Improve code-correctness script (#8659)

- Sort failures alphabetically
- Add way to suppress error when necessary
- Add way to run test on a subset of files for testing
- Fix case where number of files is less than number of workers

.github/workflows/presubmit.yml

@@ -19,6 +19,8 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4.1.6
+        with:
+          fetch-depth: 0
       - name: Run build script
         run: |
           WORKFLOW_OS=`echo \`uname\` | sed "s/Darwin/mac/" | tr [:upper:] [:lower:]`
@@ -44,6 +46,8 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4.1.6
+        with:
+          fetch-depth: 0
       - uses: actions/setup-java@v3
         with:
           distribution: 'temurin'
@@ -60,6 +64,8 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4.1.6
+        with:
+          fetch-depth: 0
       - name: Run build script
         run: |
           cd build/ios && printf "y" | ./build.sh presubmit
@@ -102,9 +108,21 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: '3.x'
-      - name: Install python prereqs
+      - name: Cache Mesa and deps
-        run: pip install mako setuptools pyyaml
+        id: mesa-cache
-      - name: Run script
+        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: ${{ vars.MESA_VERSION }}
+        run: |
+          bash test/utils/get_mesa.sh
+      - name: Run Test
         run: |
           bash test/renderdiff/test.sh
       - uses: actions/upload-artifact@v4
@@ -122,3 +140,31 @@ jobs:
         run: source ./build/linux/ci-common.sh && ./build.sh -W debug test_filamat filament
       - name: Run test
         run: ./out/cmake-debug/libs/filamat/test_filamat --gtest_filter=MaterialCompiler.Wgsl*
+
+  code-correcteness:
+    name: code-correctness
+    runs-on: 'macos-14-xlarge'
+    steps:
+      - uses: actions/checkout@v4.1.6
+        with:
+          fetch-depth: 0
+      - name: Set up Homebrew
+        id: set-up-homebrew
+        uses: Homebrew/actions/setup-homebrew@master
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
+      - name: Install prerequisites
+        run: |
+          pip install pyyaml
+          brew install llvm
+          sudo ln -s "$(brew --prefix llvm)/bin/clang-tidy" "/usr/local/bin/clang-tidy"
+      - name: Run build script
+        # We need to build before clang-tidy can run analysis
+        run: |
+          # This will build for all three desktop backends on mac
+          ./build.sh -p desktop debug gltf_viewer
+      - name: Run test
+        run: |
+          bash test/code-correctness/test.sh

CMakeLists.txt

@@ -801,6 +801,7 @@ 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)

NEW_RELEASE_NOTES.md

@@ -7,5 +7,3 @@ for next branch cut* header.
 appropriate header in [RELEASE_NOTES.md](./RELEASE_NOTES.md).
 
 ## Release notes for next branch cut
-
-- Fix build/compile errors when upgrading to MacOS 15.4

README.md

@@ -31,7 +31,7 @@ repositories {
 }
 
 dependencies {
-    implementation 'com.google.android.filament:filament-android:1.59.0'
+    implementation 'com.google.android.filament:filament-android:1.59.3'
 }
 ```
 
@@ -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', '~> 1.59.0'
+pod 'Filament', '~> 1.59.3'
 ```
 
 ## Documentation

RELEASE_NOTES.md

@@ -7,6 +7,16 @@ 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
+
 ## v1.59.1
 
 

android/buildSrc/src/main/groovy/FilamentPlugin.groovy

@@ -142,16 +142,13 @@ abstract class MaterialCompiler extends TaskWithBinary {
                 if (!exclude_vulkan) {
                     matcArgs += ['-a', 'vulkan']
                 }
-
                 def include_webgpu = providers
                         .gradleProperty("com.google.android.filament.include-webgpu")
                         .forUseAtConfigurationTime().present
-
+                if (include_webgpu) {
-                if (!include_webgpu) {
+                    matcArgs += ['-a', 'webgpu', '--variant-filter=skinning,stereo']
-                    matcArgs += ['-a', 'webgpu']
                 }
 
-
                 def mat_no_opt = providers
                         .gradleProperty("com.google.android.filament.matnopt")
                         .forUseAtConfigurationTime().present

android/filamat-android/CMakeLists.txt

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

android/filament-android/CMakeLists.txt

@@ -21,6 +21,10 @@ 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)
@@ -123,6 +127,7 @@ target_link_libraries(filament-jni
     PRIVATE android
     PRIVATE jnigraphics
     PRIVATE utils
+    PRIVATE perfetto
 
     # libgeometry is PUBLIC because gltfio uses it.
     PUBLIC geometry
@@ -141,6 +146,7 @@ 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

@@ -35,6 +35,10 @@ 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)
@@ -121,6 +125,7 @@ set(GLTFIO_INCLUDE_DIRS
         ../../third_party/meshoptimizer/src
         ../../third_party/robin-map
         ../../third_party/stb
+        ../../third_party/perfetto
         ../../libs/utils/include
         ../../libs/ktxreader/include
 )
@@ -129,7 +134,7 @@ 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 uberzlib log stb ktxreader basis_transcoder zstd uberarchive)
+target_link_libraries(gltfio-jni filament-jni utils perfetto 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=1.59.0
+VERSION_NAME=1.59.3
 
 POM_DESCRIPTION=Real-time physically based rendering engine for Android.
 

build/common/check-headers.sh

@@ -56,10 +56,16 @@ 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 ${include}"
-    echo "#include <${include}>" >> out/check-headers/temp.cpp
+    if [[ "${include}" == "utils/Systrace.h" ]]; then
-    clang -std=c++17 -I "${FILAMENT_HEADERS}" out/check-headers/temp.cpp -c -o /dev/null
+        # 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
 done
 echo "Done!"

filament/backend/CMakeLists.txt

@@ -177,29 +177,6 @@ endif()
 if (FILAMENT_SUPPORTS_VULKAN)
     list(APPEND SRCS
             include/backend/platforms/VulkanPlatform.h
-            src/vulkan/VulkanDescriptorSetCache.cpp
-            src/vulkan/VulkanDescriptorSetCache.h
-            src/vulkan/VulkanDescriptorSetLayoutCache.cpp
-            src/vulkan/VulkanDescriptorSetLayoutCache.h
-            src/vulkan/VulkanPipelineLayoutCache.cpp
-            src/vulkan/VulkanPipelineLayoutCache.h
-            src/vulkan/memory/ResourceManager.cpp
-            src/vulkan/memory/ResourceManager.h
-            src/vulkan/memory/ResourcePointer.h
-            src/vulkan/memory/Resource.cpp
-            src/vulkan/memory/Resource.h
-            src/vulkan/platform/VulkanPlatform.cpp
-            src/vulkan/platform/VulkanPlatformSwapChainImpl.cpp
-            src/vulkan/platform/VulkanPlatformSwapChainImpl.h
-            src/vulkan/utils/Conversion.cpp
-            src/vulkan/utils/Conversion.h
-            src/vulkan/utils/Definitions.h
-            src/vulkan/utils/Helper.h
-            src/vulkan/utils/Image.h
-            src/vulkan/utils/Image.cpp
-            src/vulkan/utils/Spirv.h
-            src/vulkan/utils/Spirv.cpp
-            src/vulkan/utils/StaticVector.h
             src/vulkan/VulkanAsyncHandles.h
             src/vulkan/VulkanBlitter.cpp
             src/vulkan/VulkanBlitter.h
@@ -210,31 +187,56 @@ if (FILAMENT_SUPPORTS_VULKAN)
             src/vulkan/VulkanConstants.h
             src/vulkan/VulkanContext.cpp
             src/vulkan/VulkanContext.h
+            src/vulkan/VulkanDescriptorSetCache.cpp
+            src/vulkan/VulkanDescriptorSetCache.h
+            src/vulkan/VulkanDescriptorSetLayoutCache.cpp
+            src/vulkan/VulkanDescriptorSetLayoutCache.h
             src/vulkan/VulkanDriver.cpp
             src/vulkan/VulkanDriver.h
             src/vulkan/VulkanDriverFactory.h
+            src/vulkan/VulkanExternalImageManager.cpp
+            src/vulkan/VulkanExternalImageManager.h
             src/vulkan/VulkanFboCache.cpp
             src/vulkan/VulkanFboCache.h
             src/vulkan/VulkanHandles.cpp
             src/vulkan/VulkanHandles.h
-            src/vulkan/VulkanMemory.h
             src/vulkan/VulkanMemory.cpp
+            src/vulkan/VulkanMemory.h
             src/vulkan/VulkanPipelineCache.cpp
             src/vulkan/VulkanPipelineCache.h
+            src/vulkan/VulkanPipelineLayoutCache.cpp
+            src/vulkan/VulkanPipelineLayoutCache.h
             src/vulkan/VulkanQueryManager.cpp
             src/vulkan/VulkanQueryManager.h
+            src/vulkan/VulkanReadPixels.cpp
+            src/vulkan/VulkanReadPixels.h
             src/vulkan/VulkanSamplerCache.cpp
             src/vulkan/VulkanSamplerCache.h
             src/vulkan/VulkanStagePool.cpp
             src/vulkan/VulkanStagePool.h
             src/vulkan/VulkanSwapChain.cpp
             src/vulkan/VulkanSwapChain.h
-            src/vulkan/VulkanReadPixels.cpp
-            src/vulkan/VulkanReadPixels.h
             src/vulkan/VulkanTexture.cpp
             src/vulkan/VulkanTexture.h
             src/vulkan/VulkanYcbcrConversionCache.cpp
             src/vulkan/VulkanYcbcrConversionCache.h
+            src/vulkan/memory/Resource.cpp
+            src/vulkan/memory/Resource.h
+            src/vulkan/memory/ResourceManager.cpp
+            src/vulkan/memory/ResourceManager.h
+            src/vulkan/memory/ResourcePointer.h
+            src/vulkan/platform/VulkanPlatform.cpp
+            src/vulkan/platform/VulkanPlatformSwapChainImpl.cpp
+            src/vulkan/platform/VulkanPlatformSwapChainImpl.h
+            src/vulkan/utils/Conversion.cpp
+            src/vulkan/utils/Conversion.h
+            src/vulkan/utils/Definitions.h
+            src/vulkan/utils/Helper.h
+            src/vulkan/utils/Image.cpp
+            src/vulkan/utils/Image.h
+            src/vulkan/utils/Spirv.cpp
+            src/vulkan/utils/Spirv.h
+            src/vulkan/utils/StaticVector.h
     )
     if (LINUX OR WIN32)
         list(APPEND SRCS src/vulkan/platform/VulkanPlatformLinuxWindows.cpp)
@@ -255,10 +257,11 @@ if (FILAMENT_SUPPORTS_WEBGPU)
             src/webgpu/WebGPUConstants.h
             src/webgpu/WebGPUDriver.cpp
             src/webgpu/WebGPUDriver.h
-            src/webgpu/WebGPUSwapChain.cpp
-            src/webgpu/WebGPUSwapChain.h
             src/webgpu/WebGPUHandles.cpp
             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)
@@ -507,7 +510,10 @@ 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
@@ -531,6 +537,9 @@ 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

@@ -55,4 +55,9 @@ 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/platforms/VulkanPlatform.h

@@ -104,10 +104,6 @@ public:
 
         // Semaphore to be signaled once the image is available.
         VkSemaphore imageReadySemaphore = VK_NULL_HANDLE;
-
-        // A function called right before vkQueueSubmit. After this call, the image must be 
-        // available. This pointer can be null if imageReadySemaphore is not VK_NULL_HANDLE.
-        std::function<void(SwapChainPtr handle)> explicitImageReadyWait = nullptr;
     };
 
     VulkanPlatform();
@@ -298,6 +294,16 @@ 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
          */
@@ -308,11 +314,6 @@ public:
          */
         uint32_t height;
 
-        /**
-         * The layerCount of the external image
-         */
-        uint32_t layerCount;
-
         /**
          * The layer count of the external image
          */
@@ -328,11 +329,6 @@ 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.
          */
@@ -352,20 +348,61 @@ 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);
 
-    virtual VkSampler createExternalSampler(SamplerYcbcrConversion chroma,
+    // Note that the image metadata might change per-frame, hence we need a method for extracting
-            SamplerParams sampler, uint32_t internalFormat);
+    // it.
+    virtual ExternalImageMetadata extractExternalImageMetadata(ExternalImageHandleRef image) const {
+        return {};
+    }
 
-    virtual VkImageView createExternalImageView(SamplerYcbcrConversion chroma,
+    struct ImageData {
-            uint32_t internalFormat, VkImage image, VkImageSubresourceRange range,
+        struct Bundle {
-            VkImageViewType viewType, VkComponentMapping swizzle);
+            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 {};
+    }
 
 protected:
     virtual ExtensionSet getSwapchainInstanceExtensions() const;
@@ -378,20 +415,6 @@ 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:
-    Platform::ExternalImageHandle UTILS_PUBLIC createExternalImage(AHardwareBuffer const* buffer,
+    ExternalImageHandle UTILS_PUBLIC createExternalImage(AHardwareBuffer const* buffer,
             bool sRGB) noexcept;
 
     struct UTILS_PUBLIC ExternalImageDescAndroid {
@@ -39,31 +39,26 @@ 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

@@ -38,6 +38,12 @@ 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 (SYSTRACE_TAG) {
+    if constexpr (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 (SYSTRACE_TAG) {
+    if constexpr (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);
-    MetalVertexBufferInfo const* const vbi = handle_cast<MetalVertexBufferInfo>(vertexBuffer->vbih);
+    primitive->vertexBuffer = vertexBuffer;
-    primitive->setBuffers(vbi, vertexBuffer, indexBuffer);
+    primitive->indexBuffer = indexBuffer;
     primitive->type = pt;
 }
 

filament/backend/src/metal/MetalHandles.h

@@ -194,12 +194,8 @@ 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;
 };
@@ -380,7 +376,6 @@ 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

@@ -536,15 +536,6 @@ 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/opengl/GLUtils.cpp

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

filament/backend/src/opengl/GLUtils.h

@@ -17,29 +17,26 @@
 #ifndef TNT_FILAMENT_BACKEND_OPENGL_GLUTILS_H
 #define TNT_FILAMENT_BACKEND_OPENGL_GLUTILS_H
 
-#include <utils/compiler.h>
 #include <utils/debug.h>
-#include <utils/Log.h>
+#include <utils/ostream.h>
 
 #include <backend/DriverEnums.h>
 
 #include <string_view>
 #include <unordered_set>
 
-#include <stdint.h>
 #include <stddef.h>
-#include <string.h>
+#include <stdint.h>
 
 #include "gl_headers.h"
 
-namespace filament::backend {
+namespace filament::backend::GLUtils {
-namespace GLUtils {
 
-const char* getGLError(GLenum error) noexcept;
+std::string_view getGLErrorString(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;
 
-const char* getFramebufferStatus(GLenum err) noexcept;
+std::string_view getFramebufferStatusString(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;
 
@@ -53,7 +50,7 @@ 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 type) noexcept {
+constexpr GLuint getComponentCount(ElementType const type) noexcept {
     using ElementType = ElementType;
     switch (type) {
         case ElementType::BYTE:
@@ -87,27 +84,29 @@ constexpr GLuint getComponentCount(ElementType type) noexcept {
         case ElementType::USHORT4:
             return 4;
     }
+    // should never happen
+    return 1;
 }
 
 // ------------------------------------------------------------------------------------------------
 // Our enums to GLenum conversions
 // ------------------------------------------------------------------------------------------------
 
-constexpr GLbitfield getAttachmentBitfield(TargetBufferFlags flags) noexcept {
+constexpr GLbitfield getAttachmentBitfield(TargetBufferFlags const 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 usage) noexcept {
+constexpr GLenum getBufferUsage(BufferUsage const usage) noexcept {
     switch (usage) {
         case BufferUsage::STATIC:
             return GL_STATIC_DRAW;
@@ -116,7 +115,7 @@ constexpr GLenum getBufferUsage(BufferUsage usage) noexcept {
     }
 }
 
-constexpr GLenum getBufferBindingType(BufferObjectBinding bindingType) noexcept {
+constexpr GLenum getBufferBindingType(BufferObjectBinding const bindingType) noexcept {
     switch (bindingType) {
         case BufferObjectBinding::VERTEX:
             return GL_ARRAY_BUFFER;
@@ -135,13 +134,15 @@ constexpr GLenum getBufferBindingType(BufferObjectBinding bindingType) noexcept
             return 0x90D2; // just to return something
 #endif
     }
+    // should never happen
+    return GL_ARRAY_BUFFER;
 }
 
-constexpr GLboolean getNormalization(bool normalized) noexcept {
+constexpr GLboolean getNormalization(bool const normalized) noexcept {
     return GLboolean(normalized ? GL_TRUE : GL_FALSE);
 }
 
-constexpr GLenum getComponentType(ElementType type) noexcept {
+constexpr GLenum getComponentType(ElementType const type) noexcept {
     using ElementType = ElementType;
     switch (type) {
         case ElementType::BYTE:
@@ -184,9 +185,11 @@ constexpr GLenum getComponentType(ElementType type) noexcept {
             return GL_HALF_FLOAT_OES;
 #endif
     }
+    // should never happen
+    return GL_INT;
 }
 
-constexpr GLenum getTextureTargetNotExternal(SamplerType target) noexcept {
+constexpr GLenum getTextureTargetNotExternal(SamplerType const target) noexcept {
     switch (target) {
         case SamplerType::SAMPLER_2D:
             return GL_TEXTURE_2D;
@@ -202,14 +205,16 @@ constexpr GLenum getTextureTargetNotExternal(SamplerType target) noexcept {
             // we should never be here
             return GL_TEXTURE_2D;
     }
+    // should never happen
+    return GL_TEXTURE_2D;
 }
 
-constexpr GLenum getCubemapTarget(uint16_t layer) noexcept {
+constexpr GLenum getCubemapTarget(uint16_t const layer) noexcept {
     assert_invariant(layer <= 5);
     return GL_TEXTURE_CUBE_MAP_POSITIVE_X + layer;
 }
 
-constexpr GLenum getWrapMode(SamplerWrapMode mode) noexcept {
+constexpr GLenum getWrapMode(SamplerWrapMode const mode) noexcept {
     using SamplerWrapMode = SamplerWrapMode;
     switch (mode) {
         case SamplerWrapMode::REPEAT:
@@ -219,6 +224,8 @@ constexpr GLenum getWrapMode(SamplerWrapMode mode) noexcept {
         case SamplerWrapMode::MIRRORED_REPEAT:
             return GL_MIRRORED_REPEAT;
     }
+    // should never happen
+    return GL_CLAMP_TO_EDGE;
 }
 
 constexpr GLenum getTextureFilter(SamplerMinFilter filter) noexcept {
@@ -234,6 +241,8 @@ 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 {
@@ -241,7 +250,7 @@ constexpr GLenum getTextureFilter(SamplerMagFilter filter) noexcept {
 }
 
 
-constexpr GLenum getBlendEquationMode(BlendEquation mode) noexcept {
+constexpr GLenum getBlendEquationMode(BlendEquation const mode) noexcept {
     using BlendEquation = BlendEquation;
     switch (mode) {
         case BlendEquation::ADD:               return GL_FUNC_ADD;
@@ -250,9 +259,11 @@ constexpr GLenum getBlendEquationMode(BlendEquation 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 mode) noexcept {
+constexpr GLenum getBlendFunctionMode(BlendFunction const mode) noexcept {
     using BlendFunction = BlendFunction;
     switch (mode) {
         case BlendFunction::ZERO:                  return GL_ZERO;
@@ -267,9 +278,11 @@ constexpr GLenum getBlendFunctionMode(BlendFunction 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 func) noexcept {
+constexpr GLenum getCompareFunc(SamplerCompareFunc const func) noexcept {
     switch (func) {
         case SamplerCompareFunc::LE:    return GL_LEQUAL;
         case SamplerCompareFunc::GE:    return GL_GEQUAL;
@@ -280,28 +293,30 @@ constexpr GLenum getCompareFunc(SamplerCompareFunc 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 mode) noexcept {
+constexpr GLenum getTextureCompareMode(SamplerCompareMode const mode) noexcept {
     return mode == SamplerCompareMode::NONE ?
            GL_NONE : GL_COMPARE_REF_TO_TEXTURE;
 }
 
-constexpr GLenum getTextureCompareFunc(SamplerCompareFunc func) noexcept {
+constexpr GLenum getTextureCompareFunc(SamplerCompareFunc const func) noexcept {
     return getCompareFunc(func);
 }
 #endif
 
-constexpr GLenum getDepthFunc(SamplerCompareFunc func) noexcept {
+constexpr GLenum getDepthFunc(SamplerCompareFunc const func) noexcept {
     return getCompareFunc(func);
 }
 
-constexpr GLenum getStencilFunc(SamplerCompareFunc func) noexcept {
+constexpr GLenum getStencilFunc(SamplerCompareFunc const func) noexcept {
     return getCompareFunc(func);
 }
 
-constexpr GLenum getStencilOp(StencilOperation op) noexcept {
+constexpr GLenum getStencilOp(StencilOperation const op) noexcept {
     switch (op) {
         case StencilOperation::KEEP:        return GL_KEEP;
         case StencilOperation::ZERO:        return GL_ZERO;
@@ -312,9 +327,11 @@ constexpr GLenum getStencilOp(StencilOperation 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 format) noexcept {
+constexpr GLenum getFormat(PixelDataFormat const format) noexcept {
     using PixelDataFormat = PixelDataFormat;
     switch (format) {
         case PixelDataFormat::RGB:              return GL_RGB;
@@ -336,9 +353,11 @@ constexpr GLenum getFormat(PixelDataFormat format) noexcept {
         default: return GL_NONE;
 #endif
     }
+    // should never happen
+    return GL_RGBA;
 }
 
-constexpr GLenum getType(PixelDataType type) noexcept {
+constexpr GLenum getType(PixelDataType const type) noexcept {
     using PixelDataType = PixelDataType;
     switch (type) {
         case PixelDataType::UBYTE:                return GL_UNSIGNED_BYTE;
@@ -360,10 +379,12 @@ constexpr GLenum getType(PixelDataType 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 c) noexcept {
+constexpr GLenum getSwizzleChannel(TextureSwizzle const c) noexcept {
     using TextureSwizzle = TextureSwizzle;
     switch (c) {
         case TextureSwizzle::SUBSTITUTE_ZERO:   return GL_ZERO;
@@ -373,10 +394,12 @@ constexpr GLenum getSwizzleChannel(TextureSwizzle 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 mode) noexcept {
+constexpr GLenum getCullingMode(CullingMode const mode) noexcept {
     switch (mode) {
         case CullingMode::NONE:
             // should never happen
@@ -388,11 +411,13 @@ constexpr GLenum getCullingMode(CullingMode 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 format) noexcept {
+        TextureFormat const format) noexcept {
     switch (format) {
         case TextureFormat::R8:         return { 0x1909 /*GL_LUMINANCE*/, GL_UNSIGNED_BYTE };
         case TextureFormat::RGB8:       return { GL_RGB,                  GL_UNSIGNED_BYTE };
@@ -413,7 +438,7 @@ 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 format) noexcept {
+constexpr /* inline */ GLenum getInternalFormat(TextureFormat const format) noexcept {
     switch (format) {
 
         /* Formats supported by our ES2 implementations */
@@ -661,7 +686,7 @@ public:
 
 unordered_string_set split(const char* extensions) noexcept;
 
-} // namespace GLUtils
+} // namespace filament::backend::GLUtils
-} // namespace filament::backend
+
 
 #endif // TNT_FILAMENT_BACKEND_OPENGL_GLUTILS_H

filament/backend/src/opengl/OpenGLDriver.cpp

@@ -2098,6 +2098,7 @@ 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

@@ -85,6 +85,7 @@ 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 <atomic>
+#include <array>
-#include <condition_variable>
-#include <deque>
 #include <functional>
 #include <memory>
 #include <mutex>
-#include <thread>
+#include <tuple>
 #include <utility>
 #include <vector>
 
+#include <stdint.h>
+
 namespace filament::backend {
 
 class OpenGLDriver;
@@ -57,6 +57,8 @@ 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);
 
@@ -82,6 +84,7 @@ 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
@@ -90,6 +93,12 @@ 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);
@@ -97,7 +106,7 @@ public:
 private:
     struct Job {
         template<typename FUNC>
-        Job(FUNC&& fn) : fn(std::forward<FUNC>(fn)) {}
+        Job(FUNC&& fn) : fn(std::forward<FUNC>(fn)) {} // NOLINT(*-explicit-constructor)
         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) {
@@ -126,39 +135,49 @@ private:
     using ContainerType = std::tuple<CompilerPriorityQueue, program_token_t, Job>;
     std::vector<ContainerType> mRunAtNextTickOps;
 
-    GLuint initialize(ShaderCompilerService::program_token_t& token) noexcept;
+    GLuint initialize(program_token_t& token);
+    void ensureTokenIsReady(program_token_t const& token);
 
-    static void getProgramFromCompilerPool(program_token_t& token) noexcept;
+    void runAtNextTick(CompilerPriorityQueue priority, program_token_t const& token,
-
+            Job job) 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 token) noexcept;
+    bool cancelTickOp(program_token_t const& token) noexcept;
-    // order of insertion is important
+
+    // 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;
 };
 
 } // namespace filament::backend

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

@@ -17,9 +17,11 @@
 #define COREVIDEO_SILENCE_GL_DEPRECATION
 
 #include "CocoaExternalImage.h"
-#include <utils/Panic.h>
 #include "../GLUtils.h"
 
+#include <utils/Panic.h>
+#include <utils/Log.h>
+
 namespace filament::backend {
 
 static const char *s_vertex = R"SHADER(#version 410 core

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

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

filament/backend/src/ostream.cpp

@@ -15,6 +15,7 @@
  */
 
 #include <backend/BufferDescriptor.h>
+#include <backend/BufferObjectStreamDescriptor.h>
 #include <backend/DescriptorSetOffsetArray.h>
 #include <backend/DriverEnums.h>
 #include <backend/PipelineState.h>
@@ -437,6 +438,10 @@ 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

@@ -295,6 +295,8 @@ 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];
@@ -304,6 +306,7 @@ void CommandBufferPool::gc() {
         }
     });
     mSubmitted &= ~reclaimed;
+    FVK_SYSTRACE_END();
 }
 
 void CommandBufferPool::update() {
@@ -333,7 +336,9 @@ 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);
+    }
     update();
 }
 

filament/backend/src/vulkan/VulkanConstants.h

@@ -156,8 +156,8 @@ static_assert(FVK_ENABLED(FVK_DEBUG_VALIDATION));
     #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_NAME(__func__)
+    #define FVK_SYSTRACE_SCOPE()        SYSTRACE_CALL()
-    #define FVK_PROFILE_MARKER(marker)  FVK_SYSTRACE_SCOPE()
+    #define FVK_PROFILE_MARKER(marker)  SYSTRACE_CALL()
 
 #else
     #define FVK_SYSTRACE_CONTEXT()

filament/backend/src/vulkan/VulkanContext.h

@@ -70,13 +70,11 @@ struct VulkanRenderPass {
 // context are stored in VulkanPlatform.
 struct VulkanContext {
 public:
-    inline uint32_t selectMemoryType(uint32_t flags, VkFlags reqs) const {
+    static uint32_t selectMemoryType(VkPhysicalDeviceMemoryProperties const& memoryProperties,
-        if ((reqs & VK_MEMORY_PROPERTY_PROTECTED_BIT) != 0) {
+            uint32_t flags, VkFlags reqs) {
-            assert_invariant(isProtectedMemorySupported() == true);
-        }
         for (uint32_t i = 0; i < VK_MAX_MEMORY_TYPES; i++) {
             if (flags & 1) {
-                if ((mMemoryProperties.memoryTypes[i].propertyFlags & reqs) == reqs) {
+                if ((memoryProperties.memoryTypes[i].propertyFlags & reqs) == reqs) {
                     return i;
                 }
             }
@@ -85,6 +83,13 @@ public:
         return (uint32_t) VK_MAX_MEMORY_TYPES;
     }
 
+    inline uint32_t selectMemoryType(uint32_t flags, VkFlags reqs) const {
+        if ((reqs & VK_MEMORY_PROPERTY_PROTECTED_BIT) != 0) {
+            assert_invariant(isProtectedMemorySupported());
+        }
+        return selectMemoryType(mMemoryProperties, flags, reqs);
+    }
+
     inline fvkutils::VkFormatList const& getAttachmentDepthStencilFormats() const {
         return mDepthStencilFormats;
     }
@@ -118,7 +123,7 @@ public:
     }
 
     inline bool isMultiviewEnabled() const noexcept {
-        return mMultiviewEnabled;
+        return mPhysicalDeviceVk11Features.multiview == VK_TRUE;
     }
 
     inline bool isClipDistanceSupported() const noexcept {
@@ -142,6 +147,9 @@ private:
     VkPhysicalDeviceProperties2 mPhysicalDeviceProperties = {
         .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROPERTIES_2,
     };
+    VkPhysicalDeviceVulkan11Features mPhysicalDeviceVk11Features = {
+        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_1_FEATURES,
+    };
     VkPhysicalDeviceFeatures2 mPhysicalDeviceFeatures = {
         .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2,
     };
@@ -154,7 +162,6 @@ private:
     };
     bool mDebugMarkersSupported = false;
     bool mDebugUtilsSupported = false;
-    bool mMultiviewEnabled = false;
     bool mLazilyAllocatedMemorySupported = false;
     bool mProtectedMemorySupported = false;
 

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
@@ -203,11 +203,10 @@ public:
     DescriptorInfinitePool(VkDevice device)
         : mDevice(device) {}
 
-    VkDescriptorSet obtainSet(fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout) {
+    VkDescriptorSet obtainSet(DescriptorCount const& count, VkDescriptorSetLayout vklayout) {
-        auto const vklayout = layout->getVkLayout();
         DescriptorPool* sameTypePool = nullptr;
         for (auto& pool: mPools) {
-            if (!pool->canAllocate(layout->count)) {
+            if (!pool->canAllocate(count)) {
                 continue;
             }
             if (auto set = pool->obtainSet(vklayout); set != VK_NULL_HANDLE) {
@@ -225,8 +224,7 @@ public:
         }
 
         // We need to increase the set of pools by one.
-        mPools.push_back(std::make_unique<DescriptorPool>(mDevice,
+        mPools.push_back(std::make_unique<DescriptorPool>(mDevice, count, capacity));
-                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?");
@@ -276,32 +274,36 @@ void VulkanDescriptorSetCache::unbind(uint8_t setIndex) {
 }
 
 void VulkanDescriptorSetCache::commit(VulkanCommandBuffer* commands,
-        VkPipelineLayout pipelineLayout, fvkutils::DescriptorSetMask const& setMask) {
+        VkPipelineLayout pipelineLayout, fvkutils::DescriptorSetMask const& useExternalSamplers,
+        fvkutils::DescriptorSetMask const& setMask) {
     // setMask indicates the set of descriptor sets the driver wants to bind, curMask is the
     // actual set of sets that *needs* to be bound.
     fvkutils::DescriptorSetMask curMask = setMask;
 
-    auto& updateSets = mStashedSets;
+    auto const& updateSets = mStashedSets;
-    auto& lastBoundSets = mLastBoundInfo.boundSets;
+    curMask.forEachSetBit([&](size_t index) {
-
+        if (!updateSets[index]) {
-    setMask.forEachSetBit([&](size_t index) {
-        if (!updateSets[index] || updateSets[index] == lastBoundSets[index]) {
             curMask.unset(index);
         }
     });
 
-    if (curMask.none() &&
+    if (mLastBoundInfo.pipelineLayout == pipelineLayout) {
-            (mLastBoundInfo.pipelineLayout == pipelineLayout && mLastBoundInfo.setMask == setMask &&
+        auto& lastBoundSets = mLastBoundInfo.boundSets;
-                    mLastBoundInfo.boundSets == updateSets)) {
+        curMask.forEachSetBit([&](size_t index) {
-        return;
+            if (updateSets[index] == lastBoundSets[index] && !useExternalSamplers[index]) {
+                curMask.unset(index);
+            }
+        });
     }
 
-    curMask.forEachSetBit([&updateSets, commands, pipelineLayout](size_t index) {
+    curMask.forEachSetBit([&](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, &set->vkSet, set->uniqueDynamicUboCount, set->getOffsets()->data());
+                1, &vkset, set->uniqueDynamicUboCount, set->getOffsets()->data());
         commands->acquire(set);
     });
 
@@ -327,25 +329,26 @@ void VulkanDescriptorSetCache::updateBuffer(fvkmemory::resource_ptr<VulkanDescri
     if (set->dynamicUboMask.test(binding)) {
         type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC;
     }
-    VkWriteDescriptorSet const descriptorWrite = {
+    VkWriteDescriptorSet descriptorWrite = {
         .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
-        .dstSet = set->vkSet,
+        .dstSet = set->getVkSet(),
         .dstBinding = binding,
         .descriptorCount = 1,
         .descriptorType = type,
         .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::updateSampler(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
+void VulkanDescriptorSetCache::updateSamplerImpl(VkDescriptorSet vkset, uint8_t binding,
-        uint8_t binding, fvkmemory::resource_ptr<VulkanTexture> texture,
+        fvkmemory::resource_ptr<VulkanTexture> texture, VkSampler sampler) noexcept {
-        VkSampler sampler) noexcept {
-    VkDescriptorImageInfo info{
-        .sampler = sampler,
-        .imageLayout = fvkutils::getVkLayout(texture->getDefaultLayout()),
-    };
     VkImageSubresourceRange range = texture->getPrimaryViewRange();
     VkImageViewType const expectedType = texture->getViewType();
     if (any(texture->usage & TextureUsage::DEPTH_ATTACHMENT) &&
@@ -355,18 +358,35 @@ void VulkanDescriptorSetCache::updateSampler(fvkmemory::resource_ptr<VulkanDescr
         range.levelCount = 1;
         range.layerCount = 1;
     }
-    info.imageView = texture->getView(range);
+    VkDescriptorImageInfo info{
+        .sampler = sampler,
+        .imageView = texture->getView(range),
+        .imageLayout = fvkutils::getVkLayout(texture->getDefaultLayout()),
+    };
 
-    VkWriteDescriptorSet const descriptorWrite = {
+    VkWriteDescriptorSet descriptorWrite = {
         .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
         .pNext = nullptr,
-        .dstSet = set->vkSet,
+        .dstSet = vkset,
         .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);
 }
 
@@ -376,24 +396,34 @@ 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);
+    auto const vkSet = mDescriptorPool->obtainSet(layout->count, layout->getVkLayout());
     auto const& count = layout->count;
     auto const vklayout = layout->getVkLayout();
-    return fvkmemory::resource_ptr<VulkanDescriptorSet>::make(mResourceManager, handle, vkSet,
+    auto set = fvkmemory::resource_ptr<VulkanDescriptorSet>::make(
-            layout->bitmask.dynamicUbo, layout->count.dynamicUbo,
+            mResourceManager, handle, layout->bitmask.dynamicUbo, layout->count.dynamicUbo,
-            [vkSet, count, vklayout, this](VulkanDescriptorSet*) {
+            [vkSet, count, vklayout, this](
+                    VulkanDescriptorSet*) { this->manualRecycle(count, vklayout, vkSet); },
+            vkSet);
+    return set;
+}
+
+VkDescriptorSet VulkanDescriptorSetCache::getVkSet(DescriptorCount const& count,
+        VkDescriptorSetLayout vklayout) {
+    return mDescriptorPool->obtainSet(count, vklayout);
+}
+
+void VulkanDescriptorSetCache::manualRecycle(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);
     }
-            });
 }
 
-void VulkanDescriptorSetCache::gc() {
+void VulkanDescriptorSetCache::gc() { mStashedSets = {}; }
-    mStashedSets = {};
-}
 
 } // namespace filament::backend

filament/backend/src/vulkan/VulkanDescriptorSetCache.h

@@ -41,6 +41,9 @@ public:
             VulkanDescriptorSetLayout::UNIQUE_DESCRIPTOR_SET_COUNT;
 
     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();
@@ -54,6 +57,10 @@ 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;
 
@@ -63,18 +70,28 @@ 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 meant to be used with external samplers
+    void manualRecycle(VulkanDescriptorSetLayout::Count const& count, VkDescriptorSetLayout vklayout,
+            VkDescriptorSet vkSet);
+
+    DescriptorSetArray const& getBoundSets() const { return mStashedSets; }
+
     void gc();
 
 private:
-    class DescriptorInfinitePool;
+    void updateSamplerImpl(VkDescriptorSet set, uint8_t binding,
+            fvkmemory::resource_ptr<VulkanTexture> texture, VkSampler sampler) noexcept;
 
-    using DescriptorSetArray =
+    class DescriptorInfinitePool;
-            std::array<fvkmemory::resource_ptr<VulkanDescriptorSet>, UNIQUE_DESCRIPTOR_SET_COUNT>;
 
     VkDevice mDevice;
     fvkmemory::ResourceManager* mResourceManager;

filament/backend/src/vulkan/VulkanDescriptorSetLayoutCache.cpp

@@ -18,6 +18,8 @@
 
 #include "VulkanHandles.h"
 
+#include <utils/Hash.h>
+
 namespace filament::backend {
 
 namespace {
@@ -58,6 +60,56 @@ uint32_t appendBindings(VkDescriptorSetLayoutBinding* toBind, VkDescriptorType t
     return count;
 }
 
+uint32_t appendSamplerBindings(VkDescriptorSetLayoutBinding* toBind,
+        fvkutils::SamplerBitmask const& mask, fvkutils::SamplerBitmask const& external,
+        utils::FixedCapacityVector<VkSampler> const& immutableSamplers) {
+    using Bitmask = fvkutils::SamplerBitmask;
+    uint32_t count = 0;
+    Bitmask alreadySeen;
+    uint8_t immutableIndex = 0;
+    size_t const immutableSamplerCount = immutableSamplers.size();
+    mask.forEachSetBit([&](size_t index) {
+        VkShaderStageFlags stages = 0;
+        uint32_t binding = 0;
+        if (index < fvkutils::getFragmentStageShift<Bitmask>()) {
+            binding = (uint32_t) index;
+            stages |= VK_SHADER_STAGE_VERTEX_BIT;
+            auto fragIndex = index + fvkutils::getFragmentStageShift<Bitmask>();
+            if (mask.test(fragIndex)) {
+                stages |= VK_SHADER_STAGE_FRAGMENT_BIT;
+                alreadySeen.set(fragIndex);
+            }
+        } else if (!alreadySeen.test(index)) {
+            // We are in fragment stage bits
+            binding = (uint32_t) (index - fvkutils::getFragmentStageShift<Bitmask>());
+            stages |= VK_SHADER_STAGE_FRAGMENT_BIT;
+        }
+
+        if (stages) {
+            toBind[count++] = {
+                .binding = binding,
+                .descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
+                .descriptorCount = 1,
+                .stageFlags = stages,
+                .pImmutableSamplers = external[index] && immutableSamplerCount > immutableIndex
+                                              ? &immutableSamplers[immutableIndex++]
+                                              : nullptr,
+            };
+        }
+    });
+    return count;
+}
+
+uint64_t computeImmutableSamplerHash(utils::FixedCapacityVector<VkSampler> const& samplers) {
+    size_t const size = samplers.size();
+    if (size == 0) {
+        return 0;
+    } else if (size == 1) {
+        return (uint64_t) samplers[0];
+    }
+    return utils::hash::murmur3((uint32_t*) samplers.data(), samplers.size() * 2, 0);
+}
+
 } // anonymous namespace
 
 VulkanDescriptorSetLayoutCache::VulkanDescriptorSetLayoutCache(VkDevice device,
@@ -73,37 +125,45 @@ void VulkanDescriptorSetLayoutCache::terminate() noexcept {
     }
 }
 
-fvkmemory::resource_ptr<VulkanDescriptorSetLayout> VulkanDescriptorSetLayoutCache::createLayout(
+VkDescriptorSetLayout VulkanDescriptorSetLayoutCache::getVkLayout(
-        Handle<HwDescriptorSetLayout> handle, backend::DescriptorSetLayout&& info) {
+        VulkanDescriptorSetLayout::Bitmask const& bitmasks,
-    auto layout = fvkmemory::resource_ptr<VulkanDescriptorSetLayout>::make(mResourceManager, handle,
+        fvkutils::SamplerBitmask externalSamplers,
-            info);
+        utils::FixedCapacityVector<VkSampler> immutableSamplers) {
-    VkDescriptorSetLayout vklayout = VK_NULL_HANDLE;
+    LayoutKey key = {
-    auto const& bitmasks = layout->bitmask;
+        .bitmask = bitmasks,
-    if (auto itr = mVkLayouts.find(bitmasks); itr != mVkLayouts.end()) {
+        .immutableSamplerHash = computeImmutableSamplerHash(immutableSamplers),
-        vklayout = itr->second;
+    };
-    } else {
+    if (auto itr = mVkLayouts.find(key); itr != mVkLayouts.end()) {
+        return itr->second;
+    }
+
     VkDescriptorSetLayoutBinding toBind[VulkanDescriptorSetLayout::MAX_BINDINGS];
     uint32_t count = 0;
     count += appendBindings(&toBind[count], VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC,
             bitmasks.dynamicUbo);
     count += appendBindings(&toBind[count], VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, bitmasks.ubo);
-        count += appendBindings(&toBind[count], VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
+    count += appendSamplerBindings(&toBind[count], bitmasks.sampler, externalSamplers,
-                bitmasks.sampler);
+            immutableSamplers);
     count += appendBindings(&toBind[count], VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT,
             bitmasks.inputAttachment);
 
     assert_invariant(count != 0 && "Need at least one binding for descriptor set layout.");
     VkDescriptorSetLayoutCreateInfo dlinfo = {
         .sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO,
-            .pNext = nullptr,
         .bindingCount = count,
         .pBindings = toBind,
     };
-
+    VkDescriptorSetLayout vklayout;
     vkCreateDescriptorSetLayout(mDevice, &dlinfo, VKALLOC, &vklayout);
-        mVkLayouts[bitmasks] = vklayout;
+    mVkLayouts[key] = vklayout;
+    return vklayout;
 }
-    layout->setVkLayout(vklayout);
+
+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));
     return layout;
 }
 

filament/backend/src/vulkan/VulkanDescriptorSetLayoutCache.h

@@ -26,12 +26,11 @@
 #include <backend/TargetBufferInfo.h>
 
 #include <utils/bitset.h>
+#include <utils/FixedCapacityVector.h>
 
 #include <bluevk/BlueVK.h>
 #include <tsl/robin_map.h>
 
-#include <memory>
-
 namespace filament::backend {
 
 class VulkanDescriptorSetLayoutCache {
@@ -41,21 +40,35 @@ public:
 
     void terminate() noexcept;
 
+    // Just a wrapper around getVkLayout()
     fvkmemory::resource_ptr<VulkanDescriptorSetLayout> createLayout(
             Handle<HwDescriptorSetLayout> handle, backend::DescriptorSetLayout&& info);
 
+    // This method is meant to be used with external samplers
+    VkDescriptorSetLayout getVkLayout(VulkanDescriptorSetLayout::Bitmask const& bitmasks,
+            fvkutils::SamplerBitmask externalSamplers,
+            utils::FixedCapacityVector<VkSampler> immutableSamplers = {});
+
 private:
     VkDevice mDevice;
     fvkmemory::ResourceManager* mResourceManager;
 
-    using BitmaskGroup = VulkanDescriptorSetLayout::Bitmask;
+    struct LayoutKey {
-    using BitmaskGroupHashFn = utils::hash::MurmurHashFn<BitmaskGroup>;
+        // this describes the layout using bitset.
-    struct BitmaskGroupEqual {
+        VulkanDescriptorSetLayout::Bitmask bitmask = {};
-        bool operator()(BitmaskGroup const& k1, BitmaskGroup const& k2) const { return k1 == k2; }
+        // number of immutable samplers can be arbitrary; so we hash them into 64-bit.
+        uint64_t immutableSamplerHash = 0;
+    };
+    static_assert(sizeof(LayoutKey) == 48);
+
+    using LayoutKeyHashFn = utils::hash::MurmurHashFn<LayoutKey>;
+    struct LayoutKeyEqual {
+        bool operator()(LayoutKey const& k1, LayoutKey const& k2) const {
+            return k1.bitmask == k2.bitmask && k1.immutableSamplerHash == k2.immutableSamplerHash;
+        }
     };
 
-    tsl::robin_map<BitmaskGroup, VkDescriptorSetLayout, BitmaskGroupHashFn, BitmaskGroupEqual>
+    tsl::robin_map<LayoutKey, VkDescriptorSetLayout, LayoutKeyHashFn, LayoutKeyEqual> mVkLayouts;
-            mVkLayouts;
 };
 
 } // namespace filament::backend

filament/backend/src/vulkan/VulkanDriver.cpp

@@ -30,7 +30,6 @@
 #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>
@@ -198,11 +197,9 @@ Dispatcher VulkanDriver::getDispatcher() const noexcept {
 }
 
 VulkanDriver::VulkanDriver(VulkanPlatform* platform, VulkanContext const& context,
-        Platform::DriverConfig const& driverConfig) noexcept
+        Platform::DriverConfig const& driverConfig)
     : mPlatform(platform),
-      mResourceManager(
+      mResourceManager(driverConfig.handleArenaSize, driverConfig.disableHandleUseAfterFreeCheck,
-              driverConfig.handleArenaSize,
-              driverConfig.disableHandleUseAfterFreeCheck,
               driverConfig.disableHeapHandleTags),
       mAllocator(createAllocator(mPlatform->getInstance(), mPlatform->getPhysicalDevice(),
               mPlatform->getDevice())),
@@ -221,6 +218,8 @@ 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) {
 
@@ -251,7 +250,7 @@ VulkanDriver::~VulkanDriver() noexcept = default;
 
 UTILS_NOINLINE
 Driver* VulkanDriver::create(VulkanPlatform* platform, VulkanContext const& context,
-         Platform::DriverConfig const& driverConfig) noexcept {
+         Platform::DriverConfig const& driverConfig) {
 #if 0
     // this is useful for development, but too verbose even for debug builds
     // For reference on a 64-bits machine in Release mode:
@@ -313,7 +312,7 @@ void VulkanDriver::terminate() {
 
     mCurrentSwapChain = {};
     mDefaultRenderTarget = {};
-    mBoundPipeline = {};
+    mPipelineState = {};
 
     mQueryManager.terminate();
 
@@ -325,9 +324,13 @@ void VulkanDriver::terminate() {
 
     mCommands.terminate();
 
+    // Must come before samplerCache, ycbcrConversionCache, descriptorSetCache,
+    // descriptorSetLayoutCache
+    mExternalImageManager.terminate();
+
     mStagePool.terminate();
     mPipelineCache.terminate();
-    mFramebufferCache.reset();
+    mFramebufferCache.terminate();
     mSamplerCache.terminate();
     mDescriptorSetLayoutCache.terminate();
     mDescriptorSetCache.terminate();
@@ -381,6 +384,10 @@ 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,
@@ -421,12 +428,17 @@ void VulkanDriver::updateDescriptorSetTexture(
     auto set = resource_ptr<VulkanDescriptorSet>::cast(&mResourceManager, dsh);
     auto texture = resource_ptr<VulkanTexture>::cast(&mResourceManager, th);
 
-    // TODO: YcbcrConversion?
+    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);
+    }
 }
 
 void VulkanDriver::flush(int) {
@@ -446,6 +458,7 @@ 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);
@@ -456,12 +469,14 @@ 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();
@@ -471,12 +486,14 @@ 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);
@@ -487,12 +504,14 @@ 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);
@@ -503,12 +522,14 @@ 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();
@@ -518,6 +539,7 @@ void VulkanDriver::destroyBufferObject(Handle<HwBufferObject> boh) {
     if (!boh) {
         return;
     }
+    FVK_SYSTRACE_SCOPE();
     auto bo = resource_ptr<VulkanBufferObject>::cast(&mResourceManager, boh);
     bo.dec();
 }
@@ -563,41 +585,48 @@ 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 const& metadata = mPlatform->getExternalImageMetadata(externalImage);
+    auto metadata = mPlatform->extractExternalImageMetadata(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);
 
-    VkMemoryPropertyFlags const requiredMemoryFlags = any(usage & TextureUsage::UPLOADABLE)
+    // We do not check the format since AHB could return both a known format and an external format.
-                                                              ? VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
+    // In which case, we choose one or the other, but this choice is not known to the client.
-                                                              : VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;
+    // Therefore the following lines are commented out.
-    uint32_t const memoryTypeIndex =
+    // assert_invariant(format == metadata.filamentFormat);
-            mContext.selectMemoryType(metadata.memoryTypeBits, requiredMemoryFlags);
+    // assert_invariant(fvkutils::getVkFormat(format) == metadata.format);
-    FILAMENT_CHECK_POSTCONDITION(memoryTypeIndex != VK_MAX_MEMORY_TYPES)
-            << "failed to find a valid memory type for external image memory.";
 
-    VkImage vkimg;
+    auto imgData = mPlatform->createVkImageFromExternal(externalImage);
-    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, vkimg, deviceMemory,
+            mPlatform->getDevice(), mAllocator, &mResourceManager, &mCommands, vkimage, memory,
-            metadata.format, VK_NULL_HANDLE, metadata.samples, metadata.width, metadata.height,
+            vkformat, conversion, metadata.samples, metadata.width, metadata.height,
-            metadata.layerCount, usage, mStagePool);
+            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);
+    }
 
     texture.inc();
 }
@@ -630,6 +659,8 @@ 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) {
@@ -746,6 +777,7 @@ 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.
@@ -787,6 +819,7 @@ 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();
 }
@@ -798,6 +831,10 @@ 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 {
@@ -922,6 +959,10 @@ 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) {
@@ -1482,7 +1523,6 @@ void VulkanDriver::endRenderPass(int) {
     // pipeline barrier between framebuffer writes and shader reads.
     rt->emitBarriersEndRenderPass(*mCurrentRenderPass.commandBuffer);
 
-    mRenderPassFboInfo = {};
     mCurrentRenderPass.renderTarget = {};
     mCurrentRenderPass.renderPass = VK_NULL_HANDLE;
 
@@ -1523,7 +1563,7 @@ void VulkanDriver::makeCurrent(Handle<HwSwapChain> drawSch, Handle<HwSwapChain>
     swapChain->acquire(resized);
 
     if (resized) {
-        mFramebufferCache.reset();
+        mFramebufferCache.resetFramebuffers();
     }
 
     if (UTILS_LIKELY(mDefaultRenderTarget)) {
@@ -1542,10 +1582,10 @@ void VulkanDriver::commit(Handle<HwSwapChain> sch) {
 
 void VulkanDriver::setPushConstant(backend::ShaderStage stage, uint8_t index,
         backend::PushConstantVariant value) {
-    assert_invariant(mBoundPipeline.program && "Expect a program when writing to push constants");
+    assert_invariant(mPipelineState.program && "Expect a program when writing to push constants");
     assert_invariant(mCurrentRenderPass.commandBuffer && "Should be called within a renderpass");
-    mBoundPipeline.program->writePushConstant(mCurrentRenderPass.commandBuffer->buffer(),
+    mPipelineState.program->writePushConstant(mCurrentRenderPass.commandBuffer->buffer(),
-            mBoundPipeline.pipelineLayout, stage, index, value);
+            mPipelineState.pipelineLayout, stage, index, value);
 }
 
 void VulkanDriver::insertEventMarker(char const* string) {
@@ -1724,16 +1764,69 @@ 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, programHandle);
+    auto program = resource_ptr<VulkanProgram>::cast(&mResourceManager, pipelineState.program);
     commands->acquire(program);
 
     // Update the VK raster state.
@@ -1775,28 +1868,11 @@ void VulkanDriver::bindPipeline(PipelineState const& pipelineState) {
     mPipelineCache.bindPrimitiveTopology(topology);
     mPipelineCache.bindVertexArray(attribDesc, bufferDesc, vbi->getAttributeCount());
 
-    auto& setLayouts = pipelineState.pipelineLayout.setLayout;
+    // Note that we cannot reinit mPipeline because the .bindInDraw metadata that needs to carry
-    VulkanDescriptorSetLayout::DescriptorSetLayoutArray layoutList;
+    // over even on bind.
-    uint8_t layoutCount = 0;
+    mPipelineState.program = program;
-    std::transform(setLayouts.begin(), setLayouts.end(), layoutList.begin(),
+    mPipelineState.pipelineLayout = pipelineLayout;
-            [&](Handle<HwDescriptorSetLayout> handle) -> VkDescriptorSetLayout {
+    mPipelineState.descriptorSetMask = descriptorSetMask;
-                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);
@@ -1841,15 +1917,41 @@ 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;
 
-    mDescriptorSetCache.commit(mCurrentRenderPass.commandBuffer,
+    fvkutils::DescriptorSetMask setsWithExternalSamplers = {};
-            mBoundPipeline.pipelineLayout,
+    if (doBindInDraw) {
-            mBoundPipeline.descriptorSetMask);
+        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);
 
     // Finally, make the actual draw call. TODO: support subranges
-    const uint32_t firstIndex = indexOffset;
+    uint32_t const firstIndex = indexOffset;
-    const int32_t vertexOffset = 0;
+    constexpr int32_t vertexOffset = 0;
-    const uint32_t firstInstId = 0;
+    constexpr uint32_t firstInstId = 0;
 
     vkCmdDrawIndexed(cmdbuffer, indexCount, instanceCount, firstIndex, vertexOffset, firstInstId);
 }

filament/backend/src/vulkan/VulkanDriver.h

@@ -30,6 +30,7 @@
 #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"
@@ -54,7 +55,7 @@ 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) noexcept;
+            Platform::DriverConfig const& driverConfig);
 
 #if FVK_ENABLED(FVK_DEBUG_DEBUG_UTILS)
     // Encapsulates the VK_EXT_debug_utils extension.  In particular, we use
@@ -89,8 +90,8 @@ private:
     void debugCommandBegin(CommandStream* cmds, bool synchronous,
             const char* methodName) noexcept override;
 
-    inline VulkanDriver(VulkanPlatform* platform, VulkanContext const& context,
+    VulkanDriver(VulkanPlatform* platform, VulkanContext const& context,
-            Platform::DriverConfig const& driverConfig) noexcept;
+            Platform::DriverConfig const& driverConfig);
 
     ~VulkanDriver() noexcept override;
 
@@ -119,6 +120,8 @@ private:
 
 private:
     void collectGarbage();
+    void bindPipelineImpl(PipelineState const& pipelineState, VkPipelineLayout pipelineLayout,
+            fvkutils::DescriptorSetMask descriptorSetMask);
 
     VulkanPlatform* mPlatform = nullptr;
     fvkmemory::ResourceManager mResourceManager;
@@ -143,21 +146,39 @@ private:
     VulkanDescriptorSetLayoutCache mDescriptorSetLayoutCache;
     VulkanDescriptorSetCache mDescriptorSetCache;
     VulkanQueryManager mQueryManager;
+    VulkanExternalImageManager mExternalImageManager;
 
     // This is necessary for us to write to push constants after binding a pipeline.
-    struct {
+    using DescriptorSetLayoutHandleList = std::array<resource_ptr<VulkanDescriptorSetLayout>,
-        resource_ptr<VulkanProgram> program;
+            VulkanDescriptorSetLayout::UNIQUE_DESCRIPTOR_SET_COUNT>;
-        VkPipelineLayout pipelineLayout;
+
-        fvkutils::DescriptorSetMask descriptorSetMask;
+    struct BindInDrawBundle {
-    } mBoundPipeline = {};
+        PipelineState pipelineState = {};
+        DescriptorSetLayoutHandleList dsLayoutHandles = {};
+        fvkutils::DescriptorSetMask descriptorSetMask = {};
+        resource_ptr<VulkanProgram> program = {};
+    };
 
-    // We need to store information about a render pass to enable better barriers at the end of a
-    // renderpass.
     struct {
-        using AttachmentArray =
+        // For push constant
-                fvkutils::StaticVector<VulkanAttachment, MAX_RENDERTARGET_ATTACHMENT_TEXTURES>;
+        resource_ptr<VulkanProgram> program = {};
-        AttachmentArray attachments;
+        // For push commiting dynamic ubos in draw()
-    } mRenderPassFboInfo = {};
+        VkPipelineLayout pipelineLayout = VK_NULL_HANDLE;
+        fvkutils::DescriptorSetMask descriptorSetMask = {};
+
+        std::pair<bool, BindInDrawBundle> bindInDraw = {false, {}};
+    } mPipelineState = {};
+
+    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;
 
     bool const mIsSRGBSwapChainSupported;
     backend::StereoscopicType const mStereoscopicType;

filament/backend/src/vulkan/VulkanExternalImageManager.cpp

@@ -0,0 +1,294 @@
+/*
+ * 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

@@ -0,0 +1,121 @@
+/*
+ * 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

@@ -330,9 +330,17 @@ 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 "
+    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) << ", "
-        << "depth = " << (hasDepth ? 1 : 0) << ", "
+             << "needsResolveMask = " << int(config.needsResolveMask) << ", "
+             << "usesLazilyAllocatedMemory = " << int(config.usesLazilyAllocatedMemory) << ", "
+             << "viewCount = " << int(config.viewCount) << ", "
              << "colorAttachmentCount[0] = " << subpasses[0].colorAttachmentCount
              << utils::io::endl;
 #endif
@@ -340,15 +348,21 @@ VkRenderPass VulkanFboCache::getRenderPass(RenderPassKey const& config) noexcept
     return renderPass;
 }
 
-void VulkanFboCache::reset() noexcept {
+void VulkanFboCache::resetFramebuffers() noexcept {
-    for (auto pair : mFramebufferCache) {
+    for (const auto& pair: mFramebufferCache) {
         mRenderPassRefCount[pair.first.renderPass]--;
         vkDestroyFramebuffer(mDevice, pair.second.handle, VKALLOC);
     }
     mFramebufferCache.clear();
-    for (auto pair : mRenderPassCache) {
+}
+
+void VulkanFboCache::terminate() noexcept {
+    resetFramebuffers();
+
+    for (const auto& pair: mRenderPassCache) {
         vkDestroyRenderPass(mDevice, pair.second.handle, VKALLOC);
     }
+    mRenderPassRefCount.clear();
     mRenderPassCache.clear();
 }
 

filament/backend/src/vulkan/VulkanFboCache.h

@@ -106,8 +106,11 @@ 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 reset() noexcept;
+    void terminate() noexcept;
 
 private:
     VkDevice mDevice;

filament/backend/src/vulkan/VulkanHandles.cpp

@@ -30,6 +30,7 @@
 
 #include <backend/platforms/VulkanPlatform.h>
 
+#include <utils/compiler.h> // UTILS_FALLTHROUGH
 #include <utils/Panic.h>    // ASSERT_POSTCONDITION
 
 using namespace bluevk;
@@ -89,8 +90,9 @@ BitmaskGroup fromBackendLayout(DescriptorSetLayout const& layout) {
                 }
                 break;
             }
-            // TODO: properly handle external sampler
             case DescriptorType::SAMPLER_EXTERNAL:
+                fromStageFlags(binding.stageFlags, binding.binding, mask.externalSampler);
+                UTILS_FALLTHROUGH;
             case DescriptorType::SAMPLER: {
                 fromStageFlags(binding.stageFlags, binding.binding, mask.sampler);
                 break;
@@ -147,11 +149,18 @@ void VulkanDescriptorSet::acquire(fvkmemory::resource_ptr<VulkanBufferObject> ob
     mResources.push_back(obj);
 }
 
-VulkanDescriptorSetLayout::VulkanDescriptorSetLayout(DescriptorSetLayout const& layout)
+VulkanDescriptorSetLayout::VulkanDescriptorSetLayout(DescriptorSetLayout&& layout,
+        VkDescriptorSetLayout vkLayout)
     : bitmask(fromBackendLayout(layout)),
-      count(Count::fromLayoutBitmask(bitmask)) {}
+      count(Count::fromLayoutBitmask(bitmask)),
+      mVkLayout(vkLayout) {}
 
-PushConstantDescription::PushConstantDescription(backend::Program const& program) noexcept {
+VulkanDescriptorSetLayout::Bitmask VulkanDescriptorSetLayout::Bitmask::fromLayoutDescription(
+        DescriptorSetLayout const& layout) {
+    return fromBackendLayout(layout);
+}
+
+PushConstantDescription::PushConstantDescription(backend::Program const& program) {
     mRangeCount = 0;
     for (auto stage : { ShaderStage::VERTEX, ShaderStage::FRAGMENT, ShaderStage::COMPUTE }) {
         auto const& constants = program.getPushConstants(stage);

filament/backend/src/vulkan/VulkanHandles.h

@@ -66,18 +66,23 @@ struct VulkanDescriptorSetLayout : public HwDescriptorSetLayout, fvkmemory::Reso
 
     // The bitmask representation of a set layout.
     struct Bitmask {
-        // TODO: better utiltize the space below and use bitset instead.
         fvkutils::UniformBufferBitmask ubo;         // 8 bytes
         fvkutils::UniformBufferBitmask dynamicUbo;  // 8 bytes
         fvkutils::SamplerBitmask sampler;           // 8 bytes
         fvkutils::InputAttachmentBitmask inputAttachment; // 8 bytes
 
+        // This is a subset of the sampler field.
+        fvkutils::SamplerBitmask externalSampler; // 8 bytes
+
         bool operator==(Bitmask const& right) const {
             return ubo == right.ubo && dynamicUbo == right.dynamicUbo && sampler == right.sampler &&
-                   inputAttachment == right.inputAttachment;
+                   inputAttachment == right.inputAttachment &&
+                   externalSampler == right.externalSampler;
         }
+
+        static Bitmask fromLayoutDescription(DescriptorSetLayout const& layout);
     };
-    static_assert(sizeof(Bitmask) == 32);
+    static_assert(sizeof(Bitmask) == 40);
 
     // This is a convenience struct to quickly check layout compatibility in terms of descriptor set
     // pools.
@@ -117,18 +122,32 @@ struct VulkanDescriptorSetLayout : public HwDescriptorSetLayout, fvkmemory::Reso
         }
     };
 
-    VulkanDescriptorSetLayout(DescriptorSetLayout const& layout);
+    VulkanDescriptorSetLayout(DescriptorSetLayout&& layout, VkDescriptorSetLayout vkLayout);
 
+    // Note that we don't destroy the vklayout. This is done by the layout cache.
     ~VulkanDescriptorSetLayout() = default;
 
-    VkDescriptorSetLayout getVkLayout() const { return mVkLayout; }
+    VkDescriptorSetLayout getVkLayout() const noexcept { return mVkLayout; }
-    void setVkLayout(VkDescriptorSetLayout vklayout) { mVkLayout = vklayout; }
+
+    VkDescriptorSetLayout getExternalSamplerVkLayout() const noexcept {
+        return mExternalSamplerVkLayout;
+    }
+
+    void setExternalSamplerVkLayout(VkDescriptorSetLayout vklayout) noexcept {
+        mExternalSamplerVkLayout = vklayout;
+    }
+
+    bool hasExternalSamplers() const noexcept { return bitmask.externalSampler.count() > 0; }
 
     Bitmask const bitmask;
     Count const count;
 
 private:
-    VkDescriptorSetLayout mVkLayout = VK_NULL_HANDLE;
+    // 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;
 };
 
 struct VulkanDescriptorSet : public HwDescriptorSet, fvkmemory::Resource {
@@ -137,19 +156,39 @@ public:
     // can use to repackage the vk handle.
     using OnRecycle = std::function<void(VulkanDescriptorSet*)>;
 
-    VulkanDescriptorSet(VkDescriptorSet rawSet,
+    VulkanDescriptorSet(
             fvkutils::UniformBufferBitmask const& dynamicUboMask,
             uint8_t uniqueDynamicUboCount,
-            OnRecycle&& onRecycleFn)
+            OnRecycle&& onRecycleFn, VkDescriptorSet vkSet)
-        : vkSet(rawSet),
+        : dynamicUboMask(dynamicUboMask),
-          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 {
+        return mVkSet;
+    }
+
+    VkDescriptorSet getExternalSamplerVkSet() const noexcept {
+        return mExternalSamplerVkSet;
+    }
+
+    void setExternalSamplerVkSet(VkDescriptorSet vkset, OnRecycle onRecycle) {
+        mExternalSamplerVkSet = vkset;
+        if (mOnRecycleExternalSamplerFn) {
+            mOnRecycleExternalSamplerFn(this);
+        }
+        mOnRecycleExternalSamplerFn = onRecycle;
     }
 
     void setOffsets(backend::DescriptorSetOffsetArray&& offsets) noexcept {
@@ -163,21 +202,24 @@ public:
     void acquire(fvkmemory::resource_ptr<VulkanTexture> texture);
     void acquire(fvkmemory::resource_ptr<VulkanBufferObject> buffer);
 
-    VkDescriptorSet const vkSet;
     fvkutils::UniformBufferBitmask const dynamicUboMask;
     uint8_t const uniqueDynamicUboCount;
 
 private:
+    VkDescriptorSet const mVkSet;
+    VkDescriptorSet mExternalSamplerVkSet = 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) noexcept;
+    explicit PushConstantDescription(backend::Program const& program);
 
     VkPushConstantRange const* getVkRanges() const noexcept { return mRanges; }
     uint32_t getVkRangeCount() const noexcept { return mRangeCount; }

filament/backend/src/vulkan/VulkanPipelineCache.cpp

@@ -35,7 +35,12 @@ using namespace bluevk;
 namespace filament::backend {
 
 VulkanPipelineCache::VulkanPipelineCache(VkDevice device)
-        : mDevice(device) {}
+    : mDevice(device) {
+    VkPipelineCacheCreateInfo createInfo = {
+        .sType = VK_STRUCTURE_TYPE_PIPELINE_CACHE_CREATE_INFO,
+    };
+    bluevk::vkCreatePipelineCache(mDevice, &createInfo, VKALLOC, &mPipelineCache);
+}
 
 void VulkanPipelineCache::bindLayout(VkPipelineLayout layout) noexcept {
     mPipelineRequirements.layout = layout;
@@ -61,9 +66,13 @@ 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);
     }
+}
 
 VulkanPipelineCache::PipelineCacheEntry* VulkanPipelineCache::createPipeline() noexcept {
     assert_invariant(mPipelineRequirements.shaders[0] && "Vertex shader is not bound.");
@@ -215,7 +224,7 @@ VulkanPipelineCache::PipelineCacheEntry* VulkanPipelineCache::createPipeline() n
     PipelineCacheEntry cacheEntry = {
         .lastUsed = mCurrentTime,
     };
-    VkResult error = vkCreateGraphicsPipelines(mDevice, VK_NULL_HANDLE, 1, &pipelineCreateInfo,
+    VkResult error = vkCreateGraphicsPipelines(mDevice, mPipelineCache, 1, &pipelineCreateInfo,
             VKALLOC, &cacheEntry.handle);
     assert_invariant(error == VK_SUCCESS);
     if (error != VK_SUCCESS) {
@@ -271,6 +280,8 @@ void VulkanPipelineCache::terminate() noexcept {
     }
     mPipelines.clear();
     mBoundPipeline = {};
+
+    vkDestroyPipelineCache(mDevice, mPipelineCache, VKALLOC);
 }
 
 void VulkanPipelineCache::gc() noexcept {

filament/backend/src/vulkan/VulkanPipelineCache.h

@@ -198,6 +198,10 @@ 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() noexcept {
+void VulkanReadPixels::runUntilComplete() {
     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() noexcept;
+    void runUntilComplete();
 
 private:
     VkDevice mDevice = VK_NULL_HANDLE;

filament/backend/src/vulkan/VulkanSamplerCache.cpp

@@ -28,13 +28,20 @@ namespace filament::backend {
 VulkanSamplerCache::VulkanSamplerCache(VkDevice device)
     : mDevice(device) {}
 
-VkSampler VulkanSamplerCache::getSampler(Params params) noexcept {
+VkSampler VulkanSamplerCache::getSampler(Params params) {
     auto iter = mCache.find(params);
     if (UTILS_LIKELY(iter != mCache.end())) {
         return iter->second;
     }
+    VkSamplerYcbcrConversionInfo ycbcrConversion = {
+        .sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_INFO,
+        .conversion = params.conversion,
+    };
+
     auto const& samplerParams = params.sampler;
-    VkSamplerCreateInfo samplerInfo{ .sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO,
+    VkSamplerCreateInfo samplerInfo{
+        .sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO,
+        .pNext = params.conversion != VK_NULL_HANDLE ? &ycbcrConversion : VK_NULL_HANDLE,
         .magFilter = fvkutils::getFilter(samplerParams.filterMag),
         .minFilter = fvkutils::getFilter(samplerParams.filterMin),
         .mipmapMode = fvkutils::getMipmapMode(samplerParams.filterMin),
@@ -48,7 +55,8 @@ VkSampler VulkanSamplerCache::getSampler(Params params) noexcept {
         .minLod = 0.0f,
         .maxLod = fvkutils::getMaxLod(samplerParams.filterMin),
         .borderColor = VK_BORDER_COLOR_INT_OPAQUE_BLACK,
-        .unnormalizedCoordinates = VK_FALSE };
+        .unnormalizedCoordinates = VK_FALSE,
+    };
     VkSampler sampler;
     VkResult result = vkCreateSampler(mDevice, &samplerInfo, VKALLOC, &sampler);
     FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS) << "Unable to create sampler."

filament/backend/src/vulkan/VulkanSamplerCache.h

@@ -38,7 +38,7 @@ public:
     static_assert(sizeof(Params) == 16);
 
     explicit VulkanSamplerCache(VkDevice device);
-    VkSampler getSampler(Params params) noexcept;
+    VkSampler getSampler(Params params);
     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 = FVK_MAX_COMMAND_BUFFERS;
+static constexpr uint32_t TIME_BEFORE_EVICTION = 3;
 
 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.insert(stage);
+        mUsedStages.push_back(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.insert(stage);
+    mUsedStages.push_back(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.insert(image);
+            mUsedImages.push_back(image);
             return image;
         }
     }
@@ -89,7 +89,7 @@ VulkanStageImage const* VulkanStagePool::acquireImage(PixelDataFormat format, Pi
         .lastAccessed = mCurrentFrame,
     });
 
-    mUsedImages.insert(image);
+    mUsedImages.push_back(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.insert(stage);
+            mUsedStages.push_back(stage);
         }
     }
 
@@ -185,7 +185,7 @@ void VulkanStagePool::gc() noexcept {
             image->lastAccessed = mCurrentFrame;
             mFreeImages.insert(image);
         } else {
-            mUsedImages.insert(image);
+            mUsedImages.push_back(image);
         }
     }
     FVK_SYSTRACE_END();

filament/backend/src/vulkan/VulkanStagePool.h

@@ -22,6 +22,7 @@
 
 #include <map>
 #include <unordered_set>
+#include <vector>
 
 namespace filament::backend {
 
@@ -73,10 +74,10 @@ 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::unordered_set<VulkanStage const*> mUsedStages;
+    std::vector<VulkanStage const*> mUsedStages;
 
     std::unordered_set<VulkanStageImage const*> mFreeImages;
-    std::unordered_set<VulkanStageImage const*> mUsedImages;
+    std::vector<VulkanStageImage const*> mUsedImages;
 
     // Store the current "time" (really just a frame count) and LRU eviction parameters.
     uint64_t mCurrentFrame = 0;

filament/backend/src/vulkan/VulkanSwapChain.cpp

@@ -108,11 +108,6 @@ void VulkanSwapChain::present() {
 
     mCommands->flush();
 
-    // call the image ready wait function
-    if (mExplicitImageReadyWait != nullptr) {
-        mExplicitImageReadyWait(swapChain);
-    }
-
     // We only present if it is not headless. No-op for headless.
     if (!mHeadless) {
         VkSemaphore const finishedDrawing = mCommands->acquireFinishedSignal();
@@ -146,7 +141,6 @@ void VulkanSwapChain::acquire(bool& resized) {
     VulkanPlatform::ImageSyncData imageSyncData;
     VkResult const result = mPlatform->acquire(swapChain, &imageSyncData);
     mCurrentSwapIndex = imageSyncData.imageIndex;
-    mExplicitImageReadyWait = imageSyncData.explicitImageReadyWait;
     FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS || result == VK_SUBOPTIMAL_KHR)
             << "Cannot acquire in swapchain. error=" << static_cast<int32_t>(result);
     if (imageSyncData.imageReadySemaphore != VK_NULL_HANDLE) {

filament/backend/src/vulkan/VulkanSwapChain.h

@@ -49,7 +49,9 @@ struct VulkanSwapChain : public HwSwapChain, fvkmemory::Resource {
 
     void present();
 
-    void acquire(bool& reized);
+    // Acquire a new image from the swapchain. If the image is not available it would wait until it
+    // is.
+    void acquire(bool& resized);
 
     fvkmemory::resource_ptr<VulkanTexture> getCurrentColor() const noexcept {
         uint32_t const imageIndex = mCurrentSwapIndex;
@@ -99,7 +101,6 @@ private:
     VkExtent2D mExtent;
     uint32_t mLayerCount;
     uint32_t mCurrentSwapIndex;
-    std::function<void(Platform::SwapChain* handle)> mExplicitImageReadyWait = nullptr;
     bool mAcquired;
     bool mIsFirstRenderPass;
 };

filament/backend/src/vulkan/VulkanTexture.cpp

@@ -223,8 +223,7 @@ 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, bool isExternalFormat, VkImageUsageFlags usage,
+        VkSamplerYcbcrConversion ycbcrConversion, VkImageUsageFlags usage, bool isProtected)
-        bool isProtected)
     : mStagePool(stagePool),
       mCommands(commands),
       mAllocator(allocator),
@@ -234,17 +233,17 @@ VulkanTextureState::VulkanTextureState(VulkanStagePool& stagePool, VulkanCommand
       mVkFormat(format),
       mViewType(viewType),
       mFullViewRange{ fvkutils::getImageAspect(format), 0, levels, 0, layerCount },
-      mYcbcr{ ycbcrConversion, isExternalFormat },
+      mYcbcr{ ycbcrConversion },
       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 {
@@ -272,7 +271,7 @@ VkImageView VulkanTextureState::getImageView(VkImageSubresourceRange range, VkIm
         .flags = 0,
         .image = mTextureImage,
         .viewType = viewType,
-        .format = mYcbcr.isExternalFormat ? VK_FORMAT_UNDEFINED : mVkFormat,
+        .format = mYcbcr.conversion != VK_NULL_HANDLE ? VK_FORMAT_UNDEFINED : mVkFormat,
         .components = swizzle,
         .subresourceRange = range,
     };
@@ -294,7 +293,6 @@ 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;
@@ -424,8 +422,7 @@ 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 */, false /*isExternalFormat*/, imageInfo.usage,
+            VK_NULL_HANDLE /* ycbcrConversion */, imageInfo.usage, isProtected);
-            isProtected);
 
     // Spec out the "primary" VkImageView that shaders use to sample from the image.
     mPrimaryViewRange = mState->mFullViewRange;
@@ -764,15 +761,13 @@ void VulkanTexture::setLayout(VkImageSubresourceRange const& range, VulkanLayout
     }
 }
 
-void VulkanTexture::setYcbcrConversion(VkSamplerYcbcrConversion conversion, bool isExternalFormat) {
+void VulkanTexture::setYcbcrConversion(VkSamplerYcbcrConversion conversion) {
     // 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

@@ -40,8 +40,7 @@ struct VulkanTextureState : public fvkmemory::Resource {
     VulkanTextureState(VulkanStagePool& stagePool, VulkanCommands* commands, VmaAllocator allocator,
             VkDevice device, VkImage image, VkDeviceMemory deviceMemory, VkFormat format,
             VkImageViewType viewType, uint8_t levels, uint8_t layerCount,
-            VkSamplerYcbcrConversion ycbcrConversion, bool isExternalFormat,
+            VkSamplerYcbcrConversion ycbcrConversion, VkImageUsageFlags usage, bool isProtected);
-            VkImageUsageFlags usage, bool isProtected);
 
     ~VulkanTextureState();
 
@@ -86,10 +85,9 @@ private:
     // conversion matrix per-frame.
     struct Ycbcr {
         VkSamplerYcbcrConversion conversion;
-        bool isExternalFormat;
 
         bool operator==(Ycbcr const& other) const {
-            return conversion == other.conversion && isExternalFormat == other.isExternalFormat;
+            return conversion == other.conversion;
         }
 
         bool operator!=(Ycbcr const& other) const {
@@ -209,7 +207,7 @@ 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, bool isExternal);
+    void setYcbcrConversion(VkSamplerYcbcrConversion conversion);
 
 #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) noexcept {
+        VulkanYcbcrConversionCache::Params params) {
     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 = VK_FORMAT_UNDEFINED,
+        .format = params.format,
         .ycbcrModel = fvkutils::getYcbcrModelConversion(chroma.ycbcrModel),
         .ycbcrRange = fvkutils::getYcbcrRange(chroma.ycbcrRange),
         .components = fvkutils::getSwizzleMap(swizzleArray),
@@ -52,6 +52,7 @@ VkSamplerYcbcrConversion VulkanYcbcrConversionCache::getConversion(
         .chromaFilter = fvkutils::getFilter(chroma.chromaFilter),
     };
 
+    // We could put this in the platform class, but that seems like a bit of an overkill
 #if defined(__ANDROID__)
     VkExternalFormatANDROID externalFormat = {
         .sType = VK_STRUCTURE_TYPE_EXTERNAL_FORMAT_ANDROID,
@@ -59,6 +60,7 @@ VkSamplerYcbcrConversion VulkanYcbcrConversionCache::getConversion(
     };
     if (params.externalFormat) {
         conversionInfo.pNext = &externalFormat;
+        conversionInfo.format = VK_FORMAT_UNDEFINED;
     }
 #endif
 

filament/backend/src/vulkan/VulkanYcbcrConversionCache.h

@@ -30,14 +30,14 @@ namespace filament::backend {
 class VulkanYcbcrConversionCache {
 public:
     struct Params {
-        SamplerYcbcrConversion conversion = {};
+        SamplerYcbcrConversion conversion = {}; // 4
-        uint32_t padding = 0;
+        VkFormat format;                        // 4
-        uint64_t externalFormat = 0;
+        uint64_t externalFormat = 0;            // 8
     };
     static_assert(sizeof(Params) == 16);
 
     explicit VulkanYcbcrConversionCache(VkDevice device);
-    VkSamplerYcbcrConversion getConversion(Params params) noexcept;
+    VkSamplerYcbcrConversion getConversion(Params params);
     void terminate() noexcept;
 
 private:
@@ -47,7 +47,8 @@ private:
         bool operator()(Params lhs, Params rhs) const noexcept {
             SamplerYcbcrConversion::EqualTo equal;
             return equal(lhs.conversion, rhs.conversion) &&
-                   lhs.externalFormat == rhs.externalFormat;
+                   lhs.externalFormat == rhs.externalFormat &&
+                   lhs.format == rhs.format;
         }
     };
     using ConversionHashFn = utils::hash::MurmurHashFn<Params>;

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

@@ -31,6 +31,8 @@ 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);
@@ -49,6 +51,7 @@ 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

@@ -132,6 +132,10 @@ 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

@@ -211,6 +211,9 @@ ExtensionSet getDeviceExtensions(VkPhysicalDevice device) {
         VK_KHR_DEDICATED_ALLOCATION_EXTENSION_NAME,
         VK_KHR_SAMPLER_YCBCR_CONVERSION_EXTENSION_NAME,
         VK_ANDROID_EXTERNAL_MEMORY_ANDROID_HARDWARE_BUFFER_EXTENSION_NAME,
+        VK_EXT_QUEUE_FAMILY_FOREIGN_EXTENSION_NAME,
+        // 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__)
@@ -326,7 +329,9 @@ VkInstance createInstance(ExtensionSet const& requiredExts) {
 }
 
 VkDevice createLogicalDevice(VkPhysicalDevice physicalDevice,
-        VkPhysicalDeviceFeatures2 const& features, uint32_t graphicsQueueFamilyIndex,
+        VkPhysicalDeviceFeatures2 const& features,
+        VkPhysicalDeviceVulkan11Features const& vk11Features,
+        uint32_t graphicsQueueFamilyIndex,
         uint32_t protectedGraphicsQueueFamilyIndex, ExtensionSet const& deviceExtensions,
         bool requestImageView2DOn3DImage) {
     VkDevice device;
@@ -359,14 +364,28 @@ VkDevice createLogicalDevice(VkPhysicalDevice physicalDevice,
 
     // We could simply enable all supported features, but since that may have performance
     // consequences let's just enable the features we need.
-    VkPhysicalDeviceFeatures enabledFeatures{
+    VkPhysicalDeviceFeatures enabledFeatures = {
         .depthClamp = features.features.depthClamp,
         .samplerAnisotropy = features.features.samplerAnisotropy,
         .textureCompressionETC2 = features.features.textureCompressionETC2,
         .textureCompressionBC = features.features.textureCompressionBC,
         .shaderClipDistance = features.features.shaderClipDistance,
     };
-    deviceCreateInfo.pEnabledFeatures = &enabledFeatures;
+
+    VkPhysicalDeviceFeatures2 enabledFeatures2 = {
+        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2,
+        .features = enabledFeatures,
+    };
+    chainStruct(&deviceCreateInfo, &enabledFeatures2);
+
+    VkPhysicalDeviceVulkan11Features enabledVk11Features = {
+        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_1_FEATURES,
+        .multiview = vk11Features.multiview,
+#if defined(__ANDROID__)
+        .samplerYcbcrConversion = vk11Features.samplerYcbcrConversion,
+#endif
+    };
+    chainStruct(&deviceCreateInfo, &enabledVk11Features);
 
     deviceCreateInfo.enabledExtensionCount = (uint32_t) requestExtensions.size();
     deviceCreateInfo.ppEnabledExtensionNames = requestExtensions.data();
@@ -383,7 +402,7 @@ VkDevice createLogicalDevice(VkPhysicalDevice physicalDevice,
 
     VkPhysicalDeviceMultiviewFeaturesKHR multiview = {
         .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MULTIVIEW_FEATURES_KHR,
-        .multiview = VK_TRUE,
+        .multiview = vk11Features.multiview,
         .multiviewGeometryShader = VK_FALSE,
         .multiviewTessellationShader = VK_FALSE,
     };
@@ -734,6 +753,7 @@ Driver* VulkanPlatform::createDriver(void* sharedContext,
         .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROTECTED_MEMORY_PROPERTIES,
     };
     chainStruct(&context.mPhysicalDeviceFeatures, &queryProtectedMemoryFeatures);
+    chainStruct(&context.mPhysicalDeviceFeatures, &context.mPhysicalDeviceVk11Features);
     chainStruct(&context.mPhysicalDeviceProperties, &protectedMemoryProperties);
 
     // Initialize the following fields: physicalDeviceProperties, memoryProperties,
@@ -795,8 +815,8 @@ Driver* VulkanPlatform::createDriver(void* sharedContext,
     }
 
     if (mImpl->mDevice == VK_NULL_HANDLE) {
-        mImpl->mDevice =
+        mImpl->mDevice = createLogicalDevice(mImpl->mPhysicalDevice,
-                createLogicalDevice(mImpl->mPhysicalDevice, context.mPhysicalDeviceFeatures,
+                context.mPhysicalDeviceFeatures, context.mPhysicalDeviceVk11Features,
                 mImpl->mGraphicsQueueFamilyIndex, mImpl->mProtectedGraphicsQueueFamilyIndex,
                 deviceExts, requestPortabilitySubsetImageView2DOn3DImage);
     }
@@ -826,12 +846,10 @@ Driver* VulkanPlatform::createDriver(void* sharedContext,
     if (!mImpl->mSharedContext) {
         context.mDebugUtilsSupported = setContains(instExts, VK_EXT_DEBUG_UTILS_EXTENSION_NAME);
         context.mDebugMarkersSupported = setContains(deviceExts, VK_EXT_DEBUG_MARKER_EXTENSION_NAME);
-        context.mMultiviewEnabled = setContains(deviceExts, VK_KHR_MULTIVIEW_EXTENSION_NAME);
     } else {
         VulkanSharedContext const* scontext = (VulkanSharedContext const*) sharedContext;
         context.mDebugUtilsSupported = scontext->debugUtilsSupported;
         context.mDebugMarkersSupported = scontext->debugMarkersSupported;
-        context.mMultiviewEnabled = scontext->multiviewSupported;
     }
 
     // Check the availability of lazily allocated memory
@@ -977,30 +995,6 @@ 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>
 
@@ -39,6 +39,14 @@ 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;
     }
 
@@ -57,7 +65,7 @@ VkFormat transformVkFormat(VkFormat format, bool sRGB) {
 }
 
 bool isProtectedFromUsage(uint64_t usage) {
-    return (usage & AHARDWAREBUFFER_USAGE_PROTECTED_CONTENT) ? true : false;
+    return usage & AHARDWAREBUFFER_USAGE_PROTECTED_CONTENT;
 }
 
 std::pair<VkFormat, VkImageUsageFlags> getVKFormatAndUsage(const AHardwareBuffer_Desc& desc,
@@ -120,7 +128,9 @@ std::pair<VkFormat, VkImageUsageFlags> getVKFormatAndUsage(const AHardwareBuffer
     usage = 0;
     if (desc.usage & AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE) {
         usage |= VK_IMAGE_USAGE_SAMPLED_BIT;
-        usage |= VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT;
+
+        // We shouldn't be using external samplers as input attachments
+        // usage |= VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT;
     }
     if (desc.usage & AHARDWAREBUFFER_USAGE_GPU_FRAMEBUFFER) {
         if (isDepthFormat) {
@@ -136,87 +146,37 @@ std::pair<VkFormat, VkImageUsageFlags> getVKFormatAndUsage(const AHardwareBuffer
     return { format, usage };
 }
 
-VulkanPlatform::ImageData allocateExternalImage(AHardwareBuffer* buffer, VkDevice device,
+std::pair<TextureFormat, TextureUsage> getFilamentFormatAndUsage(const AHardwareBuffer_Desc& desc,
-        VulkanPlatform::ExternalImageMetadata const& metadata, uint32_t memoryTypeIndex,
+        bool sRGB) {
-        VkImageUsageFlags usage) {
+    auto const format = mapToFilamentFormat(desc.format, sRGB);
-    VulkanPlatform::ImageData data;
+    return {
-
+        format,
-    // if external format we need to specifiy it in the allocation
+        mapToFilamentUsage(desc.usage, format),
-    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() = default;
+VulkanPlatformAndroid::ExternalImageVulkanAndroid::~ExternalImageVulkanAndroid() {
+    if (__builtin_available(android 26, *)) {
+        if (aHardwareBuffer) {
+            AHardwareBuffer_release(aHardwareBuffer);
+        }
+    }
+}
 
 Platform::ExternalImageHandle VulkanPlatformAndroid::createExternalImage(
         AHardwareBuffer const* buffer, bool sRGB) noexcept {
     if (__builtin_available(android 26, *)) {
+        auto bufferImpl = const_cast<AHardwareBuffer*>(buffer);
+        AHardwareBuffer_acquire(bufferImpl);
+
         AHardwareBuffer_Desc hardwareBufferDescription = {};
         AHardwareBuffer_describe(buffer, &hardwareBufferDescription);
 
         auto* const p = new (std::nothrow) ExternalImageVulkanAndroid;
         p->aHardwareBuffer = const_cast<AHardwareBuffer*>(buffer);
         p->sRGB = sRGB;
-        p->height = hardwareBufferDescription.height;
-        p->width = hardwareBufferDescription.width;
-        TextureFormat textureFormat = mapToFilamentFormat(hardwareBufferDescription.format, sRGB);
-        p->format = textureFormat;
-        p->usage = mapToFilamentUsage(hardwareBufferDescription.usage, textureFormat);
         return Platform::ExternalImageHandle{ p };
     }
 
@@ -225,23 +185,20 @@ Platform::ExternalImageHandle VulkanPlatformAndroid::createExternalImage(
 
 VulkanPlatformAndroid::ExternalImageDescAndroid VulkanPlatformAndroid::getExternalImageDesc(
         ExternalImageHandleRef externalImage) const noexcept {
-    auto const* fvkExternalImage =
+    auto metadata = extractExternalImageMetadata(externalImage);
-            static_cast<ExternalImageVulkanAndroid const*>(externalImage.get());
-
     return {
-        .width = fvkExternalImage->width,
+        .width = metadata.width,
-        .height = fvkExternalImage->height,
+        .height = metadata.height,
-        .format = fvkExternalImage->format,
+        .format = metadata.filamentFormat,
-        .usage = fvkExternalImage->usage,
+        .usage = metadata.filamentUsage,
     };
 }
 
-VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::getExternalImageMetadata(
+VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::extractExternalImageMetadata(
-        ExternalImageHandleRef externalImage) {
+        ExternalImageHandleRef image) const {
-    auto const* fvkExternalImage =
+    auto const* fvkExternalImage = static_cast<ExternalImageVulkanAndroid const*>(image.get());
-            static_cast<ExternalImageVulkanAndroid const*>(externalImage.get());
 
-    ExternalImageMetadata metadata;
+    ExternalImageMetadata metadata = {};
     AHardwareBuffer* buffer = fvkExternalImage->aHardwareBuffer;
     if (__builtin_available(android 26, *)) {
         AHardwareBuffer_Desc bufferDesc;
@@ -249,16 +206,29 @@ VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::getExternalImageMet
         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,
@@ -268,138 +238,155 @@ VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::getExternalImageMet
     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.allocationSize = properties.allocationSize;
     metadata.memoryTypeBits = properties.memoryTypeBits;
+
+    metadata.ycbcrConversionComponents = formatInfo.samplerYcbcrConversionComponents;
+    metadata.ycbcrModel = formatInfo.suggestedYcbcrModel;
+    metadata.ycbcrRange = formatInfo.suggestedYcbcrRange;
+    metadata.xChromaOffset = formatInfo.suggestedXChromaOffset;
+    metadata.yChromaOffset = formatInfo.suggestedYChromaOffset;
+
     return metadata;
 }
 
-VulkanPlatformAndroid::ImageData VulkanPlatformAndroid::createExternalImageData(
+VulkanPlatform::ImageData VulkanPlatformAndroid::createVkImageFromExternal(
-        ExternalImageHandleRef externalImage, const ExternalImageMetadata& metadata,
+        ExternalImageHandleRef externalImage) const {
-        uint32_t memoryTypeIndex, VkImageUsageFlags usage) {
+    auto metadata = extractExternalImageMetadata(externalImage);
+
     auto const* fvkExternalImage =
             static_cast<ExternalImageVulkanAndroid const*>(externalImage.get());
-    ImageData data = allocateExternalImage(fvkExternalImage->aHardwareBuffer, getDevice(), metadata,
+    AHardwareBuffer* buffer = fvkExternalImage->aHardwareBuffer;
-            memoryTypeIndex, usage);
+
-    VkResult result = vkBindImageMemory(getDevice(), data.first, data.second, 0);
+    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;
+    };
+
+    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;
+
+        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 data;
+        return memory;
+    };
+
+    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 };
     }
 
-VkImageView VulkanPlatform::createExternalImageViewImpl(VkDevice device, SamplerYcbcrConversion chroma,
+    return {
-            uint32_t internalFormat, VkImage image, VkImageSubresourceRange range,
+        .internal = internal,
-            VkImageViewType viewType, VkComponentMapping swizzle){
+        .external = external,
-    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,
-        .conversion = conversion,
-    };
-
-    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 {
@@ -413,7 +400,7 @@ 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,
     };
@@ -427,17 +414,6 @@ 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{};

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

@@ -24,7 +24,6 @@
 #include <bluevk/BlueVK.h>
 
 // Platform specific includes and defines
-#if defined(__APPLE__)
 #include <Cocoa/Cocoa.h>
 #import <Metal/Metal.h>
 #import <QuartzCore/CAMetalLayer.h>
@@ -32,21 +31,6 @@
 #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;
 
@@ -54,43 +38,14 @@ 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;
-    #if defined(__APPLE__)
     NSView* nsview = (__bridge NSView*) nativeWindow;
     FILAMENT_CHECK_POSTCONDITION(nsview) << "Unable to obtain Metal-backed NSView.";
 
@@ -104,21 +59,6 @@ VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHRImpl(void* nativ
             (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(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)
-            << "vkCreateIOSSurfaceMVK failed. error=" << static_cast<int32_t>(result);
-#endif
     return std::make_tuple(surface, VkExtent2D{});
 }
 

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

@@ -84,30 +84,6 @@ 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

@@ -51,6 +51,8 @@ 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;
@@ -668,4 +670,111 @@ VkShaderStageFlags getShaderStageFlags(ShaderStageFlags stageFlags) {
     return flags;
 }
 
+VkSamplerYcbcrModelConversion getYcbcrModelConversion(
+    SamplerYcbcrModelConversion model) {
+    switch (model) {
+    case SamplerYcbcrModelConversion::RGB_IDENTITY:
+        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY;
+    case SamplerYcbcrModelConversion::YCBCR_IDENTITY:
+        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY;
+    case SamplerYcbcrModelConversion::YCBCR_709:
+        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709;
+    case SamplerYcbcrModelConversion::YCBCR_601:
+        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601;
+    case SamplerYcbcrModelConversion::YCBCR_2020:
+        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020;
+    default:
+        assert_invariant(false &&
+            "Unknown data type, conversion is not supported.");
+    }
+}
+
+VkSamplerYcbcrRange getYcbcrRange(SamplerYcbcrRange range) {
+    switch (range) {
+    case SamplerYcbcrRange::ITU_FULL:
+        return VK_SAMPLER_YCBCR_RANGE_ITU_FULL;
+    case SamplerYcbcrRange::ITU_NARROW:
+        return VK_SAMPLER_YCBCR_RANGE_ITU_NARROW;
+    default:
+        assert_invariant(false &&
+            "Unknown data type, conversion is not supported.");
+    }
+}
+
+VkChromaLocation getChromaLocation(ChromaLocation loc) {
+    switch (loc) {
+    case ChromaLocation::COSITED_EVEN:
+        return VK_CHROMA_LOCATION_COSITED_EVEN;
+    case ChromaLocation::MIDPOINT:
+        return VK_CHROMA_LOCATION_MIDPOINT;
+    default:
+        assert_invariant(false &&
+            "Unknown data type, conversion is not supported.");
+    }
+}
+
+SamplerYcbcrModelConversion getYcbcrModelConversionFilament(VkSamplerYcbcrModelConversion model) {
+    switch (model) {
+        case VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY:
+            return SamplerYcbcrModelConversion::RGB_IDENTITY;
+        case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY:
+            return SamplerYcbcrModelConversion::YCBCR_IDENTITY;
+        case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709:
+            return SamplerYcbcrModelConversion::YCBCR_709;
+        case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601:
+            return SamplerYcbcrModelConversion::YCBCR_601;
+        case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020:
+            return SamplerYcbcrModelConversion::YCBCR_2020;
+        default:
+            assert_invariant(false && "Unknown data type, conversion is not supported.");
+            return {};
+    }
+}
+
+SamplerYcbcrRange getYcbcrRangeFilament(VkSamplerYcbcrRange range) {
+    switch (range) {
+        case VK_SAMPLER_YCBCR_RANGE_ITU_FULL:
+            return SamplerYcbcrRange::ITU_FULL;
+        case VK_SAMPLER_YCBCR_RANGE_ITU_NARROW:
+            return SamplerYcbcrRange::ITU_NARROW;
+        default:
+            assert_invariant(false && "Unknown data type, conversion is not supported.");
+            return {};
+    }
+}
+
+ChromaLocation getChromaLocationFilament(VkChromaLocation loc) {
+    switch (loc) {
+        case VK_CHROMA_LOCATION_COSITED_EVEN:
+            return ChromaLocation::COSITED_EVEN;
+        case VK_CHROMA_LOCATION_MIDPOINT:
+            return ChromaLocation::MIDPOINT;
+        default:
+            assert_invariant(false && "Unknown data type, conversion is not supported.");
+            return {};
+    }
+}
+
+TextureSwizzle getSwizzleFilament(VkComponentSwizzle c, uint8_t rgbaIndex) {
+    switch (c) {
+        case VK_COMPONENT_SWIZZLE_ZERO:
+            return TextureSwizzle::SUBSTITUTE_ZERO;
+        case VK_COMPONENT_SWIZZLE_ONE:
+            return TextureSwizzle::SUBSTITUTE_ONE;
+        case VK_COMPONENT_SWIZZLE_IDENTITY:
+            return (TextureSwizzle) (((uint8_t) TextureSwizzle::CHANNEL_0) + rgbaIndex);
+        case VK_COMPONENT_SWIZZLE_R:
+            return TextureSwizzle::CHANNEL_0;
+        case VK_COMPONENT_SWIZZLE_G:
+            return TextureSwizzle::CHANNEL_1;
+        case VK_COMPONENT_SWIZZLE_B:
+            return TextureSwizzle::CHANNEL_2;
+        case VK_COMPONENT_SWIZZLE_A:
+            return TextureSwizzle::CHANNEL_3;
+        default:
+            assert_invariant(false && "Unknown data type, conversion is not supported.");
+            return {};
+    }
+}
+
 } // namespace filament::backend::fvkutils

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

@@ -69,6 +69,12 @@ VkSamplerYcbcrModelConversion getYcbcrModelConversion(SamplerYcbcrModelConversio
 VkSamplerYcbcrRange getYcbcrRange(SamplerYcbcrRange range);
 VkChromaLocation getChromaLocation(ChromaLocation loc);
 
+// Ycbcr related functions
+SamplerYcbcrModelConversion getYcbcrModelConversionFilament(VkSamplerYcbcrModelConversion model);
+SamplerYcbcrRange getYcbcrRangeFilament(VkSamplerYcbcrRange range);
+ChromaLocation getChromaLocationFilament(VkChromaLocation loc);
+TextureSwizzle getSwizzleFilament(VkComponentSwizzle c, uint8_t rgbaIndex);
+
 inline VkImageViewType getViewType(SamplerType target) {
     switch (target) {
         case SamplerType::SAMPLER_CUBEMAP:

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

@@ -348,6 +348,10 @@ using SamplerBitmask = utils::bitset64;
 // general.
 using InputAttachmentBitmask = utils::bitset64;
 
+constexpr uint8_t MAX_DESCRIPTOR_SET_BITMASK_BITS =
+        std::max(std::max(sizeof(UniformBufferBitmask), sizeof(SamplerBitmask)),
+                sizeof(InputAttachmentBitmask)) * 8;
+
 template<typename Bitmask>
 static constexpr uint8_t getVertexStageShift() noexcept {
     // We assume the bottom half of bits are for vertex stages.

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

@@ -184,6 +184,46 @@ 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) {
@@ -193,49 +233,6 @@ uint8_t reduceSampleCount(uint8_t sampleCount, VkSampleCountFlags mask) {
     return mostSignificantBit((sampleCount - 1) & mask);
 }
 
-VkSamplerYcbcrModelConversion getYcbcrModelConversion(
-    SamplerYcbcrModelConversion model) {
-    switch (model) {
-    case SamplerYcbcrModelConversion::RGB_IDENTITY:
-        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY;
-    case SamplerYcbcrModelConversion::YCBCR_IDENTITY:
-        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY;
-    case SamplerYcbcrModelConversion::YCBCR_709:
-        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709;
-    case SamplerYcbcrModelConversion::YCBCR_601:
-        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601;
-    case SamplerYcbcrModelConversion::YCBCR_2020:
-        return VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020;
-    default:
-        assert_invariant(false &&
-            "Unknown data type, conversion is not supported.");
-    }
-}
-
-VkSamplerYcbcrRange getYcbcrRange(SamplerYcbcrRange range) {
-    switch (range) {
-    case SamplerYcbcrRange::ITU_FULL:
-        return VK_SAMPLER_YCBCR_RANGE_ITU_FULL;
-    case SamplerYcbcrRange::ITU_NARROW:
-        return VK_SAMPLER_YCBCR_RANGE_ITU_NARROW;
-    default:
-        assert_invariant(false &&
-            "Unknown data type, conversion is not supported.");
-    }
-}
-
-VkChromaLocation getChromaLocation(ChromaLocation loc) {
-    switch (loc) {
-    case ChromaLocation::COSITED_EVEN:
-        return VK_CHROMA_LOCATION_COSITED_EVEN;
-    case ChromaLocation::MIDPOINT:
-        return VK_CHROMA_LOCATION_MIDPOINT;
-    default:
-        assert_invariant(false &&
-            "Unknown data type, conversion is not supported.");
-    }
-}
-
 } // namespace filament::backend::fvkutils
 
 bool operator<(const VkImageSubresourceRange& a, const VkImageSubresourceRange& b) {

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

@@ -98,6 +98,8 @@ 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

@@ -0,0 +1,150 @@
+/*
+ * 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

@@ -16,13 +16,12 @@
 
 #include "webgpu/WebGPUDriver.h"
 
-#include "webgpu/WebGPUConstants.h"
+#include "WebGPUSwapChain.h"
 #include <backend/platforms/WebGPUPlatform.h>
 
 #include "CommandStreamDispatcher.h"
 #include "DriverBase.h"
 #include "private/backend/Dispatcher.h"
-
 #include <backend/DriverEnums.h>
 #include <backend/Handle.h>
 
@@ -184,8 +183,6 @@ void printAdapterDetails(wgpu::Adapter const& adapter) {
 }
 #endif
 
-
-
 #if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
 void printDeviceDetails(wgpu::Device const& device) {
     wgpu::SupportedFeatures supportedFeatures{};
@@ -229,6 +226,15 @@ 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;
@@ -262,9 +268,6 @@ void WebGPUDriver::tick(int) {
 
 void WebGPUDriver::beginFrame(int64_t monotonic_clock_ns,
         int64_t refreshIntervalNs, uint32_t frameId) {
-    wgpu::CommandEncoderDescriptor commandEncoderDescriptor{};
-    commandEncoderDescriptor.nextInChain = nullptr;
-    mCommandEncoder = mDevice.CreateCommandEncoder(&commandEncoderDescriptor);
 }
 
 void WebGPUDriver::setFrameScheduledCallback(Handle<HwSwapChain> sch,
@@ -281,12 +284,6 @@ void WebGPUDriver::setPresentationTime(int64_t monotonic_clock_ns) {
 }
 
 void WebGPUDriver::endFrame(uint32_t frameId) {
-    // FWGPU_LOGW << __FUNCTION__<< "\n";
-    mQueue.Submit(1, &mCommandBuffer);
-    mCommandEncoder = nullptr;
-    mCommandBuffer = nullptr;
-    mTextureView = nullptr;
-    mSwapChain->Present();
 }
 
 void WebGPUDriver::flush(int) {
@@ -296,37 +293,52 @@ 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) {
@@ -336,16 +348,19 @@ 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 {
-    // TODO:  use webgpu handle allocator from.
+    return allocHandle<WebGPUSwapChain>();
-    //        https://github.com/google/filament/pull/8566
-    // return allocAndConstructHandle<HwSwapChain>();
-    return Handle<HwSwapChain>((Handle<HwSwapChain>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwSwapChain> WebGPUDriver::createSwapChainHeadlessS() noexcept {
@@ -361,7 +376,7 @@ Handle<HwTexture> WebGPUDriver::importTextureS() noexcept {
 }
 
 Handle<HwProgram> WebGPUDriver::createProgramS() noexcept {
-    return Handle<HwProgram>((Handle<HwProgram>::HandleId) mNextFakeHandle++);
+    return allocHandle<WGPUProgram>();
 }
 
 Handle<HwFence> WebGPUDriver::createFenceS() noexcept {
@@ -377,7 +392,7 @@ Handle<HwIndexBuffer> WebGPUDriver::createIndexBufferS() noexcept {
 }
 
 Handle<HwTexture> WebGPUDriver::createTextureViewS() noexcept {
-    return allocHandle<WGPUTexture>();
+    return Handle<HwTexture>((Handle<HwTexture>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwBufferObject> WebGPUDriver::createBufferObjectS() noexcept {
@@ -393,11 +408,11 @@ Handle<HwVertexBuffer> WebGPUDriver::createVertexBufferS() noexcept {
 }
 
 Handle<HwDescriptorSet> WebGPUDriver::createDescriptorSetS() noexcept {
-    return Handle<HwDescriptorSet>((Handle<HwDescriptorSet>::HandleId) mNextFakeHandle++);
+    return allocHandle<WebGPUDescriptorSet>();
 }
 
 Handle<HwRenderPrimitive> WebGPUDriver::createRenderPrimitiveS() noexcept {
-    return Handle<HwRenderPrimitive>((Handle<HwRenderPrimitive>::HandleId) mNextFakeHandle++);
+    return allocHandle<WGPURenderPrimitive>();
 }
 
 Handle<HwVertexBufferInfo> WebGPUDriver::createVertexBufferInfoS() noexcept {
@@ -405,7 +420,7 @@ Handle<HwVertexBufferInfo> WebGPUDriver::createVertexBufferInfoS() noexcept {
 }
 
 Handle<HwTexture> WebGPUDriver::createTextureViewSwizzleS() noexcept {
-    return allocHandle<WGPUTexture>();
+    return Handle<HwTexture>((Handle<HwTexture>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwRenderTarget> WebGPUDriver::createDefaultRenderTargetS() noexcept {
@@ -413,8 +428,7 @@ Handle<HwRenderTarget> WebGPUDriver::createDefaultRenderTargetS() noexcept {
 }
 
 Handle<HwDescriptorSetLayout> WebGPUDriver::createDescriptorSetLayoutS() noexcept {
-    return Handle<HwDescriptorSetLayout>(
+    return allocHandle<WebGPUDescriptorSetLayout>();
-            (Handle<HwDescriptorSetLayout>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwTexture> WebGPUDriver::createTextureExternalImageS() noexcept {
@@ -430,43 +444,14 @@ Handle<HwTexture> WebGPUDriver::createTextureExternalImagePlaneS() noexcept {
 }
 
 void WebGPUDriver::createSwapChainR(Handle<HwSwapChain> sch, void* nativeWindow, uint64_t flags) {
-    // TODO:  use webgpu handle allocator from.
+    mNativeWindow = nativeWindow;
-    //        https://github.com/google/filament/pull/8566
-    // HwSwapChain* hwSwapChain = handleCast<HwSwapChain*>(sch);
     assert_invariant(!mSwapChain);
     wgpu::Surface surface = mPlatform.createSurface(nativeWindow, flags);
-    mAdapter = mPlatform.requestAdapter(surface);
+
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
+    wgpu::Extent2D surfaceSize = mPlatform.getSurfaceExtent(mNativeWindow);
-    printAdapterDetails(mAdapter);
+    mSwapChain = constructHandle<WebGPUSwapChain>(sch, std::move(surface), surfaceSize, mAdapter,
-#endif
+            mDevice, flags);
-    mDevice = mPlatform.requestDevice(mAdapter);
+    assert_invariant(mSwapChain);
-#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
-    printDeviceDetails(mDevice);
-#endif
-    mQueue = mDevice.GetQueue();
-    mSwapChain = std::make_unique<WebGPUSwapChain>(std::move(surface), mAdapter, mDevice, flags);
-    // TODO configure the surface (maybe before or after creating the swapchain?
-    //                             how do we get the surface extent?)
-    // TODO actually create the swapchain
-    // auto onQueueWorkDone = [](wgpu::QueueWorkDoneStatus status, void* /* pUserData */) {
-        // FWGPU_LOGW << "Queued work finished with status: " << status << std::endl;
-    // };
-    // mQueue.OnSubmittedWorkDone(wgpu::CallbackMode::WaitAnyOnly, [](wgpu::QueueWorkDoneStatus status, void* pUserdata) {
-    //     FWGPU_LOGW << "Queued work finished with status:\n";
-    // }, nullptr /* pUserData */);
-    void* userDataPtr = nullptr;
-    mQueue.OnSubmittedWorkDone(
-        wgpu::CallbackMode::AllowProcessEvents,
-        [](wgpu::QueueWorkDoneStatus status, void* pUserData) {
-            FWGPU_LOGW << "Queued work finished with status: " << static_cast<int>(status) << "\n";
-            if (pUserData == nullptr) {
-                // Expected case
-            } else {
-                FWGPU_LOGW << "Unexpected non-null pUserData received.\n";
-            }
-        },
-        userDataPtr /* pUserData */
-    );
     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."
@@ -479,38 +464,40 @@ 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) {}
+        uint8_t attributeCount, AttributeArray attributes) {
+    constructHandle<WGPUVertexBufferInfo>(vbih, bufferCount, attributeCount, attributes);
+}
 
 void WebGPUDriver::createVertexBufferR(Handle<HwVertexBuffer> vbh, uint32_t vertexCount,
-        Handle<HwVertexBufferInfo> vbih) {}
+        Handle<HwVertexBufferInfo> vbih) {
+    auto* vertexBufferInfo = handleCast<WGPUVertexBufferInfo>(vbih);
+    constructHandle<WGPUVertexBuffer>(vbh, mDevice, vertexCount, vertexBufferInfo->bufferCount,
+            vbih);
+}
 
 void WebGPUDriver::createIndexBufferR(Handle<HwIndexBuffer> ibh, ElementType elementType,
-        uint32_t indexCount, BufferUsage usage) {}
+        uint32_t indexCount, BufferUsage usage) {
+    auto elementSize = static_cast<uint8_t>(getElementTypeSize(elementType));
+    constructHandle<WGPUIndexBuffer>(ibh, mDevice, elementSize, indexCount);
+}
 
 void WebGPUDriver::createBufferObjectR(Handle<HwBufferObject> boh, uint32_t byteCount,
-        BufferObjectBinding bindingType, BufferUsage usage) {}
+        BufferObjectBinding bindingType, BufferUsage usage) {
+    constructHandle<WGPUBufferObject>(boh, mDevice, bindingType, byteCount);
+}
 
 void WebGPUDriver::createTextureR(Handle<HwTexture> th, SamplerType target, uint8_t levels,
         TextureFormat format, uint8_t samples, uint32_t w, uint32_t h, uint32_t depth,
         TextureUsage usage) {}
 
 void WebGPUDriver::createTextureViewR(Handle<HwTexture> th, Handle<HwTexture> srch,
-        uint8_t baseLevel, uint8_t levelCount) {
+        uint8_t baseLevel, uint8_t levelCount) {}
-    // FWGPU_LOGW << __FUNCTION__<< "\n";
-    WGPUTexture const* src = handleCast<WGPUTexture>(srch);
-    (void) src;
-    // textures.insert(
-    //         constructHandle<WGPUTexture>(th, src, baseLevel, levelCount));
-}
 
 void WebGPUDriver::createTextureViewSwizzleR(Handle<HwTexture> th, Handle<HwTexture> srch,
         backend::TextureSwizzle r, backend::TextureSwizzle g, backend::TextureSwizzle b,
@@ -533,9 +520,20 @@ 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) {}
+        Handle<HwIndexBuffer> ibh, PrimitiveType pt) {
+    assert_invariant(mDevice);
 
-void WebGPUDriver::createProgramR(Handle<HwProgram> ph, Program&& program) {}
+    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::createDefaultRenderTargetR(Handle<HwRenderTarget> rth, int) {
     assert_invariant(!mDefaultRenderTarget);
@@ -552,10 +550,15 @@ void WebGPUDriver::createFenceR(Handle<HwFence> fh, int) {}
 void WebGPUDriver::createTimerQueryR(Handle<HwTimerQuery> tqh, int) {}
 
 void WebGPUDriver::createDescriptorSetLayoutR(Handle<HwDescriptorSetLayout> dslh,
-        backend::DescriptorSetLayout&& info) {}
+        backend::DescriptorSetLayout&& info) {
+    constructHandle<WebGPUDescriptorSetLayout>(dslh, std::move(info), mDevice);
+}
 
 void WebGPUDriver::createDescriptorSetR(Handle<HwDescriptorSet> dsh,
-        Handle<HwDescriptorSetLayout> dslh) {}
+        Handle<HwDescriptorSetLayout> dslh) {
+    auto layout = handleCast<WebGPUDescriptorSetLayout>(dslh);
+    constructHandle<WebGPUDescriptorSet>(dsh, layout->getLayout(), layout->getLayoutSize());
+}
 
 Handle<HwStream> WebGPUDriver::createStreamNative(void* nativeStream) {
     return {};
@@ -595,7 +598,7 @@ bool WebGPUDriver::isTextureFormatSupported(TextureFormat format) {
 }
 
 bool WebGPUDriver::isTextureSwizzleSupported() {
-    return true;
+    return false;
 }
 
 bool WebGPUDriver::isTextureFormatMipmappable(TextureFormat format) {
@@ -684,29 +687,30 @@ size_t WebGPUDriver::getMaxArrayTextureLayers() {
 
 void WebGPUDriver::updateIndexBuffer(Handle<HwIndexBuffer> ibh, BufferDescriptor&& p,
         uint32_t byteOffset) {
-    scheduleDestroy(std::move(p));
+    updateGPUBuffer(handleCast<WGPUIndexBuffer>(ibh), std::move(p), byteOffset);
 }
 
 void WebGPUDriver::updateBufferObject(Handle<HwBufferObject> ibh, BufferDescriptor&& p,
         uint32_t byteOffset) {
-    scheduleDestroy(std::move(p));
+    updateGPUBuffer(handleCast<WGPUBufferObject>(ibh), std::move(p), byteOffset);
 }
 
-void WebGPUDriver::updateBufferObjectUnsynchronized(Handle<HwBufferObject> ibh, BufferDescriptor&& p,
+void WebGPUDriver::updateBufferObjectUnsynchronized(Handle<HwBufferObject> ibh,
-        uint32_t byteOffset) {
+        BufferDescriptor&& p, uint32_t byteOffset) {
-    scheduleDestroy(std::move(p));
+    updateGPUBuffer(handleCast<WGPUBufferObject>(ibh), std::move(p), byteOffset);
 }
 
 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,
         Handle<HwBufferObject> boh) {
     auto* vertexBuffer = handleCast<WGPUVertexBuffer>(vbh);
     auto* bufferObject = handleCast<WGPUBufferObject>(boh);
-    assert_invariant(index < vertexBuffer->mBuffers.size());
+    assert_invariant(index < vertexBuffer->buffers.size());
-    vertexBuffer->setBuffer(bufferObject, index);
+    assert_invariant(bufferObject->buffer.GetUsage() & wgpu::BufferUsage::Vertex);
-
+    vertexBuffer->buffers[index] = bufferObject->buffer;
 }
 
 void WebGPUDriver::update3DImage(Handle<HwTexture> th,
@@ -739,48 +743,72 @@ void WebGPUDriver::compilePrograms(CompilerPriorityQueue priority,
 }
 
 void WebGPUDriver::beginRenderPass(Handle<HwRenderTarget> rth, const RenderPassParams& params) {
-    // FWGPU_LOGW << __FUNCTION__<< "\n";
+    wgpu::CommandEncoderDescriptor commandEncoderDescriptor = {
-    mTextureView = mSwapChain->GetNextSurfaceTextureView(params.viewport.width, params.viewport.height);
+        .label = "command_encoder"
-    wgpu::RenderPassColorAttachment renderPassColorAttachment = {};
+    };
-    renderPassColorAttachment.view = mTextureView;
+    mCommandEncoder = mDevice.CreateCommandEncoder(&commandEncoderDescriptor);
-    renderPassColorAttachment.resolveTarget = nullptr;
+    assert_invariant(mCommandEncoder);
-    renderPassColorAttachment.loadOp = wgpu::LoadOp::Clear;
-    renderPassColorAttachment.storeOp = wgpu::StoreOp::Store;
-    renderPassColorAttachment.clearValue = wgpu::Color{1, 0 , 0 , 1};
-    renderPassColorAttachment.depthSlice = WGPU_DEPTH_SLICE_UNDEFINED;
 
-    wgpu::RenderPassDescriptor renderPassDescriptor = {};
+    // TODO: Remove this code once WebGPU pipeline is implemented
-    renderPassDescriptor.nextInChain = nullptr;
+    static float red = 1.0f;
-    renderPassDescriptor.colorAttachmentCount = 1;
+    if (red - 0.01 > 0) {
-    renderPassDescriptor.colorAttachments = &renderPassColorAttachment;
+        red -= 0.01;
-    renderPassDescriptor.depthStencilAttachment = nullptr;
+    } else {
-    renderPassDescriptor.timestampWrites = nullptr;
+        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.
+        .depthSlice = wgpu::kDepthSliceUndefined,
+        .loadOp = wgpu::LoadOp::Clear,
+        .storeOp = wgpu::StoreOp::Store,
+        .clearValue = wgpu::Color{red, 0 , 0 , 1},
+    };
+
+    wgpu::RenderPassDescriptor renderPassDescriptor = {
+        .colorAttachmentCount = 1,
+        .colorAttachments = &renderPassColorAttachment,
+        .depthStencilAttachment = nullptr,
+        .timestampWrites = nullptr,
+    };
 
     mRenderPassEncoder = mCommandEncoder.BeginRenderPass(&renderPassDescriptor);
-    mRenderPassEncoder.SetViewport((float)params.viewport.left, (float)params.viewport.bottom,
+    mRenderPassEncoder.SetViewport(params.viewport.left, params.viewport.bottom,
-            (float) params.viewport.width, (float) params.viewport.height, params.depthRange.near, params.depthRange.far);
+            params.viewport.width, params.viewport.height, params.depthRange.near, params.depthRange.far);
-            // (float) 1024/*params.viewport.width*/, (float) 640/*params.viewport.height*/, params.depthRange.near, params.depthRange.far);
 }
 
 void WebGPUDriver::endRenderPass(int) {
-    // FWGPU_LOGW << __FUNCTION__<< "\n";
     mRenderPassEncoder.End();
     mRenderPassEncoder = nullptr;
+    wgpu::CommandBufferDescriptor commandBufferDescriptor {
+        .label = "command_buffer",
+    };
+    mCommandBuffer = mCommandEncoder.Finish(&commandBufferDescriptor);
+    assert_invariant(mCommandBuffer);
 }
 
 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) {
-    wgpu::CommandBufferDescriptor commandBufferDescriptor = {};
+    mCommandEncoder = nullptr;
-    commandBufferDescriptor.nextInChain = nullptr;
+    mQueue.Submit(1, &mCommandBuffer);
-    mCommandBuffer = mCommandEncoder.Finish(&commandBufferDescriptor);
+    mCommandBuffer = nullptr;
-
+    mTextureView = nullptr;
-    // mQueue.Submit(1, &mCommandBuffer);
+    assert_invariant(mSwapChain);
-    // mCommandBuffer = nullptr;
+    mSwapChain->present();
 }
 
 void WebGPUDriver::setPushConstant(backend::ShaderStage stage, uint8_t index,
@@ -808,7 +836,7 @@ void WebGPUDriver::readPixels(Handle<HwRenderTarget> src,
     scheduleDestroy(std::move(p));
 }
 
-void WebGPUDriver::readBufferSubData(backend::BufferObjectHandle boh,
+void WebGPUDriver::readBufferSubData(Handle<HwBufferObject> boh,
         uint32_t offset, uint32_t size, backend::BufferDescriptor&& p) {
     scheduleDestroy(std::move(p));
 }
@@ -834,11 +862,22 @@ 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) {
-    // mRenderPassEncoder.DrawIndexed(indexCount, instanceCount, indexOffset, 0, 0);
-
 }
 
 void WebGPUDriver::draw(PipelineState pipelineState, Handle<HwRenderPrimitive> rph,
@@ -861,25 +900,48 @@ void WebGPUDriver::endTimerQuery(Handle<HwTimerQuery> tqh) {
 void WebGPUDriver::resetState(int) {
 }
 
-void WebGPUDriver::updateDescriptorSetBuffer(
+void WebGPUDriver::updateDescriptorSetBuffer(Handle<HwDescriptorSet> dsh,
-        backend::DescriptorSetHandle dsh,
+        backend::descriptor_binding_t binding, Handle<HwBufferObject> boh, uint32_t offset,
-        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(
+void WebGPUDriver::updateDescriptorSetTexture(Handle<HwDescriptorSet> dsh,
-        backend::DescriptorSetHandle dsh,
+        backend::descriptor_binding_t binding, Handle<HwTexture> th, SamplerParams params) {
-        backend::descriptor_binding_t binding,
+    /*
-        backend::TextureHandle th,
+    auto bindGroup = handleCast<WebGPUDescriptorSet>(dsh);
-        SamplerParams params) {
+    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::bindDescriptorSet(
+void WebGPUDriver::bindDescriptorSet(Handle<HwDescriptorSet> dsh, backend::descriptor_set_t set,
-        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

@@ -17,7 +17,8 @@
 #ifndef TNT_FILAMENT_BACKEND_WEBGPUDRIVER_H
 #define TNT_FILAMENT_BACKEND_WEBGPUDRIVER_H
 
-#include "webgpu/WebGPUSwapChain.h"
+#include "WebGPUHandles.h"
+#include "webgpu/WebGPUConstants.h"
 #include <backend/platforms/WebGPUPlatform.h>
 
 #include "DriverBase.h"
@@ -30,8 +31,6 @@
 
 #include <webgpu/webgpu_cpp.h>
 
-#include "WebGPUHandles.h"
-
 #include <cstdint>
 #include <memory>
 
@@ -41,6 +40,8 @@
 
 namespace filament::backend {
 
+class WebGPUSwapChain;
+
 /**
  * WebGPU backend (driver) implementation
  */
@@ -56,14 +57,35 @@ 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;
-    // TODO consider moving to handle allocator when ready
+    void* mNativeWindow = nullptr;
-    std::unique_ptr<WebGPUSwapChain> mSwapChain = nullptr;
+    WebGPUSwapChain* mSwapChain = nullptr;
     uint64_t mNextFakeHandle = 1;
     wgpu::CommandEncoder mCommandEncoder = nullptr;
     wgpu::TextureView mTextureView = nullptr;
@@ -103,11 +125,17 @@ private:
     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

@@ -1,19 +1,297 @@
-//
+/*
-// Created by Idris Idris Shah on 3/21/25.
+ * 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 <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 {
 
-WGPUVertexBuffer::WGPUVertexBuffer(uint32_t vextexCount, uint32_t bufferCount,
+WGPUVertexBufferInfo::WGPUVertexBufferInfo(uint8_t bufferCount, uint8_t attributeCount,
-        Handle<WGPUVertexBufferInfo> vbih)
+        AttributeArray const& attributes)
-    : HwVertexBuffer(vextexCount),
+    : HwVertexBufferInfo(bufferCount, attributeCount),
-      vbih(vbih),
+      mVertexBufferLayout(bufferCount),
-      mBuffers(MAX_VERTEX_BUFFER_COUNT) {}
+      mAttributes(bufferCount) {
-void WGPUVertexBuffer::setBuffer(WGPUBufferObject* bufferObject, uint32_t index) {}
+    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;
+        }
 
-WGPUBufferObject::WGPUBufferObject(BufferObjectBinding bindingType, uint32_t byteCount)
+        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),
+      vbih(vbih),
+      buffers(bufferCount) {}
+
+WGPUBufferObject::WGPUBufferObject(wgpu::Device const& device, BufferObjectBinding bindingType,
+        uint32_t byteCount)
     : HwBufferObject(byteCount),
-      mBindingType(bindingType) {}
+      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

@@ -1,6 +1,19 @@
-//
+/*
-// Created by Idris Idris Shah on 3/21/25.
+* 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_WEBGPUHANDLES_H
 #define TNT_FILAMENT_BACKEND_WEBGPUHANDLES_H
@@ -9,44 +22,119 @@
 
 #include <backend/DriverEnums.h>
 #include <backend/Handle.h>
+
 #include <utils/FixedCapacityVector.h>
 
 #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;
-struct WGPUVertexBufferInfo : public HwVertexBufferInfo {
+
+// 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:
     WGPUVertexBufferInfo(uint8_t bufferCount, uint8_t attributeCount,
-            AttributeArray const& attributes)
+            AttributeArray const& attributes);
-        : HwVertexBufferInfo(bufferCount, attributeCount),
+    inline  wgpu::VertexBufferLayout const* getVertexBufferLayout() const {
-          attributes(attributes) {}
+        return mVertexBufferLayout.data();
-    AttributeArray attributes;
+    }
+
+    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 {};
 };
 
 struct WGPUVertexBuffer : public HwVertexBuffer {
-    WGPUVertexBuffer(uint32_t vextexCount, uint32_t bufferCount, Handle<WGPUVertexBufferInfo> vbih);
+    WGPUVertexBuffer(wgpu::Device const &device, uint32_t vertexCount, uint32_t bufferCount,
-    void setBuffer(WGPUBufferObject* bufferObject, uint32_t index);
+                     Handle<HwVertexBufferInfo> vbih);
 
-    Handle<WGPUVertexBufferInfo> vbih;
+    Handle<HwVertexBufferInfo> vbih;
-    utils::FixedCapacityVector<wgpu::Buffer> mBuffers;
+    utils::FixedCapacityVector<wgpu::Buffer> buffers;
 };
 
 struct WGPUIndexBuffer : public HwIndexBuffer {
-    WGPUIndexBuffer(BufferUsage usage, uint8_t elementSize, uint32_t indexCount);
+    WGPUIndexBuffer(wgpu::Device const &device, uint8_t elementSize,
+                    uint32_t indexCount);
 
     wgpu::Buffer buffer;
+    wgpu::IndexFormat indexFormat;
 };
 
 struct WGPUBufferObject : HwBufferObject {
-    WGPUBufferObject(BufferObjectBinding bindingType, uint32_t byteCount);
+    WGPUBufferObject(wgpu::Device const &device, BufferObjectBinding bindingType, uint32_t byteCount);
 
-    wgpu::Buffer mBuffer;
+    wgpu::Buffer buffer = nullptr;
-    const BufferObjectBinding mBindingType;
+    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 WGPUTexture : public HwTexture {
+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.
+struct WGPUTexture : public HwTexture {
     WGPUTexture(SamplerType target, uint8_t levels, TextureFormat format, uint8_t samples,
             uint32_t width, uint32_t height, uint32_t depth, TextureUsage usage) noexcept;
 
@@ -54,13 +142,29 @@ public:
     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;
 };
 
-class WGPURenderTarget : public HwRenderTarget {
+struct WGPURenderPrimitive : public HwRenderPrimitive {
-public:
+    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.
+// Update the struct when used by WebGPU driver.
+struct WGPURenderTarget : public HwRenderTarget {
     class Attachment {
     public:
-        friend class WGPURenderTarget;
+        friend struct WGPURenderTarget;
 
         Attachment() = default;
         Attachment(WGPUTexture* gpuTexture, uint8_t level = 0, uint16_t layer = 0)

filament/backend/src/webgpu/WebGPUSwapChain.cpp

@@ -190,10 +190,13 @@ wgpu::CompositeAlphaMode selectAlphaMode(size_t availableAlphaModesCount,
     }
 }
 
-void initConfig(wgpu::SurfaceConfiguration& config, wgpu::Device& device,
+void initConfig(wgpu::SurfaceConfiguration& config, wgpu::Device const& device,
-        wgpu::SurfaceCapabilities const& capabilities, bool useSRGBColorSpace) {
+        wgpu::SurfaceCapabilities const& capabilities, wgpu::Extent2D const& surfaceSize,
+        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 =
@@ -205,8 +208,8 @@ void initConfig(wgpu::SurfaceConfiguration& config, wgpu::Device& device,
 
 namespace filament::backend {
 
-WebGPUSwapChain::WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Adapter& adapter,
+WebGPUSwapChain::WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Extent2D const& surfaceSize,
-        wgpu::Device& device, uint64_t flags)
+        wgpu::Adapter& adapter, wgpu::Device& device, uint64_t flags)
     : mSurface(surface) {
     wgpu::SurfaceCapabilities capabilities = {};
     if (!mSurface.GetCapabilities(adapter, &capabilities)) {
@@ -217,59 +220,55 @@ WebGPUSwapChain::WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Adapter& adapter
 #endif
     }
     const bool useSRGBColorSpace = (flags & SWAP_CHAIN_CONFIG_SRGB_COLORSPACE) != 0;
-    initConfig(mConfig, device, capabilities, useSRGBColorSpace);
+    initConfig(mConfig, device, capabilities, surfaceSize, useSRGBColorSpace);
+    mSurface.Configure(&mConfig);
 }
 
 WebGPUSwapChain::~WebGPUSwapChain() {
-    if (mConfigured) {
     mSurface.Unconfigure();
-        mConfigured = false;
-    }
 }
 
-void WebGPUSwapChain::GetCurrentTexture(uint32_t width, uint32_t height, wgpu::SurfaceTexture* texture) {
+void WebGPUSwapChain::setExtent(wgpu::Extent2D const& currentSurfaceSize) {
-    if (width < 1 || height < 1) {
+    FILAMENT_CHECK_POSTCONDITION(currentSurfaceSize.width > 0 || currentSurfaceSize.height > 0)
-        PANIC_LOG("WebGPUSwapChain::GetCurrentTexture: Invalid width and/or height requested.");
+            << "WebGPUSwapChain::setExtent: Invalid width " << currentSurfaceSize.width
-        return;
+            << " and/or height " << currentSurfaceSize.height << " requested.";
-    }
+    if (mConfig.width != currentSurfaceSize.width || mConfig.height != currentSurfaceSize.height) {
-    if (mConfig.width != width || mConfig.height != height || !mConfigured) {
+        mConfig.width = currentSurfaceSize.width;
-        mConfig.width = width;
+        mConfig.height = currentSurfaceSize.height;
-        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;
+    }
-        return;
 }
 
-    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;
-    GetCurrentTexture(width, height, &surfaceTexture);
+    mSurface.GetCurrentTexture(&surfaceTexture);
-    if (surfaceTexture.status != wgpu::SurfaceGetCurrentTextureStatus::Success) {
+    if (surfaceTexture.status != wgpu::SurfaceGetCurrentTextureStatus::SuccessOptimal) {
         return nullptr;
     }
-
     // Create a view for this surface texture
-    wgpu::TextureViewDescriptor textureViewDescriptor;
+    // TODO: review these initiliazations as webgpu pipeline gets mature
-    textureViewDescriptor.nextInChain = nullptr;
+    wgpu::TextureViewDescriptor textureViewDescriptor = {
-    textureViewDescriptor.label = "Surface texture view";
+        .label = "texture_view",
-    textureViewDescriptor.format = surfaceTexture.texture.GetFormat();
+        .format = surfaceTexture.texture.GetFormat(),
-    textureViewDescriptor.dimension = wgpu::TextureViewDimension::e2D;
+        .dimension = wgpu::TextureViewDimension::e2D,
-    textureViewDescriptor.baseMipLevel = 0;
+        .baseMipLevel = 0,
-    textureViewDescriptor.mipLevelCount = 1;
+        .mipLevelCount = 1,
-    textureViewDescriptor.baseArrayLayer = 0;
+        .baseArrayLayer = 0,
-    textureViewDescriptor.arrayLayerCount = 1;
+        .arrayLayerCount = 1
-    textureViewDescriptor.aspect = wgpu::TextureAspect::All;
+    };
-    wgpu::TextureView textureView = surfaceTexture.texture.CreateView(&textureViewDescriptor);
+    return surfaceTexture.texture.CreateView(&textureViewDescriptor);
-
-    return textureView;
 }
 
-void WebGPUSwapChain::Present() {
+void WebGPUSwapChain::present() {
     assert_invariant(mSurface);
     mSurface.Present();
 }

filament/backend/src/webgpu/WebGPUSwapChain.h

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

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

@@ -18,6 +18,7 @@
 
 #include <utils/Panic.h>
 
+#include <android/native_window.h>
 #include <webgpu/webgpu_cpp.h>
 
 #include <cstdint>
@@ -28,6 +29,14 @@
 
 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

@@ -24,21 +24,8 @@
 #include <cstdint>
 
 // Platform specific includes and defines
-#if defined(__APPLE__)
 #include <Cocoa/Cocoa.h>
 #import <QuartzCore/CAMetalLayer.h>
-#elif defined(FILAMENT_IOS)
-    // Metal is not available when building for the iOS simulator on Desktop.
-    #define METAL_AVAILABLE __has_include(<QuartzCore/CAMetalLayer.h>)
-    #if METAL_AVAILABLE
-        #import <Metal/Metal.h>
-        #import <QuartzCore/CAMetalLayer.h>
-    #endif
-    // is this needed?
-    #define METALVIEW_TAG 255
-#else
-    #error Not a supported Apple + WebGPU platform
-#endif
 
 /**
  * Apple (Mac OS and IOS) specific implementation aspects of the WebGPU backend
@@ -46,14 +33,19 @@
 
 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;
-#if defined(__APPLE__)
+    // Both IOS and MacOS expects CAMetalLayer.
-    auto nsView = (__bridge NSView*) nativeWindow;
+    CAMetalLayer* metalLayer = (__bridge CAMetalLayer*) nativeWindow;
-    FILAMENT_CHECK_POSTCONDITION(nsView) << "Unable to obtain Metal-backed NSView.";
-    [nsView setWantsLayer:YES];
-    id metalLayer = [CAMetalLayer layer];
-    [nsView setLayer:metalLayer];
     wgpu::SurfaceSourceMetalLayer surfaceSourceMetalLayer{};
     surfaceSourceMetalLayer.layer = (__bridge void*) metalLayer;
     wgpu::SurfaceDescriptor surfaceDescriptor = {
@@ -62,19 +54,6 @@ wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t /*flags
     };
     surface = mInstance.CreateSurface(&surfaceDescriptor);
     FILAMENT_CHECK_POSTCONDITION(surface != nullptr) << "Unable to create Metal-backed surface.";
-#elif defined(FILAMENT_IOS)
-    CAMetalLayer* metalLayer = (CAMetalLayer*) nativeWindow;
-    wgpu::SurfaceSourceMetalLayer surfaceSourceMetalLayer{};
-    surfaceSourceMetalLayer.layer = (__bridge void*) metalLayer;
-    wgpu::SurfaceDescriptor surfaceDescriptor = {
-        .nextInChain = &surfaceSourceMetalLayer,
-        .label = "metal_surface",
-    };
-    surface = mInstance.CreateSurface(&surfaceDescriptor);
-    FILAMENT_CHECK_POSTCONDITION(surface != nullptr) << "Unable to create Metal-backed surface.";
-#else
-    #error Not a supported Apple + WebGPU platform
-#endif
     return surface;
 }
 

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

@@ -79,6 +79,74 @@
 
 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

@@ -30,6 +30,16 @@
 
 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

@@ -43,24 +43,29 @@ using namespace image;
 namespace test {
 
 Backend BackendTest::sBackend = Backend::NOOP;
+OperatingSystem BackendTest::sOperatingSystem = OperatingSystem::OTHER;
 bool BackendTest::sIsMobilePlatform = false;
 
-void BackendTest::init(Backend backend, bool isMobilePlatform) {
+void BackendTest::init(Backend backend, OperatingSystem operatingSystem, 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;
 }
@@ -154,49 +159,16 @@ void BackendTest::renderTriangle(
     api.endRenderPass();
 }
 
-void BackendTest::readPixelsAndAssertHash(const char* testName, size_t width, size_t height,
+bool BackendTest::matchesEnvironment(Backend backend) {
-        Handle<HwRenderTarget> rt, uint32_t expectedHash, bool exportScreenshot) {
+    return sBackend == backend;
-    void* buffer = calloc(1, width * height * 4);
-
-    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;
-
-    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.
+bool BackendTest::matchesEnvironment(OperatingSystem operatingSystem) {
-                uint32_t hash = utils::hash::murmur3((const uint32_t*) buffer, size / 4, 0);
+    return sOperatingSystem == operatingSystem;
-                ASSERT_EQ(hash, c->expectedHash) << c->name << " failed: hashes do not match." << std::endl;
+}
 
-                free(buffer);
+bool BackendTest::matchesEnvironment(OperatingSystem operatingSystem, Backend backend) {
-                free(c->name);
+    return matchesEnvironment(operatingSystem) && matchesEnvironment(backend);
-                free(c);
-            }, (void*)c);
-    getDriverApi().readPixels(rt, 0, 0, width, height, std::move(pbd));
 }
 
 class Environment : public ::testing::Environment {
@@ -210,8 +182,8 @@ public:
     }
 };
 
-void initTests(Backend backend, bool isMobile, int& argc, char* argv[]) {
+void initTests(Backend backend, OperatingSystem operatingSystem, bool isMobile, int& argc, char* argv[]) {
-    BackendTest::init(backend, isMobile);
+    BackendTest::init(backend, operatingSystem, isMobile);
     ::testing::InitGoogleTest(&argc, argv);
     ::testing::AddGlobalTestEnvironment(new Environment);
 }

filament/backend/test/BackendTest.h

@@ -25,15 +25,17 @@
 #include "private/backend/DriverApi.h"
 
 #include "PlatformRunner.h"
+#include "ImageExpectations.h"
 
 namespace test {
 
 class BackendTest : public ::testing::Test {
 public:
 
-    static void init(Backend backend, bool isMobilePlatform);
+    static void init(Backend backend, OperatingSystem operatingSystem, bool isMobilePlatform);
 
     static Backend sBackend;
+    static OperatingSystem sOperatingSystem;
     static bool sIsMobilePlatform;
 
 protected:
@@ -64,13 +66,14 @@ 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;
@@ -78,6 +81,10 @@ 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

@@ -16,7 +16,6 @@
 
 #include "ImageExpectations.h"
 
-#include "gtest/gtest.h"
 #include "gmock/gmock.h"
 #include "absl/strings/str_format.h"
 #include "utils/Hash.h"
@@ -28,14 +27,17 @@
 #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 expectedPixelHash)
+        uint32_t expectedHash)
-        : mWidth(width), mHeight(height), mFileName(std::move(fileName)),
+    : mWidth(width),
-          mExpectedPixelHash(expectedPixelHash) {}
+      mHeight(height),
+      mExpectedPixelHash(expectedHash),
+      mFileName(std::move(fileName)) {}
 
 int ScreenshotParams::width() const {
     return mWidth;
@@ -49,24 +51,28 @@ uint32_t ScreenshotParams::expectedHash() const {
     return mExpectedPixelHash;
 }
 
-std::string ScreenshotParams::outputDirectoryPath() const {
+std::string ScreenshotParams::actualDirectoryPath() {
-    return ".";
+    return "images/actual_images";
 }
 
-std::string ScreenshotParams::generatedActualFileName() const {
+std::string ScreenshotParams::actualFileName() const {
     return absl::StrFormat("%s_actual.png", mFileName);
 }
 
-std::string ScreenshotParams::generatedActualFilePath() const {
+std::string ScreenshotParams::actualFilePath() const {
-    return absl::StrFormat("%s/%s", outputDirectoryPath(), generatedActualFileName());
+    return absl::StrFormat("%s/%s", actualDirectoryPath(), actualFileName());
 }
 
-std::string ScreenshotParams::goldenFileName() const {
+std::string ScreenshotParams::expectedDirectoryPath() {
-    return absl::StrFormat("%s_golden.png", mFileName);
+    return "images/expected_images";
 }
 
-std::string ScreenshotParams::goldenFilePath() const {
+std::string ScreenshotParams::expectedFileName() const {
-    return absl::StrFormat("%s/%s", outputDirectoryPath(), goldenFileName());
+    return absl::StrFormat("%s.png", mFileName);
+}
+
+std::string ScreenshotParams::expectedFilePath() const {
+    return absl::StrFormat("%s/%s", expectedDirectoryPath(), expectedFileName());
 }
 
 ImageExpectation::ImageExpectation(const char* fileName, int lineNumber,
@@ -91,11 +97,22 @@ 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();
-        EXPECT_THAT(actualHash, testing::Eq(mParams.expectedHash()));
+#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.
     }
 }
 
@@ -109,12 +126,13 @@ ImageExpectations::~ImageExpectations() {
 
 void ImageExpectations::addExpectation(const char* fileName, int lineNumber,
         filament::backend::RenderTargetHandle renderTarget, ScreenshotParams params) {
-    mExpectations.emplace_back(fileName, lineNumber, mApi, std::move(params), renderTarget);
+    mExpectations.emplace_back(std::make_unique<ImageExpectation>(fileName, lineNumber, mApi,
+            std::move(params), renderTarget));
 }
 
 void ImageExpectations::evaluate() {
     for (auto& expectation: mExpectations) {
-        expectation.evaluate();
+        expectation->evaluate();
     }
     mExpectations.clear();
 }
@@ -122,32 +140,28 @@ 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.generatedActualFilePath();
+        std::string filePath = internal->params.actualFilePath();
         std::ofstream pngStream(filePath, std::ios::binary | std::ios::trunc);
         image::ImageEncoder::encode(pngStream, image::ImageEncoder::Format::PNG, image, "",
                 filePath);
-        internal->bytesFilled = true;
+#endif
     };
     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() {
@@ -170,3 +184,29 @@ bool RenderTargetDump::bytesFilled() const {
 }
 
 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);
+}

filament/backend/test/ImageExpectations.h

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

filament/backend/test/PlatformRunner.cpp

@@ -0,0 +1,60 @@
+/*
+ * 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

@@ -19,6 +19,7 @@
 
 #include <stdint.h>
 #include <stddef.h>
+#include "utils/CString.h"
 
 namespace test {
 
@@ -34,6 +35,15 @@ 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;
@@ -51,9 +61,10 @@ 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, bool isMobile, int& argc, char* argv[]);
+void initTests(Backend backend, OperatingSystem operatingSystem, bool isMobile, int& argc, char* argv[]);
 
 /**
  * Test runners should call runTests when they are ready for tests to be run.
@@ -68,6 +79,6 @@ int runTests();
  */
 Backend parseArgumentsForBackend(int argc, char* argv[]);
 
-}
+} // namespace test
 
 #endif

filament/backend/test/Shader.cpp

@@ -23,30 +23,44 @@ namespace test {
 
 using namespace filament::backend;
 
-Shader::Shader(DriverApi& api, Cleanup& cleanup, ShaderConfig config) {
+Shader::Shader(DriverApi& api, Cleanup& cleanup, ShaderConfig config) : mCleanup(cleanup) {
-    utils::FixedCapacityVector<DescriptorSetLayoutBinding> kLayouts(config.uniformNames.size());
+    utils::FixedCapacityVector<DescriptorSetLayoutBinding> kLayouts(config.uniforms.size());
-    for (unsigned char i = 0; i < config.uniformNames.size(); ++i) {
+    for (unsigned char i = 0; i < config.uniforms.size(); ++i) {
-        kLayouts[i] =
+        kLayouts[i] = {
-                { DescriptorType::UNIFORM_BUFFER, ShaderStageFlags::ALL_SHADER_STAGE_FLAGS, i };
+                config.uniforms[i].type.value_or(DescriptorType::UNIFORM_BUFFER),
-    };
+                ShaderStageFlags::ALL_SHADER_STAGE_FLAGS, i };
+    }
 
+    // This assumes that the uniforms will all be in a single descriptor set at index 1.
+    // If there are shaders with uniforms in other sets then ShaderConfig will need to be expanded
+    // to accommodate that.
+    size_t kDescriptorSetIndex = 1;
     filamat::DescriptorSets descriptors;
-    for (unsigned char i = 0; i < config.uniformNames.size(); ++i) {
+    descriptors[kDescriptorSetIndex] = filamat::DescriptorSetInfo(config.uniforms.size());
-        descriptors[i + 1] = {{ config.uniformNames[i], kLayouts[i], {}}};
+    for (unsigned char i = 0; i < config.uniforms.size(); ++i) {
+        descriptors[kDescriptorSetIndex][i] = {
+                config.uniforms[i].name, kLayouts[i], config.uniforms[i].samplerInfo };
     }
     ShaderGenerator shaderGen(
             std::move(config.vertexShader), std::move(config.fragmentShader), BackendTest::sBackend,
             BackendTest::sIsMobilePlatform, std::move(descriptors));
     Program prog = shaderGen.getProgram(api);
-    for (unsigned char i = 0; i < config.uniformNames.size(); ++i) {
+
-        prog.descriptorBindings(1, {{ config.uniformNames[i], DescriptorType::UNIFORM_BUFFER, i }});
+    Program::DescriptorBindingsInfo bindingsInfo(config.uniforms.size());
+    for (unsigned char i = 0; i < config.uniforms.size(); ++i) {
+        bindingsInfo[i] = {
+                config.uniforms[i].name,
+                config.uniforms[i].type.value_or(DescriptorType::UNIFORM_BUFFER), i };
     }
+    prog.descriptorBindings(1, bindingsInfo);
     mProgram = cleanup.add(api.createProgram(std::move(prog)));
 
     mDescriptorSetLayout = cleanup.add(
             api.createDescriptorSetLayout(DescriptorSetLayout{ kLayouts }));
+}
 
-    mDescriptorSet = cleanup.add(api.createDescriptorSet(mDescriptorSetLayout));
+filament::backend::DescriptorSetHandle Shader::createDescriptorSet(DriverApi& api) const {
+    return mCleanup.add(api.createDescriptorSet(mDescriptorSetLayout));
 }
 
 filament::backend::ProgramHandle Shader::getProgram() const {
@@ -57,8 +71,4 @@ filament::backend::DescriptorSetLayoutHandle Shader::getDescriptorSetLayout() co
     return mDescriptorSetLayout;
 }
 
-filament::backend::DescriptorSetHandle Shader::getDescriptorSet() const {
-    return mDescriptorSet;
-}
-
 } // namespace test

filament/backend/test/Shader.h

@@ -18,14 +18,22 @@
 #define TNT_SHADER_H
 
 #include "Lifetimes.h"
+#include "private/filament/SamplerInterfaceBlock.h"
 
 namespace test {
 
+struct UniformConfig {
+    utils::CString name;
+    // If not specified this will be DescriptorType::UNIFORM_BUFFER
+    std::optional<filament::backend::DescriptorType> type;
+    std::optional<filament::SamplerInterfaceBlock::SamplerInfo> samplerInfo;
+};
+
 // All describing a shader that should be created.
 struct ShaderConfig {
     std::string vertexShader;
     std::string fragmentShader;
-    std::vector<utils::CString> uniformNames;
+    std::vector<UniformConfig> uniforms;
 };
 
 // All values describing a uniform.
@@ -35,6 +43,7 @@ struct ResolvedUniformBindingConfig {
     uint32_t byteOffset;
     filament::backend::descriptor_set_t set;
     filament::backend::descriptor_binding_t binding;
+    std::optional<filament::backend::DescriptorSetHandle> descriptorSet;
 };
 
 // An equivalent to ResolvedUniformBindingConfig with all fields optional.
@@ -46,6 +55,7 @@ struct UniformBindingConfig {
     std::optional<uint32_t> byteOffset;
     std::optional<filament::backend::descriptor_set_t> set;
     std::optional<filament::backend::descriptor_binding_t> binding;
+    std::optional<filament::backend::DescriptorSetHandle> descriptorSet;
 
     template<typename UniformType>
     ResolvedUniformBindingConfig resolve();
@@ -79,12 +89,14 @@ public:
 
     filament::backend::ProgramHandle getProgram() const;
     filament::backend::DescriptorSetLayoutHandle getDescriptorSetLayout() const;
-    filament::backend::DescriptorSetHandle getDescriptorSet() const;
+
+    filament::backend::DescriptorSetHandle createDescriptorSet(
+            filament::backend::DriverApi& api) const;
 
 protected:
+    Cleanup& mCleanup;
     filament::backend::ProgramHandle mProgram;
     filament::backend::DescriptorSetLayoutHandle mDescriptorSetLayout;
-    filament::backend::DescriptorSetHandle mDescriptorSet;
 };
 
 template<typename UniformType>
@@ -95,7 +107,8 @@ ResolvedUniformBindingConfig UniformBindingConfig::resolve() {
             .bufferSize = bufferSize.value_or(resolvedDataSize),
             .byteOffset = byteOffset.value_or(0),
             .set = set.value_or(1),
-            .binding = binding.value_or(0)
+            .binding = binding.value_or(0),
+            .descriptorSet = descriptorSet
     };
 }
 
@@ -120,9 +133,16 @@ void Shader::bindUniform(filament::backend::DriverApi& api,
         UniformBindingConfig config) const {
     auto resolvedConfig = config.resolve<UniformType>();
 
-    api.updateDescriptorSetBuffer(getDescriptorSet(), resolvedConfig.binding, hwBuffer, 0,
+    filament::backend::DescriptorSetHandle descriptorSet;
+    if (resolvedConfig.descriptorSet.has_value()) {
+        descriptorSet = *resolvedConfig.descriptorSet;
+    } else {
+        descriptorSet = createDescriptorSet(api);
+    }
+
+    api.updateDescriptorSetBuffer(descriptorSet, resolvedConfig.binding, hwBuffer, 0,
             resolvedConfig.bufferSize);
-    api.bindDescriptorSet(getDescriptorSet(), resolvedConfig.set, {});
+    api.bindDescriptorSet(descriptorSet, resolvedConfig.set, {});
 }
 
 template<typename UniformType>

filament/backend/test/SharedShaders.cpp

@@ -0,0 +1,253 @@
+/*
+ * Copyright (C) 2021 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 "SharedShaders.h"
+
+#include "Shader.h"
+#include "absl/strings/str_format.h"
+#include "gtest/gtest.h"
+
+namespace test {
+
+using namespace filament::backend;
+
+namespace {
+
+// A shader stored in pieces so that uniform declarations can be injected.
+struct ShaderText {
+    std::string mPrefix;
+    std::string mBody;
+
+    std::string withUniform(const std::string& uniformText) const {
+        return absl::StrFormat("%s\n%s\n%s", mPrefix.c_str(), uniformText.c_str(), mBody.c_str());
+    }
+};
+
+std::optional<ShaderText> GetGlslVertexShader(VertexShaderType type) {
+    switch (type) {
+        case VertexShaderType::Noop: {
+            return ShaderText{
+                    R"(
+#version 450 core
+layout(location = 0) in vec4 mesh_position;
+)", R"(
+void main() {
+    gl_Position = vec4(mesh_position.xy, 0.0, 1.0);
+#if defined(TARGET_VULKAN_ENVIRONMENT)
+    // In Vulkan, clip space is Y-down. In OpenGL and Metal, clip space is Y-up.
+    gl_Position.y = -gl_Position.y;
+#endif
+})" };
+        }
+        case VertexShaderType::Simple: {
+            return ShaderText{
+                    R"(
+#version 450 core
+layout(location = 0) in vec4 mesh_position;
+)", R"(
+void main() {
+    gl_Position = vec4(
+            mesh_position.xy * (params.scaleMinusOne.xy + 1.0) + params.offset.xy,
+            params.scaleMinusOne.z + 1.0,
+            1.0);
+#if defined(TARGET_VULKAN_ENVIRONMENT)
+    // In Vulkan, clip space is Y-down. In OpenGL and Metal, clip space is Y-up.
+    gl_Position.y = -gl_Position.y;
+#endif
+})" };
+        }
+        case VertexShaderType::Textured: {
+            return ShaderText{
+                    R"(
+#version 450 core
+layout(location = 0) in vec4 mesh_position;
+layout(location = 0) out vec2 uv;
+)", R"(
+void main() {
+    gl_Position = vec4(mesh_position.xy, 0.0, 1.0);
+    uv = (mesh_position.xy * 0.5 + 0.5);
+#if defined(TARGET_VULKAN_ENVIRONMENT)
+    // In Vulkan, clip space is Y-down. In OpenGL and Metal, clip space is Y-up.
+    gl_Position.y = -gl_Position.y;
+#endif
+})" };
+        }
+        default:
+            return std::nullopt;
+    }
+}
+
+std::optional<ShaderText> GetGlslFragmentShader(FragmentShaderType type) {
+    switch (type) {
+        case FragmentShaderType::White: {
+            return ShaderText{
+                    R"(
+#version 450 core
+precision mediump int; precision highp float;
+layout(location = 0) out vec4 fragColor;
+)", R"(
+void main() {
+    fragColor = vec4(1.0, 1.0, 1.0, 1.0);
+})" };
+        }
+        case FragmentShaderType::SolidColored: {
+            return ShaderText{
+                    R"(
+#version 450 core
+precision mediump int; precision highp float;
+layout(location = 0) out vec4 fragColor;
+)", R"(
+void main() {
+    fragColor = params.color;
+})" };
+        }
+        case FragmentShaderType::Textured: {
+            return ShaderText{
+                    R"(
+#version 450 core
+precision mediump int; precision highp float;
+layout(location = 0) out vec4 fragColor;
+layout(location = 0) in vec2 uv;
+)", R"(
+void main() {
+    fragColor = texture(test_tex, uv);
+})" };
+        }
+        default:
+            return std::nullopt;
+    }
+}
+
+std::optional<std::string> GetGlslUniform(ShaderUniformType type) {
+    switch (type) {
+        case ShaderUniformType::None: {
+            return "";
+        }
+        case ShaderUniformType::Simple: {
+            return R"(
+layout(binding = 0, set = 1) uniform Params {
+    highp vec4 color;
+    // Use scaleMinusOne instead of scale so that a 0 initialized value is a good default
+    highp vec4 scaleMinusOne;
+    highp vec4 offset;
+} params;
+)";
+        }
+        case ShaderUniformType::SimpleWithPadding: {
+            return R"(
+layout(binding = 0, set = 1) uniform Params {
+    highp vec4 padding[4];  // offset of 64 bytes
+
+    highp vec4 color;
+    // Use scaleMinusOne instead of scale so that a 0 initialized value is a good default
+    highp vec4 scaleMinusOne;
+    highp vec4 offset;
+} params;
+)";
+        }
+        case ShaderUniformType::Sampler: {
+            return R"(
+layout(location = 0, set = 1) uniform sampler2D test_tex;
+)";
+        }
+        default:
+            return std::nullopt;
+    }
+}
+
+std::vector<UniformConfig> GetUniformConfig(ShaderUniformType type) {
+    switch (type) {
+        case ShaderUniformType::None: {
+            return {};
+        }
+        case ShaderUniformType::Simple: {
+            return {{ "Params" }};
+        }
+        case ShaderUniformType::SimpleWithPadding: {
+            return {{ "Params" }};
+        }
+        case ShaderUniformType::Sampler: {
+            filament::SamplerInterfaceBlock::SamplerInfo samplerInfo{
+                    "backend_test", "test_tex", 0,
+                    SamplerType::SAMPLER_2D, SamplerFormat::FLOAT, Precision::HIGH, false };
+            return {{
+                            "test_tex", DescriptorType::SAMPLER, samplerInfo
+                    }};
+        }
+        default:
+            abort();
+    }
+}
+
+ShaderLanguage getShaderLanguage(const Backend& backend) {
+    switch (backend) {
+        case Backend::METAL:
+            return ShaderLanguage::MSL;
+        case Backend::WEBGPU:
+            return ShaderLanguage::WGSL;
+        case Backend::VULKAN:
+        case Backend::NOOP:
+        case Backend::OPENGL:
+        default: {
+            return ShaderLanguage::GLSL;
+        }
+    }
+}
+
+} // namespace
+
+Shader SharedShaders::makeShader(filament::backend::DriverApi& api, Cleanup& cleanup,
+        ShaderRequest request) {
+    std::optional<ShaderText> vertex;
+    std::optional<ShaderText> fragment;
+    std::optional<std::string> uniform;
+    if (getShaderLanguage(BackendTest::sBackend) != ShaderLanguage::GLSL) {
+        // TODO: If any shaders need backend/shader language specific shaders rather than transpiled
+        // versions of the GLSL shader, check environment.
+    }
+    vertex = GetGlslVertexShader(request.mVertexType);
+    fragment = GetGlslFragmentShader(request.mFragmentType);
+    uniform = GetGlslUniform(request.mUniformType);
+    if (vertex.has_value() && fragment.has_value() && uniform.has_value()) {
+        return Shader(
+                api, cleanup, ShaderConfig{
+                        vertex->withUniform(*uniform), fragment->withUniform(*uniform),
+                        GetUniformConfig(request.mUniformType)}
+        );
+    }
+    abort();
+}
+
+std::string SharedShaders::getVertexShaderText(VertexShaderType vertex, ShaderUniformType uniform) {
+    std::optional<ShaderText> vertexText = GetGlslVertexShader(vertex);
+    std::optional<std::string> uniformText = GetGlslUniform(uniform);
+    if (!vertexText.has_value() || !uniformText.has_value()) {
+        abort();
+    }
+    return vertexText->withUniform(*uniformText);
+}
+
+std::string SharedShaders::getFragmentShaderText(FragmentShaderType fragment,
+        ShaderUniformType uniform) {
+    std::optional<ShaderText> fragmentText = GetGlslFragmentShader(fragment);
+    std::optional<std::string> uniformText = GetGlslUniform(uniform);
+    if (!fragmentText.has_value() || !uniformText.has_value()) {
+        abort();
+    }
+    return fragmentText->withUniform(*uniformText);
+}
+
+} // namespace test

filament/backend/test/SharedShaders.h

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2021 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_SHAREDSHADERS_H
+#define TNT_SHAREDSHADERS_H
+
+#include "Shader.h"
+#include "SharedShadersConstants.h"
+#include "Lifetimes.h"
+#include "PlatformRunner.h"
+
+namespace test {
+
+enum class ShaderLanguage : uint8_t {
+    GLSL,
+    MSL,
+    WGSL
+};
+
+struct ShaderRequest {
+    VertexShaderType mVertexType;
+    FragmentShaderType mFragmentType;
+    ShaderUniformType mUniformType;
+};
+
+class SharedShaders {
+public:
+    static Shader makeShader(filament::backend::DriverApi& api, Cleanup& cleanup,
+            ShaderRequest request);
+    static std::string getVertexShaderText(VertexShaderType vertex, ShaderUniformType uniform);
+    static std::string getFragmentShaderText(FragmentShaderType fragment,
+            ShaderUniformType uniform);
+};
+
+} // namespace test
+
+#endif //TNT_SHAREDSHADERS_H

filament/backend/test/SharedShadersConstants.h

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2021 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_SHAREDSHADERSCONSTANTS_H
+#define TNT_SHAREDSHADERSCONSTANTS_H
+
+#include "math/mathfwd.h"
+
+enum class ShaderUniformType : uint8_t {
+    None,
+    Simple,
+    SimpleWithPadding,
+    Sampler,
+};
+
+struct SimpleMaterialParams {
+    filament::math::float4 color;
+    // 1.0 will be added to this value before use.
+    // The XY values are used to scale position inputs and the Z value is used to set the output
+    // position's Z value.
+    filament::math::float4 scaleMinusOne;
+    // Offset will be applied after scale
+    filament::math::float4 offset;
+};
+
+struct SimpleWithPaddingMaterialParams {
+    // The associated uniform structure in the shader will have 64 bytes of padding at the beginning
+    // So users of this struct will need to add 64 bytes to its size and offset all uniform writes.
+    filament::math::float4 color;
+    // 1.0 will be added to this value before use.
+    // The XY values are used to scale position inputs and the Z value is used to set the output
+    // position's Z value.
+    filament::math::float4 scaleMinusOne;
+    // Offset will be applied after scale
+    filament::math::float4 offset;
+};
+
+enum class VertexShaderType : uint8_t {
+    Noop,
+    Simple,
+    Textured
+};
+
+enum class FragmentShaderType : uint8_t {
+    White,
+    SolidColored,
+    Textured
+};
+
+#endif //TNT_SHAREDSHADERSCONSTANTS_H

filament/backend/test/Skip.cpp

@@ -0,0 +1,96 @@
+/*
+ * 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

@@ -0,0 +1,55 @@
+/*
+ * 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