield)GL_COLOR_BUFFER_BIT;
     }
     if (any(flags & TargetBufferFlags::DEPTH)) {
-        mask |= GLbitfield(GL_DEPTH_BUFFER_BIT);
+        mask |= (GLbitfield)GL_DEPTH_BUFFER_BIT;
     }
     if (any(flags & TargetBufferFlags::STENCIL)) {
-        mask |= GLbitfield(GL_STENCIL_BUFFER_BIT);
+        mask |= (GLbitfield)GL_STENCIL_BUFFER_BIT;
     }
     return mask;
 }
 
-constexpr GLenum getBufferUsage(BufferUsage const usage) noexcept {
+constexpr GLenum getBufferUsage(BufferUsage usage) noexcept {
     switch (usage) {
         case BufferUsage::STATIC:
             return GL_STATIC_DRAW;
@@ -115,7 +116,7 @@ constexpr GLenum getBufferUsage(BufferUsage const usage) noexcept {
     }
 }
 
-constexpr GLenum getBufferBindingType(BufferObjectBinding const bindingType) noexcept {
+constexpr GLenum getBufferBindingType(BufferObjectBinding bindingType) noexcept {
     switch (bindingType) {
         case BufferObjectBinding::VERTEX:
             return GL_ARRAY_BUFFER;
@@ -134,15 +135,13 @@ constexpr GLenum getBufferBindingType(BufferObjectBinding const bindingType) noe
             return 0x90D2; // just to return something
 #endif
     }
-    // should never happen
-    return GL_ARRAY_BUFFER;
 }
 
-constexpr GLboolean getNormalization(bool const normalized) noexcept {
+constexpr GLboolean getNormalization(bool normalized) noexcept {
     return GLboolean(normalized ? GL_TRUE : GL_FALSE);
 }
 
-constexpr GLenum getComponentType(ElementType const type) noexcept {
+constexpr GLenum getComponentType(ElementType type) noexcept {
     using ElementType = ElementType;
     switch (type) {
         case ElementType::BYTE:
@@ -185,11 +184,9 @@ constexpr GLenum getComponentType(ElementType const type) noexcept {
             return GL_HALF_FLOAT_OES;
 #endif
     }
-    // should never happen
-    return GL_INT;
 }
 
-constexpr GLenum getTextureTargetNotExternal(SamplerType const target) noexcept {
+constexpr GLenum getTextureTargetNotExternal(SamplerType target) noexcept {
     switch (target) {
         case SamplerType::SAMPLER_2D:
             return GL_TEXTURE_2D;
@@ -205,16 +202,14 @@ constexpr GLenum getTextureTargetNotExternal(SamplerType const target) noexcept
             // we should never be here
             return GL_TEXTURE_2D;
     }
-    // should never happen
-    return GL_TEXTURE_2D;
 }
 
-constexpr GLenum getCubemapTarget(uint16_t const layer) noexcept {
+constexpr GLenum getCubemapTarget(uint16_t layer) noexcept {
     assert_invariant(layer <= 5);
     return GL_TEXTURE_CUBE_MAP_POSITIVE_X + layer;
 }
 
-constexpr GLenum getWrapMode(SamplerWrapMode const mode) noexcept {
+constexpr GLenum getWrapMode(SamplerWrapMode mode) noexcept {
     using SamplerWrapMode = SamplerWrapMode;
     switch (mode) {
         case SamplerWrapMode::REPEAT:
@@ -224,8 +219,6 @@ constexpr GLenum getWrapMode(SamplerWrapMode const mode) noexcept {
         case SamplerWrapMode::MIRRORED_REPEAT:
             return GL_MIRRORED_REPEAT;
     }
-    // should never happen
-    return GL_CLAMP_TO_EDGE;
 }
 
 constexpr GLenum getTextureFilter(SamplerMinFilter filter) noexcept {
@@ -241,8 +234,6 @@ constexpr GLenum getTextureFilter(SamplerMinFilter filter) noexcept {
             return GL_NEAREST_MIPMAP_NEAREST
                    - GLenum(SamplerMinFilter::NEAREST_MIPMAP_NEAREST) + GLenum(filter);
     }
-    // should never happen
-    return GL_NEAREST;
 }
 
 constexpr GLenum getTextureFilter(SamplerMagFilter filter) noexcept {
@@ -250,7 +241,7 @@ constexpr GLenum getTextureFilter(SamplerMagFilter filter) noexcept {
 }
 
 
-constexpr GLenum getBlendEquationMode(BlendEquation const mode) noexcept {
+constexpr GLenum getBlendEquationMode(BlendEquation mode) noexcept {
     using BlendEquation = BlendEquation;
     switch (mode) {
         case BlendEquation::ADD:               return GL_FUNC_ADD;
@@ -259,11 +250,9 @@ constexpr GLenum getBlendEquationMode(BlendEquation const mode) noexcept {
         case BlendEquation::MIN:               return GL_MIN;
         case BlendEquation::MAX:               return GL_MAX;
     }
-    // should never happen
-    return GL_FUNC_ADD;
 }
 
-constexpr GLenum getBlendFunctionMode(BlendFunction const mode) noexcept {
+constexpr GLenum getBlendFunctionMode(BlendFunction mode) noexcept {
     using BlendFunction = BlendFunction;
     switch (mode) {
         case BlendFunction::ZERO:                  return GL_ZERO;
@@ -278,11 +267,9 @@ constexpr GLenum getBlendFunctionMode(BlendFunction const mode) noexcept {
         case BlendFunction::ONE_MINUS_DST_ALPHA:   return GL_ONE_MINUS_DST_ALPHA;
         case BlendFunction::SRC_ALPHA_SATURATE:    return GL_SRC_ALPHA_SATURATE;
     }
-    // should never happen
-    return GL_ONE;
 }
 
-constexpr GLenum getCompareFunc(SamplerCompareFunc const func) noexcept {
+constexpr GLenum getCompareFunc(SamplerCompareFunc func) noexcept {
     switch (func) {
         case SamplerCompareFunc::LE:    return GL_LEQUAL;
         case SamplerCompareFunc::GE:    return GL_GEQUAL;
@@ -293,30 +280,28 @@ constexpr GLenum getCompareFunc(SamplerCompareFunc const func) noexcept {
         case SamplerCompareFunc::A:     return GL_ALWAYS;
         case SamplerCompareFunc::N:     return GL_NEVER;
     }
-    // should never happen
-    return GL_LEQUAL;
 }
 
 #ifndef FILAMENT_SILENCE_NOT_SUPPORTED_BY_ES2
-constexpr GLenum getTextureCompareMode(SamplerCompareMode const mode) noexcept {
+constexpr GLenum getTextureCompareMode(SamplerCompareMode mode) noexcept {
     return mode == SamplerCompareMode::NONE ?
            GL_NONE : GL_COMPARE_REF_TO_TEXTURE;
 }
 
-constexpr GLenum getTextureCompareFunc(SamplerCompareFunc const func) noexcept {
+constexpr GLenum getTextureCompareFunc(SamplerCompareFunc func) noexcept {
     return getCompareFunc(func);
 }
 #endif
 
-constexpr GLenum getDepthFunc(SamplerCompareFunc const func) noexcept {
+constexpr GLenum getDepthFunc(SamplerCompareFunc func) noexcept {
     return getCompareFunc(func);
 }
 
-constexpr GLenum getStencilFunc(SamplerCompareFunc const func) noexcept {
+constexpr GLenum getStencilFunc(SamplerCompareFunc func) noexcept {
     return getCompareFunc(func);
 }
 
-constexpr GLenum getStencilOp(StencilOperation const op) noexcept {
+constexpr GLenum getStencilOp(StencilOperation op) noexcept {
     switch (op) {
         case StencilOperation::KEEP:        return GL_KEEP;
         case StencilOperation::ZERO:        return GL_ZERO;
@@ -327,11 +312,9 @@ constexpr GLenum getStencilOp(StencilOperation const op) noexcept {
         case StencilOperation::DECR_WRAP:   return GL_DECR_WRAP;
         case StencilOperation::INVERT:      return GL_INVERT;
     }
-    // should never happen
-    return GL_KEEP;
 }
 
-constexpr GLenum getFormat(PixelDataFormat const format) noexcept {
+constexpr GLenum getFormat(PixelDataFormat format) noexcept {
     using PixelDataFormat = PixelDataFormat;
     switch (format) {
         case PixelDataFormat::RGB:              return GL_RGB;
@@ -353,11 +336,9 @@ constexpr GLenum getFormat(PixelDataFormat const format) noexcept {
         default: return GL_NONE;
 #endif
     }
-    // should never happen
-    return GL_RGBA;
 }
 
-constexpr GLenum getType(PixelDataType const type) noexcept {
+constexpr GLenum getType(PixelDataType type) noexcept {
     using PixelDataType = PixelDataType;
     switch (type) {
         case PixelDataType::UBYTE:                return GL_UNSIGNED_BYTE;
@@ -379,12 +360,10 @@ constexpr GLenum getType(PixelDataType const type) noexcept {
         default: return GL_NONE;
 #endif
     }
-    // should never happen
-    return GL_UNSIGNED_INT;
 }
 
 #if !defined(__EMSCRIPTEN__)  && !defined(FILAMENT_SILENCE_NOT_SUPPORTED_BY_ES2)
-constexpr GLenum getSwizzleChannel(TextureSwizzle const c) noexcept {
+constexpr GLenum getSwizzleChannel(TextureSwizzle c) noexcept {
     using TextureSwizzle = TextureSwizzle;
     switch (c) {
         case TextureSwizzle::SUBSTITUTE_ZERO:   return GL_ZERO;
@@ -394,12 +373,10 @@ constexpr GLenum getSwizzleChannel(TextureSwizzle const c) noexcept {
         case TextureSwizzle::CHANNEL_2:         return GL_BLUE;
         case TextureSwizzle::CHANNEL_3:         return GL_ALPHA;
     }
-    // should never happen
-    return GL_RED;
 }
 #endif
 
-constexpr GLenum getCullingMode(CullingMode const mode) noexcept {
+constexpr GLenum getCullingMode(CullingMode mode) noexcept {
     switch (mode) {
         case CullingMode::NONE:
             // should never happen
@@ -411,13 +388,11 @@ constexpr GLenum getCullingMode(CullingMode const mode) noexcept {
         case CullingMode::FRONT_AND_BACK:
             return GL_FRONT_AND_BACK;
     }
-    // should never happen
-    return GL_FRONT_AND_BACK;
 }
 
 // ES2 supported internal formats for texturing and how they  map to a format/type
 constexpr std::pair<GLenum, GLenum> textureFormatToFormatAndType(
-        TextureFormat const format) noexcept {
+        TextureFormat format) noexcept {
     switch (format) {
         case TextureFormat::R8:         return { 0x1909 /*GL_LUMINANCE*/, GL_UNSIGNED_BYTE };
         case TextureFormat::RGB8:       return { GL_RGB,                  GL_UNSIGNED_BYTE };
@@ -438,7 +413,7 @@ constexpr std::pair<GLenum, GLenum> textureFormatToFormatAndType(
 // clang loses it on this one, and generates a huge jump table when
 // inlined. So we don't  mark it as inline (only constexpr) which solves the problem,
 // strangely, when not inlined, clang simply generates an array lookup.
-constexpr /* inline */ GLenum getInternalFormat(TextureFormat const format) noexcept {
+constexpr /* inline */ GLenum getInternalFormat(TextureFormat format) noexcept {
     switch (format) {
 
         /* Formats supported by our ES2 implementations */
@@ -686,7 +661,7 @@ public:
 
 unordered_string_set split(const char* extensions) noexcept;
 
-} // namespace filament::backend::GLUtils
-
+} // namespace GLUtils
+} // namespace filament::backend
 
 #endif // TNT_FILAMENT_BACKEND_OPENGL_GLUTILS_H

filament/backend/src/opengl/OpenGLDriver.cpp

@@ -2098,7 +2098,6 @@ void OpenGLDriver::setAcquiredImage(Handle<HwStream> sh, void* hwbuffer, const m
 
     glstream->user_thread.pending = mPlatform.transformAcquiredImage({
             hwbuffer, cb, userData, handler });
-    glstream->user_thread.transform = transform;
 
     if (glstream->user_thread.pending.image != nullptr) {
         // If there's no pending image, do nothing. Note that GL_OES_EGL_image does not let you pass

filament/backend/src/opengl/OpenGLProgram.cpp

@@ -85,7 +85,6 @@ OpenGLProgram::~OpenGLProgram() noexcept {
         delete lazyInitializationData;
 
         ShaderCompilerService::terminate(mToken);
-        assert_invariant(!mToken);
     }
 
     delete [] mUniformsRecords;

filament/backend/src/opengl/ShaderCompilerService.h

@@ -24,23 +24,23 @@
 #include "OpenGLBlobCache.h"
 
 #include <backend/CallbackHandler.h>
-#include <backend/DriverEnums.h>
 #include <backend/Program.h>
 
 #include <utils/CString.h>
 #include <utils/FixedCapacityVector.h>
+#include <utils/Invocable.h>
 #include <utils/JobSystem.h>
 
-#include <array>
+#include <atomic>
+#include <condition_variable>
+#include <deque>
 #include <functional>
 #include <memory>
 #include <mutex>
-#include <tuple>
+#include <thread>
 #include <utility>
 #include <vector>
 
-#include <stdint.h>
-
 namespace filament::backend {
 
 class OpenGLDriver;
@@ -57,8 +57,6 @@ class ShaderCompilerService {
 
 public:
     using program_token_t = std::shared_ptr<OpenGLProgramToken>;
-    using shaders_t = std::array<GLuint, Program::SHADER_TYPE_COUNT>;
-    using shaders_source_t = std::array<utils::CString, Program::SHADER_TYPE_COUNT>;
 
     explicit ShaderCompilerService(OpenGLDriver& driver);
 
@@ -84,7 +82,6 @@ public:
     void tick();
 
     // Destroys a valid token and all associated resources. Used to "cancel" a program compilation.
-    // This function is not called if `initialize(token)` is already invoked.
     static void terminate(program_token_t& token);
 
     // stores a user data pointer in the token
@@ -93,12 +90,6 @@ public:
     // retrieves the user data pointer stored in the token
     static void* getUserData(const program_token_t& token) noexcept;
 
-    // Issue one callback handle.
-    CallbackManager::Handle issueCallbackHandle() const noexcept;
-
-    // Return a callback handle to the callback manager.
-    void submitCallbackHandle(CallbackManager::Handle handle) noexcept;
-
     // call the callback when all active programs are ready
     void notifyWhenAllProgramsAreReady(
             CallbackHandler* handler, CallbackHandler::Callback callback, void* user);
@@ -106,7 +97,7 @@ public:
 private:
     struct Job {
         template<typename FUNC>
-        Job(FUNC&& fn) : fn(std::forward<FUNC>(fn)) {} // NOLINT(*-explicit-constructor)
+        Job(FUNC&& fn) : fn(std::forward<FUNC>(fn)) {}
         Job(std::function<bool(Job const& job)> fn,
                 CallbackHandler* handler, void* user, CallbackHandler::Callback callback)
                 : fn(std::move(fn)), handler(handler), user(user), callback(callback) {
@@ -135,49 +126,39 @@ private:
     using ContainerType = std::tuple<CompilerPriorityQueue, program_token_t, Job>;
     std::vector<ContainerType> mRunAtNextTickOps;
 
-    GLuint initialize(program_token_t& token);
-    void ensureTokenIsReady(program_token_t const& token);
+    GLuint initialize(ShaderCompilerService::program_token_t& token) noexcept;
 
-    void runAtNextTick(CompilerPriorityQueue priority, program_token_t const& token,
-            Job job) noexcept;
+    static void getProgramFromCompilerPool(program_token_t& token) noexcept;
+
+    static void compileShaders(
+            OpenGLContext& context,
+            Program::ShaderSource shadersSource,
+            utils::FixedCapacityVector<Program::SpecializationConstant> const& specializationConstants,
+            bool multiview,
+            std::array<GLuint, Program::SHADER_TYPE_COUNT>& outShaders,
+            std::array<utils::CString, Program::SHADER_TYPE_COUNT>& outShaderSourceCode) noexcept;
+
+    static void process_GOOGLE_cpp_style_line_directive(OpenGLContext& context,
+            char* source, size_t len) noexcept;
+
+    static void process_OVR_multiview2(OpenGLContext& context, int32_t eyeCount,
+            char* source, size_t len) noexcept;
+
+    static std::string_view process_ARB_shading_language_packing(OpenGLContext& context) noexcept;
+
+    static std::array<std::string_view, 3> splitShaderSource(std::string_view source) noexcept;
+
+    static GLuint linkProgram(OpenGLContext& context,
+            std::array<GLuint, Program::SHADER_TYPE_COUNT> shaders,
+            utils::FixedCapacityVector<std::pair<utils::CString, uint8_t>> const& attributes) noexcept;
+
+    static bool checkProgramStatus(program_token_t const& token) noexcept;
+
+    void runAtNextTick(CompilerPriorityQueue priority,
+            const program_token_t& token, Job job) noexcept;
     void executeTickOps() noexcept;
-    bool cancelTickOp(program_token_t const& token) noexcept;
-
-    // Compile shaders with the given `shaderSource`. `gl.shaders` is always populated with valid
-    // shader IDs after this method. But this doesn't necessarily mean the shaders are successfully
-    // compiled. Errors can be checked by calling `checkCompileStatus` later.
-    static void compileShaders(OpenGLContext& context, Program::ShaderSource shadersSource,
-            utils::FixedCapacityVector<Program::SpecializationConstant> const&
-                    specializationConstants,
-            bool multiview, program_token_t const& token) noexcept;
-
-    // Check if the shader compilation is completed. You may want to call this when the extension
-    // `KHR_parallel_shader_compile` is enabled.
-    static bool isCompileCompleted(program_token_t const& token) noexcept;
-
-    // Check compilation status of the shaders and log errors on failure.
-    static void checkCompileStatus(program_token_t const& token) noexcept;
-
-    // Create a program by linking the compiled shaders. `gl.program` is always populated with a
-    // valid program ID after this method. But this doesn't necessarily mean the program is
-    // successfully linked. Errors can be checked by calling `checkLinkStatusAndCleanupShaders`
-    // later.
-    static void linkProgram(OpenGLContext const& context, program_token_t const& token) noexcept;
-
-    // Check if the program link is completed. You may want to call this when the extension
-    // `KHR_parallel_shader_compile` is enabled.
-    static bool isLinkCompleted(program_token_t const& token) noexcept;
-
-    // Check link status of the program and log errors on failure. Return the result of the link.
-    // Also cleanup shaders regardless of the result.
-    static bool checkLinkStatusAndCleanupShaders(program_token_t const& token) noexcept;
-
-    // Try caching the program if we haven't done it yet. Cache it only when the program is valid.
-    static void tryCachingProgram(OpenGLBlobCache& cache, OpenGLPlatform& platform,
-            program_token_t const& token) noexcept;
-
-    // Cleanup GL resources.
-    static void cleanupProgramAndShaders(program_token_t const& token) noexcept;
+    bool cancelTickOp(program_token_t token) noexcept;
+    // order of insertion is important
 };
 
 } // namespace filament::backend

filament/backend/src/opengl/platforms/CocoaExternalImage.mm

@@ -17,10 +17,8 @@
 #define COREVIDEO_SILENCE_GL_DEPRECATION
 
 #include "CocoaExternalImage.h"
-#include "../GLUtils.h"
-
 #include <utils/Panic.h>
-#include <utils/Log.h>
+#include "../GLUtils.h"
 
 namespace filament::backend {
 

filament/backend/src/opengl/platforms/CocoaTouchExternalImage.mm

@@ -28,7 +28,6 @@
 #include <utils/compiler.h>
 #include <utils/Panic.h>
 #include <utils/debug.h>
-#include <utils/Log.h>
 
 namespace filament::backend {
 

filament/backend/src/ostream.cpp

@@ -15,7 +15,6 @@
  */
 
 #include <backend/BufferDescriptor.h>
-#include <backend/BufferObjectStreamDescriptor.h>
 #include <backend/DescriptorSetOffsetArray.h>
 #include <backend/DriverEnums.h>
 #include <backend/PipelineState.h>
@@ -438,10 +437,6 @@ io::ostream& operator<<(io::ostream& out, BufferDescriptor const& b) {
     << ", user=" << b.getUser() << " }";
 }
 
-io::ostream& operator<<(io::ostream& out, const BufferObjectStreamDescriptor& b) {
-    return out << "BufferObjectStreamDescriptor{ streams(" << b.mStreams.size() << ")=... }";
-}
-
 io::ostream& operator<<(io::ostream& out, PixelBufferDescriptor const& b) {
     BufferDescriptor const& base = static_cast<BufferDescriptor const&>(b);
     return out << "PixelBufferDescriptor{ " << base

filament/backend/src/vulkan/VulkanCommands.cpp

@@ -295,8 +295,6 @@ VulkanCommandBuffer& CommandBufferPool::getRecording() {
 }
 
 void CommandBufferPool::gc() {
-    FVK_SYSTRACE_CONTEXT();
-    FVK_SYSTRACE_START("CommandBufferPool::gc");
     ActiveBuffers reclaimed;
     mSubmitted.forEachSetBit([this,&reclaimed] (size_t index) {
         auto& buffer = mBuffers[index];
@@ -306,7 +304,6 @@ void CommandBufferPool::gc() {
         }
     });
     mSubmitted &= ~reclaimed;
-    FVK_SYSTRACE_END();
 }
 
 void CommandBufferPool::update() {
@@ -336,9 +333,7 @@ void CommandBufferPool::wait() {
     mSubmitted.forEachSetBit([this, &count, &fences] (size_t index) {
         fences[count++] = mBuffers[index]->getVkFence();
     });
-    if (count) {
-        vkWaitForFences(mDevice, count, fences, VK_TRUE, UINT64_MAX);
-    }
+    vkWaitForFences(mDevice, count, fences, VK_TRUE, UINT64_MAX);
     update();
 }
 

filament/backend/src/vulkan/VulkanConstants.h

@@ -152,12 +152,12 @@ static_assert(FVK_ENABLED(FVK_DEBUG_VALIDATION));
 #elif FVK_ENABLED(FVK_DEBUG_SYSTRACE)
 
     #include <utils/Systrace.h>
-
+    
     #define FVK_SYSTRACE_CONTEXT()      SYSTRACE_CONTEXT()
     #define FVK_SYSTRACE_START(marker)  SYSTRACE_NAME_BEGIN(marker)
     #define FVK_SYSTRACE_END()          SYSTRACE_NAME_END()
-    #define FVK_SYSTRACE_SCOPE()        SYSTRACE_CALL()
-    #define FVK_PROFILE_MARKER(marker)  SYSTRACE_CALL()
+    #define FVK_SYSTRACE_SCOPE()        SYSTRACE_NAME(__func__)
+    #define FVK_PROFILE_MARKER(marker)  FVK_SYSTRACE_SCOPE()
 
 #else
     #define FVK_SYSTRACE_CONTEXT()

filament/backend/src/vulkan/VulkanDescriptorSetCache.cpp

@@ -31,8 +31,8 @@ namespace filament::backend {
 
 namespace {
 
+using DescriptorCount = VulkanDescriptorSetLayout::Count;
 using DescriptorSetLayoutArray = VulkanDescriptorSetCache::DescriptorSetLayoutArray;
-using DescriptorCount = VulkanDescriptorSetCache::DescriptorCount;
 
 // We create a pool for each layout as defined by the number of descriptors of each type. For
 // example, a layout of
@@ -203,10 +203,11 @@ public:
     DescriptorInfinitePool(VkDevice device)
         : mDevice(device) {}
 
-    VkDescriptorSet obtainSet(DescriptorCount const& count, VkDescriptorSetLayout vklayout) {
+    VkDescriptorSet obtainSet(fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout) {
+        auto const vklayout = layout->getVkLayout();
         DescriptorPool* sameTypePool = nullptr;
         for (auto& pool: mPools) {
-            if (!pool->canAllocate(count)) {
+            if (!pool->canAllocate(layout->count)) {
                 continue;
             }
             if (auto set = pool->obtainSet(vklayout); set != VK_NULL_HANDLE) {
@@ -224,7 +225,8 @@ public:
         }
 
         // We need to increase the set of pools by one.
-        mPools.push_back(std::make_unique<DescriptorPool>(mDevice, count, capacity));
+        mPools.push_back(std::make_unique<DescriptorPool>(mDevice,
+                DescriptorCount::fromLayoutBitmask(layout->bitmask), capacity));
         auto& pool = mPools.back();
         auto ret = pool->obtainSet(vklayout);
         assert_invariant(ret != VK_NULL_HANDLE && "failed to obtain a set?");
@@ -274,36 +276,39 @@ void VulkanDescriptorSetCache::unbind(uint8_t setIndex) {
 }
 
 void VulkanDescriptorSetCache::commit(VulkanCommandBuffer* commands,
-        VkPipelineLayout pipelineLayout, fvkutils::DescriptorSetMask const& useExternalSamplers,
-        fvkutils::DescriptorSetMask const& setMask) {
+        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 const& updateSets = mStashedSets;
-    curMask.forEachSetBit([&](size_t index) {
-        if (!updateSets[index]) {
-            curMask.unset(index);
-        }
-    });
+    auto& updateSets = mStashedSets;
+    bool const pipelineLayoutIsSame = mLastBoundInfo.pipelineLayout == pipelineLayout;
 
-    if (mLastBoundInfo.pipelineLayout == pipelineLayout) {
+    if (pipelineLayoutIsSame) {
         auto& lastBoundSets = mLastBoundInfo.boundSets;
-        curMask.forEachSetBit([&](size_t index) {
-            if (updateSets[index] == lastBoundSets[index] && !useExternalSamplers[index]) {
+        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;
+        }
+    } else {
+        setMask.forEachSetBit([&](size_t index) {
+            if (!updateSets[index]) {
                 curMask.unset(index);
             }
         });
     }
 
-    curMask.forEachSetBit([&](size_t index) {
+    curMask.forEachSetBit([&updateSets, commands, pipelineLayout](size_t index) {
         // This code actually binds the descriptor sets.
         auto set = updateSets[index];
         VkCommandBuffer const cmdbuffer = commands->buffer();
-        VkDescriptorSet vkset = useExternalSamplers[index] ? set->getExternalSamplerVkSet() :
-            set->getVkSet();
         vkCmdBindDescriptorSets(cmdbuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, index,
-                1, &vkset, set->uniqueDynamicUboCount, set->getOffsets()->data());
+                1, &set->getVkSet(), set->uniqueDynamicUboCount, set->getOffsets()->data());
         commands->acquire(set);
     });
 
@@ -329,7 +334,7 @@ void VulkanDescriptorSetCache::updateBuffer(fvkmemory::resource_ptr<VulkanDescri
     if (set->dynamicUboMask.test(binding)) {
         type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC;
     }
-    VkWriteDescriptorSet descriptorWrite = {
+    VkWriteDescriptorSet const descriptorWrite = {
         .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
         .dstSet = set->getVkSet(),
         .dstBinding = binding,
@@ -338,17 +343,12 @@ void VulkanDescriptorSetCache::updateBuffer(fvkmemory::resource_ptr<VulkanDescri
         .pBufferInfo = &info,
     };
     vkUpdateDescriptorSets(mDevice, 1, &descriptorWrite, 0, nullptr);
-
-    if (auto externalSamplerSet = set->getExternalSamplerVkSet();
-            externalSamplerSet != VK_NULL_HANDLE) {
-        descriptorWrite.dstSet = externalSamplerSet;
-        vkUpdateDescriptorSets(mDevice, 1, &descriptorWrite, 0, nullptr);
-    }
     set->acquire(bufferObject);
 }
 
-void VulkanDescriptorSetCache::updateSamplerImpl(VkDescriptorSet vkset, uint8_t binding,
-        fvkmemory::resource_ptr<VulkanTexture> texture, VkSampler sampler) noexcept {
+void VulkanDescriptorSetCache::updateSampler(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
+        uint8_t binding, fvkmemory::resource_ptr<VulkanTexture> texture,
+        VkSampler sampler) noexcept {
     VkImageSubresourceRange range = texture->getPrimaryViewRange();
     VkImageViewType const expectedType = texture->getViewType();
     if (any(texture->usage & TextureUsage::DEPTH_ATTACHMENT) &&
@@ -364,29 +364,16 @@ void VulkanDescriptorSetCache::updateSamplerImpl(VkDescriptorSet vkset, uint8_t
         .imageLayout = fvkutils::getVkLayout(texture->getDefaultLayout()),
     };
 
-    VkWriteDescriptorSet descriptorWrite = {
+    VkWriteDescriptorSet const descriptorWrite = {
         .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
         .pNext = nullptr,
-        .dstSet = vkset,
+        .dstSet = set->getVkSet(),
         .dstBinding = binding,
         .descriptorCount = 1,
         .descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
         .pImageInfo = &info,
     };
     vkUpdateDescriptorSets(mDevice, 1, &descriptorWrite, 0, nullptr);
-}
-
-void VulkanDescriptorSetCache::updateSampler(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
-        uint8_t binding, fvkmemory::resource_ptr<VulkanTexture> texture,
-        VkSampler sampler) noexcept {
-    updateSamplerImpl(set->getVkSet(), binding, texture, sampler);
-    set->acquire(texture);
-}
-
-void VulkanDescriptorSetCache::updateSamplerForExternalSamplerSet(
-        fvkmemory::resource_ptr<VulkanDescriptorSet> set, uint8_t binding,
-        fvkmemory::resource_ptr<VulkanTexture> texture) noexcept {
-    updateSamplerImpl(set->getExternalSamplerVkSet(), binding, texture, VK_NULL_HANDLE);
     set->acquire(texture);
 }
 
@@ -396,32 +383,32 @@ void VulkanDescriptorSetCache::updateInputAttachment(
     // TOOD: fill this in.
 }
 
-
 fvkmemory::resource_ptr<VulkanDescriptorSet> VulkanDescriptorSetCache::createSet(
         Handle<HwDescriptorSet> handle, fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout) {
-    auto const vkSet = mDescriptorPool->obtainSet(layout->count, layout->getVkLayout());
+    auto const vkSet = getVkSet(layout);
     auto const& count = layout->count;
     auto const vklayout = layout->getVkLayout();
-    auto set = fvkmemory::resource_ptr<VulkanDescriptorSet>::make(
-            mResourceManager, handle, layout->bitmask.dynamicUbo, layout->count.dynamicUbo,
-            [vkSet, count, vklayout, this](
-                    VulkanDescriptorSet*) { this->manualRecycle(count, vklayout, vkSet); },
-            vkSet);
+    auto set = fvkmemory::resource_ptr<VulkanDescriptorSet>::make(mResourceManager, handle,
+            layout->bitmask.dynamicUbo, layout->count.dynamicUbo,
+            [vkSet, count, vklayout, this](VulkanDescriptorSet*) {
+                // Note that mDescriptorPool could be gone due to terminate (when the backend shuts
+                // down).
+                if (mDescriptorPool) {
+                    mDescriptorPool->recycle(count, vklayout, vkSet);
+                }
+            });
+    set->setVkSet(vkSet);
     return set;
 }
 
-VkDescriptorSet VulkanDescriptorSetCache::getVkSet(DescriptorCount const& count,
-        VkDescriptorSetLayout vklayout) {
-    return mDescriptorPool->obtainSet(count, vklayout);
+VkDescriptorSet VulkanDescriptorSetCache::getVkSet(
+        fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout) {
+    return mDescriptorPool->obtainSet(layout);
 }
 
-void VulkanDescriptorSetCache::manualRecycle(VulkanDescriptorSetLayout::Count const& count,
+void VulkanDescriptorSetCache::manualRecyle(VulkanDescriptorSetLayout::Count const& count,
         VkDescriptorSetLayout vklayout, VkDescriptorSet vkSet) {
-    // Note that mDescriptorPool could be gone due to terminate (when the backend shuts
-    // down).
-    if (mDescriptorPool) {
-        mDescriptorPool->recycle(count, vklayout, vkSet);
-    }
+    mDescriptorPool->recycle(count, vklayout, vkSet);
 }
 
 void VulkanDescriptorSetCache::gc() { mStashedSets = {}; }

filament/backend/src/vulkan/VulkanDescriptorSetCache.h

@@ -43,7 +43,6 @@ public:
     using DescriptorSetLayoutArray = VulkanDescriptorSetLayout::DescriptorSetLayoutArray;
     using DescriptorSetArray =
             std::array<fvkmemory::resource_ptr<VulkanDescriptorSet>, UNIQUE_DESCRIPTOR_SET_COUNT>;
-    using DescriptorCount = VulkanDescriptorSetLayout::Count;
 
     VulkanDescriptorSetCache(VkDevice device, fvkmemory::ResourceManager* resourceManager);
     ~VulkanDescriptorSetCache();
@@ -57,10 +56,6 @@ public:
     void updateSampler(fvkmemory::resource_ptr<VulkanDescriptorSet> set, uint8_t binding,
             fvkmemory::resource_ptr<VulkanTexture> texture, VkSampler sampler) noexcept;
 
-    void updateSamplerForExternalSamplerSet(fvkmemory::resource_ptr<VulkanDescriptorSet> set, uint8_t binding,
-            fvkmemory::resource_ptr<VulkanTexture> texture) noexcept;
-
-
     void updateInputAttachment(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
             VulkanAttachment const& attachment) noexcept;
 
@@ -70,17 +65,17 @@ public:
     void unbind(uint8_t setIndex);
 
     void commit(VulkanCommandBuffer* commands, VkPipelineLayout pipelineLayout,
-            fvkutils::DescriptorSetMask const& useExternalSamplerMask,
             fvkutils::DescriptorSetMask const& setMask);
 
     fvkmemory::resource_ptr<VulkanDescriptorSet> createSet(Handle<HwDescriptorSet> handle,
             fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);
 
-    // This method is meant to be used with external samplers
-    VkDescriptorSet getVkSet(DescriptorCount const& count, VkDescriptorSetLayout vklayout);
+    // This method is only meant to be used with external samplers (or internally within this
+    // class).
+    VkDescriptorSet getVkSet(fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);
 
-    // This method is meant to be used with external samplers
-    void manualRecycle(VulkanDescriptorSetLayout::Count const& count, VkDescriptorSetLayout vklayout,
+    // 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; }
@@ -88,9 +83,6 @@ public:
     void gc();
 
 private:
-    void updateSamplerImpl(VkDescriptorSet set, uint8_t binding,
-            fvkmemory::resource_ptr<VulkanTexture> texture, VkSampler sampler) noexcept;
-
     class DescriptorInfinitePool;
 
     VkDevice mDevice;

filament/backend/src/vulkan/VulkanDescriptorSetLayoutCache.cpp

@@ -127,7 +127,6 @@ void VulkanDescriptorSetLayoutCache::terminate() noexcept {
 
 VkDescriptorSetLayout VulkanDescriptorSetLayoutCache::getVkLayout(
         VulkanDescriptorSetLayout::Bitmask const& bitmasks,
-        fvkutils::SamplerBitmask externalSamplers,
         utils::FixedCapacityVector<VkSampler> immutableSamplers) {
     LayoutKey key = {
         .bitmask = bitmasks,
@@ -142,7 +141,7 @@ VkDescriptorSetLayout VulkanDescriptorSetLayoutCache::getVkLayout(
     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, externalSamplers,
+    count += appendSamplerBindings(&toBind[count], bitmasks.sampler, bitmasks.externalSampler,
             immutableSamplers);
     count += appendBindings(&toBind[count], VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT,
             bitmasks.inputAttachment);
@@ -161,9 +160,9 @@ VkDescriptorSetLayout VulkanDescriptorSetLayoutCache::getVkLayout(
 
 fvkmemory::resource_ptr<VulkanDescriptorSetLayout> VulkanDescriptorSetLayoutCache::createLayout(
         Handle<HwDescriptorSetLayout> handle, backend::DescriptorSetLayout&& info) {
-    BitmaskGroup maskGroup = VulkanDescriptorSetLayout::Bitmask::fromLayoutDescription(info);
     auto layout = fvkmemory::resource_ptr<VulkanDescriptorSetLayout>::make(mResourceManager, handle,
-            std::move(info), getVkLayout(maskGroup, maskGroup.externalSampler));
+            info);
+    layout->setVkLayout(getVkLayout(layout->bitmask));
     return layout;
 }
 

filament/backend/src/vulkan/VulkanDescriptorSetLayoutCache.h

@@ -46,7 +46,6 @@ public:
 
     // This method is meant to be used with external samplers
     VkDescriptorSetLayout getVkLayout(VulkanDescriptorSetLayout::Bitmask const& bitmasks,
-            fvkutils::SamplerBitmask externalSamplers,
             utils::FixedCapacityVector<VkSampler> immutableSamplers = {});
 
 private:

filament/backend/src/vulkan/VulkanDriver.cpp

@@ -30,6 +30,7 @@
 #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>
@@ -197,9 +198,11 @@ Dispatcher VulkanDriver::getDispatcher() const noexcept {
 }
 
 VulkanDriver::VulkanDriver(VulkanPlatform* platform, VulkanContext const& context,
-        Platform::DriverConfig const& driverConfig)
+        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())),
@@ -218,8 +221,6 @@ VulkanDriver::VulkanDriver(VulkanPlatform* platform, VulkanContext const& contex
       mDescriptorSetLayoutCache(mPlatform->getDevice(), &mResourceManager),
       mDescriptorSetCache(mPlatform->getDevice(), &mResourceManager),
       mQueryManager(mPlatform->getDevice()),
-      mExternalImageManager(platform, &mSamplerCache, &mYcbcrConversionCache, &mDescriptorSetCache,
-              &mDescriptorSetLayoutCache),
       mIsSRGBSwapChainSupported(mPlatform->getCustomization().isSRGBSwapChainSupported),
       mStereoscopicType(driverConfig.stereoscopicType) {
 
@@ -250,7 +251,7 @@ VulkanDriver::~VulkanDriver() noexcept = default;
 
 UTILS_NOINLINE
 Driver* VulkanDriver::create(VulkanPlatform* platform, VulkanContext const& context,
-         Platform::DriverConfig const& driverConfig) {
+         Platform::DriverConfig const& driverConfig) noexcept {
 #if 0
     // this is useful for development, but too verbose even for debug builds
     // For reference on a 64-bits machine in Release mode:
@@ -312,7 +313,7 @@ void VulkanDriver::terminate() {
 
     mCurrentSwapChain = {};
     mDefaultRenderTarget = {};
-    mPipelineState = {};
+    mBoundPipeline = {};
 
     mQueryManager.terminate();
 
@@ -324,13 +325,9 @@ void VulkanDriver::terminate() {
 
     mCommands.terminate();
 
-    // Must come before samplerCache, ycbcrConversionCache, descriptorSetCache,
-    // descriptorSetLayoutCache
-    mExternalImageManager.terminate();
-
     mStagePool.terminate();
     mPipelineCache.terminate();
-    mFramebufferCache.terminate();
+    mFramebufferCache.reset();
     mSamplerCache.terminate();
     mDescriptorSetLayoutCache.terminate();
     mDescriptorSetCache.terminate();
@@ -384,10 +381,6 @@ 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,
@@ -428,17 +421,12 @@ 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);
-        mExternalImageManager.clearTextureBinding(set, binding);
-    }
+    // TODO: YcbcrConversion?
+    VulkanSamplerCache::Params cacheParams = {
+        .sampler = params,
+    };
+    VkSampler const vksampler = mSamplerCache.getSampler(cacheParams);
+    mDescriptorSetCache.updateSampler(set, binding, texture, vksampler);
 }
 
 void VulkanDriver::flush(int) {
@@ -458,7 +446,6 @@ void VulkanDriver::finish(int dummy) {
 void VulkanDriver::createRenderPrimitiveR(Handle<HwRenderPrimitive> rph,
         Handle<HwVertexBuffer> vbh, Handle<HwIndexBuffer> ibh,
         PrimitiveType pt) {
-    FVK_SYSTRACE_SCOPE();
     auto vb = resource_ptr<VulkanVertexBuffer>::cast(&mResourceManager, vbh);
     auto ib = resource_ptr<VulkanIndexBuffer>::cast(&mResourceManager, ibh);
     auto ptr = resource_ptr<VulkanRenderPrimitive>::make(&mResourceManager, rph, pt, vb, ib);
@@ -469,14 +456,12 @@ void VulkanDriver::destroyRenderPrimitive(Handle<HwRenderPrimitive> rph) {
     if (!rph) {
         return;
     }
-    FVK_SYSTRACE_SCOPE();
     auto ptr = resource_ptr<VulkanRenderPrimitive>::cast(&mResourceManager, rph);
     ptr.dec();
 }
 
 void VulkanDriver::createVertexBufferInfoR(Handle<HwVertexBufferInfo> vbih, uint8_t bufferCount,
         uint8_t attributeCount, AttributeArray attributes) {
-    FVK_SYSTRACE_SCOPE();
     auto vbi = resource_ptr<VulkanVertexBufferInfo>::make(&mResourceManager, vbih, bufferCount,
             attributeCount, attributes);
     vbi.inc();
@@ -486,14 +471,12 @@ void VulkanDriver::destroyVertexBufferInfo(Handle<HwVertexBufferInfo> vbih) {
     if (!vbih) {
         return;
     }
-    FVK_SYSTRACE_SCOPE();
     auto vbi = resource_ptr<VulkanVertexBufferInfo>::cast(&mResourceManager, vbih);
     vbi.dec();
 }
 
 void VulkanDriver::createVertexBufferR(Handle<HwVertexBuffer> vbh, uint32_t vertexCount,
         Handle<HwVertexBufferInfo> vbih) {
-    FVK_SYSTRACE_SCOPE();
     auto vbi = resource_ptr<VulkanVertexBufferInfo>::cast(&mResourceManager, vbih);
     auto vb = resource_ptr<VulkanVertexBuffer>::make(&mResourceManager, vbh, mContext, mStagePool,
             vertexCount, vbi);
@@ -504,14 +487,12 @@ void VulkanDriver::destroyVertexBuffer(Handle<HwVertexBuffer> vbh) {
     if (!vbh) {
         return;
     }
-    FVK_SYSTRACE_SCOPE();
     auto vb = resource_ptr<VulkanVertexBuffer>::cast(&mResourceManager, vbh);
     vb.dec();
 }
 
 void VulkanDriver::createIndexBufferR(Handle<HwIndexBuffer> ibh, ElementType elementType,
         uint32_t indexCount, BufferUsage usage) {
-    FVK_SYSTRACE_SCOPE();
     auto elementSize = (uint8_t) getElementTypeSize(elementType);
     auto ib = resource_ptr<VulkanIndexBuffer>::make(&mResourceManager, ibh, mAllocator, mStagePool,
             elementSize, indexCount);
@@ -522,14 +503,12 @@ void VulkanDriver::destroyIndexBuffer(Handle<HwIndexBuffer> ibh) {
     if (!ibh) {
         return;
     }
-    FVK_SYSTRACE_SCOPE();
     auto ib = resource_ptr<VulkanIndexBuffer>::cast(&mResourceManager, ibh);
     ib.dec();
 }
 
 void VulkanDriver::createBufferObjectR(Handle<HwBufferObject> boh, uint32_t byteCount,
         BufferObjectBinding bindingType, BufferUsage usage) {
-    FVK_SYSTRACE_SCOPE();
     auto bo = resource_ptr<VulkanBufferObject>::make(&mResourceManager, boh, mAllocator, mStagePool,
             byteCount, bindingType);
     bo.inc();
@@ -539,7 +518,6 @@ void VulkanDriver::destroyBufferObject(Handle<HwBufferObject> boh) {
     if (!boh) {
         return;
     }
-    FVK_SYSTRACE_SCOPE();
     auto bo = resource_ptr<VulkanBufferObject>::cast(&mResourceManager, boh);
     bo.dec();
 }
@@ -585,48 +563,41 @@ void VulkanDriver::createTextureExternalImage2R(Handle<HwTexture> th, backend::S
         backend::TextureFormat format, uint32_t width, uint32_t height, backend::TextureUsage usage,
         Platform::ExternalImageHandleRef externalImage) {
     FVK_SYSTRACE_SCOPE();
-    auto metadata = mPlatform->extractExternalImageMetadata(externalImage);
+    auto const& metadata = mPlatform->getExternalImageMetadata(externalImage);
+    if (metadata.isProtected) {
+        usage |= backend::TextureUsage::PROTECTED;
+    }
+
+    VkImageUsageFlags vkUsage = metadata.usage;
+    if (any(usage & TextureUsage::BLIT_SRC)) {
+        vkUsage |= VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
+    }
+
+    if (any(usage & (TextureUsage::BLIT_DST | TextureUsage::UPLOADABLE))) {
+        vkUsage |= VK_IMAGE_USAGE_TRANSFER_DST_BIT;
+    }
 
     assert_invariant(width == metadata.width);
     assert_invariant(height == metadata.height);
+    assert_invariant(fvkutils::getVkFormat(format) == metadata.format);
 
-    // We do not check the format since AHB could return both a known format and an external format.
-    // In which case, we choose one or the other, but this choice is not known to the client.
-    // Therefore the following lines are commented out.
-    // assert_invariant(format == metadata.filamentFormat);
-    // assert_invariant(fvkutils::getVkFormat(format) == metadata.format);
+    VkMemoryPropertyFlags const requiredMemoryFlags = any(usage & TextureUsage::UPLOADABLE)
+                                                              ? VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
+                                                              : VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;
+    uint32_t const memoryTypeIndex =
+            mContext.selectMemoryType(metadata.memoryTypeBits, requiredMemoryFlags);
+    FILAMENT_CHECK_POSTCONDITION(memoryTypeIndex != VK_MAX_MEMORY_TYPES)
+            << "failed to find a valid memory type for external image memory.";
 
-    auto imgData = mPlatform->createVkImageFromExternal(externalImage);
+    VkImage vkimg;
+    VkDeviceMemory deviceMemory;
+    std::tie(vkimg, deviceMemory) =
+            mPlatform->createExternalImageData(externalImage, metadata, memoryTypeIndex, vkUsage);
 
-    assert_invariant(imgData.internal.valid() || imgData.external.valid());
-
-    VkFormat vkformat = metadata.format;
-    VkImage vkimage = VK_NULL_HANDLE;
-    VkDeviceMemory memory = VK_NULL_HANDLE;
-    if (imgData.internal.valid()) {
-        metadata.externalFormat = 0;
-        vkimage = imgData.internal.image;
-        memory = imgData.internal.memory;
-    } else { // imgData.external.valid()
-        vkformat = VK_FORMAT_UNDEFINED;
-        vkimage = imgData.external.image;
-        memory = imgData.external.memory;
-    }
-
-    VkSamplerYcbcrConversion const conversion =
-            mExternalImageManager.getVkSamplerYcbcrConversion(metadata);
     auto texture = resource_ptr<VulkanTexture>::make(&mResourceManager, th, mContext,
-            mPlatform->getDevice(), mAllocator, &mResourceManager, &mCommands, vkimage, memory,
-            vkformat, conversion, metadata.samples, metadata.width, metadata.height,
-            metadata.layers, usage, mStagePool);
-    auto& commands = mCommands.get();
-    // Unlike uploaded textures or swapchains, we need to explicit transition this
-    // texture into the read layout.
-    texture->transitionLayout(&commands, texture->getPrimaryViewRange(), VulkanLayout::READ_ONLY);
-
-    if (imgData.external.valid()) {
-        mExternalImageManager.addExternallySampledTexture(texture, externalImage);
-    }
+            mPlatform->getDevice(), mAllocator, &mResourceManager, &mCommands, vkimg, deviceMemory,
+            metadata.format, VK_NULL_HANDLE, metadata.samples, metadata.width, metadata.height,
+            metadata.layerCount, usage, mStagePool);
 
     texture.inc();
 }
@@ -659,8 +630,6 @@ 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) {
@@ -777,7 +746,6 @@ void VulkanDriver::createFenceR(Handle<HwFence> fh, int) {
 }
 
 void VulkanDriver::createSwapChainR(Handle<HwSwapChain> sch, void* nativeWindow, uint64_t flags) {
-    FVK_SYSTRACE_SCOPE();
     // Running gc() to guard against an edge case where the old swapchains need to have been
     // destroyed before the new swapchain can be created. Otherwise, we would fail
     // vkCreateSwapchainKHR with VK_ERROR_NATIVE_WINDOW_IN_USE_KHR.
@@ -819,7 +787,6 @@ void VulkanDriver::createTimerQueryR(Handle<HwTimerQuery> tqh, int) {
 
 void VulkanDriver::createDescriptorSetLayoutR(Handle<HwDescriptorSetLayout> dslh,
         backend::DescriptorSetLayout&& info) {
-    FVK_SYSTRACE_SCOPE();
     auto layout = mDescriptorSetLayoutCache.createLayout(dslh, std::move(info));
     layout.inc();
 }
@@ -831,10 +798,6 @@ void VulkanDriver::createDescriptorSetR(Handle<HwDescriptorSet> dsh,
             fvkmemory::resource_ptr<VulkanDescriptorSetLayout>::cast(&mResourceManager, dslh);
     auto set = mDescriptorSetCache.createSet(dsh, layout);
     set.inc();
-
-    if (layout->hasExternalSamplers()) {
-        mAppState.hasExternalSamplerLayouts = true;
-    }
 }
 
 Handle<HwVertexBufferInfo> VulkanDriver::createVertexBufferInfoS() noexcept {
@@ -959,10 +922,6 @@ void VulkanDriver::destroyDescriptorSetLayout(Handle<HwDescriptorSetLayout> dslh
 void VulkanDriver::destroyDescriptorSet(Handle<HwDescriptorSet> dsh) {
     auto set = resource_ptr<VulkanDescriptorSet>::cast(&mResourceManager, dsh);
     set.dec();
-
-    if (mAppState.hasExternalSamplers() && set->getExternalSamplerVkSet() != VK_NULL_HANDLE) {
-        mExternalImageManager.removeDescriptorSet(set);
-    }
 }
 
 Handle<HwStream> VulkanDriver::createStreamNative(void* nativeStream) {
@@ -1523,6 +1482,7 @@ void VulkanDriver::endRenderPass(int) {
     // pipeline barrier between framebuffer writes and shader reads.
     rt->emitBarriersEndRenderPass(*mCurrentRenderPass.commandBuffer);
 
+    mRenderPassFboInfo = {};
     mCurrentRenderPass.renderTarget = {};
     mCurrentRenderPass.renderPass = VK_NULL_HANDLE;
 
@@ -1563,7 +1523,7 @@ void VulkanDriver::makeCurrent(Handle<HwSwapChain> drawSch, Handle<HwSwapChain>
     swapChain->acquire(resized);
 
     if (resized) {
-        mFramebufferCache.resetFramebuffers();
+        mFramebufferCache.reset();
     }
 
     if (UTILS_LIKELY(mDefaultRenderTarget)) {
@@ -1582,10 +1542,10 @@ 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) {
@@ -1764,69 +1724,16 @@ void VulkanDriver::blitDEPRECATED(TargetBufferFlags buffers,
 }
 
 void VulkanDriver::bindPipeline(PipelineState const& pipelineState) {
-    // This resets all of the pipeline states; the most relevant (needing reset) is .bindInDraw.
-    mPipelineState = {};
-
-    auto& setLayouts = pipelineState.pipelineLayout.setLayout;
-    DescriptorSetLayoutHandleList layoutHandles;
-    uint8_t layoutCount = 0;
-    std::transform(setLayouts.begin(), setLayouts.end(), layoutHandles.begin(),
-            [&](auto const& handle) -> resource_ptr<VulkanDescriptorSetLayout> {
-                if (!handle) {
-                    return {};
-                }
-                layoutCount++;
-                return resource_ptr<VulkanDescriptorSetLayout>::cast(&mResourceManager, handle);
-            });
-
-    constexpr uint8_t descriptorSetMaskTable[4] = {0x1, 0x3, 0x7, 0xF};
-    fvkutils::DescriptorSetMask const descriptorSetMask =
-            fvkutils::DescriptorSetMask(descriptorSetMaskTable[layoutCount]);
-
-    if (mAppState.hasExternalSamplers()) {
-        auto const haveExternalSamplers = [&](auto layoutHandle) {
-            if (!layoutHandle) {
-                return false;
-            }
-            return layoutHandle->hasExternalSamplers();
-        };
-        if (std::any_of(layoutHandles.begin(), layoutHandles.end(), haveExternalSamplers)) {
-            BindInDrawBundle bundle = {
-                .pipelineState = pipelineState,
-                .dsLayoutHandles = layoutHandles,
-                .descriptorSetMask = descriptorSetMask,
-            };
-            mPipelineState.bindInDraw = { true, bundle };
-            return;
-        }
-    }
-
-    // The normal, non-external sampler path
-    using VkDescriptorSetLayoutArray = VulkanPipelineLayoutCache::DescriptorSetLayoutArray;
-    VkDescriptorSetLayoutArray vkLayouts;
-    std::transform(layoutHandles.begin(), layoutHandles.end(), vkLayouts.begin(),
-            [](auto const& layout) -> VkDescriptorSetLayout {
-                if (!layout) {
-                    return VK_NULL_HANDLE;
-                }
-                return layout->getVkLayout();
-            });
-    auto program = resource_ptr<VulkanProgram>::cast(&mResourceManager, pipelineState.program);
-    auto pipelineLayout = mPipelineLayoutCache.getLayout(vkLayouts, program);
-    bindPipelineImpl(pipelineState, pipelineLayout, descriptorSetMask);
-}
-
-void VulkanDriver::bindPipelineImpl(PipelineState const& pipelineState,
-        VkPipelineLayout pipelineLayout, fvkutils::DescriptorSetMask descriptorSetMask) {
     FVK_SYSTRACE_SCOPE();
     auto commands = mCurrentRenderPass.commandBuffer;
     auto vbi = resource_ptr<VulkanVertexBufferInfo>::cast(&mResourceManager,
             pipelineState.vertexBufferInfo);
 
+    Handle<HwProgram> programHandle = pipelineState.program;
     RasterState const& rasterState = pipelineState.rasterState;
     PolygonOffset const& depthOffset = pipelineState.polygonOffset;
 
-    auto program = resource_ptr<VulkanProgram>::cast(&mResourceManager, pipelineState.program);
+    auto program = resource_ptr<VulkanProgram>::cast(&mResourceManager, programHandle);
     commands->acquire(program);
 
     // Update the VK raster state.
@@ -1868,11 +1775,28 @@ void VulkanDriver::bindPipelineImpl(PipelineState const& pipelineState,
     mPipelineCache.bindPrimitiveTopology(topology);
     mPipelineCache.bindVertexArray(attribDesc, bufferDesc, vbi->getAttributeCount());
 
-    // Note that we cannot reinit mPipeline because the .bindInDraw metadata that needs to carry
-    // over even on bind.
-    mPipelineState.program = program;
-    mPipelineState.pipelineLayout = pipelineLayout;
-    mPipelineState.descriptorSetMask = descriptorSetMask;
+    auto& setLayouts = pipelineState.pipelineLayout.setLayout;
+    VulkanDescriptorSetLayout::DescriptorSetLayoutArray layoutList;
+    uint8_t layoutCount = 0;
+    std::transform(setLayouts.begin(), setLayouts.end(), layoutList.begin(),
+            [&](Handle<HwDescriptorSetLayout> handle) -> VkDescriptorSetLayout {
+                if (!handle) {
+                    return VK_NULL_HANDLE;
+                }
+                auto layout =
+                        resource_ptr<VulkanDescriptorSetLayout>::cast(&mResourceManager, handle);
+                layoutCount++;
+                return layout->getVkLayout();
+            });
+    auto pipelineLayout = mPipelineLayoutCache.getLayout(layoutList, program);
+
+    constexpr uint8_t descriptorSetMaskTable[4] = {0x1, 0x3, 0x7, 0xF};
+
+    mBoundPipeline = {
+        .program = program,
+        .pipelineLayout = pipelineLayout,
+        .descriptorSetMask = fvkutils::DescriptorSetMask(descriptorSetMaskTable[layoutCount]),
+    };
 
     mPipelineCache.bindLayout(pipelineLayout);
     mPipelineCache.bindPipeline(mCurrentRenderPass.commandBuffer);
@@ -1917,41 +1841,15 @@ void VulkanDriver::bindDescriptorSet(
 void VulkanDriver::draw2(uint32_t indexOffset, uint32_t indexCount, uint32_t instanceCount) {
     FVK_SYSTRACE_SCOPE();
     VkCommandBuffer cmdbuffer = mCurrentRenderPass.commandBuffer->buffer();
-    auto const& [doBindInDraw, bundle] = mPipelineState.bindInDraw;
 
-    fvkutils::DescriptorSetMask setsWithExternalSamplers = {};
-    if (doBindInDraw) {
-        auto& layoutHandles = bundle.dsLayoutHandles;
-        setsWithExternalSamplers = mExternalImageManager.prepareBindSets(layoutHandles,
-                mDescriptorSetCache.getBoundSets());
-
-        VulkanDescriptorSetLayout::DescriptorSetLayoutArray vklayouts;
-        for (size_t i = 0; i < layoutHandles.size(); i++) {
-            if (!layoutHandles[i]) {
-                vklayouts[i] = VK_NULL_HANDLE;
-                continue;
-            }
-            if (setsWithExternalSamplers[i]) {
-                vklayouts[i] = layoutHandles[i]->getExternalSamplerVkLayout();
-            } else {
-                vklayouts[i] = layoutHandles[i]->getVkLayout();
-            }
-        }
-        auto program =
-                resource_ptr<VulkanProgram>::cast(&mResourceManager, bundle.pipelineState.program);
-        VkPipelineLayout const pipelineLayout = mPipelineLayoutCache.getLayout(vklayouts, program);
-        if (pipelineLayout != mPipelineState.pipelineLayout) {
-            bindPipelineImpl(bundle.pipelineState, pipelineLayout, bundle.descriptorSetMask);
-        }
-        mPipelineState.bindInDraw.first = false;
-    }
-    mDescriptorSetCache.commit(mCurrentRenderPass.commandBuffer, mPipelineState.pipelineLayout,
-            setsWithExternalSamplers, mPipelineState.descriptorSetMask);
+    mDescriptorSetCache.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);
 }

filament/backend/src/vulkan/VulkanDriver.h

@@ -30,7 +30,6 @@
 #include "VulkanYcbcrConversionCache.h"
 #include "vulkan/VulkanDescriptorSetCache.h"
 #include "vulkan/VulkanDescriptorSetLayoutCache.h"
-#include "vulkan/VulkanExternalImageManager.h"
 #include "vulkan/VulkanPipelineLayoutCache.h"
 #include "vulkan/memory/ResourceManager.h"
 #include "vulkan/memory/ResourcePointer.h"
@@ -55,7 +54,7 @@ constexpr uint8_t MAX_RENDERTARGET_ATTACHMENT_TEXTURES =
 class VulkanDriver final : public DriverBase {
 public:
     static Driver* create(VulkanPlatform* platform, VulkanContext const& context,
-            Platform::DriverConfig const& driverConfig);
+            Platform::DriverConfig const& driverConfig) noexcept;
 
 #if FVK_ENABLED(FVK_DEBUG_DEBUG_UTILS)
     // Encapsulates the VK_EXT_debug_utils extension.  In particular, we use
@@ -90,8 +89,8 @@ private:
     void debugCommandBegin(CommandStream* cmds, bool synchronous,
             const char* methodName) noexcept override;
 
-    VulkanDriver(VulkanPlatform* platform, VulkanContext const& context,
-            Platform::DriverConfig const& driverConfig);
+    inline VulkanDriver(VulkanPlatform* platform, VulkanContext const& context,
+            Platform::DriverConfig const& driverConfig) noexcept;
 
     ~VulkanDriver() noexcept override;
 
@@ -120,8 +119,6 @@ private:
 
 private:
     void collectGarbage();
-    void bindPipelineImpl(PipelineState const& pipelineState, VkPipelineLayout pipelineLayout,
-            fvkutils::DescriptorSetMask descriptorSetMask);
 
     VulkanPlatform* mPlatform = nullptr;
     fvkmemory::ResourceManager mResourceManager;
@@ -146,39 +143,21 @@ private:
     VulkanDescriptorSetLayoutCache mDescriptorSetLayoutCache;
     VulkanDescriptorSetCache mDescriptorSetCache;
     VulkanQueryManager mQueryManager;
-    VulkanExternalImageManager mExternalImageManager;
 
     // This is necessary for us to write to push constants after binding a pipeline.
-    using DescriptorSetLayoutHandleList = std::array<resource_ptr<VulkanDescriptorSetLayout>,
-            VulkanDescriptorSetLayout::UNIQUE_DESCRIPTOR_SET_COUNT>;
-
-    struct BindInDrawBundle {
-        PipelineState pipelineState = {};
-        DescriptorSetLayoutHandleList dsLayoutHandles = {};
-        fvkutils::DescriptorSetMask descriptorSetMask = {};
-        resource_ptr<VulkanProgram> program = {};
-    };
-
     struct {
-        // For push constant
-        resource_ptr<VulkanProgram> program = {};
-        // For push commiting dynamic ubos in draw()
-        VkPipelineLayout pipelineLayout = VK_NULL_HANDLE;
-        fvkutils::DescriptorSetMask descriptorSetMask = {};
-
-        std::pair<bool, BindInDrawBundle> bindInDraw = {false, {}};
-    } mPipelineState = {};
+        resource_ptr<VulkanProgram> program;
+        VkPipelineLayout pipelineLayout;
+        fvkutils::DescriptorSetMask descriptorSetMask;
+    } mBoundPipeline = {};
 
+    // 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;

filament/backend/src/vulkan/VulkanExternalImageManager.cpp

@@ -1,294 +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 {
-
-using Bitmask = fvkutils::UniformBufferBitmask;
-static_assert(sizeof(Bitmask) * 8 == fvkutils::MAX_DESCRIPTOR_SET_BITMASK_BITS);
-
-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());
-}
-
-using ImageData = VulkanExternalImageManager::VulkanExternalImageManager::ImageData;
-ImageData& findImage(std::vector<ImageData>& images,
-        fvkmemory::resource_ptr<VulkanTexture> texture) {
-    auto itr = std::find_if(images.begin(), images.end(), [&](ImageData const& data) {
-        return data.image == texture;
-    });
-    assert_invariant(itr != images.end());
-    return *itr;
-}
-
-void copySet(VkDevice device, VkDescriptorSet srcSet, VkDescriptorSet dstSet, Bitmask bindings) {
-    // TODO: fix the size for better memory management
-    std::vector<VkCopyDescriptorSet> copies;
-    bindings.forEachSetBit([&](size_t index) {
-        copies.push_back({
-            .sType = VK_STRUCTURE_TYPE_COPY_DESCRIPTOR_SET,
-            .srcSet = srcSet,
-            .srcBinding = (uint32_t) index,
-            .dstSet = dstSet,
-            .dstBinding = (uint32_t) index,
-            .descriptorCount = 1,
-        });
-    });
-    vkUpdateDescriptorSets(device, 0, nullptr, copies.size(), copies.data());
-}
-
-Bitmask foldBitsInHalf(Bitmask bitset) {
-    Bitmask outBitset;
-    bitset.forEachSetBit([&](size_t index) {
-        constexpr size_t BITMASK_LOWER_BITS_LEN = sizeof(outBitset) * 4;
-        outBitset.set(index % BITMASK_LOWER_BITS_LEN);
-    });
-    return outBitset;
-}
-
-}// namespace
-
-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() {
-    mSetBindings.clear();
-    mImages.clear();
-}
-
-void VulkanExternalImageManager::onBeginFrame() {
-    std::for_each(mImages.begin(), mImages.end(), [](ImageData& image) {
-        image.hasBeenValidated = false;
-    });
-    std::for_each(mSetBindings.begin(), mSetBindings.end(), [](SetBindingInfo& info) {
-        info.bound = false;
-    });
-}
-
-fvkutils::DescriptorSetMask VulkanExternalImageManager::prepareBindSets(LayoutArray const& layouts,
-        SetArray const& sets) {
-    fvkutils::DescriptorSetMask shouldUseExternalSampler{};
-    for (uint8_t i = 0; i < sets.size(); i++) {
-        auto set = sets[i];
-        auto layout = layouts[i];
-        if (!set || !layout) {
-            continue;
-        }
-        if (hasExternalSampler(set)) {
-            updateSetAndLayout(set, layout);
-            shouldUseExternalSampler.set(i);
-        }
-    }
-    return shouldUseExternalSampler;
-}
-
-bool VulkanExternalImageManager::hasExternalSampler(
-        fvkmemory::resource_ptr<VulkanDescriptorSet> set) {
-    auto itr = std::find_if(mSetBindings.begin(), mSetBindings.end(),
-            [&](SetBindingInfo const& info) { return info.set == set; });
-    return itr != mSetBindings.end();
-}
-
-void VulkanExternalImageManager::updateSetAndLayout(
-        fvkmemory::resource_ptr<VulkanDescriptorSet> set,
-        fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout) {
-    utils::FixedCapacityVector<
-            std::tuple<uint8_t, VkSampler, fvkmemory::resource_ptr<VulkanTexture>>>
-            samplerAndBindings;
-    samplerAndBindings.reserve(MAX_SAMPLER_COUNT);
-
-    fvkutils::SamplerBitmask actualExternalSamplers;
-    for (auto& bindingInfo : mSetBindings) {
-        if (bindingInfo.set != set || bindingInfo.bound) {
-            continue;
-        }
-        auto& imageData = findImage(mImages, bindingInfo.image);
-        updateImage(&imageData);
-
-        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,
-        });
-        actualExternalSamplers.set(bindingInfo.binding);
-        samplerAndBindings.push_back({ bindingInfo.binding, sampler, bindingInfo.image });
-        bindingInfo.bound = true;
-    }
-
-    if (samplerAndBindings.empty()) {
-        return;
-    }
-
-    // Sort by binding number
-    std::sort(samplerAndBindings.begin(), samplerAndBindings.end(), [](auto const& a, auto const& b) {
-        return std::get<0>(a) < std::get<0>(b);
-    });
-
-    utils::FixedCapacityVector<VkSampler> outSamplers;
-    outSamplers.reserve(MAX_SAMPLER_COUNT);
-    std::for_each(samplerAndBindings.begin(), samplerAndBindings.end(),
-            [&](auto const& b) { outSamplers.push_back(std::get<1>(b)); });
-
-    VkDescriptorSetLayout const oldLayout = layout->getExternalSamplerVkLayout();
-    VkDescriptorSetLayout const newLayout = mDescriptorSetLayoutCache->getVkLayout(layout->bitmask,
-            actualExternalSamplers, outSamplers);
-
-    // Need to copy the set
-    VkDescriptorSet const oldSet = set->getExternalSamplerVkSet();
-    if (oldLayout != newLayout || oldSet == VK_NULL_HANDLE) {
-        // Build a new descriptor set from the new layout
-        VkDescriptorSet const newSet = mDescriptorSetCache->getVkSet(layout->count, newLayout);
-        auto const ubo = layout->bitmask.ubo | layout->bitmask.dynamicUbo;
-        auto const samplers = layout->bitmask.sampler & (~actualExternalSamplers);
-
-        // 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);
-        VkDescriptorSet const srcSet = oldSet != VK_NULL_HANDLE ? oldSet : set->getVkSet();
-        copySet(mPlatform->getDevice(), srcSet, newSet, copyBindings);
-
-        set->setExternalSamplerVkSet(newSet, [&](VulkanDescriptorSet*) {
-            mDescriptorSetCache->manualRecycle(layout->count, newLayout, newSet);
-        });
-        if (oldLayout != newLayout) {
-            layout->setExternalSamplerVkLayout(newLayout);
-        }
-    }
-
-    // Update the external samplers in the set
-    for (auto& [binding, sampler, image]: samplerAndBindings) {
-        mDescriptorSetCache->updateSamplerForExternalSamplerSet(set, binding, image);
-    }
-}
-
-VkSamplerYcbcrConversion VulkanExternalImageManager::getVkSamplerYcbcrConversion(
-        VulkanPlatform::ExternalImageMetadata const& metadata) {
-    // This external image does not require external sampler (YUV conversion).
-    if (metadata.externalFormat == 0 && !fvkutils::isVKYcbcrConversionFormat(metadata.format)) {
-        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.format,
-        .externalFormat = metadata.externalFormat,
-    };
-    return mYcbcrConversionCache->getConversion(ycbcrParams);
-}
-
-void VulkanExternalImageManager::updateImage(ImageData* image) {
-    if (image->hasBeenValidated) {
-        return;
-    }
-    image->hasBeenValidated = true;
-
-    auto metadata = mPlatform->extractExternalImageMetadata(image->platformHandle);
-    auto vkYcbcr = getVkSamplerYcbcrConversion(metadata);
-    if (vkYcbcr == image->conversion) {
-        return;
-    }
-
-    image->image->setYcbcrConversion(vkYcbcr);
-    image->conversion = vkYcbcr;
-    return;
-}
-
-void VulkanExternalImageManager::removeDescriptorSet(
-        fvkmemory::resource_ptr<VulkanDescriptorSet> inSet) {
-    erasep<SetBindingInfo>(mSetBindings,
-            [&](auto const& bindingInfo) { return (bindingInfo.set == inSet); });
-}
-
-void VulkanExternalImageManager::bindExternallySampledTexture(
-        fvkmemory::resource_ptr<VulkanDescriptorSet> set, uint8_t bindingPoint,
-        fvkmemory::resource_ptr<VulkanTexture> image, SamplerParams samplerParams) {
-    // Should we do duplicate validation here?
-    auto& imageData = findImage(mImages, image);
-    mSetBindings.push_back({ bindingPoint, imageData.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.image == image;
-    });
-}
-
-bool VulkanExternalImageManager::isExternallySampledTexture(
-        fvkmemory::resource_ptr<VulkanTexture> image) const {
-    return std::find_if(mImages.begin(), mImages.end(), [&](auto const& imageData) {
-        return imageData.image == image;
-    }) != mImages.end();
-}
-
-void VulkanExternalImageManager::clearTextureBinding(
-        fvkmemory::resource_ptr<VulkanDescriptorSet> set, uint8_t bindingPoint) {
-    erasep<SetBindingInfo>(mSetBindings, [&](auto const& bindingInfo) {
-        return (bindingInfo.set == set && bindingInfo.binding == bindingPoint);
-    });
-}
-
-} // namesapce filament::backend

filament/backend/src/vulkan/VulkanExternalImageManager.h

@@ -1,121 +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>;
-
-    using LayoutArray = std::array<fvkmemory::resource_ptr<VulkanDescriptorSetLayout>,
-            VulkanDescriptorSetLayout::UNIQUE_DESCRIPTOR_SET_COUNT>;
-
-    using VkLayoutArray = VulkanDescriptorSetLayout::DescriptorSetLayoutArray;
-
-    // Returns  bitmask to indicate whether or not to use the external sampler version of each
-    // descriptor set.
-    fvkutils::DescriptorSetMask prepareBindSets(LayoutArray const& layouts, SetArray const& sets);
-
-    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 clearTextureBinding(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
-                             uint8_t bindingPoint);
-
-    void addExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> external,
-            Platform::ExternalImageHandleRef platformHandleRef);
-
-    void removeExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> image);
-
-    bool isExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> image) const;
-
-    VkSamplerYcbcrConversion getVkSamplerYcbcrConversion(
-            VulkanPlatform::ExternalImageMetadata const& metadata);
-
-    struct ImageData {
-        fvkmemory::resource_ptr<VulkanTexture> image;
-        Platform::ExternalImageHandle platformHandle;
-        bool hasBeenValidated = false; // indicates whether the image has been validated *this frame*
-        VkSamplerYcbcrConversion conversion = VK_NULL_HANDLE;
-    };
-
-private:
-    bool hasExternalSampler(fvkmemory::resource_ptr<VulkanDescriptorSet> set);
-
-    void updateSetAndLayout(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
-            fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);
-
-    void 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;
-        bool bound = false;
-    };
-
-    // Use vectors instead of hash maps because we only expect small number of entries.
-    std::vector<SetBindingInfo> mSetBindings;
-    std::vector<ImageData> mImages;
-};
-
-} // filament::backend
-
-#endif // TNT_FILAMENT_BACKEND_CACHING_VULKANEXTERNALIMAGEMANAGER_H

filament/backend/src/vulkan/VulkanFboCache.cpp

@@ -330,39 +330,25 @@ VkRenderPass VulkanFboCache::getRenderPass(RenderPassKey const& config) noexcept
     mRenderPassCache[config] = {renderPass, mCurrentTime};
 
 #if FVK_ENABLED(FVK_DEBUG_FBO_CACHE)
-    FVK_LOGD << "Created render pass " << renderPass << " with ";
-    for (int i = 0; i < MRT::MAX_SUPPORTED_RENDER_TARGET_COUNT; ++i) {
-        FVK_LOGD << (int) config.colorFormat[i] << " ";
-    }
-    FVK_LOGD << ", "
-             << "depth = " << config.depthFormat << ", "
-             << "initialDepthLayout = " << (int) config.initialDepthLayout << ", "
-             << "samples = " << int(config.samples) << ", "
-             << "needsResolveMask = " << int(config.needsResolveMask) << ", "
-             << "usesLazilyAllocatedMemory = " << int(config.usesLazilyAllocatedMemory) << ", "
-             << "viewCount = " << int(config.viewCount) << ", "
-             << "colorAttachmentCount[0] = " << subpasses[0].colorAttachmentCount
-             << utils::io::endl;
-#endif
+    FVK_LOGD << "Created render pass " << renderPass << " with "
+        << "samples = " << int(config.samples) << ", "
+        << "depth = " << (hasDepth ? 1 : 0) << ", "
+        << "colorAttachmentCount[0] = " << subpasses[0].colorAttachmentCount
+        << utils::io::endl;
+    #endif
 
     return renderPass;
 }
 
-void VulkanFboCache::resetFramebuffers() noexcept {
-    for (const auto& pair: mFramebufferCache) {
+void VulkanFboCache::reset() noexcept {
+    for (auto pair : mFramebufferCache) {
         mRenderPassRefCount[pair.first.renderPass]--;
         vkDestroyFramebuffer(mDevice, pair.second.handle, VKALLOC);
     }
     mFramebufferCache.clear();
-}
-
-void VulkanFboCache::terminate() noexcept {
-    resetFramebuffers();
-
-    for (const auto& pair: mRenderPassCache) {
+    for (auto pair : mRenderPassCache) {
         vkDestroyRenderPass(mDevice, pair.second.handle, VKALLOC);
     }
-    mRenderPassRefCount.clear();
     mRenderPassCache.clear();
 }
 

filament/backend/src/vulkan/VulkanFboCache.h

@@ -106,11 +106,8 @@ public:
     // Evicts old unused Vulkan objects. Call this once per frame.
     void gc() noexcept;
 
-    // Frees all Framebuffer objects. Call this every time a the swapchain is resized
-    void resetFramebuffers() noexcept;
-
     // Frees all Vulkan objects. Call this during shutdown before the device is destroyed.
-    void terminate() noexcept;
+    void reset() noexcept;
 
 private:
     VkDevice mDevice;

filament/backend/src/vulkan/VulkanHandles.cpp

@@ -149,18 +149,11 @@ void VulkanDescriptorSet::acquire(fvkmemory::resource_ptr<VulkanBufferObject> ob
     mResources.push_back(obj);
 }
 
-VulkanDescriptorSetLayout::VulkanDescriptorSetLayout(DescriptorSetLayout&& layout,
-        VkDescriptorSetLayout vkLayout)
+VulkanDescriptorSetLayout::VulkanDescriptorSetLayout(DescriptorSetLayout const& layout)
     : bitmask(fromBackendLayout(layout)),
-      count(Count::fromLayoutBitmask(bitmask)),
-      mVkLayout(vkLayout) {}
+      count(Count::fromLayoutBitmask(bitmask)) {}
 
-VulkanDescriptorSetLayout::Bitmask VulkanDescriptorSetLayout::Bitmask::fromLayoutDescription(
-        DescriptorSetLayout const& layout) {
-    return fromBackendLayout(layout);
-}
-
-PushConstantDescription::PushConstantDescription(backend::Program const& program) {
+PushConstantDescription::PushConstantDescription(backend::Program const& program) noexcept {
     mRangeCount = 0;
     for (auto stage : { ShaderStage::VERTEX, ShaderStage::FRAGMENT, ShaderStage::COMPUTE }) {
         auto const& constants = program.getPushConstants(stage);

filament/backend/src/vulkan/VulkanHandles.h

@@ -71,7 +71,7 @@ struct VulkanDescriptorSetLayout : public HwDescriptorSetLayout, fvkmemory::Reso
         fvkutils::SamplerBitmask sampler;           // 8 bytes
         fvkutils::InputAttachmentBitmask inputAttachment; // 8 bytes
 
-        // This is a subset of the sampler field.
+        // This is a subset of the bitmask.sampler field.
         fvkutils::SamplerBitmask externalSampler; // 8 bytes
 
         bool operator==(Bitmask const& right) const {
@@ -79,8 +79,6 @@ struct VulkanDescriptorSetLayout : public HwDescriptorSetLayout, fvkmemory::Reso
                    inputAttachment == right.inputAttachment &&
                    externalSampler == right.externalSampler;
         }
-
-        static Bitmask fromLayoutDescription(DescriptorSetLayout const& layout);
     };
     static_assert(sizeof(Bitmask) == 40);
 
@@ -122,20 +120,16 @@ struct VulkanDescriptorSetLayout : public HwDescriptorSetLayout, fvkmemory::Reso
         }
     };
 
-    VulkanDescriptorSetLayout(DescriptorSetLayout&& layout, VkDescriptorSetLayout vkLayout);
+    VulkanDescriptorSetLayout(DescriptorSetLayout const& layout);
 
     // Note that we don't destroy the vklayout. This is done by the layout cache.
     ~VulkanDescriptorSetLayout() = default;
 
-    VkDescriptorSetLayout getVkLayout() const noexcept { return mVkLayout; }
+    VkDescriptorSetLayout const& getVkLayout() const noexcept { return mVkLayout; }
 
-    VkDescriptorSetLayout getExternalSamplerVkLayout() const noexcept {
-        return mExternalSamplerVkLayout;
-    }
-
-    void setExternalSamplerVkLayout(VkDescriptorSetLayout vklayout) noexcept {
-        mExternalSamplerVkLayout = vklayout;
-    }
+    // 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; }
 
@@ -143,11 +137,7 @@ struct VulkanDescriptorSetLayout : public HwDescriptorSetLayout, fvkmemory::Reso
     Count const count;
 
 private:
-    // This is the layout without any immutable samplers.
-    VkDescriptorSetLayout const mVkLayout = VK_NULL_HANDLE;
-
-    // This is the layout with immutable samplers, and can be updated.
-    VkDescriptorSetLayout mExternalSamplerVkLayout = VK_NULL_HANDLE;
+    VkDescriptorSetLayout mVkLayout = VK_NULL_HANDLE;
 };
 
 struct VulkanDescriptorSet : public HwDescriptorSet, fvkmemory::Resource {
@@ -159,37 +149,23 @@ public:
     VulkanDescriptorSet(
             fvkutils::UniformBufferBitmask const& dynamicUboMask,
             uint8_t uniqueDynamicUboCount,
-            OnRecycle&& onRecycleFn, VkDescriptorSet vkSet)
+            OnRecycle&& onRecycleFn)
         : dynamicUboMask(dynamicUboMask),
           uniqueDynamicUboCount(uniqueDynamicUboCount),
-          mVkSet(vkSet),
           mOnRecycleFn(std::move(onRecycleFn)) {}
 
-    // NOLINTNEXTLINE(bugprone-exception-escape)
     ~VulkanDescriptorSet() {
         if (mOnRecycleFn) {
             mOnRecycleFn(this);
         }
-        if (mOnRecycleExternalSamplerFn) {
-            mOnRecycleExternalSamplerFn(this);
-        }
     }
 
-    VkDescriptorSet getVkSet() const noexcept {
+    VkDescriptorSet const& getVkSet() const noexcept {
         return mVkSet;
     }
 
-    VkDescriptorSet getExternalSamplerVkSet() const noexcept {
-        return mExternalSamplerVkSet;
-    }
-
-    void setExternalSamplerVkSet(VkDescriptorSet vkset, OnRecycle onRecycle) {
-        mExternalSamplerVkSet = vkset;
-        if (mOnRecycleExternalSamplerFn) {
-            mOnRecycleExternalSamplerFn(this);
-        }
-        mOnRecycleExternalSamplerFn = onRecycle;
-    }
+    // 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);
@@ -206,20 +182,17 @@ public:
     uint8_t const uniqueDynamicUboCount;
 
 private:
-    VkDescriptorSet const mVkSet;
-    VkDescriptorSet mExternalSamplerVkSet = VK_NULL_HANDLE;
-
+    VkDescriptorSet mVkSet = VK_NULL_HANDLE;
     backend::DescriptorSetOffsetArray mOffsets;
     std::vector<fvkmemory::resource_ptr<fvkmemory::Resource>> mResources;
     OnRecycle mOnRecycleFn;
-    OnRecycle mOnRecycleExternalSamplerFn;
 };
 
 using PushConstantNameArray = utils::FixedCapacityVector<char const*>;
 using PushConstantNameByStage = std::array<PushConstantNameArray, Program::SHADER_TYPE_COUNT>;
 
 struct PushConstantDescription {
-    explicit PushConstantDescription(backend::Program const& program);
+    explicit PushConstantDescription(backend::Program const& program) noexcept;
 
     VkPushConstantRange const* getVkRanges() const noexcept { return mRanges; }
     uint32_t getVkRangeCount() const noexcept { return mRangeCount; }

filament/backend/src/vulkan/VulkanPipelineCache.cpp

@@ -35,12 +35,7 @@ using namespace bluevk;
 namespace filament::backend {
 
 VulkanPipelineCache::VulkanPipelineCache(VkDevice device)
-    : mDevice(device) {
-    VkPipelineCacheCreateInfo createInfo = {
-        .sType = VK_STRUCTURE_TYPE_PIPELINE_CACHE_CREATE_INFO,
-    };
-    bluevk::vkCreatePipelineCache(mDevice, &createInfo, VKALLOC, &mPipelineCache);
-}
+        : mDevice(device) {}
 
 void VulkanPipelineCache::bindLayout(VkPipelineLayout layout) noexcept {
     mPipelineRequirements.layout = layout;
@@ -66,12 +61,8 @@ void VulkanPipelineCache::bindPipeline(VulkanCommandBuffer* commands) {
     // If an error occurred, allow higher levels to handle it gracefully.
     assert_invariant(cacheEntry != nullptr && "Failed to create/find pipeline");
 
-
-    static PipelineEqual equal;
-    if (!equal(mBoundPipeline, mPipelineRequirements)) {
-        mBoundPipeline = mPipelineRequirements;
-        vkCmdBindPipeline(cmdbuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, cacheEntry->handle);
-    }
+    mBoundPipeline = mPipelineRequirements;
+    vkCmdBindPipeline(cmdbuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, cacheEntry->handle);
 }
 
 VulkanPipelineCache::PipelineCacheEntry* VulkanPipelineCache::createPipeline() noexcept {
@@ -224,7 +215,7 @@ VulkanPipelineCache::PipelineCacheEntry* VulkanPipelineCache::createPipeline() n
     PipelineCacheEntry cacheEntry = {
         .lastUsed = mCurrentTime,
     };
-    VkResult error = vkCreateGraphicsPipelines(mDevice, mPipelineCache, 1, &pipelineCreateInfo,
+    VkResult error = vkCreateGraphicsPipelines(mDevice, VK_NULL_HANDLE, 1, &pipelineCreateInfo,
             VKALLOC, &cacheEntry.handle);
     assert_invariant(error == VK_SUCCESS);
     if (error != VK_SUCCESS) {
@@ -280,8 +271,6 @@ void VulkanPipelineCache::terminate() noexcept {
     }
     mPipelines.clear();
     mBoundPipeline = {};
-
-    vkDestroyPipelineCache(mDevice, mPipelineCache, VKALLOC);
 }
 
 void VulkanPipelineCache::gc() noexcept {

filament/backend/src/vulkan/VulkanPipelineCache.h

@@ -198,10 +198,6 @@ private:
     // Immutable state.
     VkDevice mDevice = VK_NULL_HANDLE;
 
-    // Vuklan Driver pipeline cache handle. In the cases a pipeline has been  evicted by the `gc`,
-    // recreating the same pipeline is cheaper, helping with frame stalling.
-    VkPipelineCache mPipelineCache = VK_NULL_HANDLE;
-
     // Current requirements for the pipeline layout, pipeline, and descriptor sets.
     PipelineKey mPipelineRequirements = {};
 

filament/backend/src/vulkan/VulkanReadPixels.cpp

@@ -335,7 +335,7 @@ void VulkanReadPixels::run(fvkmemory::resource_ptr<VulkanRenderTarget> srcTarget
     mTaskHandler->post(std::move(waitFenceFunc), std::move(cleanPbdFunc));
 }
 
-void VulkanReadPixels::runUntilComplete() {
+void VulkanReadPixels::runUntilComplete() noexcept {
     if (!mTaskHandler) {
         return;
     }

filament/backend/src/vulkan/VulkanReadPixels.h

@@ -79,7 +79,7 @@ public:
             OnReadCompleteFunction const& readCompleteFunc);
 
     // This method will block until all of the in-flight requests are complete.
-    void runUntilComplete();
+    void runUntilComplete() noexcept;
 
 private:
     VkDevice mDevice = VK_NULL_HANDLE;

filament/backend/src/vulkan/VulkanSamplerCache.cpp

@@ -28,7 +28,7 @@ namespace filament::backend {
 VulkanSamplerCache::VulkanSamplerCache(VkDevice device)
     : mDevice(device) {}
 
-VkSampler VulkanSamplerCache::getSampler(Params params) {
+VkSampler VulkanSamplerCache::getSampler(Params params) noexcept {
     auto iter = mCache.find(params);
     if (UTILS_LIKELY(iter != mCache.end())) {
         return iter->second;

filament/backend/src/vulkan/VulkanSamplerCache.h

@@ -38,7 +38,7 @@ public:
     static_assert(sizeof(Params) == 16);
 
     explicit VulkanSamplerCache(VkDevice device);
-    VkSampler getSampler(Params params);
+    VkSampler getSampler(Params params) noexcept;
     void terminate() noexcept;
 private:
     VkDevice mDevice;

filament/backend/src/vulkan/VulkanStagePool.cpp

@@ -24,7 +24,7 @@
 
 #include <utils/Panic.h>
 
-static constexpr uint32_t TIME_BEFORE_EVICTION = 3;
+static constexpr uint32_t TIME_BEFORE_EVICTION = FVK_MAX_COMMAND_BUFFERS;
 
 namespace filament::backend {
 
@@ -39,7 +39,7 @@ VulkanStage const* VulkanStagePool::acquireStage(uint32_t numBytes) {
         auto stage = iter->second;
         mFreeStages.erase(iter);
         stage->lastAccessed = mCurrentFrame;
-        mUsedStages.push_back(stage);
+        mUsedStages.insert(stage);
         return stage;
     }
     // We were not able to find a sufficiently large stage, so create a new one.
@@ -51,7 +51,7 @@ VulkanStage const* VulkanStagePool::acquireStage(uint32_t numBytes) {
     });
 
     // Create the VkBuffer.
-    mUsedStages.push_back(stage);
+    mUsedStages.insert(stage);
     VkBufferCreateInfo bufferInfo {
         .sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,
         .size = numBytes,
@@ -77,7 +77,7 @@ VulkanStageImage const* VulkanStagePool::acquireImage(PixelDataFormat format, Pi
         if (image->format == vkformat && image->width == width && image->height == height) {
             mFreeImages.erase(image);
             image->lastAccessed = mCurrentFrame;
-            mUsedImages.push_back(image);
+            mUsedImages.insert(image);
             return image;
         }
     }
@@ -89,7 +89,7 @@ VulkanStageImage const* VulkanStagePool::acquireImage(PixelDataFormat format, Pi
         .lastAccessed = mCurrentFrame,
     });
 
-    mUsedImages.push_back(image);
+    mUsedImages.insert(image);
 
     const VkImageCreateInfo imageInfo = {
         .sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,
@@ -161,7 +161,7 @@ void VulkanStagePool::gc() noexcept {
             stage->lastAccessed = mCurrentFrame;
             mFreeStages.insert(std::make_pair(stage->capacity, stage));
         } else {
-            mUsedStages.push_back(stage);
+            mUsedStages.insert(stage);
         }
     }
 
@@ -185,7 +185,7 @@ void VulkanStagePool::gc() noexcept {
             image->lastAccessed = mCurrentFrame;
             mFreeImages.insert(image);
         } else {
-            mUsedImages.push_back(image);
+            mUsedImages.insert(image);
         }
     }
     FVK_SYSTRACE_END();

filament/backend/src/vulkan/VulkanStagePool.h

@@ -22,7 +22,6 @@
 
 #include <map>
 #include <unordered_set>
-#include <vector>
 
 namespace filament::backend {
 
@@ -74,10 +73,10 @@ private:
     std::multimap<uint32_t, VulkanStage const*> mFreeStages;
 
     // Simple unordered set for stashing a list of in-use stages that can be reclaimed later.
-    std::vector<VulkanStage const*> mUsedStages;
+    std::unordered_set<VulkanStage const*> mUsedStages;
 
     std::unordered_set<VulkanStageImage const*> mFreeImages;
-    std::vector<VulkanStageImage const*> mUsedImages;
+    std::unordered_set<VulkanStageImage const*> mUsedImages;
 
     // Store the current "time" (really just a frame count) and LRU eviction parameters.
     uint64_t mCurrentFrame = 0;

filament/backend/src/vulkan/VulkanTexture.cpp

@@ -223,7 +223,8 @@ VkImageUsageFlags getUsage(VulkanContext const& context, uint8_t samples,
 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, VkImageUsageFlags usage, bool isProtected)
+        VkSamplerYcbcrConversion ycbcrConversion, bool isExternalFormat, VkImageUsageFlags usage,
+        bool isProtected)
     : mStagePool(stagePool),
       mCommands(commands),
       mAllocator(allocator),
@@ -233,17 +234,17 @@ VulkanTextureState::VulkanTextureState(VulkanStagePool& stagePool, VulkanCommand
       mVkFormat(format),
       mViewType(viewType),
       mFullViewRange{ fvkutils::getImageAspect(format), 0, levels, 0, layerCount },
-      mYcbcr{ ycbcrConversion },
+      mYcbcr{ ycbcrConversion, isExternalFormat },
       mDefaultLayout(getDefaultLayoutImpl(usage)),
       mUsage(usage),
       mIsProtected(isProtected) {}
 
 VulkanTextureState::~VulkanTextureState() {
-    clearCachedImageViews();
     if (mTextureImageMemory != VK_NULL_HANDLE) {
         vkDestroyImage(mDevice, mTextureImage, VKALLOC);
         vkFreeMemory(mDevice, mTextureImageMemory, VKALLOC);
     }
+    clearCachedImageViews();
 }
 
 void VulkanTextureState::clearCachedImageViews() noexcept {
@@ -271,7 +272,7 @@ VkImageView VulkanTextureState::getImageView(VkImageSubresourceRange range, VkIm
         .flags = 0,
         .image = mTextureImage,
         .viewType = viewType,
-        .format = mYcbcr.conversion != VK_NULL_HANDLE ? VK_FORMAT_UNDEFINED : mVkFormat,
+        .format = mYcbcr.isExternalFormat ? VK_FORMAT_UNDEFINED : mVkFormat,
         .components = swizzle,
         .subresourceRange = range,
     };
@@ -293,6 +294,7 @@ VulkanTexture::VulkanTexture(VulkanContext const& context, VkDevice device, VmaA
               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))) {
     mPrimaryViewRange = mState->mFullViewRange;
@@ -422,7 +424,8 @@ VulkanTexture::VulkanTexture(VkDevice device, VkPhysicalDevice physicalDevice,
     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 */, imageInfo.usage, isProtected);
+            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;
@@ -761,13 +764,15 @@ void VulkanTexture::setLayout(VkImageSubresourceRange const& range, VulkanLayout
     }
 }
 
-void VulkanTexture::setYcbcrConversion(VkSamplerYcbcrConversion conversion) {
+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();

filament/backend/src/vulkan/VulkanTexture.h

@@ -40,7 +40,8 @@ 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, VkImageUsageFlags usage, bool isProtected);
+            VkSamplerYcbcrConversion ycbcrConversion, bool isExternalFormat,
+            VkImageUsageFlags usage, bool isProtected);
 
     ~VulkanTextureState();
 
@@ -85,9 +86,10 @@ private:
     // conversion matrix per-frame.
     struct Ycbcr {
         VkSamplerYcbcrConversion conversion;
+        bool isExternalFormat;
 
         bool operator==(Ycbcr const& other) const {
-            return conversion == other.conversion;
+            return conversion == other.conversion && isExternalFormat == other.isExternalFormat;
         }
 
         bool operator!=(Ycbcr const& other) const {
@@ -207,7 +209,7 @@ struct VulkanTexture : public HwTexture, fvkmemory::Resource {
     // 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);
+    void setYcbcrConversion(VkSamplerYcbcrConversion conversion, bool isExternal);
 
 #if FVK_ENABLED(FVK_DEBUG_TEXTURE)
     void print() const;

filament/backend/src/vulkan/VulkanYcbcrConversionCache.cpp

@@ -33,7 +33,7 @@ VulkanYcbcrConversionCache::VulkanYcbcrConversionCache(VkDevice device)
     : mDevice(device) {}
 
 VkSamplerYcbcrConversion VulkanYcbcrConversionCache::getConversion(
-        VulkanYcbcrConversionCache::Params params) {
+        VulkanYcbcrConversionCache::Params params) noexcept {
     auto iter = mCache.find(params);
     if (UTILS_LIKELY(iter != mCache.end())) {
         return iter->second;
@@ -43,7 +43,7 @@ VkSamplerYcbcrConversion VulkanYcbcrConversionCache::getConversion(
     TextureSwizzle const swizzleArray[] = { chroma.r, chroma.g, chroma.b, chroma.a };
     VkSamplerYcbcrConversionCreateInfo conversionInfo = {
         .sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_CREATE_INFO,
-        .format = params.format,
+        .format = fvkutils::getVkFormat(params.format),
         .ycbcrModel = fvkutils::getYcbcrModelConversion(chroma.ycbcrModel),
         .ycbcrRange = fvkutils::getYcbcrRange(chroma.ycbcrRange),
         .components = fvkutils::getSwizzleMap(swizzleArray),

filament/backend/src/vulkan/VulkanYcbcrConversionCache.h

@@ -30,14 +30,15 @@ namespace filament::backend {
 class VulkanYcbcrConversionCache {
 public:
     struct Params {
-        SamplerYcbcrConversion conversion = {}; // 4
-        VkFormat format;                        // 4
-        uint64_t externalFormat = 0;            // 8
+        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);
+    VkSamplerYcbcrConversion getConversion(Params params) noexcept;
     void terminate() noexcept;
 
 private:
@@ -47,8 +48,7 @@ private:
         bool operator()(Params lhs, Params rhs) const noexcept {
             SamplerYcbcrConversion::EqualTo equal;
             return equal(lhs.conversion, rhs.conversion) &&
-                   lhs.externalFormat == rhs.externalFormat &&
-                   lhs.format == rhs.format;
+                   lhs.externalFormat == rhs.externalFormat;
         }
     };
     using ConversionHashFn = utils::hash::MurmurHashFn<Params>;

filament/backend/src/vulkan/memory/ResourceManager.cpp

@@ -31,8 +31,6 @@ ResourceManager::ResourceManager(size_t arenaSize, bool disableUseAfterFreeCheck
     : mHandleAllocatorImpl("Handles", arenaSize, disableUseAfterFreeCheck, disablePoolHandleTags) {}
 
 void ResourceManager::gc() noexcept {
-    FVK_SYSTRACE_CONTEXT();
-    FVK_SYSTRACE_START("ResourceManager::gc");
     auto destroyAll = [this](GcList& list) {
         for (auto const& [type, id]: list) {
             destroyWithType(type, id);
@@ -51,7 +49,6 @@ void ResourceManager::gc() noexcept {
     GcList gcs;
     std::swap(gcs, mGcList);
     destroyAll(gcs);
-    FVK_SYSTRACE_END();
 }
 
 void ResourceManager::terminate() noexcept {

filament/backend/src/vulkan/memory/ResourcePointer.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);
     }

filament/backend/src/vulkan/platform/VulkanPlatform.cpp

@@ -212,8 +212,6 @@ ExtensionSet getDeviceExtensions(VkPhysicalDevice device) {
         VK_KHR_SAMPLER_YCBCR_CONVERSION_EXTENSION_NAME,
         VK_ANDROID_EXTERNAL_MEMORY_ANDROID_HARDWARE_BUFFER_EXTENSION_NAME,
         VK_EXT_QUEUE_FAMILY_FOREIGN_EXTENSION_NAME,
-        // This is needed for external images.  See VulkanPlatformAndroid
-        VK_KHR_IMAGE_FORMAT_LIST_EXTENSION_NAME,
 #endif
         // MoltenVk is the only non-conformant implementation we're interested in.
 #if defined(__APPLE__)
@@ -995,6 +993,30 @@ VkQueue VulkanPlatform::getProtectedGraphicsQueue() const noexcept {
     return mImpl->mProtectedGraphicsQueue;
 }
 
+VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadata(
+        ExternalImageHandleRef externalImage) {
+    return getExternalImageMetadataImpl(externalImage, mImpl->mDevice);
+}
+
+VulkanPlatform::ImageData VulkanPlatform::createExternalImageData(
+        ExternalImageHandleRef externalImage, const ExternalImageMetadata& metadata,
+        uint32_t memoryTypeIndex, VkImageUsageFlags usage) {
+    return createExternalImageDataImpl(externalImage, mImpl->mDevice, metadata, memoryTypeIndex,
+            usage);
+}
+
+VkSampler VulkanPlatform::createExternalSampler(SamplerYcbcrConversion chroma,
+        SamplerParams sampler, uint32_t internalFormat) {
+    return createExternalSamplerImpl(mImpl->mDevice, chroma, sampler, internalFormat);
+}
+
+VkImageView VulkanPlatform::createExternalImageView(SamplerYcbcrConversion chroma,
+        uint32_t internalFormat, VkImage image, VkImageSubresourceRange range,
+        VkImageViewType viewType, VkComponentMapping swizzle) {
+    return createExternalImageViewImpl(mImpl->mDevice, chroma, internalFormat, image, range,
+            viewType, swizzle);
+}
+
 ExtensionSet VulkanPlatform::getSwapchainInstanceExtensions() const {
     return getSwapchainInstanceExtensionsImpl();
 }

filament/backend/src/vulkan/platform/VulkanPlatformAndroid.cpp

@@ -15,14 +15,14 @@
  */
 #include <backend/platforms/VulkanPlatformAndroid.h>
 
-#include "vulkan/VulkanConstants.h"
-#include "vulkan/VulkanContext.h"
-
 #include <backend/DriverEnums.h>
 #include <private/backend/BackendUtilsAndroid.h>
 
+#include "vulkan/VulkanConstants.h"
+
 #include <utils/Panic.h>
 #include "vulkan/utils/Image.h"
+#include "vulkan/utils/Conversion.h"
 
 #include <bluevk/BlueVK.h>
 
@@ -39,14 +39,6 @@ namespace {
 
 VkFormat transformVkFormat(VkFormat format, bool sRGB) {
     if (!sRGB) {
-        switch (format) {
-            case VK_FORMAT_R8G8B8A8_SRGB:
-               return VK_FORMAT_R8G8B8A8_UNORM;
-            case VK_FORMAT_R8G8B8_SRGB:
-                return VK_FORMAT_R8G8B8_UNORM;
-            default:
-                break;
-        }
         return format;
     }
 
@@ -65,7 +57,7 @@ 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,
@@ -128,9 +120,7 @@ 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) {
@@ -146,37 +136,87 @@ 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, uint32_t memoryTypeIndex,
+        VkImageUsageFlags usage) {
+    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,
+        // pass down the format (external means we don't have it VK defined)
+        .externalFormat = metadata.externalFormat,
     };
+    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.samples = metadata.samples;
+    imageInfo.usage = usage;
+
+    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 = memoryTypeIndex,
+    };
+    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
 
-VulkanPlatformAndroid::ExternalImageVulkanAndroid::~ExternalImageVulkanAndroid() {
-    if (__builtin_available(android 26, *)) {
-        if (aHardwareBuffer) {
-            AHardwareBuffer_release(aHardwareBuffer);
-        }
-    }
-}
+VulkanPlatformAndroid::ExternalImageVulkanAndroid::~ExternalImageVulkanAndroid() = default;
 
 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 };
     }
 
@@ -185,20 +225,23 @@ Platform::ExternalImageHandle VulkanPlatformAndroid::createExternalImage(
 
 VulkanPlatformAndroid::ExternalImageDescAndroid VulkanPlatformAndroid::getExternalImageDesc(
         ExternalImageHandleRef externalImage) const noexcept {
-    auto metadata = extractExternalImageMetadata(externalImage);
+    auto const* fvkExternalImage =
+            static_cast<ExternalImageVulkanAndroid const*>(externalImage.get());
+
     return {
-        .width = metadata.width,
-        .height = metadata.height,
-        .format = metadata.filamentFormat,
-        .usage = metadata.filamentUsage,
+        .width = fvkExternalImage->width,
+        .height = fvkExternalImage->height,
+        .format = fvkExternalImage->format,
+        .usage = fvkExternalImage->usage,
     };
 }
 
-VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::extractExternalImageMetadata(
-        ExternalImageHandleRef image) const {
-    auto const* fvkExternalImage = static_cast<ExternalImageVulkanAndroid const*>(image.get());
+VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::getExternalImageMetadata(
+        ExternalImageHandleRef externalImage) {
+    auto const* fvkExternalImage =
+            static_cast<ExternalImageVulkanAndroid const*>(externalImage.get());
 
-    ExternalImageMetadata metadata = {};
+    ExternalImageMetadata metadata;
     AHardwareBuffer* buffer = fvkExternalImage->aHardwareBuffer;
     if (__builtin_available(android 26, *)) {
         AHardwareBuffer_Desc bufferDesc;
@@ -206,29 +249,16 @@ 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;
 
     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,
@@ -238,155 +268,138 @@ VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::extractExternalImag
     FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
             << "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)";
-
-    bool const requiresConversion =
-        metadata.format == VK_FORMAT_UNDEFINED ||
-        fvkutils::isVKYcbcrConversionFormat(metadata.format);
-    if (requiresConversion) {
-      metadata.format = VK_FORMAT_UNDEFINED;
-      metadata.usage = VK_IMAGE_USAGE_SAMPLED_BIT;
-      metadata.externalFormat = formatInfo.externalFormat;
-    } else {
-      metadata.externalFormat = 0;
-    }
-
+    metadata.externalFormat = formatInfo.externalFormat;
     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;
 }
 
-VulkanPlatform::ImageData VulkanPlatformAndroid::createVkImageFromExternal(
-        ExternalImageHandleRef externalImage) const {
-    auto metadata = extractExternalImageMetadata(externalImage);
-
+VulkanPlatformAndroid::ImageData VulkanPlatformAndroid::createExternalImageData(
+        ExternalImageHandleRef externalImage, const ExternalImageMetadata& metadata,
+        uint32_t memoryTypeIndex, VkImageUsageFlags usage) {
     auto const* fvkExternalImage =
             static_cast<ExternalImageVulkanAndroid const*>(externalImage.get());
-    AHardwareBuffer* buffer = fvkExternalImage->aHardwareBuffer;
+    ImageData data = allocateExternalImage(fvkExternalImage->aHardwareBuffer, getDevice(), metadata,
+            memoryTypeIndex, usage);
+    VkResult result = vkBindImageMemory(getDevice(), data.first, data.second, 0);
+    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+        << "vkBindImageMemory error=" << static_cast<int32_t>(result);
+    return data;
+}
 
-    VkDevice const device = getDevice();
-    VkPhysicalDevice const physicalDevice = getPhysicalDevice();
-    auto buildImage = [&](ExternalImageMetadata const& metadata) {
-        bool const isExternal = metadata.externalFormat != 0;
-        VkExternalFormatANDROID const externalFormat = {
-            .sType = VK_STRUCTURE_TYPE_EXTERNAL_FORMAT_ANDROID,
-            .pNext = nullptr,
-            .externalFormat = metadata.externalFormat,
-        };
-        VkExternalMemoryImageCreateInfo externalCreateInfo = {
-            .sType = VK_STRUCTURE_TYPE_EXTERNAL_MEMORY_IMAGE_CREATE_INFO,
-            .pNext = isExternal ? &externalFormat : nullptr,
-            .handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID,
-        };
-
-        VkFormat formats[2] = {};
-        VkImageFormatListCreateInfo imageFormatListInfo = {
-            .sType = VK_STRUCTURE_TYPE_IMAGE_FORMAT_LIST_CREATE_INFO,
-            .pNext = nullptr,
-            .viewFormatCount = 2,
-            .pViewFormats = formats,
-        };
-
-        if (fvkExternalImage->sRGB) {
-            formats[0] = metadata.format;
-            formats[1] = transformVkFormat(metadata.format, /*sRGB=*/false);
-            imageFormatListInfo.pNext = externalCreateInfo.pNext;
-            externalCreateInfo.pNext = &imageFormatListInfo;
-        }
-
-        VkImageCreateInfo const imageInfo = {
-            .sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,
-            .pNext = &externalCreateInfo,
-            .flags = fvkExternalImage->sRGB ? VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT : 0u,
-            .imageType = VK_IMAGE_TYPE_2D,
-            // For non external images, use the same format as the AHB, which isn't in SRGB
-            // Fix VUID-VkMemoryAllocateInfo-pNext-02387
-            .format = transformVkFormat(metadata.format, /*sRGB=*/false),
-            .extent = {
-                metadata.width,
-                metadata.height,
-                1u,
-            },
-            .mipLevels = 1,
-            .arrayLayers = metadata.layers,
-            .samples = metadata.samples,
-            .usage = metadata.usage,
-        };
-        VkImage image;
-        VkResult result = vkCreateImage(device, &imageInfo, VKALLOC, &image);
-        FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
-            << "vkCreateImage failed with error=" << static_cast<int32_t>(result);
-        return image;
+VkImageView VulkanPlatform::createExternalImageViewImpl(VkDevice device, SamplerYcbcrConversion chroma,
+            uint32_t internalFormat, VkImage image, VkImageSubresourceRange range,
+            VkImageViewType viewType, VkComponentMapping swizzle){
+    VkExternalFormatANDROID externalFormat = {
+        .sType = VK_STRUCTURE_TYPE_EXTERNAL_FORMAT_ANDROID,
+        .externalFormat = internalFormat,
     };
 
-    auto allocMem = [&](VkImage image, ExternalImageMetadata const& metadata) {
-        bool const isExternal = metadata.externalFormat != 0;
-        // 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(physicalDevice, &memoryProperties);
-        VkMemoryPropertyFlags requiredMemoryFlags =
-                !isExternal && any(metadata.filamentUsage & TextureUsage::UPLOADABLE)
-                        ? VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
-                        : VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;
+    TextureSwizzle const swizzleArray[] = {chroma.r, chroma.g, chroma.b, chroma.a};
+    VkSamplerYcbcrConversionCreateInfo conversionInfo = {
+        .sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_CREATE_INFO,
+        .pNext = &externalFormat,
+        .format = VK_FORMAT_UNDEFINED,
+        .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),
+    };
+    VkSamplerYcbcrConversion conversion = VK_NULL_HANDLE;
+    VkResult result = vkCreateSamplerYcbcrConversion(device, &conversionInfo,
+                                                     nullptr, &conversion);
+    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+        << "Unable to create Ycbcr Conversion."
+        << " error=" << static_cast<int32_t>(result);
 
-        if (any(metadata.filamentUsage & TextureUsage::PROTECTED)) {
-            requiredMemoryFlags |= VK_MEMORY_PROPERTY_PROTECTED_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;
-        VkResult 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);
-        FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
-                << "vkBindImageMemory error=" << static_cast<int32_t>(result);
-        return memory;
+    VkSamplerYcbcrConversionInfo samplerYcbcrConversionInfo = {
+        .sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_INFO,
+        .conversion = conversion,
     };
 
-    VulkanPlatform::ImageData::Bundle internal = {}, external = {};
-    auto img = buildImage(metadata);
-    auto mem = allocMem(img, metadata);
-
-    // Note that we're always choosing a non-externally sampled format if it exists.
-    if (metadata.externalFormat == 0) {
-        internal = { img, mem };
-    } else {
-        external = { img, mem };
-    }
-
-    return {
-        .internal = internal,
-        .external = external,
+    VkImageViewCreateInfo viewInfo = {
+        .sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO,
+        .pNext = &samplerYcbcrConversionInfo,
+        .flags = 0,
+        .image = image,
+        .viewType = viewType,
+        .format = VK_FORMAT_UNDEFINED,
+        .components = swizzle,
+        .subresourceRange = range,
     };
+    VkImageView imageView;
+    result = vkCreateImageView(device, &viewInfo, VKALLOC, &imageView);
+    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+        << "Unable to create VkImageView."
+        << " error=" << static_cast<int32_t>(result);
+
+    return imageView;
+}
+
+VkSampler VulkanPlatform::createExternalSamplerImpl(
+        VkDevice device, SamplerYcbcrConversion chroma, SamplerParams params,
+        uint32_t internalFormat) {
+    VkExternalFormatANDROID externalFormat = {
+        .sType = VK_STRUCTURE_TYPE_EXTERNAL_FORMAT_ANDROID,
+        .externalFormat = internalFormat,
+    };
+
+    TextureSwizzle const swizzleArray[] = {chroma.r, chroma.g, chroma.b, chroma.a};
+    VkSamplerYcbcrConversionCreateInfo conversionInfo = {
+        .sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_CREATE_INFO,
+        .pNext = &externalFormat,
+        .format = VK_FORMAT_UNDEFINED,
+        .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),
+    };
+    VkSamplerYcbcrConversion conversion = VK_NULL_HANDLE;
+    VkResult result = vkCreateSamplerYcbcrConversion(device, &conversionInfo,
+                                                     nullptr, &conversion);
+    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+        << "Unable to create Ycbcr Conversion."
+        << " error=" << static_cast<int32_t>(result);
+
+    VkSamplerYcbcrConversionInfo samplerYcbcrConversionInfo = {
+        .sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_INFO,
+        .pNext = nullptr,
+        .conversion = conversion,
+    };
+
+    VkSamplerCreateInfo samplerInfo = {
+        .sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO,
+        .pNext = &samplerYcbcrConversionInfo,
+        .magFilter = fvkutils::getFilter(params.filterMag),
+        .minFilter = fvkutils::getFilter(params.filterMin),
+        .mipmapMode = fvkutils::getMipmapMode(params.filterMin),
+        .addressModeU = fvkutils::getWrapMode(params.wrapS),
+        .addressModeV = fvkutils::getWrapMode(params.wrapT),
+        .addressModeW = fvkutils::getWrapMode(params.wrapR),
+        .anisotropyEnable = params.anisotropyLog2 == 0 ? VK_FALSE : VK_TRUE,
+        .maxAnisotropy = (float)(1u << params.anisotropyLog2),
+        .compareEnable = fvkutils::getCompareEnable(params.compareMode),
+        .compareOp = fvkutils::getCompareOp(params.compareFunc),
+        .minLod = 0.0f,
+        .maxLod = fvkutils::getMaxLod(params.filterMin),
+        .borderColor = VK_BORDER_COLOR_INT_OPAQUE_BLACK,
+        .unnormalizedCoordinates = VK_FALSE,
+    };
+    VkSampler sampler;
+    result = vkCreateSampler(device, &samplerInfo, VKALLOC, &sampler);
+    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+        << "Unable to create sampler."
+        << " error=" << static_cast<int32_t>(result);
+    return sampler;
 }
 
 VulkanPlatform::ExtensionSet VulkanPlatformAndroid::getSwapchainInstanceExtensions() const {
@@ -400,7 +413,7 @@ VulkanPlatform::SurfaceBundle VulkanPlatformAndroid::createVkSurfaceKHR(void* na
     VkSurfaceKHR surface;
     VkExtent2D extent;
 
-    VkAndroidSurfaceCreateInfoKHR const createInfo = {
+    VkAndroidSurfaceCreateInfoKHR const createInfo{
         .sType = VK_STRUCTURE_TYPE_ANDROID_SURFACE_CREATE_INFO_KHR,
         .window = (ANativeWindow*) nativeWindow,
     };
@@ -414,9 +427,20 @@ VulkanPlatform::SurfaceBundle VulkanPlatformAndroid::createVkSurfaceKHR(void* na
 // Deprecated platform dependent helper methods
 VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensionsImpl() { return {}; }
 
+VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device) {
+    return ExternalImageMetadata{};
+}
+
+VulkanPlatform::ImageData VulkanPlatform::createExternalImageDataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device,
+        const ExternalImageMetadata& metadata, uint32_t memoryTypeIndex, VkImageUsageFlags usage) {
+    return ImageData{};
+}
+
 VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHRImpl(void* nativeWindow,
         VkInstance instance, uint64_t flags) noexcept {
     return SurfaceBundle{};
 }
 
-} // namespace filament::backend
+}// namespace filament::backend

filament/backend/src/vulkan/platform/VulkanPlatformApple.mm

@@ -24,12 +24,28 @@
 #include <bluevk/BlueVK.h>
 
 // Platform specific includes and defines
-#include <Cocoa/Cocoa.h>
-#import <Metal/Metal.h>
-#import <QuartzCore/CAMetalLayer.h>
+#if defined(__APPLE__)
+    #include <Cocoa/Cocoa.h>
+    #import <Metal/Metal.h>
+    #import <QuartzCore/CAMetalLayer.h>
 
-#ifndef VK_MVK_macos_surface
-    #error VK_MVK_macos_surface is not defined
+    #ifndef VK_MVK_macos_surface
+         #error VK_MVK_macos_surface is not defined
+    #endif
+#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
+
+    #ifndef VK_MVK_ios_surface
+        #error VK_MVK_ios_surface is not defined
+    #endif
+    #define METALVIEW_TAG 255
+#else
+    #error Not a supported Apple + Vulkan platform
 #endif
 
 using namespace bluevk;
@@ -38,28 +54,72 @@ namespace filament::backend {
 
 VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensionsImpl() {
     ExtensionSet const ret = {
+    #if defined(__APPLE__)
         VK_MVK_MACOS_SURFACE_EXTENSION_NAME,  // TODO: replace with VK_EXT_metal_surface
+    #elif defined(FILAMENT_IOS) && defined(METAL_AVAILABLE)
+        VK_MVK_IOS_SURFACE_EXTENSION_NAME,
+    #endif
     };
     return ret;
 }
 
+VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device) {
+    return {};
+}
+
+VulkanPlatform::ImageData VulkanPlatform::createExternalImageDataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device,
+        const ExternalImageMetadata& metadata, uint32_t memoryTypeIndex, VkImageUsageFlags usage) {
+    return {};
+}
+
+VkSampler VulkanPlatform::createExternalSamplerImpl(VkDevice device,
+    SamplerYcbcrConversion chroma,
+    SamplerParams sampler,
+    uint32_t internalFormat) {
+    return VK_NULL_HANDLE;
+}
+
+VkImageView VulkanPlatform::createExternalImageViewImpl(VkDevice device,
+        SamplerYcbcrConversion chroma, uint32_t internalFormat, VkImage image,
+        VkImageSubresourceRange range, VkImageViewType viewType, VkComponentMapping swizzle) {
+    return VK_NULL_HANDLE;
+}
+
 VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHRImpl(void* nativeWindow,
         VkInstance instance, uint64_t flags) noexcept {
     VkSurfaceKHR surface;
-    NSView* nsview = (__bridge NSView*) nativeWindow;
-    FILAMENT_CHECK_POSTCONDITION(nsview) << "Unable to obtain Metal-backed NSView.";
+    #if defined(__APPLE__)
+        NSView* nsview = (__bridge NSView*) nativeWindow;
+        FILAMENT_CHECK_POSTCONDITION(nsview) << "Unable to obtain Metal-backed NSView.";
 
+        // Create the VkSurface.
+        FILAMENT_CHECK_POSTCONDITION(vkCreateMacOSSurfaceMVK)
+                << "Unable to load vkCreateMacOSSurfaceMVK.";
+        VkMacOSSurfaceCreateInfoMVK createInfo = {};
+        createInfo.sType = VK_STRUCTURE_TYPE_MACOS_SURFACE_CREATE_INFO_MVK;
+        createInfo.pView = (__bridge void*) nsview;
+        VkResult result = vkCreateMacOSSurfaceMVK((VkInstance) instance, &createInfo, VKALLOC,
+                (VkSurfaceKHR*) &surface);
+        FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+                << "vkCreateMacOSSurfaceMVK. error=" << static_cast<int32_t>(result);
+#elif defined(FILAMENT_IOS) && defined(METAL_AVAILABLE)
+    CAMetalLayer* metalLayer = (CAMetalLayer*) nativeWindow;
     // Create the VkSurface.
-    FILAMENT_CHECK_POSTCONDITION(vkCreateMacOSSurfaceMVK)
-            << "Unable to load vkCreateMacOSSurfaceMVK.";
-    VkMacOSSurfaceCreateInfoMVK createInfo = {};
-    createInfo.sType = VK_STRUCTURE_TYPE_MACOS_SURFACE_CREATE_INFO_MVK;
-    createInfo.pView = (__bridge void*) nsview;
-    VkResult result = vkCreateMacOSSurfaceMVK((VkInstance) instance, &createInfo, VKALLOC,
+    FILAMENT_CHECK_POSTCONDITION(vkCreateIOSSurfaceMVK)
+            << "Unable to load vkCreateIOSSurfaceMVK function.";
+    VkIOSSurfaceCreateInfoMVK createInfo = {};
+    createInfo.sType = VK_STRUCTURE_TYPE_IOS_SURFACE_CREATE_INFO_MVK;
+    createInfo.pNext = NULL;
+    createInfo.flags = 0;
+    createInfo.pView = metalLayer;
+    VkResult result = vkCreateIOSSurfaceMVK((VkInstance) instance, &createInfo, VKALLOC,
             (VkSurfaceKHR*) &surface);
     FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
-            << "vkCreateMacOSSurfaceMVK. error=" << static_cast<int32_t>(result);
-    return std::make_tuple(surface, VkExtent2D{});
+            << "vkCreateIOSSurfaceMVK failed. error=" << static_cast<int32_t>(result);
+#endif
+        return std::make_tuple(surface, VkExtent2D{});
 }
 
 } // namespace filament::backend

filament/backend/src/vulkan/platform/VulkanPlatformLinuxWindows.cpp

@@ -84,6 +84,30 @@ using namespace bluevk;
 
 namespace filament::backend {
 
+VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device) {
+    return {};
+}
+
+VulkanPlatform::ImageData VulkanPlatform::createExternalImageDataImpl(
+        ExternalImageHandleRef externalImage, VkDevice device,
+        const ExternalImageMetadata& metadata, uint32_t memoryTypeIndex, VkImageUsageFlags usage) {
+    return {};
+}
+
+VkSampler VulkanPlatform::createExternalSamplerImpl(VkDevice device,
+    SamplerYcbcrConversion chroma,
+    SamplerParams sampler,
+    uint32_t internalFormat) {
+    return VK_NULL_HANDLE;
+}
+
+VkImageView VulkanPlatform::createExternalImageViewImpl(VkDevice device,
+        SamplerYcbcrConversion chroma, uint32_t internalFormat, VkImage image,
+        VkImageSubresourceRange range, VkImageViewType viewType, VkComponentMapping swizzle) {
+    return VK_NULL_HANDLE;
+}
+
 VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensionsImpl() {
     VulkanPlatform::ExtensionSet const ret = {
 #if defined(__linux__) && defined(FILAMENT_SUPPORTS_WAYLAND)

filament/backend/src/vulkan/utils/Conversion.cpp

@@ -51,8 +51,6 @@ VkFormat getVkFormat(ElementType type, bool normalized, bool integer) {
                 return VK_FORMAT_UNDEFINED;
         }
     }
-
-    // Non-normalized case
     switch (type) {
         // Single Component Types
         case ElementType::BYTE: return integer ? VK_FORMAT_R8_SINT : VK_FORMAT_R8_SSCALED;

filament/backend/src/vulkan/utils/Image.cpp

@@ -184,46 +184,6 @@ bool isVkStencilFormat(VkFormat format) {
     return (getImageAspect(format) & VK_IMAGE_ASPECT_STENCIL_BIT) != 0;
 }
 
-bool isVKYcbcrConversionFormat(VkFormat format) {
-    switch (format) {
-        case VK_FORMAT_G8B8G8R8_422_UNORM:
-        case VK_FORMAT_B8G8R8G8_422_UNORM:
-        case VK_FORMAT_G8_B8_R8_3PLANE_420_UNORM:
-        case VK_FORMAT_G8_B8R8_2PLANE_420_UNORM:
-        case VK_FORMAT_G8_B8_R8_3PLANE_422_UNORM:
-        case VK_FORMAT_G8_B8R8_2PLANE_422_UNORM:
-        case VK_FORMAT_G8_B8_R8_3PLANE_444_UNORM:
-        case VK_FORMAT_G10X6B10X6G10X6R10X6_422_UNORM_4PACK16:
-        case VK_FORMAT_B10X6G10X6R10X6G10X6_422_UNORM_4PACK16:
-        case VK_FORMAT_G10X6_B10X6_R10X6_3PLANE_420_UNORM_3PACK16:
-        case VK_FORMAT_G10X6_B10X6R10X6_2PLANE_420_UNORM_3PACK16:
-        case VK_FORMAT_G10X6_B10X6_R10X6_3PLANE_422_UNORM_3PACK16:
-        case VK_FORMAT_G10X6_B10X6R10X6_2PLANE_422_UNORM_3PACK16:
-        case VK_FORMAT_G10X6_B10X6_R10X6_3PLANE_444_UNORM_3PACK16:
-        case VK_FORMAT_G12X4B12X4G12X4R12X4_422_UNORM_4PACK16:
-        case VK_FORMAT_B12X4G12X4R12X4G12X4_422_UNORM_4PACK16:
-        case VK_FORMAT_G12X4_B12X4_R12X4_3PLANE_420_UNORM_3PACK16:
-        case VK_FORMAT_G12X4_B12X4R12X4_2PLANE_420_UNORM_3PACK16:
-        case VK_FORMAT_G12X4_B12X4_R12X4_3PLANE_422_UNORM_3PACK16:
-        case VK_FORMAT_G12X4_B12X4R12X4_2PLANE_422_UNORM_3PACK16:
-        case VK_FORMAT_G12X4_B12X4_R12X4_3PLANE_444_UNORM_3PACK16:
-        case VK_FORMAT_G16B16G16R16_422_UNORM:
-        case VK_FORMAT_B16G16R16G16_422_UNORM:
-        case VK_FORMAT_G16_B16_R16_3PLANE_420_UNORM:
-        case VK_FORMAT_G16_B16R16_2PLANE_420_UNORM:
-        case VK_FORMAT_G16_B16_R16_3PLANE_422_UNORM:
-        case VK_FORMAT_G16_B16R16_2PLANE_422_UNORM:
-        case VK_FORMAT_G16_B16_R16_3PLANE_444_UNORM:
-        case VK_FORMAT_G8_B8R8_2PLANE_444_UNORM:
-        case VK_FORMAT_G10X6_B10X6R10X6_2PLANE_444_UNORM_3PACK16:
-        case VK_FORMAT_G12X4_B12X4R12X4_2PLANE_444_UNORM_3PACK16:
-        case VK_FORMAT_G16_B16R16_2PLANE_444_UNORM:
-            return true;
-        default:
-            return false;
-    }
-}
-
 static uint32_t mostSignificantBit(uint32_t x) { return 1ul << (31ul - utils::clz(x)); }
 
 uint8_t reduceSampleCount(uint8_t sampleCount, VkSampleCountFlags mask) {

filament/backend/src/vulkan/utils/Image.h

@@ -98,8 +98,6 @@ bool isVkDepthFormat(VkFormat format);
 
 bool isVkStencilFormat(VkFormat format);
 
-bool isVKYcbcrConversionFormat(VkFormat format);
-
 VkImageAspectFlags getImageAspect(VkFormat format);
 
 uint8_t reduceSampleCount(uint8_t sampleCount, VkSampleCountFlags mask);

filament/backend/src/webgpu/WGPUProgram.cpp

@@ -1,150 +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 "WebGPUHandles.h"
-
-#include "WebGPUConstants.h"
-
-#include "DriverBase.h"
-#include <backend/DriverEnums.h>
-#include <backend/Program.h>
-
-#include <utils/Panic.h>
-#include <utils/ostream.h>
-
-#include <webgpu/webgpu_cpp.h>
-
-#include <sstream>
-#include <string_view>
-#include <vector>
-
-namespace filament::backend {
-
-namespace {
-
-[[nodiscard]] constexpr std::string_view toString(ShaderStage stage) {
-    switch (stage) {
-        case ShaderStage::VERTEX:
-            return "vertex";
-        case ShaderStage::FRAGMENT:
-            return "fragment";
-        case ShaderStage::COMPUTE:
-            return "compute";
-    }
-}
-
-[[nodiscard]] wgpu::ShaderModule createShaderModule(wgpu::Device& device, const char* programName,
-        std::array<utils::FixedCapacityVector<uint8_t>, Program::SHADER_TYPE_COUNT> const&
-                shaderSource,
-        ShaderStage stage) {
-    utils::FixedCapacityVector<uint8_t> const& sourceBytes =
-            shaderSource[static_cast<size_t>(stage)];
-    if (sourceBytes.empty()) {
-        return nullptr;// nothing to compile, the shader was not provided
-    }
-    wgpu::ShaderModuleWGSLDescriptor wgslDescriptor{};
-    wgslDescriptor.code = wgpu::StringView(reinterpret_cast<const char*>(sourceBytes.data()));
-    std::stringstream labelStream;
-    labelStream << programName << " " << toString(stage) << " shader";
-    auto label = labelStream.str();
-    wgpu::ShaderModuleDescriptor descriptor{
-        .nextInChain = &wgslDescriptor,
-        .label = label.data()
-    };
-    wgpu::ShaderModule module = device.CreateShaderModule(&descriptor);
-    FILAMENT_CHECK_POSTCONDITION(module != nullptr) << "Failed to create " << descriptor.label;
-    module.GetCompilationInfo(wgpu::CallbackMode::AllowSpontaneous,
-            [&descriptor](auto const& status, wgpu::CompilationInfo const* info) {
-                switch (status) {
-                    case wgpu::CompilationInfoRequestStatus::CallbackCancelled:
-                        FWGPU_LOGW << "Shader compilation info callback cancelled for "
-                                   << descriptor.label << "?" << utils::io::endl;
-                        return;
-                    case wgpu::CompilationInfoRequestStatus::Success:
-                        break;
-                }
-                if (info != nullptr) {
-                    std::stringstream errorStream;
-                    int errorCount = 0;
-                    for (size_t msgIndex = 0; msgIndex < info->messageCount; msgIndex++) {
-                        wgpu::CompilationMessage const& message = info->messages[msgIndex];
-                        switch (message.type) {
-                            case wgpu::CompilationMessageType::Info:
-                                FWGPU_LOGI << descriptor.label << ": " << message.message
-                                           << " line#:" << message.lineNum
-                                           << " linePos:" << message.linePos
-                                           << " offset:" << message.offset
-                                           << " length:" << message.length << utils::io::endl;
-                                break;
-                            case wgpu::CompilationMessageType::Warning:
-                                FWGPU_LOGW << "Warning compiling " << descriptor.label << ": "
-                                           << message.message << " line#:" << message.lineNum
-                                           << " linePos:" << message.linePos
-                                           << " offset:" << message.offset
-                                           << " length:" << message.length << utils::io::endl;
-                                break;
-                            case wgpu::CompilationMessageType::Error:
-                                errorCount++;
-                                errorStream << "Error " << errorCount << " : "
-                                            << std::string_view(message.message)
-                                            << " line#:" << message.lineNum
-                                            << " linePos:" << message.linePos
-                                            << " offset:" << message.offset
-                                            << " length:" << message.length << "\n";
-                                break;
-                        }
-                    }
-                    FILAMENT_CHECK_POSTCONDITION(errorCount < 1)
-                            << errorCount << " error(s) compiling " << descriptor.label << ":\n"
-                            << errorStream.str();
-                }
-                FWGPU_LOGD << descriptor.label << " compiled successfully" << utils::io::endl;
-            });
-    return module;
-}
-
-std::vector<wgpu::ConstantEntry> convertConstants(
-        utils::FixedCapacityVector<filament::backend::Program::SpecializationConstant> const&
-                constantsInfo) {
-    std::vector<wgpu::ConstantEntry> constants(constantsInfo.size());
-    for (size_t i = 0; i < constantsInfo.size(); i++) {
-        filament::backend::Program::SpecializationConstant const& specConstant = constantsInfo[i];
-        wgpu::ConstantEntry& constantEntry = constants[i];
-        constantEntry.key = wgpu::StringView(std::to_string(specConstant.id));
-        if (auto* v = std::get_if<int32_t>(&specConstant.value)) {
-            constantEntry.value = static_cast<double>(*v);
-        } else if (auto* f = std::get_if<float>(&specConstant.value)) {
-            constantEntry.value = static_cast<double>(*f);
-        } else if (auto* b = std::get_if<bool>(&specConstant.value)) {
-            constantEntry.value = *b ? 0.0 : 1.0;
-        }
-    }
-    return constants;
-}
-
-}// namespace
-
-WGPUProgram::WGPUProgram(wgpu::Device& device, Program& program)
-    : HwProgram(program.getName()),
-      vertexShaderModule(createShaderModule(device, name.c_str_safe(), program.getShadersSource(),
-              ShaderStage::VERTEX)),
-      fragmentShaderModule(createShaderModule(device, name.c_str_safe(), program.getShadersSource(),
-              ShaderStage::FRAGMENT)),
-      computeShaderModule(createShaderModule(device, name.c_str_safe(), program.getShadersSource(),
-              ShaderStage::COMPUTE)),
-      constants(convertConstants(program.getSpecializationConstants())) {}
-
-}// namespace filament::backend

filament/backend/src/webgpu/WebGPUDriver.cpp

@@ -16,7 +16,7 @@
 
 #include "webgpu/WebGPUDriver.h"
 
-#include "WebGPUSwapChain.h"
+#include "webgpu/WebGPUConstants.h"
 #include <backend/platforms/WebGPUPlatform.h>
 
 #include "CommandStreamDispatcher.h"
@@ -183,6 +183,8 @@ void printAdapterDetails(wgpu::Adapter const& adapter) {
 }
 #endif
 
+
+
 #if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
 void printDeviceDetails(wgpu::Device const& device) {
     wgpu::SupportedFeatures supportedFeatures{};
@@ -226,15 +228,6 @@ WebGPUDriver::WebGPUDriver(WebGPUPlatform& platform, const Platform::DriverConfi
 #if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
     printInstanceDetails(mPlatform.getInstance());
 #endif
-    mAdapter = mPlatform.requestAdapter(nullptr);
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-    printAdapterDetails(mAdapter);
-#endif
-    mDevice = mPlatform.requestDevice(mAdapter);
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-    printDeviceDetails(mDevice);
-#endif
-    mQueue = mDevice.GetQueue();
 }
 
 WebGPUDriver::~WebGPUDriver() noexcept = default;
@@ -293,52 +286,37 @@ void WebGPUDriver::finish(int) {
 }
 
 void WebGPUDriver::destroyRenderPrimitive(Handle<HwRenderPrimitive> rph) {
-   if (rph) {
-        destructHandle<WGPURenderPrimitive>(rph);
-    }
 }
 
 void WebGPUDriver::destroyVertexBufferInfo(Handle<HwVertexBufferInfo> vbih) {
-   if (vbih) {
-        destructHandle<WGPUVertexBufferInfo>(vbih);
-    }
 }
 
 void WebGPUDriver::destroyVertexBuffer(Handle<HwVertexBuffer> vbh) {
-    if (vbh) {
-        destructHandle<WGPUVertexBuffer>(vbh);
-    }
 }
 
 void WebGPUDriver::destroyIndexBuffer(Handle<HwIndexBuffer> ibh) {
-    if (ibh) {
-        destructHandle<WGPUIndexBuffer>(ibh);
-    }
 }
 
 void WebGPUDriver::destroyBufferObject(Handle<HwBufferObject> boh) {
-    if (boh) {
-        destructHandle<WGPUBufferObject>(boh);
-    }
 }
 
 void WebGPUDriver::destroyTexture(Handle<HwTexture> th) {
 }
 
 void WebGPUDriver::destroyProgram(Handle<HwProgram> ph) {
-    if (ph) {
-        destructHandle<WGPUProgram>(ph);
-    }
 }
 
 void WebGPUDriver::destroyRenderTarget(Handle<HwRenderTarget> rth) {
 }
 
 void WebGPUDriver::destroySwapChain(Handle<HwSwapChain> sch) {
-    if (sch) {
-        destructHandle<WebGPUSwapChain>(sch);
-    }
     mSwapChain = nullptr;
+    // TODO:  use webgpu handle allocator from
+    //        https://github.com/google/filament/pull/8566
+//    if (sch) {
+//        HwSwapChain* hwSwapChain = handleCast<HwSwapChain*>(sch);
+//        destruct(sch, hwSwapChain);
+//    }
 }
 
 void WebGPUDriver::destroyStream(Handle<HwStream> sh) {
@@ -348,19 +326,16 @@ void WebGPUDriver::destroyTimerQuery(Handle<HwTimerQuery> tqh) {
 }
 
 void WebGPUDriver::destroyDescriptorSetLayout(Handle<HwDescriptorSetLayout> tqh) {
-    if (tqh) {
-        destructHandle<WebGPUDescriptorSetLayout>(tqh);
-    }
 }
 
 void WebGPUDriver::destroyDescriptorSet(Handle<HwDescriptorSet> tqh) {
-    if (tqh) {
-        destructHandle<WebGPUDescriptorSet>(tqh);
-    }
 }
 
 Handle<HwSwapChain> WebGPUDriver::createSwapChainS() noexcept {
-    return allocHandle<WebGPUSwapChain>();
+    // TODO:  use webgpu handle allocator from.
+    //        https://github.com/google/filament/pull/8566
+    // return allocAndConstructHandle<HwSwapChain>();
+    return Handle<HwSwapChain>((Handle<HwSwapChain>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwSwapChain> WebGPUDriver::createSwapChainHeadlessS() noexcept {
@@ -376,7 +351,7 @@ Handle<HwTexture> WebGPUDriver::importTextureS() noexcept {
 }
 
 Handle<HwProgram> WebGPUDriver::createProgramS() noexcept {
-    return allocHandle<WGPUProgram>();
+    return Handle<HwProgram>((Handle<HwProgram>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwFence> WebGPUDriver::createFenceS() noexcept {
@@ -408,11 +383,11 @@ Handle<HwVertexBuffer> WebGPUDriver::createVertexBufferS() noexcept {
 }
 
 Handle<HwDescriptorSet> WebGPUDriver::createDescriptorSetS() noexcept {
-    return allocHandle<WebGPUDescriptorSet>();
+    return Handle<HwDescriptorSet>((Handle<HwDescriptorSet>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwRenderPrimitive> WebGPUDriver::createRenderPrimitiveS() noexcept {
-    return allocHandle<WGPURenderPrimitive>();
+    return Handle<HwRenderPrimitive>((Handle<HwRenderPrimitive>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwVertexBufferInfo> WebGPUDriver::createVertexBufferInfoS() noexcept {
@@ -428,7 +403,8 @@ Handle<HwRenderTarget> WebGPUDriver::createDefaultRenderTargetS() noexcept {
 }
 
 Handle<HwDescriptorSetLayout> WebGPUDriver::createDescriptorSetLayoutS() noexcept {
-    return allocHandle<WebGPUDescriptorSetLayout>();
+    return Handle<HwDescriptorSetLayout>(
+            (Handle<HwDescriptorSetLayout>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwTexture> WebGPUDriver::createTextureExternalImageS() noexcept {
@@ -444,14 +420,21 @@ Handle<HwTexture> WebGPUDriver::createTextureExternalImagePlaneS() noexcept {
 }
 
 void WebGPUDriver::createSwapChainR(Handle<HwSwapChain> sch, void* nativeWindow, uint64_t flags) {
-    mNativeWindow = nativeWindow;
+    // TODO:  use webgpu handle allocator from.
+    //        https://github.com/google/filament/pull/8566
+    // HwSwapChain* hwSwapChain = handleCast<HwSwapChain*>(sch);
     assert_invariant(!mSwapChain);
     wgpu::Surface surface = mPlatform.createSurface(nativeWindow, flags);
-
-    wgpu::Extent2D surfaceSize = mPlatform.getSurfaceExtent(mNativeWindow);
-    mSwapChain = constructHandle<WebGPUSwapChain>(sch, std::move(surface), surfaceSize, mAdapter,
-            mDevice, flags);
-    assert_invariant(mSwapChain);
+    mAdapter = mPlatform.requestAdapter(surface);
+#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
+    printAdapterDetails(mAdapter);
+#endif
+    mDevice = mPlatform.requestDevice(mAdapter);
+#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
+    printDeviceDetails(mDevice);
+#endif
+    mQueue = mDevice.GetQueue();
+    mSwapChain = std::make_unique<WebGPUSwapChain>(std::move(surface), mAdapter, mDevice, flags);
     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."
@@ -464,33 +447,25 @@ void WebGPUDriver::createSwapChainR(Handle<HwSwapChain> sch, void* nativeWindow,
                   "rebuilding Filament with that flag, e.g. ./build.sh -x "
                << FWGPU_PRINT_SYSTEM << " ..." << utils::io::endl;
 #endif
+    // TODO:  use webgpu handle allocator from.
+    //        https://github.com/google/filament/pull/8566
+    // hwSwapChain->swapChain = mSwapChain.get();
 }
 
 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) {
-    constructHandle<WGPUVertexBufferInfo>(vbih, bufferCount, attributeCount, attributes);
-}
+        uint8_t attributeCount, AttributeArray attributes) {}
 
 void WebGPUDriver::createVertexBufferR(Handle<HwVertexBuffer> vbh, uint32_t vertexCount,
-        Handle<HwVertexBufferInfo> vbih) {
-    auto* vertexBufferInfo = handleCast<WGPUVertexBufferInfo>(vbih);
-    constructHandle<WGPUVertexBuffer>(vbh, mDevice, vertexCount, vertexBufferInfo->bufferCount,
-            vbih);
-}
+        Handle<HwVertexBufferInfo> vbih) {}
 
 void WebGPUDriver::createIndexBufferR(Handle<HwIndexBuffer> ibh, ElementType elementType,
-        uint32_t indexCount, BufferUsage usage) {
-    auto elementSize = static_cast<uint8_t>(getElementTypeSize(elementType));
-    constructHandle<WGPUIndexBuffer>(ibh, mDevice, elementSize, indexCount);
-}
+        uint32_t indexCount, BufferUsage usage) {}
 
 void WebGPUDriver::createBufferObjectR(Handle<HwBufferObject> boh, uint32_t byteCount,
-        BufferObjectBinding bindingType, BufferUsage usage) {
-    constructHandle<WGPUBufferObject>(boh, mDevice, bindingType, 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,
@@ -520,20 +495,9 @@ void WebGPUDriver::importTextureR(Handle<HwTexture> th, intptr_t id, SamplerType
         uint32_t depth, TextureUsage usage) {}
 
 void WebGPUDriver::createRenderPrimitiveR(Handle<HwRenderPrimitive> rph, Handle<HwVertexBuffer> vbh,
-        Handle<HwIndexBuffer> ibh, PrimitiveType pt) {
-    assert_invariant(mDevice);
+        Handle<HwIndexBuffer> ibh, PrimitiveType pt) {}
 
-    auto* renderPrimitive = constructHandle<WGPURenderPrimitive>(rph);
-    auto* vertexBuffer = handleCast<WGPUVertexBuffer>(vbh);
-    auto* indexBuffer = handleCast<WGPUIndexBuffer>(ibh);
-    renderPrimitive->vertexBuffer = vertexBuffer;
-    renderPrimitive->indexBuffer = indexBuffer;
-    renderPrimitive->type = pt;
-}
-
-void WebGPUDriver::createProgramR(Handle<HwProgram> ph, Program&& program) {
-    constructHandle<WGPUProgram>(ph, mDevice, program);
-}
+void WebGPUDriver::createProgramR(Handle<HwProgram> ph, Program&& program) {}
 
 void WebGPUDriver::createDefaultRenderTargetR(Handle<HwRenderTarget> rth, int) {
     assert_invariant(!mDefaultRenderTarget);
@@ -550,15 +514,10 @@ void WebGPUDriver::createFenceR(Handle<HwFence> fh, int) {}
 void WebGPUDriver::createTimerQueryR(Handle<HwTimerQuery> tqh, int) {}
 
 void WebGPUDriver::createDescriptorSetLayoutR(Handle<HwDescriptorSetLayout> dslh,
-        backend::DescriptorSetLayout&& info) {
-    constructHandle<WebGPUDescriptorSetLayout>(dslh, std::move(info), mDevice);
-}
+        backend::DescriptorSetLayout&& info) {}
 
 void WebGPUDriver::createDescriptorSetR(Handle<HwDescriptorSet> dsh,
-        Handle<HwDescriptorSetLayout> dslh) {
-    auto layout = handleCast<WebGPUDescriptorSetLayout>(dslh);
-    constructHandle<WebGPUDescriptorSet>(dsh, layout->getLayout(), layout->getLayoutSize());
-}
+        Handle<HwDescriptorSetLayout> dslh) {}
 
 Handle<HwStream> WebGPUDriver::createStreamNative(void* nativeStream) {
     return {};
@@ -598,7 +557,7 @@ bool WebGPUDriver::isTextureFormatSupported(TextureFormat format) {
 }
 
 bool WebGPUDriver::isTextureSwizzleSupported() {
-    return false;
+    return true;
 }
 
 bool WebGPUDriver::isTextureFormatMipmappable(TextureFormat format) {
@@ -687,21 +646,20 @@ size_t WebGPUDriver::getMaxArrayTextureLayers() {
 
 void WebGPUDriver::updateIndexBuffer(Handle<HwIndexBuffer> ibh, BufferDescriptor&& p,
         uint32_t byteOffset) {
-    updateGPUBuffer(handleCast<WGPUIndexBuffer>(ibh), std::move(p), byteOffset);
+    scheduleDestroy(std::move(p));
 }
 
 void WebGPUDriver::updateBufferObject(Handle<HwBufferObject> ibh, BufferDescriptor&& p,
         uint32_t byteOffset) {
-    updateGPUBuffer(handleCast<WGPUBufferObject>(ibh), std::move(p), byteOffset);
+    scheduleDestroy(std::move(p));
 }
 
-void WebGPUDriver::updateBufferObjectUnsynchronized(Handle<HwBufferObject> ibh,
-        BufferDescriptor&& p, uint32_t byteOffset) {
-    updateGPUBuffer(handleCast<WGPUBufferObject>(ibh), std::move(p), byteOffset);
+void WebGPUDriver::updateBufferObjectUnsynchronized(Handle<HwBufferObject> ibh, BufferDescriptor&& p,
+        uint32_t byteOffset) {
+    scheduleDestroy(std::move(p));
 }
 
 void WebGPUDriver::resetBufferObject(Handle<HwBufferObject> boh) {
-    // Is there something that needs to be done here? Vulkan has left it unimplemented.
 }
 
 void WebGPUDriver::setVertexBufferObject(Handle<HwVertexBuffer> vbh, uint32_t index,
@@ -709,8 +667,7 @@ void WebGPUDriver::setVertexBufferObject(Handle<HwVertexBuffer> vbh, uint32_t in
     auto* vertexBuffer = handleCast<WGPUVertexBuffer>(vbh);
     auto* bufferObject = handleCast<WGPUBufferObject>(boh);
     assert_invariant(index < vertexBuffer->buffers.size());
-    assert_invariant(bufferObject->buffer.GetUsage() & wgpu::BufferUsage::Vertex);
-    vertexBuffer->buffers[index] = bufferObject->buffer;
+    vertexBuffer->setBuffer(bufferObject, index);
 }
 
 void WebGPUDriver::update3DImage(Handle<HwTexture> th,
@@ -749,6 +706,9 @@ void WebGPUDriver::beginRenderPass(Handle<HwRenderTarget> rth, const RenderPassP
     mCommandEncoder = mDevice.CreateCommandEncoder(&commandEncoderDescriptor);
     assert_invariant(mCommandEncoder);
 
+    mTextureView = mSwapChain->getNextSurfaceTextureView(params.viewport.width, params.viewport.height);
+    assert_invariant(mTextureView);
+
     // TODO: Remove this code once WebGPU pipeline is implemented
     static float red = 1.0f;
     if (red - 0.01 > 0) {
@@ -756,7 +716,7 @@ void WebGPUDriver::beginRenderPass(Handle<HwRenderTarget> rth, const RenderPassP
     } else {
         red = 1.0f;
     }
-    assert_invariant(mTextureView);
+
     wgpu::RenderPassColorAttachment renderPassColorAttachment = {
         .view = mTextureView,
         // TODO: remove this code once WebGPU Pipeline is implemented with render targets, pipeline and buffers.
@@ -792,14 +752,6 @@ void WebGPUDriver::nextSubpass(int) {
 }
 
 void WebGPUDriver::makeCurrent(Handle<HwSwapChain> drawSch, Handle<HwSwapChain> readSch) {
-    ASSERT_PRECONDITION_NON_FATAL(drawSch == readSch,
-            "WebGPU driver does not support distinct draw/read swap chains.");
-    auto* swapChain = handleCast<WebGPUSwapChain>(drawSch);
-    mSwapChain = swapChain;
-    assert_invariant(mSwapChain);
-    wgpu::Extent2D surfaceSize = mPlatform.getSurfaceExtent(mNativeWindow);
-    mTextureView = mSwapChain->getCurrentSurfaceTextureView(surfaceSize);
-    assert_invariant(mTextureView);
 }
 
 void WebGPUDriver::commit(Handle<HwSwapChain> sch) {
@@ -807,7 +759,6 @@ void WebGPUDriver::commit(Handle<HwSwapChain> sch) {
     mQueue.Submit(1, &mCommandBuffer);
     mCommandBuffer = nullptr;
     mTextureView = nullptr;
-    assert_invariant(mSwapChain);
     mSwapChain->present();
 }
 
@@ -836,7 +787,7 @@ void WebGPUDriver::readPixels(Handle<HwRenderTarget> src,
     scheduleDestroy(std::move(p));
 }
 
-void WebGPUDriver::readBufferSubData(Handle<HwBufferObject> boh,
+void WebGPUDriver::readBufferSubData(backend::BufferObjectHandle boh,
         uint32_t offset, uint32_t size, backend::BufferDescriptor&& p) {
     scheduleDestroy(std::move(p));
 }
@@ -862,19 +813,6 @@ void WebGPUDriver::bindPipeline(PipelineState const& pipelineState) {
 }
 
 void WebGPUDriver::bindRenderPrimitive(Handle<HwRenderPrimitive> rph) {
-    auto* renderPrimitive = handleCast<WGPURenderPrimitive>(rph);
-
-    // This *must* match the WGPUVertexBufferInfo that was bound in bindPipeline(). But we want
-    // to allow to call this before bindPipeline(), so the validation can only happen in draw()
-    auto vbi = handleCast<WGPUVertexBufferInfo>(renderPrimitive->vertexBuffer->vbih);
-    assert_invariant(
-            vbi->getVertexBufferLayoutSize() == renderPrimitive->vertexBuffer->buffers.size());
-    for (uint32_t i = 0; i < vbi->getVertexBufferLayoutSize(); i++) {
-        mRenderPassEncoder.SetVertexBuffer(i, renderPrimitive->vertexBuffer->buffers[i]);
-    }
-
-    mRenderPassEncoder.SetIndexBuffer(renderPrimitive->indexBuffer->buffer,
-            renderPrimitive->indexBuffer->indexFormat);
 }
 
 void WebGPUDriver::draw2(uint32_t indexOffset, uint32_t indexCount, uint32_t instanceCount) {
@@ -900,48 +838,25 @@ void WebGPUDriver::endTimerQuery(Handle<HwTimerQuery> tqh) {
 void WebGPUDriver::resetState(int) {
 }
 
-void WebGPUDriver::updateDescriptorSetBuffer(Handle<HwDescriptorSet> dsh,
-        backend::descriptor_binding_t binding, Handle<HwBufferObject> boh, uint32_t offset,
+void WebGPUDriver::updateDescriptorSetBuffer(
+        backend::DescriptorSetHandle dsh,
+        backend::descriptor_binding_t binding,
+        backend::BufferObjectHandle boh,
+        uint32_t offset,
         uint32_t size) {
-    auto bindGroup = handleCast<WebGPUDescriptorSet>(dsh);
-    auto buffer = handleCast<WGPUBufferObject>(boh);
-    if (!bindGroup->getIsLocked()) {
-        // TODO making assumptions that size and offset mean the same thing here.
-        wgpu::BindGroupEntry entry{ .binding = static_cast<uint32_t>(binding * 2),
-            .buffer = buffer->buffer,
-            .offset = offset,
-            .size = size };
-        bindGroup->addEntry(entry.binding, std::move(entry));
-    }
 }
 
-void WebGPUDriver::updateDescriptorSetTexture(Handle<HwDescriptorSet> dsh,
-        backend::descriptor_binding_t binding, Handle<HwTexture> th, SamplerParams params) {
-    /*
-    auto bindGroup = handleCast<WebGPUDescriptorSet>(dsh);
-    auto texture = handleCast<WGPUTexture>(th);
-
-    // TODO very high odds badd assumptions are in here about handling HwTexture. Revisit with more
-    // understanding. Right now assuming there is a wgpu::TextureView filled in
-    if (!bindGroup->getIsLocked()) {
-        // TODO making assumptions that size and offset mean the same thing here.
-        wgpu::BindGroupEntry tEntry{ .binding = static_cast<uint32_t>(binding * 2),
-            .textureView = texture->texView };
-        bindGroup->addEntry(tEntry.binding, std::move(tEntry));
-
-        wgpu::BindGroupEntry sEntry{ .binding = static_cast<uint32_t>(binding * 2 + 1),
-            .sampler = texture->sampler };
-        bindGroup->addEntry(sEntry.binding, std::move(sEntry));
-    }
-    //TODO Just the setup, this function stilll needs the rest of logic implemented
-     */
+void WebGPUDriver::updateDescriptorSetTexture(
+        backend::DescriptorSetHandle dsh,
+        backend::descriptor_binding_t binding,
+        backend::TextureHandle th,
+        SamplerParams params) {
 }
 
-void WebGPUDriver::bindDescriptorSet(Handle<HwDescriptorSet> dsh, backend::descriptor_set_t set,
+void WebGPUDriver::bindDescriptorSet(
+        backend::DescriptorSetHandle dsh,
+        backend::descriptor_set_t set,
         backend::DescriptorSetOffsetArray&& offsets) {
-    auto bindGroup = handleCast<WebGPUDescriptorSet>(dsh);
-    // TODO: presume we need this, use it. Probably Encoder::SetBindGroup
-    auto wbg = bindGroup->lockAndReturn(mDevice);
 }
 
 void WebGPUDriver::setDebugTag(HandleBase::HandleId handleId, utils::CString tag) {

filament/backend/src/webgpu/WebGPUDriver.h

@@ -18,7 +18,7 @@
 #define TNT_FILAMENT_BACKEND_WEBGPUDRIVER_H
 
 #include "WebGPUHandles.h"
-#include "webgpu/WebGPUConstants.h"
+#include "webgpu/WebGPUSwapChain.h"
 #include <backend/platforms/WebGPUPlatform.h>
 
 #include "DriverBase.h"
@@ -35,13 +35,11 @@
 #include <memory>
 
 #ifndef FILAMENT_WEBGPU_HANDLE_ARENA_SIZE_IN_MB
-#define FILAMENT_WEBGPU_HANDLE_ARENA_SIZE_IN_MB 8
+#    define FILAMENT_WEBGPU_HANDLE_ARENA_SIZE_IN_MB 8
 #endif
 
 namespace filament::backend {
 
-class WebGPUSwapChain;
-
 /**
  * WebGPU backend (driver) implementation
  */
@@ -57,35 +55,14 @@ private:
     [[nodiscard]] ShaderModel getShaderModel() const noexcept final;
     [[nodiscard]] ShaderLanguage getShaderLanguage() const noexcept final;
 
-    template<typename GPUBufferObject>
-    void updateGPUBuffer(GPUBufferObject* gpuBufferObject, BufferDescriptor&& bufferDescriptor,
-            uint32_t byteOffset) {
-        FILAMENT_CHECK_PRECONDITION(bufferDescriptor.buffer)
-                << "copyIntoBuffer called with a null buffer";
-        FILAMENT_CHECK_PRECONDITION(
-                bufferDescriptor.size + byteOffset <= gpuBufferObject->buffer.GetSize())
-                << "Attempting to copy " << bufferDescriptor.size << " bytes into a buffer of size "
-                << gpuBufferObject->buffer.GetSize() << " at offset " << byteOffset;
-
-        // TODO: All buffer objects are created with CopyDst usage.
-        // This may have some performance implications. That should be investigated later.
-        assert_invariant(gpuBufferObject->buffer.GetUsage() & wgpu::BufferUsage::CopyDst);
-
-        // WriteBuffer is an async call. But cpu buffer data is already written to the staging
-        // buffer on return from the WriteBuffer.
-        mQueue.WriteBuffer(gpuBufferObject->buffer, byteOffset, bufferDescriptor.buffer,
-                bufferDescriptor.size);
-        scheduleDestroy(std::move(bufferDescriptor));
-    }
-
     // the platform (e.g. OS) specific aspects of the WebGPU backend are strictly only
     // handled in the WebGPUPlatform
     WebGPUPlatform& mPlatform;
     wgpu::Adapter mAdapter = nullptr;
     wgpu::Device mDevice = nullptr;
     wgpu::Queue mQueue = nullptr;
-    void* mNativeWindow = nullptr;
-    WebGPUSwapChain* mSwapChain = nullptr;
+    // TODO consider moving to handle allocator when ready
+    std::unique_ptr<WebGPUSwapChain> mSwapChain = nullptr;
     uint64_t mNextFakeHandle = 1;
     wgpu::CommandEncoder mCommandEncoder = nullptr;
     wgpu::TextureView mTextureView = nullptr;
@@ -121,21 +98,15 @@ private:
         return mHandleAllocator.allocate<D>();
     }
 
-    template<typename D, typename B, typename... ARGS>
-    D* constructHandle(Handle<B>& handle, ARGS&&... args) noexcept {
+    template<typename D, typename B, typename ... ARGS>
+    D* constructHandle(Handle<B>& handle, ARGS&& ... args) noexcept {
         return mHandleAllocator.construct<D>(handle, std::forward<ARGS>(args)...);
     }
-
     template<typename D, typename B>
     D* handleCast(Handle<B> handle) noexcept {
         return mHandleAllocator.handle_cast<D*>(handle);
     }
 
-    template<typename D, typename B>
-    void destructHandle(Handle<B>& handle) noexcept {
-        auto* p = mHandleAllocator.handle_cast<D*>(handle);
-        mHandleAllocator.deallocate(handle, p);
-    }
 };
 
 }// namespace filament::backend

filament/backend/src/webgpu/WebGPUHandles.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2025 The Android Open Source Project
+* 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.
@@ -16,282 +16,19 @@
 
 #include "WebGPUHandles.h"
 
-#include <utility>
-
-namespace {
-constexpr wgpu::BufferUsage getBufferObjectUsage(
-        filament::backend::BufferObjectBinding bindingType) noexcept {
-    switch (bindingType) {
-        case filament::backend::BufferObjectBinding::VERTEX:
-            return wgpu::BufferUsage::Vertex;
-        case filament::backend::BufferObjectBinding::UNIFORM:
-            return wgpu::BufferUsage::Uniform;
-        case filament::backend::BufferObjectBinding::SHADER_STORAGE:
-            return wgpu::BufferUsage::Storage;
-    }
-}
-
-wgpu::Buffer createBuffer(wgpu::Device const& device, wgpu::BufferUsage usage, uint32_t size,
-        char const* label) {
-    wgpu::BufferDescriptor descriptor{ .label = label,
-        .usage = usage,
-        .size = size,
-        .mappedAtCreation = false };
-    return device.CreateBuffer(&descriptor);
-}
-
-wgpu::VertexFormat getVertexFormat(filament::backend::ElementType type, bool normalized, bool integer) {
-    using ElementType = filament::backend::ElementType;
-    using VertexFormat = wgpu::VertexFormat;
-    if (normalized) {
-        switch (type) {
-            // Single Component Types
-            case ElementType::BYTE: return VertexFormat::Snorm8;
-            case ElementType::UBYTE: return VertexFormat::Unorm8;
-            case ElementType::SHORT: return VertexFormat::Snorm16;
-            case ElementType::USHORT: return VertexFormat::Unorm16;
-            // Two Component Types
-            case ElementType::BYTE2: return VertexFormat::Snorm8x2;
-            case ElementType::UBYTE2: return VertexFormat::Unorm8x2;
-            case ElementType::SHORT2: return VertexFormat::Snorm16x2;
-            case ElementType::USHORT2: return VertexFormat::Unorm16x2;
-            // Three Component Types
-            // There is no vertex format type for 3 byte data in webgpu. Use
-            // 4 byte signed normalized type and ignore the last byte.
-            // TODO: This is to be verified.
-            case ElementType::BYTE3: return VertexFormat::Snorm8x4;    // NOT MINSPEC
-            case ElementType::UBYTE3: return VertexFormat::Unorm8x4;   // NOT MINSPEC
-            case ElementType::SHORT3: return VertexFormat::Snorm16x4;  // NOT MINSPEC
-            case ElementType::USHORT3: return VertexFormat::Unorm16x4; // NOT MINSPEC
-            // Four Component Types
-            case ElementType::BYTE4: return VertexFormat::Snorm8x4;
-            case ElementType::UBYTE4: return VertexFormat::Unorm8x4;
-            case ElementType::SHORT4: return VertexFormat::Snorm16x4;
-            case ElementType::USHORT4: return VertexFormat::Unorm8x4;
-            default:
-                FILAMENT_CHECK_POSTCONDITION(false) << "Normalized format does not exist.";
-                return VertexFormat::Float32x3;
-        }
-    }
-    switch (type) {
-        // Single Component Types
-        // There is no direct alternative for SSCALED in webgpu. Convert them to Float32 directly.
-        // This will result in increased memory on the cpu side.
-        // TODO: Is Float16 acceptable instead with some potential accuracy errors?
-        case ElementType::BYTE: return integer ? VertexFormat::Sint8 : VertexFormat::Float32;
-        case ElementType::UBYTE: return integer ? VertexFormat::Uint8 : VertexFormat::Float32;
-        case ElementType::SHORT: return integer ? VertexFormat::Sint16 : VertexFormat::Float32;
-        case ElementType::USHORT: return integer ? VertexFormat::Uint16 : VertexFormat::Float32;
-        case ElementType::HALF: return VertexFormat::Float16;
-        case ElementType::INT: return VertexFormat::Sint32;
-        case ElementType::UINT: return VertexFormat::Uint32;
-        case ElementType::FLOAT: return VertexFormat::Float32;
-        // Two Component Types
-        case ElementType::BYTE2: return integer ? VertexFormat::Sint8x2 : VertexFormat::Float32x2;
-        case ElementType::UBYTE2: return integer ? VertexFormat::Uint8x2 : VertexFormat::Float32x2;
-        case ElementType::SHORT2: return integer ? VertexFormat::Sint16x2 : VertexFormat::Float32x2;
-        case ElementType::USHORT2: return integer ? VertexFormat::Uint16x2 : VertexFormat::Float32x2;
-        case ElementType::HALF2: return VertexFormat::Float16x2;
-        case ElementType::FLOAT2: return VertexFormat::Float32x2;
-        // Three Component Types
-        case ElementType::BYTE3: return VertexFormat::Sint8x4;    // NOT MINSPEC
-        case ElementType::UBYTE3: return VertexFormat::Uint8x4;   // NOT MINSPEC
-        case ElementType::SHORT3: return VertexFormat::Sint16x4;  // NOT MINSPEC
-        case ElementType::USHORT3: return VertexFormat::Uint16x4; // NOT MINSPEC
-        case ElementType::HALF3: return VertexFormat::Float16x4;  // NOT MINSPEC
-        case ElementType::FLOAT3: return VertexFormat::Float32x3;
-        // Four Component Types
-        case ElementType::BYTE4: return integer ? VertexFormat::Sint8x4 : VertexFormat::Float32x4;
-        case ElementType::UBYTE4: return integer ? VertexFormat::Uint8x4 : VertexFormat::Float32x4;
-        case ElementType::SHORT4: return integer ? VertexFormat::Sint16x4 : VertexFormat::Float32x4;
-        case ElementType::USHORT4: return integer ? VertexFormat::Uint16x4 : VertexFormat::Float32x4;
-        case ElementType::HALF4: return VertexFormat::Float16x4;
-        case ElementType::FLOAT4: return VertexFormat::Float32x4;
-    }
-}
-
-}// namespace
-
 namespace filament::backend {
 
-WGPUVertexBufferInfo::WGPUVertexBufferInfo(uint8_t bufferCount, uint8_t attributeCount,
-        AttributeArray const& attributes)
-    : HwVertexBufferInfo(bufferCount, attributeCount),
-      mVertexBufferLayout(bufferCount),
-      mAttributes(bufferCount) {
-    assert_invariant(attributeCount > 0);
-    assert_invariant(bufferCount > 0);
-    for (uint32_t attribIndex = 0; attribIndex < attributes.size(); attribIndex++) {
-        Attribute const& attrib = attributes[attribIndex];
-        // Ignore the attributes which are not bind to vertex buffers.
-        if (attrib.buffer == Attribute::BUFFER_UNUSED) {
-            continue;
-        }
-
-        assert_invariant(attrib.buffer < bufferCount);
-        bool const isInteger = attrib.flags & Attribute::FLAG_INTEGER_TARGET;
-        bool const isNormalized = attrib.flags & Attribute::FLAG_NORMALIZED;
-        wgpu::VertexFormat vertexFormat = getVertexFormat(attrib.type, isNormalized, isInteger);
-
-        // Attributes are sequential per buffer
-        mAttributes[attrib.buffer].push_back({
-            .format = vertexFormat,
-            .offset = attrib.offset,
-            .shaderLocation = static_cast<uint32_t>(mAttributes[attrib.buffer].size()),
-        });
-
-        mVertexBufferLayout[attrib.buffer].stepMode = wgpu::VertexStepMode::Vertex;
-        if (mVertexBufferLayout[attrib.buffer].arrayStride == 0) {
-            mVertexBufferLayout[attrib.buffer].arrayStride = attrib.stride;
-        } else {
-            assert_invariant(mVertexBufferLayout[attrib.buffer].arrayStride == attrib.stride);
-        }
-    }
-
-    for (uint32_t bufferIndex = 0; bufferIndex < bufferCount; bufferIndex++) {
-        mVertexBufferLayout[bufferIndex].attributeCount = mAttributes[bufferIndex].size();
-        mVertexBufferLayout[bufferIndex].attributes = mAttributes[bufferIndex].data();
-    }
-}
-
-WGPUIndexBuffer::WGPUIndexBuffer(wgpu::Device const& device, uint8_t elementSize,
-        uint32_t indexCount)
-    : buffer(createBuffer(device, wgpu::BufferUsage::CopyDst | wgpu::BufferUsage::Index,
-              elementSize * indexCount, "index_buffer")),
-      indexFormat(elementSize == 2 ? wgpu::IndexFormat::Uint16 : wgpu::IndexFormat::Uint32) {}
-
-
-WGPUVertexBuffer::WGPUVertexBuffer(wgpu::Device const& device, uint32_t vertexCount,
-        uint32_t bufferCount, Handle<HwVertexBufferInfo> vbih)
-    : HwVertexBuffer(vertexCount),
+WGPUVertexBuffer::WGPUVertexBuffer(uint32_t vextexCount, uint32_t bufferCount,
+        Handle<WGPUVertexBufferInfo> vbih)
+    : HwVertexBuffer(vextexCount),
       vbih(vbih),
-      buffers(bufferCount) {}
+      buffers(MAX_VERTEX_BUFFER_COUNT) {}
 
-WGPUBufferObject::WGPUBufferObject(wgpu::Device const& device, BufferObjectBinding bindingType,
-        uint32_t byteCount)
+// TODO: Empty function is a place holder for verxtex buffer updates and should be
+// updated for that purpose.
+void WGPUVertexBuffer::setBuffer(WGPUBufferObject* bufferObject, uint32_t index) {}
+
+WGPUBufferObject::WGPUBufferObject(BufferObjectBinding bindingType, uint32_t byteCount)
     : HwBufferObject(byteCount),
-      buffer(createBuffer(device, wgpu::BufferUsage::CopyDst | getBufferObjectUsage(bindingType),
-              byteCount, "buffer_object")),
       bufferObjectBinding(bindingType) {}
-
-wgpu::ShaderStage WebGPUDescriptorSetLayout::filamentStageToWGPUStage(ShaderStageFlags fFlags) {
-    wgpu::ShaderStage retStages = wgpu::ShaderStage::None;
-    if (any(ShaderStageFlags::VERTEX & fFlags)) {
-        retStages |= wgpu::ShaderStage::Vertex;
-    }
-    if (any(ShaderStageFlags::FRAGMENT & fFlags)) {
-        retStages |= wgpu::ShaderStage::Fragment;
-    }
-    if (any(ShaderStageFlags::COMPUTE & fFlags)) {
-        retStages |= wgpu::ShaderStage::Compute;
-    }
-    return retStages;
-}
-
-WebGPUDescriptorSetLayout::WebGPUDescriptorSetLayout(DescriptorSetLayout const& layout,
-        wgpu::Device const& device) {
-    assert_invariant(device);
-
-    // TODO: layoutDescriptor has a "Label". Ideally we can get info on what this layout is for
-    // debugging. For now, hack an incrementing value.
-    static int layoutNum = 0;
-
-    uint samplerCount =
-            std::count_if(layout.bindings.begin(), layout.bindings.end(), [](auto& fEntry) {
-                return fEntry.type == DescriptorType::SAMPLER ||
-                       fEntry.type == DescriptorType::SAMPLER_EXTERNAL;
-            });
-
-
-    std::vector<wgpu::BindGroupLayoutEntry> wEntries;
-    wEntries.reserve(layout.bindings.size() + samplerCount);
-
-    for (auto fEntry: layout.bindings) {
-        auto& wEntry = wEntries.emplace_back();
-        wEntry.visibility = filamentStageToWGPUStage(fEntry.stageFlags);
-        wEntry.binding = fEntry.binding * 2;
-
-        switch (fEntry.type) {
-            // TODO Metal treats these the same. Is this fine?
-            case DescriptorType::SAMPLER_EXTERNAL:
-            case DescriptorType::SAMPLER: {
-                // Sampler binding is 2n+1 due to split.
-                auto& samplerEntry = wEntries.emplace_back();
-                samplerEntry.binding = fEntry.binding * 2 + 1;
-                samplerEntry.visibility = wEntry.visibility;
-                // We are simply hoping that undefined and defaults suffices here.
-                samplerEntry.sampler.type = wgpu::SamplerBindingType::Undefined;
-                wEntry.texture.sampleType = wgpu::TextureSampleType::Undefined;
-                break;
-            }
-            case DescriptorType::UNIFORM_BUFFER: {
-                wEntry.buffer.hasDynamicOffset =
-                        any(fEntry.flags & DescriptorFlags::DYNAMIC_OFFSET);
-                wEntry.buffer.type = wgpu::BufferBindingType::Uniform;
-                // TODO: Ideally we fill minBindingSize
-                break;
-            }
-
-            case DescriptorType::INPUT_ATTACHMENT: {
-                // TODO: support INPUT_ATTACHMENT. Metal does not currently.
-                PANIC_POSTCONDITION("Input Attachment is not supported");
-                break;
-            }
-
-            case DescriptorType::SHADER_STORAGE_BUFFER: {
-                // TODO: Vulkan does not support this, can we?
-                PANIC_POSTCONDITION("Shader storage is not supported");
-                break;
-            }
-        }
-
-        // Currently flags are only used to specify dynamic offset.
-
-        // UNUSED
-        // fEntry.count
-    }
-
-    wgpu::BindGroupLayoutDescriptor layoutDescriptor{
-        // TODO: layoutDescriptor has a "Label". Ideally we can get info on what this layout is for
-        // debugging. For now, hack an incrementing value.
-        .label{ "layout_" + std::to_string(++layoutNum) },
-        .entryCount = wEntries.size(),
-        .entries = wEntries.data()
-    };
-    // TODO Do we need to defer this until we have more info on textures and samplers??
-    mLayoutSize = wEntries.size();
-    mLayout = device.CreateBindGroupLayout(&layoutDescriptor);
-}
-
-WebGPUDescriptorSetLayout::~WebGPUDescriptorSetLayout() {}
-
-WebGPUDescriptorSet::WebGPUDescriptorSet(const wgpu::BindGroupLayout& layout, uint layoutSize)
-    : mLayout(layout),
-      entries(layoutSize, wgpu::BindGroupEntry{}) {
-    // Establish the size of entries based on the layout. This should be reliable and efficient.
-}
-WebGPUDescriptorSet::~WebGPUDescriptorSet() {}
-
-wgpu::BindGroup WebGPUDescriptorSet::lockAndReturn(const wgpu::Device& device) {
-    if (mBindGroup) {
-        return mBindGroup;
-    }
-    // TODO label? Should we just copy layout label?
-    wgpu::BindGroupDescriptor desc{ .layout = mLayout,
-        .entryCount = entries.size(),
-        .entries = entries.data() };
-    mBindGroup = device.CreateBindGroup(&desc);
-    return mBindGroup;
-}
-
-void WebGPUDescriptorSet::addEntry(uint index, wgpu::BindGroupEntry&& entry) {
-    if (mBindGroup) {
-        // We will keep getting hits from future updates, but shouldn't do anything
-        // Filament guarantees this won't change after things have locked.
-        return;
-    }
-    // TODO: Putting some level of trust that Filament is not going to reuse indexes or go past the
-    // layout index for efficiency. Add guards if wrong.
-    entries[index] = std::move(entry);
-}
 }// namespace filament::backend

filament/backend/src/webgpu/WebGPUHandles.h

@@ -28,109 +28,46 @@
 #include <webgpu/webgpu_cpp.h>
 
 #include <cstdint>
-#include <vector>
 
 namespace filament::backend {
 
-class WGPUProgram final : public HwProgram {
-public:
-    WGPUProgram(wgpu::Device&, Program&);
-
-    wgpu::ShaderModule vertexShaderModule = nullptr;
-    wgpu::ShaderModule fragmentShaderModule = nullptr;
-    wgpu::ShaderModule computeShaderModule = nullptr;
-    std::vector<wgpu::ConstantEntry> constants;
-};
-
 struct WGPUBufferObject;
-
-// VertexBufferInfo contains layout info for Vertex Buffer based on WebGPU structs. In WebGPU each
-// VertexBufferLayout is associated with a single vertex buffer. So number of mVertexBufferLayout
-// is equal to bufferCount. Each VertexBufferLayout can contain multiple VertexAttribute. Bind index
-// of vertex buffer is implicitly calculated by the position of VertexBufferLayout in an array.
-class WGPUVertexBufferInfo : public HwVertexBufferInfo {
-public:
+// TODO: Currently WGPUVertexBufferInfo is not used by WebGPU for useful task.
+// Update the struct when used by WebGPU driver.
+struct WGPUVertexBufferInfo : public HwVertexBufferInfo {
     WGPUVertexBufferInfo(uint8_t bufferCount, uint8_t attributeCount,
-            AttributeArray const& attributes);
-    inline  wgpu::VertexBufferLayout const* getVertexBufferLayout() const {
-        return mVertexBufferLayout.data();
-    }
-
-    inline uint32_t getVertexBufferLayoutSize() const {
-        return mVertexBufferLayout.size();
-    }
-
-    inline wgpu::VertexAttribute const* getVertexAttributeForIndex(uint32_t index) const {
-        assert_invariant(index < mAttributes.size());
-        return mAttributes[index].data();
-    }
-
-    inline uint32_t getVertexAttributeSize(uint32_t index) const {
-        assert_invariant(index < mAttributes.size());
-        return mAttributes[index].size();
-    }
-
-private:
-    // TODO: can we do better in terms on heap management.
-    std::vector<wgpu::VertexBufferLayout> mVertexBufferLayout {};
-    std::vector<std::vector<wgpu::VertexAttribute>> mAttributes {};
+            AttributeArray const& attributes)
+        : HwVertexBufferInfo(bufferCount, attributeCount),
+          attributes(attributes) {}
+    AttributeArray attributes;
 };
 
+// TODO: Currently WGPUVertexBuffer is not used by WebGPU for useful task.
+// Update the struct when used by WebGPU driver.
 struct WGPUVertexBuffer : public HwVertexBuffer {
-    WGPUVertexBuffer(wgpu::Device const &device, uint32_t vertexCount, uint32_t bufferCount,
-                     Handle<HwVertexBufferInfo> vbih);
+    WGPUVertexBuffer(uint32_t vextexCount, uint32_t bufferCount, Handle<WGPUVertexBufferInfo> vbih);
+    void setBuffer(WGPUBufferObject* bufferObject, uint32_t index);
 
-    Handle<HwVertexBufferInfo> vbih;
+    Handle<WGPUVertexBufferInfo> vbih;
     utils::FixedCapacityVector<wgpu::Buffer> buffers;
 };
 
+// TODO: Currently WGPUIndexBuffer is not used by WebGPU for useful task.
+// Update the struct when used by WebGPU driver.
 struct WGPUIndexBuffer : public HwIndexBuffer {
-    WGPUIndexBuffer(wgpu::Device const &device, uint8_t elementSize,
-                    uint32_t indexCount);
+    WGPUIndexBuffer(BufferUsage usage, uint8_t elementSize, uint32_t indexCount);
 
     wgpu::Buffer buffer;
-    wgpu::IndexFormat indexFormat;
 };
 
+// TODO: Currently WGPUVertexBufferInfo is not used by WebGPU for useful task.
+// Update the struct when used by WebGPU driver.
 struct WGPUBufferObject : HwBufferObject {
-    WGPUBufferObject(wgpu::Device const &device, BufferObjectBinding bindingType, uint32_t byteCount);
+    WGPUBufferObject(BufferObjectBinding bindingType, uint32_t byteCount);
 
-    wgpu::Buffer buffer = nullptr;
+    wgpu::Buffer buffer;
     const BufferObjectBinding bufferObjectBinding;
 };
-class WebGPUDescriptorSetLayout final : public HwDescriptorSetLayout {
-public:
-    WebGPUDescriptorSetLayout(DescriptorSetLayout const& layout, wgpu::Device const& device);
-    ~WebGPUDescriptorSetLayout();
-    [[nodiscard]] const wgpu::BindGroupLayout& getLayout() const { return mLayout; }
-    [[nodiscard]] uint getLayoutSize() const { return mLayoutSize; }
-
-private:
-    // TODO: If this is useful elsewhere, remove it from this class
-    // Convert Filament Shader Stage Flags bitmask to webgpu equivilant
-    static wgpu::ShaderStage filamentStageToWGPUStage(ShaderStageFlags fFlags);
-    uint mLayoutSize;
-    wgpu::BindGroupLayout mLayout;
-};
-
-class WebGPUDescriptorSet final : public HwDescriptorSet {
-public:
-    WebGPUDescriptorSet(const wgpu::BindGroupLayout& layout, uint layoutSize);
-    ~WebGPUDescriptorSet();
-
-    wgpu::BindGroup lockAndReturn(wgpu::Device const& device);
-    void addEntry(uint index, wgpu::BindGroupEntry&& entry);
-    [[nodiscard]] bool getIsLocked() const { return mBindGroup != nullptr; }
-
-private:
-    // TODO: Consider storing what we used to make the layout. However we need to essentially
-    // Recreate some of the info (Sampler in slot X with the actual sampler) so letting Dawn confirm
-    // there isn't a mismatch may be easiest.
-    // Also storing the wgpu ObjectBase takes care of ownership challenges in theory
-    wgpu::BindGroupLayout mLayout;
-    std::vector<wgpu::BindGroupEntry> entries;
-    wgpu::BindGroup mBindGroup;
-};
 
 // TODO: Currently WGPUTexture is not used by WebGPU for useful task.
 // Update the struct when used by WebGPU driver.
@@ -142,21 +79,6 @@ struct WGPUTexture : public HwTexture {
     WGPUTexture(WGPUTexture const* src, uint8_t baseLevel, uint8_t levelCount) noexcept;
 
     wgpu::Texture texture = nullptr;
-    // TODO: Adding this but not yet setting it up. Filament "Textures" are combined image samplers,
-    // rep both.
-    wgpu::Sampler sampler = nullptr;
-    //TODO: Not sure all the ways HwTexture is used. Overloading like this might be entirely wrong.
-    wgpu::TextureView texView = nullptr;
-};
-
-struct WGPURenderPrimitive : public HwRenderPrimitive {
-    WGPURenderPrimitive() {}
-
-    void setBuffers(WGPUVertexBufferInfo const* const vbi,
-            WGPUVertexBuffer* vertexBuffer, WGPUIndexBuffer* indexBuffer);
-
-    WGPUVertexBuffer* vertexBuffer = nullptr;
-    WGPUIndexBuffer* indexBuffer = nullptr;
 };
 
 // TODO: Currently WGPURenderTarget is not used by WebGPU for useful task.

filament/backend/src/webgpu/WebGPUSwapChain.cpp

@@ -191,12 +191,9 @@ wgpu::CompositeAlphaMode selectAlphaMode(size_t availableAlphaModesCount,
 }
 
 void initConfig(wgpu::SurfaceConfiguration& config, wgpu::Device const& device,
-        wgpu::SurfaceCapabilities const& capabilities, wgpu::Extent2D const& surfaceSize,
-        bool useSRGBColorSpace) {
+        wgpu::SurfaceCapabilities const& capabilities, bool useSRGBColorSpace) {
     config.device = device;
     config.usage = wgpu::TextureUsage::RenderAttachment;
-    config.width = surfaceSize.width;
-    config.height = surfaceSize.height;
     config.format =
             selectColorFormat(capabilities.formatCount, capabilities.formats, useSRGBColorSpace);
     config.presentMode =
@@ -208,8 +205,8 @@ void initConfig(wgpu::SurfaceConfiguration& config, wgpu::Device const& device,
 
 namespace filament::backend {
 
-WebGPUSwapChain::WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Extent2D const& surfaceSize,
-        wgpu::Adapter& adapter, wgpu::Device& device, uint64_t flags)
+WebGPUSwapChain::WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Adapter& adapter,
+        wgpu::Device& device, uint64_t flags)
     : mSurface(surface) {
     wgpu::SurfaceCapabilities capabilities = {};
     if (!mSurface.GetCapabilities(adapter, &capabilities)) {
@@ -220,42 +217,43 @@ WebGPUSwapChain::WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Extent2D const&
 #endif
     }
     const bool useSRGBColorSpace = (flags & SWAP_CHAIN_CONFIG_SRGB_COLORSPACE) != 0;
-    initConfig(mConfig, device, capabilities, surfaceSize, useSRGBColorSpace);
-    mSurface.Configure(&mConfig);
+    initConfig(mConfig, device, capabilities, useSRGBColorSpace);
 }
 
 WebGPUSwapChain::~WebGPUSwapChain() {
-    mSurface.Unconfigure();
+    if (mConfigured) {
+        mSurface.Unconfigure();
+        mConfigured = false;
+    }
 }
 
-void WebGPUSwapChain::setExtent(wgpu::Extent2D const& currentSurfaceSize) {
-    FILAMENT_CHECK_POSTCONDITION(currentSurfaceSize.width > 0 || currentSurfaceSize.height > 0)
-            << "WebGPUSwapChain::setExtent: Invalid width " << currentSurfaceSize.width
-            << " and/or height " << currentSurfaceSize.height << " requested.";
-    if (mConfig.width != currentSurfaceSize.width || mConfig.height != currentSurfaceSize.height) {
-        mConfig.width = currentSurfaceSize.width;
-        mConfig.height = currentSurfaceSize.height;
+void WebGPUSwapChain::getCurrentTexture(uint32_t width, uint32_t height, wgpu::SurfaceTexture* texture) {
+    if (width < 1 || height < 1) {
+        PANIC_LOG("WebGPUSwapChain::GetCurrentTexture: Invalid width and/or height requested.");
+        return;
+    }
+    if (mConfig.width != width || mConfig.height != height || !mConfigured) {
+        mConfig.width = width;
+        mConfig.height = height;
 #if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
         printSurfaceConfiguration(mConfig);
 #endif
-        FWGPU_LOGD << "Resizing to width " << mConfig.width << " height " << mConfig.height
-                   << utils::io::endl;
-        // TODO we may need to ensure no surface texture is flight when we do this. some
-        //      synchronization may be necessary
         mSurface.Configure(&mConfig);
+        mConfigured = true;
     }
+
+    mSurface.GetCurrentTexture(texture);
 }
 
-wgpu::TextureView WebGPUSwapChain::getCurrentSurfaceTextureView(
-        wgpu::Extent2D const& currentSurfaceSize) {
-    setExtent(currentSurfaceSize);
+wgpu::TextureView WebGPUSwapChain::getNextSurfaceTextureView(uint32_t width, uint32_t height) {
     wgpu::SurfaceTexture surfaceTexture;
-    mSurface.GetCurrentTexture(&surfaceTexture);
+    getCurrentTexture(width, height, &surfaceTexture);
     if (surfaceTexture.status != wgpu::SurfaceGetCurrentTextureStatus::SuccessOptimal) {
         return nullptr;
     }
+
     // Create a view for this surface texture
-    // TODO: review these initiliazations as webgpu pipeline gets mature
+    //TODO: review these initiliazations as webgpu pipeline gets mature
     wgpu::TextureViewDescriptor textureViewDescriptor = {
         .label = "texture_view",
         .format = surfaceTexture.texture.GetFormat(),

filament/backend/src/webgpu/WebGPUSwapChain.h

@@ -19,28 +19,26 @@
 
 #include <webgpu/webgpu_cpp.h>
 
-#include "DriverBase.h"
 #include <backend/Platform.h>
 
 #include <cstdint>
 
 namespace filament::backend {
 
-class WebGPUSwapChain final : public Platform::SwapChain, HwSwapChain {
+class WebGPUSwapChain : public Platform::SwapChain {
 public:
-    WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Extent2D const& surfaceSize,
-            wgpu::Adapter& adapter, wgpu::Device& device, uint64_t flags);
+    WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Adapter& adapter, wgpu::Device& device,
+            uint64_t flags);
     ~WebGPUSwapChain();
 
-    wgpu::TextureView getCurrentSurfaceTextureView(wgpu::Extent2D const&);
-
+    wgpu::TextureView getNextSurfaceTextureView(uint32_t width, uint32_t height);
     void present();
 
 private:
-    void setExtent(wgpu::Extent2D const&);
-
+    void getCurrentTexture(uint32_t width, uint32_t height, wgpu::SurfaceTexture*);
     wgpu::Surface mSurface = {};
     wgpu::SurfaceConfiguration mConfig = {};
+    bool mConfigured = false;
 };
 
 } // namespace filament::backend

filament/backend/src/webgpu/platform/WebGPUPlatformAndroid.cpp

@@ -18,7 +18,6 @@
 
 #include <utils/Panic.h>
 
-#include <android/native_window.h>
 #include <webgpu/webgpu_cpp.h>
 
 #include <cstdint>
@@ -29,14 +28,6 @@
 
 namespace filament::backend {
 
-wgpu::Extent2D WebGPUPlatform::getSurfaceExtent(void* nativeWindow) const {
-    ANativeWindow* window = static_cast<ANativeWindow*>(nativeWindow);
-    return wgpu::Extent2D{
-        .width = static_cast<uint32_t>(ANativeWindow_getWidth(window)),
-        .height = static_cast<uint32_t>(ANativeWindow_getHeight(window))
-    };
-}
-
 wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t /*flags*/) {
     wgpu::SurfaceSourceAndroidNativeWindow surfaceSourceAndroidWindow{};
     surfaceSourceAndroidWindow.window = nativeWindow;

filament/backend/src/webgpu/platform/WebGPUPlatformApple.mm

@@ -33,15 +33,6 @@
 
 namespace filament::backend {
 
-wgpu::Extent2D WebGPUPlatform::getSurfaceExtent(void* nativeWindow) const {
-    // Both IOS and MacOS expects CAMetalLayer.
-    CAMetalLayer* metalLayer = (__bridge CAMetalLayer*) nativeWindow;
-    return wgpu::Extent2D{
-        .width = static_cast<uint32_t>(metalLayer.drawableSize.width),
-        .height = static_cast<uint32_t>(metalLayer.drawableSize.height)
-    };
-}
-
 wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t /*flags*/) {
     wgpu::Surface surface = nullptr;
     // Both IOS and MacOS expects CAMetalLayer.

filament/backend/src/webgpu/platform/WebGPUPlatformLinux.cpp

@@ -79,74 +79,6 @@
 
 namespace filament::backend {
 
-wgpu::Extent2D WebGPUPlatform::getSurfaceExtent(void* nativeWindow) const {
-    auto surfaceExtent = wgpu::Extent2D{};
-#if defined(__linux__) && defined(FILAMENT_SUPPORTS_WAYLAND)
-    wl* ptrval = reinterpret_cast<wl*>(nativeWindow);
-    surfaceExtent.width = ptrval->width;
-    surfaceExtent.height = ptrval->height;
-    FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-            << "Unable to get window size for 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 = (SWAP_CHAIN_CONFIG_ENABLE_XCB) != 0;
-        #else
-            useXcb = true;
-        #endif
-        if (useXcb) {
-            const xcb_setup_t* setup = xcb_get_setup(g_x11.connection);
-            xcb_screen_iterator_t screen_iter = xcb_setup_roots_iterator(setup);
-            xcb_screen_t* screen = screen_iter.data;
-            surfaceExtent.width = static_cast<uint32_t>(screen->width_in_pixels);
-            surfaceExtent.height = static_cast<uint32_t>(screen->height_in_pixels);
-            FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-                    << "Unable to get window surface size for Linux (or FreeBSD) "
-                       "XCB-backed surface.";
-        }
-    #endif
-    #if defined(FILAMENT_SUPPORTS_XLIB)
-        if (!useXcb) {
-            int screenNumber = DefaultScreen(g_x11.display);
-            Screen* screen = ScreenOfDisplay(g_x11.display, screenNumber);
-            surfaceExtent.width = static_cast<uint32_t>(WidthOfScreen(screen));
-            surfaceExtent.height = static_cast<uint32_t>(HeightOfScreen(screen));
-            FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-                    << "Unable to get window surface size for Linux (or FreeBSD) "
-                       "XLib-backed surface.";
-        }
-    #endif
-    FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-            << "Cannot get window surface size for X11 surface for Linux (or FreeBSD) OS "
-               "(not built with support for XCB or XLIB?)";
-#elif defined(__linux__)
-    FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-            << "Cannot get window surface size for Linux (or FreeBSD) OS "
-               "(not built with support for Wayland or X11?)";
-#else
-    FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-            << "Not a supported (Linux) OS + WebGPU platform";
-#endif
-    return surfaceExtent;
-}
-
 wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t flags) {
     wgpu::Surface surface = nullptr;
 #if defined(__linux__) && defined(FILAMENT_SUPPORTS_WAYLAND)

filament/backend/src/webgpu/platform/WebGPUPlatformWindows.cpp

@@ -30,16 +30,6 @@
 
 namespace filament::backend {
 
-wgpu::Extent2D WebGPUPlatform::getSurfaceExtent(void* nativeWindow) const {
-    HWND window = static_cast<HWND>(nativeWindow);
-    RECT windowRect;
-    GetWindowRect(window, &windowRect);
-    return wgpu::Extent2D{
-        .width = static_cast<uint32_t>(windowRect.right - windowRect.left),
-        .height = static_cast<uint32_t>(windowRect.bottom - windowRect.top)
-    };
-}
-
 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

filament/backend/test/BackendTest.cpp

@@ -43,29 +43,24 @@ using namespace image;
 namespace test {
 
 Backend BackendTest::sBackend = Backend::NOOP;
-OperatingSystem BackendTest::sOperatingSystem = OperatingSystem::OTHER;
 bool BackendTest::sIsMobilePlatform = false;
 
-void BackendTest::init(Backend backend, OperatingSystem operatingSystem, bool isMobilePlatform) {
+void BackendTest::init(Backend backend, bool isMobilePlatform) {
     sBackend = backend;
-    sOperatingSystem = operatingSystem;
     sIsMobilePlatform = isMobilePlatform;
 }
 
 BackendTest::BackendTest() : commandBufferQueue(CONFIG_MIN_COMMAND_BUFFERS_SIZE,
         CONFIG_COMMAND_BUFFERS_SIZE, /*mPaused=*/false) {
     initializeDriver();
-    mImageExpectations.emplace(getDriverApi());
 }
 
 BackendTest::~BackendTest() {
-    // Ensure all graphics commands and callbacks are finished.
-    flushAndWait();
-    mImageExpectations->evaluate();
     // Note: Don't terminate the driver for OpenGL, as it wipes away the context and removes the buffer from the screen.
     if (sBackend == Backend::OPENGL) {
         return;
     }
+    flushAndWait();
     driver->terminate();
     delete driver;
 }
@@ -159,16 +154,49 @@ void BackendTest::renderTriangle(
     api.endRenderPass();
 }
 
-bool BackendTest::matchesEnvironment(Backend backend) {
-    return sBackend == backend;
-}
+void BackendTest::readPixelsAndAssertHash(const char* testName, size_t width, size_t height,
+        Handle<HwRenderTarget> rt, uint32_t expectedHash, bool exportScreenshot) {
+    void* buffer = calloc(1, width * height * 4);
 
-bool BackendTest::matchesEnvironment(OperatingSystem operatingSystem) {
-    return sOperatingSystem == operatingSystem;
-}
+    struct Capture {
+        uint32_t expectedHash;
+        char* name;
+        bool exportScreenshot;
+        size_t width, height;
+    };
+    auto* c = new Capture();
+    c->expectedHash = expectedHash;
+    c->name = strdup(testName);
+    c->exportScreenshot = exportScreenshot;
+    c->width = width;
+    c->height = height;
 
-bool BackendTest::matchesEnvironment(OperatingSystem operatingSystem, Backend backend) {
-    return matchesEnvironment(operatingSystem) && matchesEnvironment(backend);
+    PixelBufferDescriptor pbd(buffer, width * height * 4, PixelDataFormat::RGBA, PixelDataType::UBYTE,
+            1, 0, 0, width, [](void* buffer, size_t size, void* user) {
+                auto* c = (Capture*)user;
+
+                // Export a screenshot, if requested.
+                if (c->exportScreenshot) {
+#ifndef FILAMENT_IOS
+                    LinearImage image(c->width, c->height, 4);
+                    image = toLinearWithAlpha<uint8_t>(c->width, c->height, c->width * 4,
+                            (uint8_t*) buffer);
+                    const std::string png = std::string(c->name) + ".png";
+                    std::ofstream outputStream(png.c_str(), std::ios::binary | std::ios::trunc);
+                    ImageEncoder::encode(outputStream, ImageEncoder::Format::PNG, image, "",
+                            png);
+#endif
+                }
+
+                // Hash the contents of the buffer and check that they match.
+                uint32_t hash = utils::hash::murmur3((const uint32_t*) buffer, size / 4, 0);
+                ASSERT_EQ(hash, c->expectedHash) << c->name << " failed: hashes do not match." << std::endl;
+
+                free(buffer);
+                free(c->name);
+                free(c);
+            }, (void*)c);
+    getDriverApi().readPixels(rt, 0, 0, width, height, std::move(pbd));
 }
 
 class Environment : public ::testing::Environment {
@@ -182,8 +210,8 @@ public:
     }
 };
 
-void initTests(Backend backend, OperatingSystem operatingSystem, bool isMobile, int& argc, char* argv[]) {
-    BackendTest::init(backend, operatingSystem, isMobile);
+void initTests(Backend backend, bool isMobile, int& argc, char* argv[]) {
+    BackendTest::init(backend, isMobile);
     ::testing::InitGoogleTest(&argc, argv);
     ::testing::AddGlobalTestEnvironment(new Environment);
 }

filament/backend/test/BackendTest.h

@@ -25,17 +25,15 @@
 #include "private/backend/DriverApi.h"
 
 #include "PlatformRunner.h"
-#include "ImageExpectations.h"
 
 namespace test {
 
 class BackendTest : public ::testing::Test {
 public:
 
-    static void init(Backend backend, OperatingSystem operatingSystem, bool isMobilePlatform);
+    static void init(Backend backend, bool isMobilePlatform);
 
     static Backend sBackend;
-    static OperatingSystem sOperatingSystem;
     static bool sIsMobilePlatform;
 
 protected:
@@ -66,14 +64,13 @@ protected:
             filament::backend::Handle<filament::backend::HwProgram> program,
             const filament::backend::RenderPassParams& params);
 
+    void readPixelsAndAssertHash(const char* testName, size_t width, size_t height,
+            filament::backend::Handle<filament::backend::HwRenderTarget> rt, uint32_t expectedHash,
+            bool exportScreenshot = false);
+
     filament::backend::DriverApi& getDriverApi() { return *commandStream; }
     filament::backend::Driver& getDriver() { return *driver; }
 
-    ImageExpectations& getExpectations() { return *mImageExpectations; }
-
-    static bool matchesEnvironment(Backend backend);
-    static bool matchesEnvironment(OperatingSystem operatingSystem);
-    static bool matchesEnvironment(OperatingSystem operatingSystem, Backend backend);
 private:
 
     filament::backend::Driver* driver = nullptr;
@@ -81,10 +78,6 @@ private:
     std::unique_ptr<filament::backend::DriverApi> commandStream;
 
     filament::backend::Handle<filament::backend::HwBufferObject> uniform;
-
-    // This isn't truly optional, it just needs to delay construction until after the driver has
-    // been initialized
-    std::optional<ImageExpectations> mImageExpectations;
 };
 
 } // namespace test

filament/backend/test/ImageExpectations.cpp

@@ -16,6 +16,7 @@
 
 #include "ImageExpectations.h"
 
+#include "gtest/gtest.h"
 #include "gmock/gmock.h"
 #include "absl/strings/str_format.h"
 #include "utils/Hash.h"
@@ -27,17 +28,14 @@
 #ifndef FILAMENT_IOS
 
 #include <imageio/ImageEncoder.h>
-#include <imageio/ImageDecoder.h>
 #include <image/ColorTransform.h>
 
 #endif
 
 ScreenshotParams::ScreenshotParams(int width, int height, std::string fileName,
-        uint32_t expectedHash)
-    : mWidth(width),
-      mHeight(height),
-      mExpectedPixelHash(expectedHash),
-      mFileName(std::move(fileName)) {}
+        uint32_t expectedPixelHash)
+        : mWidth(width), mHeight(height), mFileName(std::move(fileName)),
+          mExpectedPixelHash(expectedPixelHash) {}
 
 int ScreenshotParams::width() const {
     return mWidth;
@@ -51,28 +49,24 @@ uint32_t ScreenshotParams::expectedHash() const {
     return mExpectedPixelHash;
 }
 
-std::string ScreenshotParams::actualDirectoryPath() {
-    return "images/actual_images";
+std::string ScreenshotParams::outputDirectoryPath() const {
+    return ".";
 }
 
-std::string ScreenshotParams::actualFileName() const {
+std::string ScreenshotParams::generatedActualFileName() const {
     return absl::StrFormat("%s_actual.png", mFileName);
 }
 
-std::string ScreenshotParams::actualFilePath() const {
-    return absl::StrFormat("%s/%s", actualDirectoryPath(), actualFileName());
+std::string ScreenshotParams::generatedActualFilePath() const {
+    return absl::StrFormat("%s/%s", outputDirectoryPath(), generatedActualFileName());
 }
 
-std::string ScreenshotParams::expectedDirectoryPath() {
-    return "images/expected_images";
+std::string ScreenshotParams::goldenFileName() const {
+    return absl::StrFormat("%s_golden.png", mFileName);
 }
 
-std::string ScreenshotParams::expectedFileName() const {
-    return absl::StrFormat("%s.png", mFileName);
-}
-
-std::string ScreenshotParams::expectedFilePath() const {
-    return absl::StrFormat("%s/%s", expectedDirectoryPath(), expectedFileName());
+std::string ScreenshotParams::goldenFilePath() const {
+    return absl::StrFormat("%s/%s", outputDirectoryPath(), goldenFileName());
 }
 
 ImageExpectation::ImageExpectation(const char* fileName, int lineNumber,
@@ -97,22 +91,11 @@ void ImageExpectation::evaluate() {
 
 void ImageExpectation::compareImage() const {
     bool bytesFilled = mResult.bytesFilled();
-    // If this fails, it likely means that BackendTest::flushAndWait needs to be called before
-    // ImageExpectations is evaluated or destroyed.
     EXPECT_THAT(bytesFilled, testing::IsTrue())
                         << "Render target wasn't copied to the buffer for " << mFileName;
     if (bytesFilled) {
-        // Rather than directly compare the two images compare their hashes because comparing very
-        // large arrays generates way too much debug output to be useful.
         uint32_t actualHash = mResult.hash();
-#ifndef FILAMENT_IOS
-        LoadedPng loadedImage(mParams.expectedFilePath());
-        uint32_t loadedImageHash = loadedImage.hash();
-        EXPECT_THAT(actualHash, testing::Eq(loadedImageHash)) << mParams.expectedFileName();
-#endif
-        // For builds that can't load PNGs (currently iOS only) use the expected hash.
-        EXPECT_THAT(actualHash, testing::Eq(mParams.expectedHash())) << mParams.expectedFileName();
-        // TODO: Add better debug output, such as generating a diff image.
+        EXPECT_THAT(actualHash, testing::Eq(mParams.expectedHash()));
     }
 }
 
@@ -126,13 +109,12 @@ ImageExpectations::~ImageExpectations() {
 
 void ImageExpectations::addExpectation(const char* fileName, int lineNumber,
         filament::backend::RenderTargetHandle renderTarget, ScreenshotParams params) {
-    mExpectations.emplace_back(std::make_unique<ImageExpectation>(fileName, lineNumber, mApi,
-            std::move(params), renderTarget));
+    mExpectations.emplace_back(fileName, lineNumber, mApi, std::move(params), renderTarget);
 }
 
 void ImageExpectations::evaluate() {
     for (auto& expectation: mExpectations) {
-        expectation->evaluate();
+        expectation.evaluate();
     }
     mExpectations.clear();
 }
@@ -140,28 +122,32 @@ void ImageExpectations::evaluate() {
 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);
-        internal->bytesFilled = true;
-#ifndef FILAMENT_IOS
         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.actualFilePath();
+        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);
-#endif
+        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() {
@@ -183,30 +169,4 @@ bool RenderTargetDump::bytesFilled() const {
     return mInternal->bytesFilled;
 }
 
-RenderTargetDump::Internal::Internal(const ScreenshotParams& params) : params(params) {}
-
-LoadedPng::LoadedPng(std::string filePath) : mFilePath(std::move(filePath)) {
-#ifndef FILAMENT_IOS
-    std::ifstream pngStream(mFilePath, std::ios::binary);
-    image::LinearImage loadedImage = image::ImageDecoder::decode(pngStream, filePath,
-            image::ImageDecoder::ColorSpace::LINEAR);
-    size_t valuesInImage = loadedImage.getWidth() * loadedImage.getHeight() *
-                          loadedImage.getChannels();
-    // The linear image is loaded with each component as [0.0, 1.0] but should be [0, 255], so
-    // convert them.
-    mBytes = std::vector<unsigned char>(valuesInImage);
-    for (int i = 0; i < valuesInImage; ++i) {
-        mBytes[i] = static_cast<uint8_t>(loadedImage.get<float>()[i] * 255.0f);
-    }
-#endif
-    // For platforms that don't support the image loading library, leave the loaded data blank.
-}
-
-uint32_t LoadedPng::hash() const {
-    EXPECT_THAT(mBytes, testing::Not(testing::IsEmpty()))
-            << "Failed to load expected test result: " << mFilePath;
-    if (mBytes.empty()) {
-        return 0;
-    }
-    return utils::hash::murmur3((uint32_t*)mBytes.data(), mBytes.size() / 4, 0);
-}
+RenderTargetDump::Internal::Internal(const ScreenshotParams& params) : params(params) {}

filament/backend/test/ImageExpectations.h

@@ -46,12 +46,11 @@ public:
     int height() const;
     uint32_t expectedHash() const;
 
-    static std::string actualDirectoryPath();
-    std::string actualFileName() const;
-    std::string actualFilePath() const;
-    static std::string expectedDirectoryPath();
-    std::string expectedFileName() const;
-    std::string expectedFilePath() const;
+    std::string outputDirectoryPath() const;
+    std::string generatedActualFileName() const;
+    std::string generatedActualFilePath() const;
+    std::string goldenFileName() const;
+    std::string goldenFilePath() const;
 
 private:
     int mWidth;
@@ -99,17 +98,6 @@ private:
     std::unique_ptr<Internal> mInternal;
 };
 
-class LoadedPng {
-public:
-    explicit LoadedPng(std::string filePath);
-
-    uint32_t hash() const;
-
-private:
-    std::string mFilePath;
-    std::vector<unsigned char> mBytes;
-};
-
 class ImageExpectation {
 public:
     ImageExpectation(const char* fileName, int lineNumber, filament::backend::DriverApi& api,
@@ -142,8 +130,7 @@ public:
 
 private:
     filament::backend::DriverApi& mApi;
-    // Store expectations in unique pointers because they are self referential.
-    std::vector<std::unique_ptr<ImageExpectation>> mExpectations;
+    std::vector<ImageExpectation> mExpectations;
 };
 
 #endif //TNT_IMAGE_EXPECTATIONS_H

filament/backend/test/PlatformRunner.cpp

@@ -1,60 +0,0 @@
-/*
- * Copyright (C) 2019 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 "PlatformRunner.h"
-
-namespace utils {
-
-template<>
-CString to_string<test::Backend>(test::Backend backend) noexcept {
-    switch (backend) {
-        case test::Backend::OPENGL: {
-            return "OpenGL";
-        }
-        case test::Backend::VULKAN: {
-            return "Vulkan";
-        }
-        case test::Backend::METAL: {
-            return "Metal";
-        }
-        case test::Backend::WEBGPU: {
-            return "WebGPU";
-        }
-        case test::Backend::NOOP:
-        default: {
-            return "No-op";
-        }
-    }
-}
-
-template<>
-CString to_string(test::OperatingSystem os) noexcept {
-    switch (os) {
-        case test::OperatingSystem::LINUX: {
-            return "Linux";
-        }
-        case test::OperatingSystem::APPLE: {
-            return "Apple";
-        }
-        case test::OperatingSystem::OTHER:
-        default: {
-            return "Other";
-        }
-    }
-}
-
-} // namespace utils
-

filament/backend/test/PlatformRunner.h

@@ -19,7 +19,6 @@
 
 #include <stdint.h>
 #include <stddef.h>
-#include "utils/CString.h"
 
 namespace test {
 
@@ -35,15 +34,6 @@ enum class Backend : uint8_t {
     NOOP = 5,
 };
 
-enum class OperatingSystem: uint8_t {
-    OTHER = 1,
-    // Also represents android phones.
-    LINUX = 2,
-    // Also represents iOS phones.
-    APPLE = 3,
-    // TODO: When tests support windows add it here.
-};
-
 struct NativeView {
     void* ptr = nullptr;
     size_t width = 0, height = 0;
@@ -61,10 +51,9 @@ NativeView getNativeView();
  * No tests will be run yet.
  *
  * @param backend The backend to run the tests on.
- * @param operatingSystem The operating system the tests are being run on.
  * @param isMobile True if the platform is a mobile platform (iOS or Android).
  */
-void initTests(Backend backend, OperatingSystem operatingSystem, bool isMobile, int& argc, char* argv[]);
+void initTests(Backend backend, bool isMobile, int& argc, char* argv[]);
 
 /**
  * Test runners should call runTests when they are ready for tests to be run.
@@ -79,6 +68,6 @@ int runTests();
  */
 Backend parseArgumentsForBackend(int argc, char* argv[]);
 
-} // namespace test
+}
 
 #endif

filament/backend/test/Skip.cpp

@@ -1,96 +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 "Skip.h"
-
-#include <sstream>
-
-namespace test {
-
-SkipEnvironment::SkipEnvironment(test::Backend backend) : backend(backend) {}
-SkipEnvironment::SkipEnvironment(test::OperatingSystem os) : os(os) {}
-SkipEnvironment::SkipEnvironment(test::OperatingSystem os, test::Backend backend)
-    : backend(backend),
-      os(os) {}
-
-bool SkipEnvironment::matches() {
-    bool backendMatches = !backend.has_value() || *backend == BackendTest::sBackend;
-    bool osMatches = !os.has_value() || *os == BackendTest::sOperatingSystem;
-    bool isMobileMatches = !isMobile.has_value() || *isMobile == BackendTest::sIsMobilePlatform;
-    return backendMatches && osMatches && isMobileMatches;
-}
-
-std::string SkipEnvironment::describe() {
-    std::stringstream result;
-    if (matches()) {
-        result << "environment matches because " << describe_actual_environment() << ".";
-    } else {
-        result << "environment does not match because " << describe_requirements() << " but "
-               << describe_actual_environment() << ".";
-    }
-    return result.str();
-}
-
-std::string SkipEnvironment::describe_actual_environment() {
-    bool resultWritten = false;
-    std::stringstream reality;
-    if (backend.has_value()) {
-        reality << "backend was " << utils::to_string(BackendTest::sBackend).c_str();
-        resultWritten = true;
-    }
-    if (os.has_value()) {
-        if (resultWritten) {
-            reality << ", and ";
-        }
-        reality << "operating system was "
-                << utils::to_string(BackendTest::sOperatingSystem).c_str();
-        resultWritten = true;
-    }
-    if (isMobile.has_value()) {
-        if (resultWritten) {
-            reality << ", and ";
-        }
-        reality << "device " << (BackendTest::sIsMobilePlatform ? "was" : "was not") << " mobile";
-        resultWritten = true;
-    }
-    return reality.str();
-}
-
-std::string SkipEnvironment::describe_requirements() {
-    bool resultWritten = false;
-    std::stringstream requirement;
-    if (backend.has_value()) {
-        requirement << "backend needs to be " << utils::to_string(*backend).c_str();
-        resultWritten = true;
-    }
-    if (os.has_value()) {
-        if (resultWritten) {
-            requirement << ", and ";
-        }
-        requirement << "operating system needs to be " << utils::to_string(*os).c_str();
-        resultWritten = true;
-    }
-    if (isMobile.has_value() && BackendTest::sIsMobilePlatform != isMobile) {
-        if (resultWritten) {
-            requirement << ", and ";
-        }
-        requirement << "device needs to " << (*isMobile ? "be" : "not be") << " mobile";
-        resultWritten = true;
-    }
-    return requirement.str();
-}
-
-} // namespace test

filament/backend/test/Skip.h

@@ -1,55 +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_SKIP_H
-#define TNT_SKIP_H
-
-#include <gtest/gtest.h>
-#include "BackendTest.h"
-
-// skipEnvironment must be a test::SkipEnvironment
-#define SKIP_IF(skipEnvironment)                                                                   \
-do {                                                                                               \
-    SkipEnvironment skip(skipEnvironment);                                                         \
-    if (skip.matches()) {                                                                          \
-        GTEST_SKIP() << "Skipping test as the " << skip.describe();                                \
-    }                                                                                              \
-} while (false)
-
-namespace test {
-
-struct SkipEnvironment {
-    SkipEnvironment(const SkipEnvironment&) = default;
-    explicit SkipEnvironment(test::Backend backend);
-    explicit SkipEnvironment(test::OperatingSystem os);
-    SkipEnvironment(test::OperatingSystem os, test::Backend backend);
-
-    std::optional<test::Backend> backend;
-    std::optional<test::OperatingSystem> os;
-    std::optional<bool> isMobile;
-
-    bool matches();
-    // Describes the current state of either matching or mismatching.
-    std::string describe();
-    // Describe all the non-null requirements.
-    std::string describe_requirements();
-    // Describes the environment's status for all the attributes that are non-null.
-    std::string describe_actual_environment();
-};
-
-} // namespace test
-
-#endif// TNT_SKIP_H