Temporary workaround for PlatformMetal

.github/workflows/presubmit.yml

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

.gitignore

@@ -18,18 +18,3 @@ test*.json
 results
 /compile_commands.json
 /.cache
-build/.cmake/
-build/CMakeCache.txt
-build/CMakeFiles/
-build/Makefile
-build/SPIRV-Tools*
-build/cmake_install.cmake
-build/compile_commands.json
-build/filament/
-build/include/
-build/libs/
-build/mac/ninja
-build/samples/
-build/shaders/
-build/third_party/
-build/tools/

CMakeLists.txt

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

NEW_RELEASE_NOTES.md

@@ -7,3 +7,5 @@ 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:1.59.3'
+    implementation 'com.google.android.filament:filament-android:1.59.0'
 }
 ```
 
@@ -51,7 +51,7 @@ Here are all the libraries available in the group `com.google.android.filament`:
 iOS projects can use CocoaPods to install the latest release:
 
 ```shell
-pod 'Filament', '~> 1.59.3'
+pod 'Filament', '~> 1.59.0'
 ```
 
 ## Documentation

RELEASE_NOTES.md

@@ -7,16 +7,6 @@ A new header is inserted each time a *tag* is created.
 Instead, if you are authoring a PR for the main branch, add your release note to
 [NEW_RELEASE_NOTES.md](./NEW_RELEASE_NOTES.md).
 
-## v1.59.4
-
-
-## v1.59.3
-
-
-## v1.59.2
-
-- Fix build/compile errors when upgrading to MacOS 15.4
-
 ## v1.59.1
 
 

android/filamat-android/CMakeLists.txt

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

android/filament-android/CMakeLists.txt

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

android/gltfio-android/CMakeLists.txt

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

android/gradle.properties

@@ -1,5 +1,5 @@
 GROUP=com.google.android.filament
-VERSION_NAME=1.59.3
+VERSION_NAME=1.59.0
 
 POM_DESCRIPTION=Real-time physically based rendering engine for Android.
 

filament/backend/CMakeLists.txt

@@ -194,6 +194,8 @@ if (FILAMENT_SUPPORTS_VULKAN)
             src/vulkan/VulkanDriver.cpp
             src/vulkan/VulkanDriver.h
             src/vulkan/VulkanDriverFactory.h
+            src/vulkan/VulkanExternalImageManager.cpp
+            src/vulkan/VulkanExternalImageManager.h
             src/vulkan/VulkanFboCache.cpp
             src/vulkan/VulkanFboCache.h
             src/vulkan/VulkanHandles.cpp
@@ -255,11 +257,8 @@ if (FILAMENT_SUPPORTS_WEBGPU)
             src/webgpu/WebGPUConstants.h
             src/webgpu/WebGPUDriver.cpp
             src/webgpu/WebGPUDriver.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)
@@ -508,10 +507,8 @@ if (APPLE OR LINUX)
         test/Arguments.cpp
         test/ImageExpectations.cpp
         test/Lifetimes.cpp
-        test/PlatformRunner.cpp
         test/Shader.cpp
         test/SharedShaders.cpp
-        test/Skip.cpp
         test/test_FeedbackLoops.cpp
         test/test_Blit.cpp
         test/test_MissingRequiredAttributes.cpp
@@ -535,9 +532,6 @@ if (APPLE OR LINUX)
         filamat
         SPIRV
         spirv-cross-glsl)
-    # Create input/output directories for test result images.
-    file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/images/actual_images)
-    file(COPY test/expected_images DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/images)
 endif()
 
 # TODO: Disabling IOS test due to breakage wrt glslang update

filament/backend/include/backend/BufferObjectStreamDescriptor.h

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

filament/backend/include/backend/Platform.h

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

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

@@ -294,6 +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
          */
@@ -304,11 +314,6 @@ public:
          */
         uint32_t height;
 
-        /**
-         * The layerCount of the external image
-         */
-        uint32_t layerCount;
-
         /**
          * The layer count of the external image
          */
@@ -324,11 +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.
          */
@@ -348,20 +348,44 @@ 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);
+
+
+    // Note that the image metadata might change per-frame, hence we need a method for extracting
+    // it.
+    virtual ExternalImageMetadata extractExternalImageMetadata(ExternalImageHandleRef image) const {
+        return {};
+    }
 
     using ImageData = std::pair<VkImage, VkDeviceMemory>;
-    virtual ImageData createExternalImageData(ExternalImageHandleRef externalImage,
-            const ExternalImageMetadata& metadata, uint32_t memoryTypeIndex,
-            VkImageUsageFlags usage);
-
-    virtual VkSampler createExternalSampler(SamplerYcbcrConversion chroma,
-            SamplerParams sampler, uint32_t internalFormat);
-
-    virtual VkImageView createExternalImageView(SamplerYcbcrConversion chroma,
-            uint32_t internalFormat, VkImage image, VkImageSubresourceRange range,
-            VkImageViewType viewType, VkComponentMapping swizzle);
+    virtual ImageData createVkImageFromExternal(ExternalImageHandleRef image) const {
+        return { VK_NULL_HANDLE, VK_NULL_HANDLE };
+    }
 
 protected:
     virtual ExtensionSet getSwapchainInstanceExtensions() const;
@@ -374,20 +398,6 @@ 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

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

filament/backend/src/CommandStream.cpp

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

filament/backend/src/metal/PlatformMetal.mm

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

filament/backend/src/opengl/OpenGLProgram.cpp

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

filament/backend/src/opengl/ShaderCompilerService.h

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

filament/backend/src/ostream.cpp

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

filament/backend/src/vulkan/VulkanConstants.h

@@ -93,7 +93,7 @@
 #endif
 
 #ifndef NDEBUG
-#define FVK_DEBUG_FLAGS (FVK_DEBUG_PERFORMANCE | FVK_DEBUG_FORWARDED_FLAG)
+#define FVK_DEBUG_FLAGS (FVK_DEBUG_PERFORMANCE | FVK_DEBUG_FORWARDED_FLAG | FVK_DEBUG_VALIDATION)
 #else
 #define FVK_DEBUG_FLAGS 0
 #endif
@@ -152,12 +152,12 @@ static_assert(FVK_ENABLED(FVK_DEBUG_VALIDATION));
 #elif FVK_ENABLED(FVK_DEBUG_SYSTRACE)
 
     #include <utils/Systrace.h>
-
+    
     #define FVK_SYSTRACE_CONTEXT()      SYSTRACE_CONTEXT()
     #define FVK_SYSTRACE_START(marker)  SYSTRACE_NAME_BEGIN(marker)
     #define FVK_SYSTRACE_END()          SYSTRACE_NAME_END()
-    #define FVK_SYSTRACE_SCOPE()        SYSTRACE_CALL()
-    #define FVK_PROFILE_MARKER(marker)  SYSTRACE_CALL()
+    #define FVK_SYSTRACE_SCOPE()        SYSTRACE_NAME(__func__)
+    #define FVK_PROFILE_MARKER(marker)  FVK_SYSTRACE_SCOPE()
 
 #else
     #define FVK_SYSTRACE_CONTEXT()

filament/backend/src/vulkan/VulkanDriver.cpp

@@ -200,9 +200,7 @@ Dispatcher VulkanDriver::getDispatcher() const noexcept {
 VulkanDriver::VulkanDriver(VulkanPlatform* platform, VulkanContext const& context,
         Platform::DriverConfig const& driverConfig) noexcept
     : mPlatform(platform),
-      mResourceManager(
-              driverConfig.handleArenaSize,
-              driverConfig.disableHandleUseAfterFreeCheck,
+      mResourceManager(driverConfig.handleArenaSize, driverConfig.disableHandleUseAfterFreeCheck,
               driverConfig.disableHeapHandleTags),
       mAllocator(createAllocator(mPlatform->getInstance(), mPlatform->getPhysicalDevice(),
               mPlatform->getDevice())),
@@ -221,6 +219,8 @@ 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) {
 
@@ -313,7 +313,7 @@ void VulkanDriver::terminate() {
 
     mCurrentSwapChain = {};
     mDefaultRenderTarget = {};
-    mBoundPipeline = {};
+    mPipelineState = {};
 
     mQueryManager.terminate();
 
@@ -325,9 +325,13 @@ void VulkanDriver::terminate() {
 
     mCommands.terminate();
 
+    // Must come before samplerCache, ycbcrConversionCache, descriptorSetCache,
+    // descriptorSetLayoutCache
+    mExternalImageManager.terminate();
+
     mStagePool.terminate();
     mPipelineCache.terminate();
-    mFramebufferCache.terminate();
+    mFramebufferCache.reset();
     mSamplerCache.terminate();
     mDescriptorSetLayoutCache.terminate();
     mDescriptorSetCache.terminate();
@@ -381,6 +385,10 @@ 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 +429,16 @@ void VulkanDriver::updateDescriptorSetTexture(
     auto set = resource_ptr<VulkanDescriptorSet>::cast(&mResourceManager, dsh);
     auto texture = resource_ptr<VulkanTexture>::cast(&mResourceManager, th);
 
-    // TODO: YcbcrConversion?
-    VulkanSamplerCache::Params cacheParams = {
-        .sampler = params,
-    };
-    VkSampler const vksampler = mSamplerCache.getSampler(cacheParams);
-    mDescriptorSetCache.updateSampler(set, binding, texture, vksampler);
+    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);
+    }
 }
 
 void VulkanDriver::flush(int) {
@@ -563,41 +575,35 @@ 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);
-    if (metadata.isProtected) {
-        usage |= backend::TextureUsage::PROTECTED;
-    }
+    auto const& metadata = mPlatform->extractExternalImageMetadata(externalImage);
 
-    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)
-                                                              ? VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
-                                                              : VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;
-    uint32_t const memoryTypeIndex =
-            mContext.selectMemoryType(metadata.memoryTypeBits, requiredMemoryFlags);
-    FILAMENT_CHECK_POSTCONDITION(memoryTypeIndex != VK_MAX_MEMORY_TYPES)
-            << "failed to find a valid memory type for external image memory.";
+    // In theory the following are reasonable expectations, but in practice it's hard for client's
+    // to match up the dimensions of the texture with that of the AHB.
+    // assert_invariant(width == metadata.width);
+    // assert_invariant(height == metadata.height);
+    // assert_invariant(format == metadata.filamentFormat);
+    // assert_invariant(fvkutils::getVkFormat(format) == metadata.format);
 
     VkImage vkimg;
     VkDeviceMemory deviceMemory;
-    std::tie(vkimg, deviceMemory) =
-            mPlatform->createExternalImageData(externalImage, metadata, memoryTypeIndex, vkUsage);
+    std::tie(vkimg, deviceMemory) = mPlatform->createVkImageFromExternal(externalImage);
+
+    VkSamplerYcbcrConversion conversion =
+            mExternalImageManager.getVkSamplerYcbcrConversion(metadata);
 
     auto texture = resource_ptr<VulkanTexture>::make(&mResourceManager, th, mContext,
             mPlatform->getDevice(), mAllocator, &mResourceManager, &mCommands, vkimg, deviceMemory,
-            metadata.format, VK_NULL_HANDLE, metadata.samples, metadata.width, metadata.height,
-            metadata.layerCount, usage, mStagePool);
+            metadata.format, conversion, metadata.samples, metadata.width, metadata.height,
+            metadata.layers, usage, mStagePool);
+
+    if (conversion != VK_NULL_HANDLE) {
+        mExternalImageManager.addExternallySampledTexture(texture, externalImage);
+    }
+
+    // Unlike uploaded textures or swapchains, we need to explicit transition this
+    // texture into the read layout.
+    auto& commands = mCommands.get();
+    texture->transitionLayout(&commands, texture->getPrimaryViewRange(), VulkanLayout::READ_ONLY);
 
     texture.inc();
 }
@@ -630,6 +636,8 @@ 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) {
@@ -798,6 +806,11 @@ 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;
+        mExternalImageManager.addDescriptorSet(layout, set);
+    }
 }
 
 Handle<HwVertexBufferInfo> VulkanDriver::createVertexBufferInfoS() noexcept {
@@ -917,11 +930,19 @@ void VulkanDriver::destroyTimerQuery(Handle<HwTimerQuery> tqh) {
 void VulkanDriver::destroyDescriptorSetLayout(Handle<HwDescriptorSetLayout> dslh) {
     auto layout = resource_ptr<VulkanDescriptorSetLayout>::cast(&mResourceManager, dslh);
     layout.dec();
+
+    if (layout->hasExternalSamplers()) {
+        mExternalImageManager.removeDescriptorSetLayout(layout);
+    }
 }
 
 void VulkanDriver::destroyDescriptorSet(Handle<HwDescriptorSet> dsh) {
     auto set = resource_ptr<VulkanDescriptorSet>::cast(&mResourceManager, dsh);
     set.dec();
+
+    if (mAppState.hasExternalSamplers()) {
+        mExternalImageManager.removeDescriptorSet(set);
+    }
 }
 
 Handle<HwStream> VulkanDriver::createStreamNative(void* nativeStream) {
@@ -1482,7 +1503,6 @@ 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 +1543,7 @@ void VulkanDriver::makeCurrent(Handle<HwSwapChain> drawSch, Handle<HwSwapChain>
     swapChain->acquire(resized);
 
     if (resized) {
-        mFramebufferCache.resetFramebuffers();
+        mFramebufferCache.reset();
     }
 
     if (UTILS_LIKELY(mDefaultRenderTarget)) {
@@ -1542,10 +1562,10 @@ 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(),
-            mBoundPipeline.pipelineLayout, stage, index, value);
+    mPipelineState.program->writePushConstant(mCurrentRenderPass.commandBuffer->buffer(),
+            mPipelineState.pipelineLayout, stage, index, value);
 }
 
 void VulkanDriver::insertEventMarker(char const* string) {
@@ -1724,6 +1744,27 @@ void VulkanDriver::blitDEPRECATED(TargetBufferFlags buffers,
 }
 
 void VulkanDriver::bindPipeline(PipelineState const& pipelineState) {
+    // We need to determine whether to delay bindning until draw().
+    mPipelineState.bindInDraw.first = false;
+    if (mAppState.hasExternalSamplers()) {
+        auto& layouts = pipelineState.pipelineLayout.setLayout;
+        auto haveExternalSamplers = [&](auto hwHandle) {
+            if (!hwHandle) {
+                return false;
+            }
+            auto layout =
+                    resource_ptr<VulkanDescriptorSetLayout>::cast(&mResourceManager, hwHandle);
+            return layout->hasExternalSamplers();
+        };
+        if (std::any_of(layouts.begin(), layouts.end(), haveExternalSamplers)) {
+            mPipelineState.bindInDraw = { true, pipelineState };
+            return;
+        }
+    }
+    bindPipelineImpl(pipelineState);
+}
+
+void VulkanDriver::bindPipelineImpl(PipelineState const& pipelineState) {
     FVK_SYSTRACE_SCOPE();
     auto commands = mCurrentRenderPass.commandBuffer;
     auto vbi = resource_ptr<VulkanVertexBufferInfo>::cast(&mResourceManager,
@@ -1792,10 +1833,11 @@ void VulkanDriver::bindPipeline(PipelineState const& pipelineState) {
 
     constexpr uint8_t descriptorSetMaskTable[4] = {0x1, 0x3, 0x7, 0xF};
 
-    mBoundPipeline = {
+    mPipelineState = {
         .program = program,
         .pipelineLayout = pipelineLayout,
         .descriptorSetMask = fvkutils::DescriptorSetMask(descriptorSetMaskTable[layoutCount]),
+        .bindInDraw = {false, {}},
     };
 
     mPipelineCache.bindLayout(pipelineLayout);
@@ -1842,14 +1884,24 @@ void VulkanDriver::draw2(uint32_t indexOffset, uint32_t indexCount, uint32_t ins
     FVK_SYSTRACE_SCOPE();
     VkCommandBuffer cmdbuffer = mCurrentRenderPass.commandBuffer->buffer();
 
+    if (mAppState.hasExternalSamplers()) {
+        auto const& [bindInDraw, pipelineSt] = mPipelineState.bindInDraw;
+        bool const hasUpdated =
+                mExternalImageManager.prepareBindSets(mDescriptorSetCache.getBoundSets());
+        if (bindInDraw || hasUpdated) {
+            bindPipelineImpl(pipelineSt);
+        }
+        mPipelineState.bindInDraw.first = false;
+    }
+
     mDescriptorSetCache.commit(mCurrentRenderPass.commandBuffer,
-            mBoundPipeline.pipelineLayout,
-            mBoundPipeline.descriptorSetMask);
+            mPipelineState.pipelineLayout,
+            mPipelineState.descriptorSetMask);
 
     // Finally, make the actual draw call. TODO: support subranges
-    const uint32_t firstIndex = indexOffset;
-    const int32_t vertexOffset = 0;
-    const uint32_t firstInstId = 0;
+    uint32_t const firstIndex = indexOffset;
+    constexpr int32_t vertexOffset = 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"
@@ -119,6 +120,7 @@ private:
 
 private:
     void collectGarbage();
+    void bindPipelineImpl(PipelineState const& pipelineState);
 
     VulkanPlatform* mPlatform = nullptr;
     fvkmemory::ResourceManager mResourceManager;
@@ -143,21 +145,29 @@ private:
     VulkanDescriptorSetLayoutCache mDescriptorSetLayoutCache;
     VulkanDescriptorSetCache mDescriptorSetCache;
     VulkanQueryManager mQueryManager;
+    VulkanExternalImageManager mExternalImageManager;
 
     // This is necessary for us to write to push constants after binding a pipeline.
     struct {
+        // For push constant
         resource_ptr<VulkanProgram> program;
+        // For push commiting dynamic ubos in draw()
         VkPipelineLayout pipelineLayout;
         fvkutils::DescriptorSetMask descriptorSetMask;
-    } mBoundPipeline = {};
 
-    // We need to store information about a render pass to enable better barriers at the end of a
-    // renderpass.
+        std::pair<bool, PipelineState> bindInDraw = {false, {}};
+    } mPipelineState = {};
+
     struct {
-        using AttachmentArray =
-                fvkutils::StaticVector<VulkanAttachment, MAX_RENDERTARGET_ATTACHMENT_TEXTURES>;
-        AttachmentArray attachments;
-    } mRenderPassFboInfo = {};
+        // 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 +1,280 @@
+/*
+ * Copyright (C) 2025 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "VulkanExternalImageManager.h"
+
+#include "VulkanDescriptorSetCache.h"
+#include "VulkanDescriptorSetLayoutCache.h"
+#include "VulkanSamplerCache.h"
+#include "VulkanYcbcrConversionCache.h"
+#include "vulkan/memory/ResourcePointer.h"
+#include "vulkan/utils/Conversion.h"
+
+#include <backend/platforms/VulkanPlatform.h>
+
+#include <algorithm>
+
+namespace filament::backend {
+
+namespace {
+
+template<typename T>
+void erase(std::vector<T>& v, std::function<bool(T const&)> f) {
+    auto newEnd = std::remove_if(v.begin(), v.end(), f);
+    v.erase(newEnd, v.end());
+}
+
+} // anonymous
+
+VulkanExternalImageManager::VulkanExternalImageManager(VulkanPlatform* platform,
+        VulkanSamplerCache* samplerCache, VulkanYcbcrConversionCache* ycbcrConversionCache,
+        VulkanDescriptorSetCache* setCache, VulkanDescriptorSetLayoutCache* layoutCache)
+    : mPlatform(platform),
+      mSamplerCache(samplerCache),
+      mYcbcrConversionCache(ycbcrConversionCache),
+      mDescriptorSetCache(setCache),
+      mDescriptorSetLayoutCache(layoutCache) {
+}
+
+VulkanExternalImageManager::~VulkanExternalImageManager() = default;
+
+void VulkanExternalImageManager::terminate() {
+    mSetAndLayouts.clear();
+    mSetBindings.clear();
+    mImages.clear();
+}
+
+void VulkanExternalImageManager::onBeginFrame() {
+    std::for_each(mImages.begin(), mImages.end(), [](ImageData& image) {
+        image.hasBeenValidated = false;
+    });
+}
+
+bool VulkanExternalImageManager::prepareBindSets(SetArray const& sets) {
+    bool hasUpdated = false;
+    for (auto set: sets) {
+        if (!set) {
+            continue;
+        }
+        if (auto itr = std::find_if(mSetAndLayouts.begin(), mSetAndLayouts.end(),
+                    [&](auto const& setAndLayout) { return setAndLayout.first == set; });
+                itr != mSetAndLayouts.end()) {
+            hasUpdated = updateSetAndLayout(itr->first, itr->second) || hasUpdated;
+        }
+    }
+    return hasUpdated;
+}
+
+bool VulkanExternalImageManager::updateSetAndLayout(
+        fvkmemory::resource_ptr<VulkanDescriptorSet> set,
+        fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout) {
+    auto findImage = [&](fvkmemory::resource_ptr<VulkanTexture> texture) -> ImageData* {
+        auto itr = std::find_if(mImages.begin(), mImages.end(), [&](ImageData const& data) {
+            return data.ptr == texture;
+        });
+        assert_invariant(itr != mImages.end());
+        return &(*itr);
+    };
+
+    //std::vector<std::pair<uint8_t, ImageData*>> externalImages;
+    utils::FixedCapacityVector<std::pair<uint8_t, VkSampler>> samplerAndBindings;
+    samplerAndBindings.reserve(MAX_SAMPLER_COUNT);
+
+    bool hasImageUpdates = false;
+    for (auto& bindingInfo : mSetBindings) {
+        if (bindingInfo.set != set) {
+            continue;
+        }
+        auto imageData = findImage(bindingInfo.image);
+        hasImageUpdates = updateImage(imageData) || hasImageUpdates;
+
+        auto samplerParams = bindingInfo.samplerParams;
+        // according to spec, these must match chromaFilter
+        // https://registry.khronos.org/vulkan/specs/latest/man/html/VkSamplerCreateInfo.html#VUID-VkSamplerCreateInfo-minFilter-01645
+        samplerParams.filterMag = SamplerMagFilter::NEAREST;
+        samplerParams.filterMin = SamplerMinFilter::NEAREST;
+
+        auto sampler = mSamplerCache->getSampler({
+            .sampler = samplerParams,
+            .conversion = imageData->conversion,
+        });
+        samplerAndBindings.push_back({ bindingInfo.binding, sampler });
+    }
+
+    // We need to sort by binding number
+    std::sort(samplerAndBindings.begin(), samplerAndBindings.end());
+
+    utils::FixedCapacityVector<VkSampler> outSamplers;
+    outSamplers.reserve(MAX_SAMPLER_COUNT);
+    std::for_each(samplerAndBindings.begin(), samplerAndBindings.end(),
+            [&](auto const& b) { outSamplers.push_back(b.second); });
+
+    VkDescriptorSetLayout const oldLayout = layout->getVkLayout();
+    VkDescriptorSetLayout const newLayout =
+            mDescriptorSetLayoutCache->getVkLayout(layout->bitmask, outSamplers);
+    bool const hasLayoutUpdate = oldLayout != newLayout;
+    layout->setVkLayout(newLayout);
+
+    assert_invariant(
+            (!hasImageUpdates && !hasLayoutUpdate) ||
+            (hasImageUpdates && hasLayoutUpdate));
+
+    if (!hasLayoutUpdate) {
+        return false;
+    }
+
+    auto foldBitsInHalf = [](auto bitset) {
+        constexpr size_t BITMASK_LOWER_BITS_LEN = sizeof(bitset) * 4;
+        decltype(bitset) outBitset;
+        bitset.forEachSetBit([&](size_t index) { outBitset.set(index % BITMASK_LOWER_BITS_LEN); });
+        return outBitset;
+    };
+    // We need to build a new descriptor set from the new layout
+    VkDescriptorSet oldSet = set->getVkSet();
+    VkDescriptorSet newSet = mDescriptorSetCache->getVkSet(layout);
+
+    using Bitmask = fvkutils::UniformBufferBitmask;
+    static_assert(sizeof(Bitmask) * 8 == fvkutils::MAX_DESCRIPTOR_SET_BITMASK_BITS);
+
+    auto const ubo = layout->bitmask.ubo | layout->bitmask.dynamicUbo;
+    auto const samplers = layout->bitmask.sampler & (~layout->bitmask.externalSampler);
+
+    // each bitmask denotes a binding index, and separated into two stages - vertex and buffer
+    // We fold the two stages into just the lower half of the bits to denote a combined set of
+    // bindings.
+    Bitmask const copyBindings = foldBitsInHalf(ubo | samplers);
+
+    // TODO: fix the size for better memory
+    std::vector<VkCopyDescriptorSet> copies;
+    copyBindings.forEachSetBit([&](size_t index) {
+        copies.push_back({
+            .sType = VK_STRUCTURE_TYPE_COPY_DESCRIPTOR_SET,
+            .srcSet = oldSet,
+            .srcBinding = (uint32_t) index,
+            .dstSet = newSet,
+            .dstBinding = (uint32_t) index,
+            .descriptorCount = 1,
+        });
+    });
+    vkUpdateDescriptorSets(mPlatform->getDevice(), 0, nullptr, copies.size(), copies.data());
+
+    set->setVkSet(newSet);
+
+    // We need to release the vkset, which is no longer used, back into the pool.
+    mDescriptorSetCache->manualRecyle(layout->count, oldLayout, oldSet);
+
+    // We need to update the external samplers in the set
+    for (auto& bindingInfo: mSetBindings) {
+        if (bindingInfo.set != set) {
+            continue;
+        }
+        mDescriptorSetCache->updateSampler(set, bindingInfo.binding, bindingInfo.image,
+                VK_NULL_HANDLE);
+    }
+    return true;
+}
+
+VkSamplerYcbcrConversion VulkanExternalImageManager::getVkSamplerYcbcrConversion(
+        VulkanPlatform::ExternalImageMetadata const& metadata) {
+    // This external image does not require external sampler (YUV conversion).
+    if (metadata.externalFormat == 0) {
+        return VK_NULL_HANDLE;
+    }
+    VulkanYcbcrConversionCache::Params ycbcrParams = {
+        .conversion = {
+            .ycbcrModel = fvkutils::getYcbcrModelConversionFilament(metadata.ycbcrModel),
+            .r = fvkutils::getSwizzleFilament(metadata.ycbcrConversionComponents.r, 0),
+            .g = fvkutils::getSwizzleFilament(metadata.ycbcrConversionComponents.g, 1),
+            .b = fvkutils::getSwizzleFilament(metadata.ycbcrConversionComponents.b, 2),
+            .a = fvkutils::getSwizzleFilament(metadata.ycbcrConversionComponents.a, 3),
+            .ycbcrRange = fvkutils::getYcbcrRangeFilament(metadata.ycbcrRange),
+            .xChromaOffset = fvkutils::getChromaLocationFilament(metadata.xChromaOffset),
+            .yChromaOffset = fvkutils::getChromaLocationFilament(metadata.yChromaOffset),
+
+            // Unclear where to get the chromaFilter, we just assume it's nearest.
+            .chromaFilter = SamplerMagFilter::NEAREST,
+        },
+        .format = metadata.filamentFormat,
+        .externalFormat = metadata.externalFormat,
+    };
+    return mYcbcrConversionCache->getConversion(ycbcrParams);
+}
+
+bool VulkanExternalImageManager::updateImage(ImageData* image) {
+    if (image->hasBeenValidated) {
+        return false;
+    }
+    image->hasBeenValidated = true;
+
+    auto metadata = mPlatform->extractExternalImageMetadata(image->platformHandle);
+    auto vkYcbcr = getVkSamplerYcbcrConversion(metadata);
+    if (vkYcbcr == image->conversion) {
+        return false;
+    }
+
+    image->ptr->setYcbcrConversion(vkYcbcr, metadata.externalFormat != 0);
+    image->conversion = vkYcbcr;
+    return true;
+}
+
+void VulkanExternalImageManager::addDescriptorSet(
+        fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout,
+        fvkmemory::resource_ptr<VulkanDescriptorSet> set) {
+    mSetAndLayouts.push_back({set, layout});
+}
+
+void VulkanExternalImageManager::removeDescriptorSet(
+        fvkmemory::resource_ptr<VulkanDescriptorSet> inSet) {
+    erase<SetAndLayout>(mSetAndLayouts,
+            [&](auto const& setLayout) { return (setLayout.first == inSet); });
+    erase<SetBindingInfo>(mSetBindings,
+            [&](auto const& bindingInfo) { return (bindingInfo.set == inSet); });
+}
+
+void VulkanExternalImageManager::removeDescriptorSetLayout(
+        fvkmemory::resource_ptr<VulkanDescriptorSetLayout> inLayout) {
+    erase<SetAndLayout>(mSetAndLayouts,
+            [&](auto const& setLayout) { return (setLayout.second == inLayout); });
+}
+
+void VulkanExternalImageManager::bindExternallySampledTexture(
+        fvkmemory::resource_ptr<VulkanDescriptorSet> set, uint8_t bindingPoint,
+        fvkmemory::resource_ptr<VulkanTexture> image, SamplerParams samplerParams) {
+    // Should we do duplicate validation here?
+    mSetBindings.push_back({ bindingPoint, image, set, samplerParams });
+}
+
+void VulkanExternalImageManager::addExternallySampledTexture(
+        fvkmemory::resource_ptr<VulkanTexture> image,
+        Platform::ExternalImageHandleRef platformHandleRef) {
+    mImages.push_back({ image, platformHandleRef, false });
+}
+
+void VulkanExternalImageManager::removeExternallySampledTexture(
+        fvkmemory::resource_ptr<VulkanTexture> image) {
+    erase<SetBindingInfo>(mSetBindings,
+            [&](auto const& bindingInfo) { return (bindingInfo.image == image); });
+    erase<ImageData>(mImages, [&](auto const& imageData) { return imageData.ptr == image; });
+}
+
+bool VulkanExternalImageManager::isExternallySampledTexture(
+        fvkmemory::resource_ptr<VulkanTexture> image) const {
+    return std::find_if(mImages.begin(), mImages.end(),
+                   [&](auto const& imageData) { return imageData.ptr == image; }) != mImages.end();
+}
+
+
+} // namesapce filament::backend

filament/backend/src/vulkan/VulkanExternalImageManager.h

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2025 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_CACHING_VULKANEXTERNALIMAGEMANAGER_H
+#define TNT_FILAMENT_BACKEND_CACHING_VULKANEXTERNALIMAGEMANAGER_H
+
+#include "VulkanHandles.h"
+
+#include <backend/DriverEnums.h>
+
+#include <array>
+#include <vector>
+
+namespace filament::backend {
+
+class VulkanYcbcrConversionCache;
+class VulkanSamplerCache;
+class VulkanDescriptorSetLayoutCache;
+class VulkanDescriptorSetCache;
+
+// Manages the logic of external images and their quirks wrt Vulikan.
+class VulkanExternalImageManager {
+public:
+
+    VulkanExternalImageManager(
+            VulkanPlatform* platform,
+            VulkanSamplerCache* samplerCache,
+            VulkanYcbcrConversionCache* ycbcrConversionCache,
+            VulkanDescriptorSetCache* setCache,
+            VulkanDescriptorSetLayoutCache* layoutCache);
+
+    ~VulkanExternalImageManager();
+
+    void terminate();
+
+    void onBeginFrame();
+
+    using SetArray = std::array<fvkmemory::resource_ptr<VulkanDescriptorSet>,
+            VulkanDescriptorSetLayout::UNIQUE_DESCRIPTOR_SET_COUNT>;
+
+    // This sets the currently bound layouts objects for the pipeline
+    bool prepareBindSets(SetArray const& layouts);
+
+    void addDescriptorSet(fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout,
+            fvkmemory::resource_ptr<VulkanDescriptorSet> set);
+
+    void removeDescriptorSetLayout(fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);
+
+    void removeDescriptorSet(fvkmemory::resource_ptr<VulkanDescriptorSet> set);
+
+    void bindExternallySampledTexture(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
+            uint8_t bindingPoint, fvkmemory::resource_ptr<VulkanTexture> image,
+            SamplerParams samplerParams);
+
+    void addExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> image,
+            Platform::ExternalImageHandleRef platformHandleRef);
+
+    void removeExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> image);
+
+    bool isExternallySampledTexture(fvkmemory::resource_ptr<VulkanTexture> image) const;
+
+    VkSamplerYcbcrConversion getVkSamplerYcbcrConversion(
+            VulkanPlatform::ExternalImageMetadata const& metadata);
+
+private:
+
+    struct ImageData {
+        fvkmemory::resource_ptr<VulkanTexture> ptr;
+        Platform::ExternalImageHandle platformHandle;
+        bool hasBeenValidated = false; // indicates whether the image has been validated *this frame*
+        VkSamplerYcbcrConversion conversion = VK_NULL_HANDLE;
+    };
+
+    bool updateSetAndLayout(fvkmemory::resource_ptr<VulkanDescriptorSet> set,
+            fvkmemory::resource_ptr<VulkanDescriptorSetLayout> layout);
+    bool updateImage(ImageData* imageData);
+
+    VulkanPlatform* mPlatform;
+    VulkanSamplerCache* mSamplerCache;
+    VulkanYcbcrConversionCache* mYcbcrConversionCache;
+    VulkanDescriptorSetCache* mDescriptorSetCache;
+    VulkanDescriptorSetLayoutCache* mDescriptorSetLayoutCache;
+
+    using SetAndLayout = std::pair<fvkmemory::resource_ptr<VulkanDescriptorSet>,
+            fvkmemory::resource_ptr<VulkanDescriptorSetLayout>>;
+
+    struct SetBindingInfo {
+        uint8_t binding = 0;
+        fvkmemory::resource_ptr<VulkanTexture> image;
+        fvkmemory::resource_ptr<VulkanDescriptorSet> set;
+        SamplerParams samplerParams;
+    };
+
+    // Use vectors instead of hash maps because we only expect small number of entries.
+    std::vector<SetAndLayout> mSetAndLayouts;
+    std::vector<SetBindingInfo> mSetBindings;
+    std::vector<ImageData> mImages;
+};
+
+} // filament::backend
+
+#endif // TNT_FILAMENT_BACKEND_CACHING_VULKANEXTERNALIMAGEMANAGER_H

filament/backend/src/vulkan/VulkanFboCache.cpp

@@ -340,21 +340,15 @@ VkRenderPass VulkanFboCache::getRenderPass(RenderPassKey const& config) noexcept
     return renderPass;
 }
 
-void VulkanFboCache::resetFramebuffers() noexcept {
-    for (const auto& pair: mFramebufferCache) {
+void VulkanFboCache::reset() noexcept {
+    for (auto pair : mFramebufferCache) {
         mRenderPassRefCount[pair.first.renderPass]--;
         vkDestroyFramebuffer(mDevice, pair.second.handle, VKALLOC);
     }
     mFramebufferCache.clear();
-}
-
-void VulkanFboCache::terminate() noexcept {
-    resetFramebuffers();
-
-    for (const auto& pair: mRenderPassCache) {
+    for (auto pair : mRenderPassCache) {
         vkDestroyRenderPass(mDevice, pair.second.handle, VKALLOC);
     }
-    mRenderPassRefCount.clear();
     mRenderPassCache.clear();
 }
 

filament/backend/src/vulkan/VulkanFboCache.h

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

filament/backend/src/vulkan/VulkanPipelineCache.cpp

@@ -35,12 +35,7 @@ using namespace bluevk;
 namespace filament::backend {
 
 VulkanPipelineCache::VulkanPipelineCache(VkDevice device)
-    : mDevice(device) {
-    VkPipelineCacheCreateInfo createInfo = {
-        .sType = VK_STRUCTURE_TYPE_PIPELINE_CACHE_CREATE_INFO,
-    };
-    bluevk::vkCreatePipelineCache(mDevice, &createInfo, VKALLOC, &mPipelineCache);
-}
+        : mDevice(device) {}
 
 void VulkanPipelineCache::bindLayout(VkPipelineLayout layout) noexcept {
     mPipelineRequirements.layout = layout;
@@ -220,7 +215,7 @@ VulkanPipelineCache::PipelineCacheEntry* VulkanPipelineCache::createPipeline() n
     PipelineCacheEntry cacheEntry = {
         .lastUsed = mCurrentTime,
     };
-    VkResult error = vkCreateGraphicsPipelines(mDevice, mPipelineCache, 1, &pipelineCreateInfo,
+    VkResult error = vkCreateGraphicsPipelines(mDevice, VK_NULL_HANDLE, 1, &pipelineCreateInfo,
             VKALLOC, &cacheEntry.handle);
     assert_invariant(error == VK_SUCCESS);
     if (error != VK_SUCCESS) {
@@ -276,8 +271,6 @@ void VulkanPipelineCache::terminate() noexcept {
     }
     mPipelines.clear();
     mBoundPipeline = {};
-
-    vkDestroyPipelineCache(mDevice, mPipelineCache, VKALLOC);
 }
 
 void VulkanPipelineCache::gc() noexcept {

filament/backend/src/vulkan/VulkanPipelineCache.h

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

filament/backend/src/vulkan/VulkanSamplerCache.cpp

@@ -18,6 +18,7 @@
 
 #include "VulkanConstants.h"
 #include "vulkan/utils/Conversion.h"
+#include "vulkan/vulkan_core.h"
 
 #include <utils/Panic.h>
 

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

@@ -993,30 +993,6 @@ 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 "vulkan/vulkan_core.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>
 
@@ -57,7 +57,7 @@ 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 +120,9 @@ 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 +138,38 @@ std::pair<VkFormat, VkImageUsageFlags> getVKFormatAndUsage(const AHardwareBuffer
     return { format, usage };
 }
 
-VulkanPlatform::ImageData allocateExternalImage(AHardwareBuffer* buffer, VkDevice device,
-        VulkanPlatform::ExternalImageMetadata const& metadata, uint32_t memoryTypeIndex,
-        VkImageUsageFlags usage) {
-    VulkanPlatform::ImageData data;
-
-    // if external format we need to specifiy it in the allocation
-    const bool useExternalFormat = metadata.format == VK_FORMAT_UNDEFINED;
-
-    const VkExternalFormatANDROID externalFormat = {
-        .sType = VK_STRUCTURE_TYPE_EXTERNAL_FORMAT_ANDROID,
-        .pNext = nullptr,
-        // pass down the format (external means we don't have it VK defined)
-        .externalFormat = metadata.externalFormat,
+std::pair<TextureFormat, TextureUsage> getFilamentFormatAndUsage(const AHardwareBuffer_Desc& desc,
+        bool sRGB) {
+    auto const format = mapToFilamentFormat(desc.format, sRGB);
+    return {
+        format,
+        mapToFilamentUsage(desc.usage, format),
     };
-    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 +178,20 @@ Platform::ExternalImageHandle VulkanPlatformAndroid::createExternalImage(
 
 VulkanPlatformAndroid::ExternalImageDescAndroid VulkanPlatformAndroid::getExternalImageDesc(
         ExternalImageHandleRef externalImage) const noexcept {
-    auto const* fvkExternalImage =
-            static_cast<ExternalImageVulkanAndroid const*>(externalImage.get());
-
+    auto metadata = extractExternalImageMetadata(externalImage);
     return {
-        .width = fvkExternalImage->width,
-        .height = fvkExternalImage->height,
-        .format = fvkExternalImage->format,
-        .usage = fvkExternalImage->usage,
+        .width = metadata.width,
+        .height = metadata.height,
+        .format = metadata.filamentFormat,
+        .usage = metadata.filamentUsage,
     };
 }
 
-VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::getExternalImageMetadata(
-        ExternalImageHandleRef externalImage) {
-    auto const* fvkExternalImage =
-            static_cast<ExternalImageVulkanAndroid const*>(externalImage.get());
+VulkanPlatform::ExternalImageMetadata VulkanPlatformAndroid::extractExternalImageMetadata(
+        ExternalImageHandleRef image) const {
+    auto const* fvkExternalImage = static_cast<ExternalImageVulkanAndroid const*>(image.get());
 
-    ExternalImageMetadata metadata;
+    ExternalImageMetadata metadata = {};
     AHardwareBuffer* buffer = fvkExternalImage->aHardwareBuffer;
     if (__builtin_available(android 26, *)) {
         AHardwareBuffer_Desc bufferDesc;
@@ -249,16 +199,30 @@ 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 +232,116 @@ 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)";
     metadata.externalFormat = formatInfo.externalFormat;
+
+    // Choose either externalFormat > 0 or metadata.format and prefer the latter.
+    if (metadata.externalFormat > 0 &&  metadata.format != VK_FORMAT_UNDEFINED) {
+        // See VUID-VkImageCreateInfo-pNext-09457
+        metadata.usage = VK_IMAGE_USAGE_SAMPLED_BIT;
+        metadata.externalFormat = 0;
+    }
+
     metadata.allocationSize = properties.allocationSize;
     metadata.memoryTypeBits = properties.memoryTypeBits;
+
+    metadata.ycbcrConversionComponents = formatInfo.samplerYcbcrConversionComponents;
+    metadata.ycbcrModel = formatInfo.suggestedYcbcrModel;
+    metadata.ycbcrRange = formatInfo.suggestedYcbcrRange;
+    metadata.xChromaOffset = formatInfo.suggestedXChromaOffset;
+    metadata.yChromaOffset = formatInfo.suggestedYChromaOffset;
+
     return metadata;
 }
 
-VulkanPlatformAndroid::ImageData VulkanPlatformAndroid::createExternalImageData(
-        ExternalImageHandleRef externalImage, const ExternalImageMetadata& metadata,
-        uint32_t memoryTypeIndex, VkImageUsageFlags usage) {
+VulkanPlatformAndroid::ImageData VulkanPlatformAndroid::createVkImageFromExternal(
+        ExternalImageHandleRef externalImage) const {
+    auto const& metadata = extractExternalImageMetadata(externalImage);
+
     auto const* fvkExternalImage =
             static_cast<ExternalImageVulkanAndroid const*>(externalImage.get());
-    ImageData data = allocateExternalImage(fvkExternalImage->aHardwareBuffer, getDevice(), metadata,
-            memoryTypeIndex, usage);
-    VkResult result = vkBindImageMemory(getDevice(), data.first, data.second, 0);
-    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
-        << "vkBindImageMemory error=" << static_cast<int32_t>(result);
-    return data;
-}
+    AHardwareBuffer* buffer = fvkExternalImage->aHardwareBuffer;
 
-VkImageView VulkanPlatform::createExternalImageViewImpl(VkDevice device, SamplerYcbcrConversion chroma,
-            uint32_t internalFormat, VkImage image, VkImageSubresourceRange range,
-            VkImageViewType viewType, VkComponentMapping swizzle){
-    VkExternalFormatANDROID externalFormat = {
+    // if external format we need to specifiy it in the allocation
+    bool const useExternalFormat = metadata.format == VK_FORMAT_UNDEFINED;
+
+    VkExternalFormatANDROID const externalFormat = {
         .sType = VK_STRUCTURE_TYPE_EXTERNAL_FORMAT_ANDROID,
-        .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,
+        .externalFormat = metadata.externalFormat,
+    };
+    VkExternalMemoryImageCreateInfo const externalCreateInfo = {
+        .sType = VK_STRUCTURE_TYPE_EXTERNAL_MEMORY_IMAGE_CREATE_INFO,
+        .pNext = useExternalFormat ? &externalFormat : nullptr,
+        .handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID,
     };
 
-    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,
+    VkImageCreateInfo const imageInfo{
+        .sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,
+        .pNext = &externalCreateInfo,
+        .flags = useExternalFormat ? VK_IMAGE_CREATE_ALIAS_BIT : 0u,
+        .imageType = VK_IMAGE_TYPE_2D,
+        .format = metadata.format,
+        .extent = {
+            metadata.width,
+            metadata.height,
+            1u,
+        },
+        .mipLevels = 1,
+        .arrayLayers = metadata.layers,
+        .samples = metadata.samples,
+        .usage = metadata.usage,
     };
-    VkSampler sampler;
-    result = vkCreateSampler(device, &samplerInfo, VKALLOC, &sampler);
+
+    VkDevice const device = getDevice();
+
+    VkImage image;
+    VkResult result = vkCreateImage(device, &imageInfo, VKALLOC, &image);
     FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
-        << "Unable to create sampler."
-        << " error=" << static_cast<int32_t>(result);
-    return sampler;
+            << "vkCreateImage failed with error=" << static_cast<int32_t>(result);
+
+    // Allocate the memory
+    VkImportAndroidHardwareBufferInfoANDROID const androidHardwareBufferInfo = {
+        .sType = VK_STRUCTURE_TYPE_IMPORT_ANDROID_HARDWARE_BUFFER_INFO_ANDROID,
+        .buffer = buffer,
+    };
+    VkMemoryDedicatedAllocateInfo const memoryDedicatedAllocateInfo = {
+        .sType = VK_STRUCTURE_TYPE_MEMORY_DEDICATED_ALLOCATE_INFO,
+        .pNext = &androidHardwareBufferInfo,
+        .image = image,
+        .buffer = VK_NULL_HANDLE,
+    };
+
+    VkPhysicalDeviceMemoryProperties memoryProperties;
+    vkGetPhysicalDeviceMemoryProperties(getPhysicalDevice(), &memoryProperties);
+
+
+    VkMemoryPropertyFlags const requiredMemoryFlags =
+            any(metadata.filamentUsage & TextureUsage::UPLOADABLE)
+                    ? VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
+                    : VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT;
+
+    uint32_t const memoryTypeIndex = VulkanContext::selectMemoryType(memoryProperties,
+            metadata.memoryTypeBits, requiredMemoryFlags);
+
+    VkMemoryAllocateInfo const allocInfo = {
+        .sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
+        .pNext = &memoryDedicatedAllocateInfo,
+        .allocationSize = metadata.allocationSize,
+        .memoryTypeIndex = memoryTypeIndex,
+    };
+    VkDeviceMemory memory;
+    result = vkAllocateMemory(device, &allocInfo, VKALLOC, &memory);
+    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+            << "vkAllocateMemory failed with error=" << static_cast<int32_t>(result);
+
+    result = vkBindImageMemory(getDevice(), image, memory, 0);
+    FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+            << "vkBindImageMemory error=" << static_cast<int32_t>(result);
+    return { image, memory };
 }
 
 VulkanPlatform::ExtensionSet VulkanPlatformAndroid::getSwapchainInstanceExtensions() const {
@@ -427,20 +369,9 @@ VulkanPlatform::SurfaceBundle VulkanPlatformAndroid::createVkSurfaceKHR(void* na
 // Deprecated platform dependent helper methods
 VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensionsImpl() { return {}; }
 
-VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadataImpl(
-        ExternalImageHandleRef externalImage, VkDevice device) {
-    return ExternalImageMetadata{};
-}
-
-VulkanPlatform::ImageData VulkanPlatform::createExternalImageDataImpl(
-        ExternalImageHandleRef externalImage, VkDevice device,
-        const ExternalImageMetadata& metadata, uint32_t memoryTypeIndex, VkImageUsageFlags usage) {
-    return ImageData{};
-}
-
 VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHRImpl(void* nativeWindow,
         VkInstance instance, uint64_t flags) noexcept {
     return SurfaceBundle{};
 }
 
-}// namespace filament::backend
+} // namespace filament::backend

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

@@ -24,12 +24,28 @@
 #include <bluevk/BlueVK.h>
 
 // Platform specific includes and defines
-#include <Cocoa/Cocoa.h>
-#import <Metal/Metal.h>
-#import <QuartzCore/CAMetalLayer.h>
+#if defined(__APPLE__)
+    #include <Cocoa/Cocoa.h>
+    #import <Metal/Metal.h>
+    #import <QuartzCore/CAMetalLayer.h>
 
-#ifndef VK_MVK_macos_surface
-    #error VK_MVK_macos_surface is not defined
+    #ifndef VK_MVK_macos_surface
+         #error VK_MVK_macos_surface is not defined
+    #endif
+#elif defined(FILAMENT_IOS)
+    // Metal is not available when building for the iOS simulator on Desktop.
+    #define METAL_AVAILABLE __has_include(<QuartzCore/CAMetalLayer.h>)
+    #if METAL_AVAILABLE
+        #import <Metal/Metal.h>
+        #import <QuartzCore/CAMetalLayer.h>
+    #endif
+
+    #ifndef VK_MVK_ios_surface
+        #error VK_MVK_ios_surface is not defined
+    #endif
+    #define METALVIEW_TAG 255
+#else
+    #error Not a supported Apple + Vulkan platform
 #endif
 
 using namespace bluevk;
@@ -38,52 +54,48 @@ namespace filament::backend {
 
 VulkanPlatform::ExtensionSet VulkanPlatform::getSwapchainInstanceExtensionsImpl() {
     ExtensionSet const ret = {
+    #if defined(__APPLE__)
         VK_MVK_MACOS_SURFACE_EXTENSION_NAME,  // TODO: replace with VK_EXT_metal_surface
+    #elif defined(FILAMENT_IOS) && defined(METAL_AVAILABLE)
+        VK_MVK_IOS_SURFACE_EXTENSION_NAME,
+    #endif
     };
     return ret;
 }
 
-VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadataImpl(
-        ExternalImageHandleRef externalImage, VkDevice device) {
-    return {};
-}
-
-VulkanPlatform::ImageData VulkanPlatform::createExternalImageDataImpl(
-        ExternalImageHandleRef externalImage, VkDevice device,
-        const ExternalImageMetadata& metadata, uint32_t memoryTypeIndex, VkImageUsageFlags usage) {
-    return {};
-}
-
-VkSampler VulkanPlatform::createExternalSamplerImpl(VkDevice device,
-    SamplerYcbcrConversion chroma,
-    SamplerParams sampler,
-    uint32_t internalFormat) {
-    return VK_NULL_HANDLE;
-}
-
-VkImageView VulkanPlatform::createExternalImageViewImpl(VkDevice device,
-        SamplerYcbcrConversion chroma, uint32_t internalFormat, VkImage image,
-        VkImageSubresourceRange range, VkImageViewType viewType, VkComponentMapping swizzle) {
-    return VK_NULL_HANDLE;
-}
-
 VulkanPlatform::SurfaceBundle VulkanPlatform::createVkSurfaceKHRImpl(void* nativeWindow,
         VkInstance instance, uint64_t flags) noexcept {
     VkSurfaceKHR surface;
-    NSView* nsview = (__bridge NSView*) nativeWindow;
-    FILAMENT_CHECK_POSTCONDITION(nsview) << "Unable to obtain Metal-backed NSView.";
+    #if defined(__APPLE__)
+        NSView* nsview = (__bridge NSView*) nativeWindow;
+        FILAMENT_CHECK_POSTCONDITION(nsview) << "Unable to obtain Metal-backed NSView.";
 
+        // Create the VkSurface.
+        FILAMENT_CHECK_POSTCONDITION(vkCreateMacOSSurfaceMVK)
+                << "Unable to load vkCreateMacOSSurfaceMVK.";
+        VkMacOSSurfaceCreateInfoMVK createInfo = {};
+        createInfo.sType = VK_STRUCTURE_TYPE_MACOS_SURFACE_CREATE_INFO_MVK;
+        createInfo.pView = (__bridge void*) nsview;
+        VkResult result = vkCreateMacOSSurfaceMVK((VkInstance) instance, &createInfo, VKALLOC,
+                (VkSurfaceKHR*) &surface);
+        FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
+                << "vkCreateMacOSSurfaceMVK. error=" << static_cast<int32_t>(result);
+#elif defined(FILAMENT_IOS) && defined(METAL_AVAILABLE)
+    CAMetalLayer* metalLayer = (CAMetalLayer*) nativeWindow;
     // Create the VkSurface.
-    FILAMENT_CHECK_POSTCONDITION(vkCreateMacOSSurfaceMVK)
-            << "Unable to load vkCreateMacOSSurfaceMVK.";
-    VkMacOSSurfaceCreateInfoMVK createInfo = {};
-    createInfo.sType = VK_STRUCTURE_TYPE_MACOS_SURFACE_CREATE_INFO_MVK;
-    createInfo.pView = (__bridge void*) nsview;
-    VkResult result = vkCreateMacOSSurfaceMVK((VkInstance) instance, &createInfo, VKALLOC,
+    FILAMENT_CHECK_POSTCONDITION(vkCreateIOSSurfaceMVK)
+            << "Unable to load vkCreateIOSSurfaceMVK function.";
+    VkIOSSurfaceCreateInfoMVK createInfo = {};
+    createInfo.sType = VK_STRUCTURE_TYPE_IOS_SURFACE_CREATE_INFO_MVK;
+    createInfo.pNext = NULL;
+    createInfo.flags = 0;
+    createInfo.pView = metalLayer;
+    VkResult result = vkCreateIOSSurfaceMVK((VkInstance) instance, &createInfo, VKALLOC,
             (VkSurfaceKHR*) &surface);
     FILAMENT_CHECK_POSTCONDITION(result == VK_SUCCESS)
-            << "vkCreateMacOSSurfaceMVK. error=" << static_cast<int32_t>(result);
-    return std::make_tuple(surface, VkExtent2D{});
+            << "vkCreateIOSSurfaceMVK failed. error=" << static_cast<int32_t>(result);
+#endif
+        return std::make_tuple(surface, VkExtent2D{});
 }
 
 } // namespace filament::backend

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

@@ -84,30 +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/webgpu/WGPUProgram.cpp

@@ -1,150 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "WebGPUHandles.h"
-
-#include "WebGPUConstants.h"
-
-#include "DriverBase.h"
-#include <backend/DriverEnums.h>
-#include <backend/Program.h>
-
-#include <utils/Panic.h>
-#include <utils/ostream.h>
-
-#include <webgpu/webgpu_cpp.h>
-
-#include <sstream>
-#include <string_view>
-#include <vector>
-
-namespace filament::backend {
-
-namespace {
-
-[[nodiscard]] constexpr std::string_view toString(ShaderStage stage) {
-    switch (stage) {
-        case ShaderStage::VERTEX:
-            return "vertex";
-        case ShaderStage::FRAGMENT:
-            return "fragment";
-        case ShaderStage::COMPUTE:
-            return "compute";
-    }
-}
-
-[[nodiscard]] wgpu::ShaderModule createShaderModule(wgpu::Device& device, const char* programName,
-        std::array<utils::FixedCapacityVector<uint8_t>, Program::SHADER_TYPE_COUNT> const&
-                shaderSource,
-        ShaderStage stage) {
-    utils::FixedCapacityVector<uint8_t> const& sourceBytes =
-            shaderSource[static_cast<size_t>(stage)];
-    if (sourceBytes.empty()) {
-        return nullptr;// nothing to compile, the shader was not provided
-    }
-    wgpu::ShaderModuleWGSLDescriptor wgslDescriptor{};
-    wgslDescriptor.code = wgpu::StringView(reinterpret_cast<const char*>(sourceBytes.data()));
-    std::stringstream labelStream;
-    labelStream << programName << " " << toString(stage) << " shader";
-    auto label = labelStream.str();
-    wgpu::ShaderModuleDescriptor descriptor{
-        .nextInChain = &wgslDescriptor,
-        .label = label.data()
-    };
-    wgpu::ShaderModule module = device.CreateShaderModule(&descriptor);
-    FILAMENT_CHECK_POSTCONDITION(module != nullptr) << "Failed to create " << descriptor.label;
-    module.GetCompilationInfo(wgpu::CallbackMode::AllowSpontaneous,
-            [&descriptor](auto const& status, wgpu::CompilationInfo const* info) {
-                switch (status) {
-                    case wgpu::CompilationInfoRequestStatus::CallbackCancelled:
-                        FWGPU_LOGW << "Shader compilation info callback cancelled for "
-                                   << descriptor.label << "?" << utils::io::endl;
-                        return;
-                    case wgpu::CompilationInfoRequestStatus::Success:
-                        break;
-                }
-                if (info != nullptr) {
-                    std::stringstream errorStream;
-                    int errorCount = 0;
-                    for (size_t msgIndex = 0; msgIndex < info->messageCount; msgIndex++) {
-                        wgpu::CompilationMessage const& message = info->messages[msgIndex];
-                        switch (message.type) {
-                            case wgpu::CompilationMessageType::Info:
-                                FWGPU_LOGI << descriptor.label << ": " << message.message
-                                           << " line#:" << message.lineNum
-                                           << " linePos:" << message.linePos
-                                           << " offset:" << message.offset
-                                           << " length:" << message.length << utils::io::endl;
-                                break;
-                            case wgpu::CompilationMessageType::Warning:
-                                FWGPU_LOGW << "Warning compiling " << descriptor.label << ": "
-                                           << message.message << " line#:" << message.lineNum
-                                           << " linePos:" << message.linePos
-                                           << " offset:" << message.offset
-                                           << " length:" << message.length << utils::io::endl;
-                                break;
-                            case wgpu::CompilationMessageType::Error:
-                                errorCount++;
-                                errorStream << "Error " << errorCount << " : "
-                                            << std::string_view(message.message)
-                                            << " line#:" << message.lineNum
-                                            << " linePos:" << message.linePos
-                                            << " offset:" << message.offset
-                                            << " length:" << message.length << "\n";
-                                break;
-                        }
-                    }
-                    FILAMENT_CHECK_POSTCONDITION(errorCount < 1)
-                            << errorCount << " error(s) compiling " << descriptor.label << ":\n"
-                            << errorStream.str();
-                }
-                FWGPU_LOGD << descriptor.label << " compiled successfully" << utils::io::endl;
-            });
-    return module;
-}
-
-std::vector<wgpu::ConstantEntry> convertConstants(
-        utils::FixedCapacityVector<filament::backend::Program::SpecializationConstant> const&
-                constantsInfo) {
-    std::vector<wgpu::ConstantEntry> constants(constantsInfo.size());
-    for (size_t i = 0; i < constantsInfo.size(); i++) {
-        filament::backend::Program::SpecializationConstant const& specConstant = constantsInfo[i];
-        wgpu::ConstantEntry& constantEntry = constants[i];
-        constantEntry.key = wgpu::StringView(std::to_string(specConstant.id));
-        if (auto* v = std::get_if<int32_t>(&specConstant.value)) {
-            constantEntry.value = static_cast<double>(*v);
-        } else if (auto* f = std::get_if<float>(&specConstant.value)) {
-            constantEntry.value = static_cast<double>(*f);
-        } else if (auto* b = std::get_if<bool>(&specConstant.value)) {
-            constantEntry.value = *b ? 0.0 : 1.0;
-        }
-    }
-    return constants;
-}
-
-}// namespace
-
-WGPUProgram::WGPUProgram(wgpu::Device& device, Program& program)
-    : HwProgram(program.getName()),
-      vertexShaderModule(createShaderModule(device, name.c_str_safe(), program.getShadersSource(),
-              ShaderStage::VERTEX)),
-      fragmentShaderModule(createShaderModule(device, name.c_str_safe(), program.getShadersSource(),
-              ShaderStage::FRAGMENT)),
-      computeShaderModule(createShaderModule(device, name.c_str_safe(), program.getShadersSource(),
-              ShaderStage::COMPUTE)),
-      constants(convertConstants(program.getSpecializationConstants())) {}
-
-}// namespace filament::backend

filament/backend/src/webgpu/WebGPUDriver.cpp

@@ -16,7 +16,6 @@
 
 #include "webgpu/WebGPUDriver.h"
 
-#include "WebGPUSwapChain.h"
 #include "webgpu/WebGPUConstants.h"
 #include <backend/platforms/WebGPUPlatform.h>
 
@@ -228,14 +227,6 @@ WebGPUDriver::WebGPUDriver(WebGPUPlatform& platform, const Platform::DriverConfi
               driverConfig.disableHeapHandleTags) {
 #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
 }
 
@@ -265,7 +256,6 @@ void WebGPUDriver::terminate() {
 }
 
 void WebGPUDriver::tick(int) {
-    mDevice.Tick();
 }
 
 void WebGPUDriver::beginFrame(int64_t monotonic_clock_ns,
@@ -295,27 +285,15 @@ 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) {
@@ -325,19 +303,19 @@ 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) {
@@ -347,16 +325,16 @@ void WebGPUDriver::destroyTimerQuery(Handle<HwTimerQuery> tqh) {
 }
 
 void WebGPUDriver::destroyDescriptorSetLayout(Handle<HwDescriptorSetLayout> tqh) {
-    if (tqh) {
-        destructHandle<WebGPUDescriptorSetLayout>(tqh);
-    }
 }
 
 void WebGPUDriver::destroyDescriptorSet(Handle<HwDescriptorSet> tqh) {
 }
 
 Handle<HwSwapChain> WebGPUDriver::createSwapChainS() noexcept {
-    return allocHandle<WebGPUSwapChain>();
+    // TODO:  use webgpu handle allocator from.
+    //        https://github.com/google/filament/pull/8566
+    // return allocAndConstructHandle<HwSwapChain>();
+    return Handle<HwSwapChain>((Handle<HwSwapChain>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwSwapChain> WebGPUDriver::createSwapChainHeadlessS() noexcept {
@@ -364,7 +342,7 @@ Handle<HwSwapChain> WebGPUDriver::createSwapChainHeadlessS() noexcept {
 }
 
 Handle<HwTexture> WebGPUDriver::createTextureS() noexcept {
-    return allocHandle<WGPUTexture>();
+    return Handle<HwTexture>((Handle<HwTexture>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwTexture> WebGPUDriver::importTextureS() noexcept {
@@ -372,7 +350,7 @@ Handle<HwTexture> WebGPUDriver::importTextureS() noexcept {
 }
 
 Handle<HwProgram> WebGPUDriver::createProgramS() noexcept {
-    return allocHandle<WGPUProgram>();
+    return Handle<HwProgram>((Handle<HwProgram>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwFence> WebGPUDriver::createFenceS() noexcept {
@@ -392,15 +370,15 @@ Handle<HwTexture> WebGPUDriver::createTextureViewS() noexcept {
 }
 
 Handle<HwBufferObject> WebGPUDriver::createBufferObjectS() noexcept {
-    return allocHandle<WGPUBufferObject>();
+    return Handle<HwBufferObject>((Handle<HwBufferObject>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwRenderTarget> WebGPUDriver::createRenderTargetS() noexcept {
-    return allocHandle<WGPURenderTarget>();
+    return Handle<HwRenderTarget>((Handle<HwRenderTarget>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwVertexBuffer> WebGPUDriver::createVertexBufferS() noexcept {
-    return allocHandle<WGPUVertexBuffer>();
+    return Handle<HwVertexBuffer>((Handle<HwVertexBuffer>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwDescriptorSet> WebGPUDriver::createDescriptorSetS() noexcept {
@@ -408,11 +386,11 @@ Handle<HwDescriptorSet> WebGPUDriver::createDescriptorSetS() noexcept {
 }
 
 Handle<HwRenderPrimitive> WebGPUDriver::createRenderPrimitiveS() noexcept {
-    return allocHandle<WGPURenderPrimitive>();
+    return Handle<HwRenderPrimitive>((Handle<HwRenderPrimitive>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwVertexBufferInfo> WebGPUDriver::createVertexBufferInfoS() noexcept {
-    return allocHandle<WGPUVertexBufferInfo>();
+    return Handle<HwVertexBufferInfo>((Handle<HwVertexBufferInfo>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwTexture> WebGPUDriver::createTextureViewSwizzleS() noexcept {
@@ -420,11 +398,12 @@ Handle<HwTexture> WebGPUDriver::createTextureViewSwizzleS() noexcept {
 }
 
 Handle<HwRenderTarget> WebGPUDriver::createDefaultRenderTargetS() noexcept {
-    return allocHandle<WGPURenderTarget>();
+    return Handle<HwRenderTarget>((Handle<HwRenderTarget>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwDescriptorSetLayout> WebGPUDriver::createDescriptorSetLayoutS() noexcept {
-    return allocHandle<WebGPUDescriptorSetLayout>();
+    return Handle<HwDescriptorSetLayout>(
+            (Handle<HwDescriptorSetLayout>::HandleId) mNextFakeHandle++);
 }
 
 Handle<HwTexture> WebGPUDriver::createTextureExternalImageS() noexcept {
@@ -440,15 +419,21 @@ Handle<HwTexture> WebGPUDriver::createTextureExternalImagePlaneS() noexcept {
 }
 
 void WebGPUDriver::createSwapChainR(Handle<HwSwapChain> sch, void* nativeWindow, uint64_t flags) {
-    mNativeWindow = nativeWindow;
-    assert_invariant(!mSwapChain);
+    // TODO:  use webgpu handle allocator from.
+    //        https://github.com/google/filament/pull/8566
+    // HwSwapChain* hwSwapChain = handleCast<HwSwapChain*>(sch);
+    mSwapChain = nullptr;
     wgpu::Surface surface = mPlatform.createSurface(nativeWindow, flags);
-
+    mAdapter = mPlatform.requestAdapter(surface);
+#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
+    printAdapterDetails(mAdapter);
+#endif
+    mDevice = mPlatform.requestDevice(mAdapter);
+#if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
+    printDeviceDetails(mDevice);
+#endif
     mQueue = mDevice.GetQueue();
-    wgpu::Extent2D surfaceSize = mPlatform.getSurfaceExtent(mNativeWindow);
-    mSwapChain = constructHandle<WebGPUSwapChain>(sch, std::move(surface), surfaceSize, mAdapter,
-            mDevice, flags);
-    assert_invariant(mSwapChain);
+    mSwapChain = std::make_unique<WebGPUSwapChain>(std::move(surface), mAdapter, mDevice, flags);
     FWGPU_LOGW << "WebGPU support is still essentially a no-op at this point in development (only "
                   "background components have been instantiated/selected, such as surface/screen, "
                   "graphics device/GPU, etc.), thus nothing is being drawn to the screen."
@@ -461,6 +446,9 @@ 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,
@@ -508,15 +496,9 @@ void WebGPUDriver::importTextureR(Handle<HwTexture> th, intptr_t id, SamplerType
 void WebGPUDriver::createRenderPrimitiveR(Handle<HwRenderPrimitive> rph, Handle<HwVertexBuffer> vbh,
         Handle<HwIndexBuffer> ibh, PrimitiveType pt) {}
 
-void WebGPUDriver::createProgramR(Handle<HwProgram> ph, Program&& program) {
-    constructHandle<WGPUProgram>(ph, mDevice, program);
-}
+void WebGPUDriver::createProgramR(Handle<HwProgram> ph, Program&& program) {}
 
-void WebGPUDriver::createDefaultRenderTargetR(Handle<HwRenderTarget> rth, int) {
-    assert_invariant(!mDefaultRenderTarget);
-    mDefaultRenderTarget = constructHandle<WGPURenderTarget>(rth);
-    assert_invariant(mDefaultRenderTarget);
-}
+void WebGPUDriver::createDefaultRenderTargetR(Handle<HwRenderTarget> rth, int) {}
 
 void WebGPUDriver::createRenderTargetR(Handle<HwRenderTarget> rth, TargetBufferFlags targets,
         uint32_t width, uint32_t height, uint8_t samples, uint8_t layerCount, MRT color,
@@ -527,9 +509,7 @@ void WebGPUDriver::createFenceR(Handle<HwFence> fh, int) {}
 void WebGPUDriver::createTimerQueryR(Handle<HwTimerQuery> tqh, int) {}
 
 void WebGPUDriver::createDescriptorSetLayoutR(Handle<HwDescriptorSetLayout> dslh,
-        backend::DescriptorSetLayout&& info) {
-    constructHandle<WebGPUDescriptorSetLayout>(dslh, std::move(info), mDevice);
-}
+        backend::DescriptorSetLayout&& info) {}
 
 void WebGPUDriver::createDescriptorSetR(Handle<HwDescriptorSet> dsh,
         Handle<HwDescriptorSetLayout> dslh) {}
@@ -679,10 +659,6 @@ void WebGPUDriver::resetBufferObject(Handle<HwBufferObject> boh) {
 
 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->buffers.size());
-    vertexBuffer->setBuffer(bufferObject, index);
 }
 
 void WebGPUDriver::update3DImage(Handle<HwTexture> th,
@@ -715,71 +691,18 @@ void WebGPUDriver::compilePrograms(CompilerPriorityQueue priority,
 }
 
 void WebGPUDriver::beginRenderPass(Handle<HwRenderTarget> rth, const RenderPassParams& params) {
-    wgpu::CommandEncoderDescriptor commandEncoderDescriptor = {
-        .label = "command_encoder"
-    };
-    mCommandEncoder = mDevice.CreateCommandEncoder(&commandEncoderDescriptor);
-    assert_invariant(mCommandEncoder);
-    // TODO: Remove this code once WebGPU pipeline is implemented
-    static float red = 1.0f;
-    if (red - 0.01 > 0) {
-        red -= 0.01;
-    } else {
-        red = 1.0f;
-    }
-    assert_invariant(mTextureView);
-    wgpu::RenderPassColorAttachment renderPassColorAttachment = {
-        .view = mTextureView,
-        // TODO: remove this code once WebGPU Pipeline is implemented with render targets, pipeline and buffers.
-        .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(params.viewport.left, params.viewport.bottom,
-            params.viewport.width, params.viewport.height, params.depthRange.near, params.depthRange.far);
 }
 
 void WebGPUDriver::endRenderPass(int) {
-    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) {
-    mCommandEncoder = nullptr;
-    mQueue.Submit(1, &mCommandBuffer);
-    mCommandBuffer = nullptr;
-    mTextureView = nullptr;
-    assert_invariant(mSwapChain);
-    mSwapChain->present();
 }
 
 void WebGPUDriver::setPushConstant(backend::ShaderStage stage, uint8_t index,
@@ -807,7 +730,7 @@ void WebGPUDriver::readPixels(Handle<HwRenderTarget> src,
     scheduleDestroy(std::move(p));
 }
 
-void WebGPUDriver::readBufferSubData(Handle<HwBufferObject> boh,
+void WebGPUDriver::readBufferSubData(backend::BufferObjectHandle boh,
         uint32_t offset, uint32_t size, backend::BufferDescriptor&& p) {
     scheduleDestroy(std::move(p));
 }
@@ -859,22 +782,22 @@ void WebGPUDriver::resetState(int) {
 }
 
 void WebGPUDriver::updateDescriptorSetBuffer(
-        Handle<HwDescriptorSet> dsh,
+        backend::DescriptorSetHandle dsh,
         backend::descriptor_binding_t binding,
-        Handle<HwBufferObject> boh,
+        backend::BufferObjectHandle boh,
         uint32_t offset,
         uint32_t size) {
 }
 
 void WebGPUDriver::updateDescriptorSetTexture(
-        Handle<HwDescriptorSet> dsh,
+        backend::DescriptorSetHandle dsh,
         backend::descriptor_binding_t binding,
-        Handle<HwTexture> th,
+        backend::TextureHandle th,
         SamplerParams params) {
 }
 
 void WebGPUDriver::bindDescriptorSet(
-        Handle<HwDescriptorSet> dsh,
+        backend::DescriptorSetHandle dsh,
         backend::descriptor_set_t set,
         backend::DescriptorSetOffsetArray&& offsets) {
 }

filament/backend/src/webgpu/WebGPUDriver.h

@@ -17,7 +17,7 @@
 #ifndef TNT_FILAMENT_BACKEND_WEBGPUDRIVER_H
 #define TNT_FILAMENT_BACKEND_WEBGPUDRIVER_H
 
-#include "WebGPUHandles.h"
+#include "webgpu/WebGPUSwapChain.h"
 #include <backend/platforms/WebGPUPlatform.h>
 
 #include "DriverBase.h"
@@ -39,8 +39,6 @@
 
 namespace filament::backend {
 
-class WebGPUSwapChain;
-
 /**
  * WebGPU backend (driver) implementation
  */
@@ -62,14 +60,10 @@ private:
     wgpu::Adapter mAdapter = nullptr;
     wgpu::Device mDevice = nullptr;
     wgpu::Queue mQueue = nullptr;
-    void* mNativeWindow = nullptr;
-    WebGPUSwapChain* mSwapChain = nullptr;
+    // TODO consider moving to handle allocator when ready
+    std::unique_ptr<WebGPUSwapChain> mSwapChain = nullptr;
     uint64_t mNextFakeHandle = 1;
-    wgpu::CommandEncoder mCommandEncoder = nullptr;
-    wgpu::TextureView mTextureView = nullptr;
-    wgpu::RenderPassEncoder mRenderPassEncoder = nullptr;
-    wgpu::CommandBuffer mCommandBuffer = nullptr;
-    WGPURenderTarget* mDefaultRenderTarget = nullptr;
+
     /*
      * Driver interface
      */
@@ -99,21 +93,6 @@ private:
         return mHandleAllocator.allocate<D>();
     }
 
-    template<typename D, typename B, typename ... ARGS>
-    D* constructHandle(Handle<B>& handle, ARGS&& ... args) noexcept {
-        return mHandleAllocator.construct<D>(handle, std::forward<ARGS>(args)...);
-    }
-
-    template<typename D, typename B>
-    D* handleCast(Handle<B> handle) noexcept {
-        return mHandleAllocator.handle_cast<D*>(handle);
-    }
-
-    template<typename D, typename B>
-    void destructHandle(Handle<B>& handle) noexcept {
-        auto* p = mHandleAllocator.handle_cast<D*>(handle);
-        return mHandleAllocator.deallocate(handle, p);
-    }
 };
 
 }// namespace filament::backend

filament/backend/src/webgpu/WebGPUHandles.cpp

@@ -1,152 +0,0 @@
-/*
-* Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "WebGPUHandles.h"
-
-#include <utility>
-
-namespace {
-
-wgpu::Buffer createIndexBuffer(wgpu::Device const& device, uint8_t elementSize, uint32_t indexCount) {
-    wgpu::BufferDescriptor descriptor{ .label = "index_buffer",
-        .usage = wgpu::BufferUsage::CopyDst | wgpu::BufferUsage::Index,
-        .size = elementSize * indexCount,
-        .mappedAtCreation = false };
-    return device.CreateBuffer(&descriptor);
-}
-} // namespace
-
-namespace filament::backend {
-
-
-WGPUIndexBuffer::WGPUIndexBuffer(wgpu::Device const& device, uint8_t elementSize,
-        uint32_t indexCount)
-    : buffer(createIndexBuffer(device, elementSize, indexCount)) {}
-
-
-WGPUVertexBuffer::WGPUVertexBuffer(wgpu::Device const &device, uint32_t vextexCount, uint32_t bufferCount,
-                                   Handle<WGPUVertexBufferInfo> vbih)
-        : HwVertexBuffer(vextexCount),
-          vbih(vbih),
-          buffers(bufferCount) {
-    wgpu::BufferDescriptor descriptor {
-            .usage = wgpu::BufferUsage::CopyDst | wgpu::BufferUsage::Vertex,
-            .size = vextexCount * bufferCount,
-            .mappedAtCreation = false };
-
-    for (uint32_t i = 0; i < bufferCount; ++i) {
-        descriptor.label = ("vertex_buffer_" + std::to_string(i)).c_str();
-        buffers[i] = device.CreateBuffer(&descriptor);
-    }
-}
-
-// TODO: Empty function is a place holder for verxtex buffer updates and should be
-// updated for that purpose.
-void WGPUVertexBuffer::setBuffer(WGPUBufferObject* bufferObject, uint32_t index) {}
-
-WGPUBufferObject::WGPUBufferObject(BufferObjectBinding bindingType, uint32_t byteCount)
-    : HwBufferObject(byteCount),
-      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??
-    mLayout = device.CreateBindGroupLayout(&layoutDescriptor);
-}
-WebGPUDescriptorSetLayout::~WebGPUDescriptorSetLayout() {}
-}// namespace filament::backend

filament/backend/src/webgpu/WebGPUHandles.h

@@ -1,167 +0,0 @@
-/*
-* Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-
-#ifndef TNT_FILAMENT_BACKEND_WEBGPUHANDLES_H
-#define TNT_FILAMENT_BACKEND_WEBGPUHANDLES_H
-
-#include "DriverBase.h"
-
-#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;
-// TODO: Currently WGPUVertexBufferInfo is not used by WebGPU for useful task.
-// Update the struct when used by WebGPU driver.
-struct WGPUVertexBufferInfo : public HwVertexBufferInfo {
-    WGPUVertexBufferInfo(uint8_t bufferCount, uint8_t attributeCount,
-            AttributeArray const& attributes)
-        : HwVertexBufferInfo(bufferCount, attributeCount),
-          attributes(attributes) {}
-    AttributeArray attributes;
-};
-
-struct WGPUVertexBuffer : public HwVertexBuffer {
-    WGPUVertexBuffer(wgpu::Device const &device, uint32_t vextexCount, uint32_t bufferCount,
-                     Handle<WGPUVertexBufferInfo> vbih);
-
-    void setBuffer(WGPUBufferObject *bufferObject, uint32_t index);
-
-    Handle<WGPUVertexBufferInfo> vbih;
-    utils::FixedCapacityVector<wgpu::Buffer> buffers;
-};
-
-struct WGPUIndexBuffer : public HwIndexBuffer {
-    WGPUIndexBuffer(wgpu::Device const &device, uint8_t elementSize,
-                    uint32_t indexCount);
-
-    wgpu::Buffer buffer;
-};
-
-// TODO: Currently WGPUVertexBufferInfo is not used by WebGPU for useful task.
-// Update the struct when used by WebGPU driver.
-struct WGPUBufferObject : HwBufferObject {
-    WGPUBufferObject(BufferObjectBinding bindingType, uint32_t byteCount);
-
-    wgpu::Buffer buffer;
-    const BufferObjectBinding bufferObjectBinding;
-};
-class WebGPUDescriptorSetLayout : public HwDescriptorSetLayout {
-public:
-    WebGPUDescriptorSetLayout(DescriptorSetLayout const& layout, wgpu::Device const& device);
-    ~WebGPUDescriptorSetLayout();
-
-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);
-
-    wgpu::BindGroupLayout mLayout;
-};
-
-// 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;
-
-    // constructors for creating texture views
-    WGPUTexture(WGPUTexture const* src, uint8_t baseLevel, uint8_t levelCount) noexcept;
-
-    wgpu::Texture texture = nullptr;
-};
-
-struct WGPURenderPrimitive : public HwRenderPrimitive {
-    WGPURenderPrimitive();
-
-    void setBuffers(WGPUVertexBufferInfo const* const vbi,
-            WGPUVertexBuffer* vertexBuffer, WGPUIndexBuffer* indexBuffer);
-
-    WGPUVertexBuffer* vertexBuffer = nullptr;
-    WGPUIndexBuffer* indexBuffer = nullptr;
-};
-
-// TODO: Currently WGPURenderTarget is not used by WebGPU for useful task.
-// Update the struct when used by WebGPU driver.
-struct WGPURenderTarget : public HwRenderTarget {
-    class Attachment {
-    public:
-        friend struct WGPURenderTarget;
-
-        Attachment() = default;
-        Attachment(WGPUTexture* gpuTexture, uint8_t level = 0, uint16_t layer = 0)
-            : level(level),
-              layer(layer),
-              texture(gpuTexture->texture),
-              mWGPUTexture(gpuTexture) {}
-
-        uint8_t level = 0;
-        uint16_t layer = 0;
-
-    private:
-        wgpu::Texture texture = nullptr;
-        WGPUTexture* mWGPUTexture = nullptr;
-    };
-
-    WGPURenderTarget(uint32_t width, uint32_t height, uint8_t samples,
-            Attachment colorAttachments[MRT::MAX_SUPPORTED_RENDER_TARGET_COUNT]);
-    WGPURenderTarget()
-        : HwRenderTarget(0, 0),
-          defaultRenderTarget(true) {}
-
-    void setUpRenderPassAttachments(wgpu::RenderPassDescriptor* descriptor,
-            const RenderPassParams& params);
-
-    math::uint2 getAttachmentSize() noexcept;
-
-    bool isDefaultRenderTarget() const { return defaultRenderTarget; }
-    uint8_t getSamples() const { return samples; }
-
-    Attachment getDrawColorAttachment(size_t index);
-    Attachment getReadColorAttachment(size_t index);
-
-private:
-    static wgpu::LoadOp getLoadAction(const RenderPassParams& params, TargetBufferFlags buffer);
-    static wgpu::LoadOp getStoreAction(const RenderPassParams& params, TargetBufferFlags buffer);
-
-    bool defaultRenderTarget = false;
-    uint8_t samples = 1;
-
-    Attachment color[MRT::MAX_SUPPORTED_RENDER_TARGET_COUNT] = {};
-    math::uint2 attachmentSize = {};
-};
-
-}// namespace filament::backend
-#endif// TNT_FILAMENT_BACKEND_WEBGPUHANDLES_H

filament/backend/src/webgpu/WebGPUSwapChain.cpp

@@ -190,13 +190,10 @@ wgpu::CompositeAlphaMode selectAlphaMode(size_t availableAlphaModesCount,
     }
 }
 
-void initConfig(wgpu::SurfaceConfiguration& config, wgpu::Device const& device,
-        wgpu::SurfaceCapabilities const& capabilities, wgpu::Extent2D const& surfaceSize,
-        bool useSRGBColorSpace) {
+void initConfig(wgpu::SurfaceConfiguration& config, wgpu::Device& device,
+        wgpu::SurfaceCapabilities const& capabilities, bool useSRGBColorSpace) {
     config.device = device;
     config.usage = wgpu::TextureUsage::RenderAttachment;
-    config.width = surfaceSize.width;
-    config.height = surfaceSize.height;
     config.format =
             selectColorFormat(capabilities.formatCount, capabilities.formats, useSRGBColorSpace);
     config.presentMode =
@@ -208,8 +205,8 @@ void initConfig(wgpu::SurfaceConfiguration& config, wgpu::Device const& device,
 
 namespace filament::backend {
 
-WebGPUSwapChain::WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Extent2D const& surfaceSize,
-        wgpu::Adapter& adapter, wgpu::Device& device, uint64_t flags)
+WebGPUSwapChain::WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Adapter& adapter,
+        wgpu::Device& device, uint64_t flags)
     : mSurface(surface) {
     wgpu::SurfaceCapabilities capabilities = {};
     if (!mSurface.GetCapabilities(adapter, &capabilities)) {
@@ -220,57 +217,33 @@ WebGPUSwapChain::WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Extent2D const&
 #endif
     }
     const bool useSRGBColorSpace = (flags & SWAP_CHAIN_CONFIG_SRGB_COLORSPACE) != 0;
-    initConfig(mConfig, device, capabilities, surfaceSize, useSRGBColorSpace);
-    mSurface.Configure(&mConfig);
+    initConfig(mConfig, device, capabilities, useSRGBColorSpace);
 }
 
 WebGPUSwapChain::~WebGPUSwapChain() {
-    mSurface.Unconfigure();
+    if (mConfigured) {
+        mSurface.Unconfigure();
+        mConfigured = false;
+    }
 }
 
-void WebGPUSwapChain::setExtent(wgpu::Extent2D const& currentSurfaceSize) {
-    FILAMENT_CHECK_POSTCONDITION(currentSurfaceSize.width > 0 || currentSurfaceSize.height > 0)
-            << "WebGPUSwapChain::setExtent: Invalid width " << currentSurfaceSize.width
-            << " and/or height " << currentSurfaceSize.height << " requested.";
-    if (mConfig.width != currentSurfaceSize.width || mConfig.height != currentSurfaceSize.height) {
-        mConfig.width = currentSurfaceSize.width;
-        mConfig.height = currentSurfaceSize.height;
+void WebGPUSwapChain::GetCurrentTexture(uint32_t width, uint32_t height, wgpu::SurfaceTexture* texture) {
+    if (width < 1 || height < 1) {
+        PANIC_LOG("WebGPUSwapChain::GetCurrentTexture: Invalid width and/or height requested.");
+        return;
+    }
+    if (mConfig.width != width || mConfig.height != height || !mConfigured) {
+        mConfig.width = width;
+        mConfig.height = height;
 #if FWGPU_ENABLED(FWGPU_PRINT_SYSTEM)
         printSurfaceConfiguration(mConfig);
 #endif
-        FWGPU_LOGD << "Resizing to width " << mConfig.width << " height " << mConfig.height
-                   << utils::io::endl;
-        // TODO we may need to ensure no surface texture is flight when we do this. some
-        //      synchronization may be necessary
         mSurface.Configure(&mConfig);
+        mConfigured = true;
+        return;
     }
-}
 
-wgpu::TextureView WebGPUSwapChain::getCurrentSurfaceTextureView(
-        wgpu::Extent2D const& currentSurfaceSize) {
-    setExtent(currentSurfaceSize);
-    wgpu::SurfaceTexture surfaceTexture;
-    mSurface.GetCurrentTexture(&surfaceTexture);
-    if (surfaceTexture.status != wgpu::SurfaceGetCurrentTextureStatus::SuccessOptimal) {
-        return nullptr;
-    }
-    // Create a view for this surface texture
-    // TODO: review these initiliazations as webgpu pipeline gets mature
-    wgpu::TextureViewDescriptor textureViewDescriptor = {
-        .label = "texture_view",
-        .format = surfaceTexture.texture.GetFormat(),
-        .dimension = wgpu::TextureViewDimension::e2D,
-        .baseMipLevel = 0,
-        .mipLevelCount = 1,
-        .baseArrayLayer = 0,
-        .arrayLayerCount = 1
-    };
-    return surfaceTexture.texture.CreateView(&textureViewDescriptor);
-}
-
-void WebGPUSwapChain::present() {
-    assert_invariant(mSurface);
-    mSurface.Present();
+    mSurface.GetCurrentTexture(texture);
 }
 
 }// namespace filament::backend

filament/backend/src/webgpu/WebGPUSwapChain.h

@@ -19,28 +19,24 @@
 
 #include <webgpu/webgpu_cpp.h>
 
-#include "DriverBase.h"
 #include <backend/Platform.h>
 
 #include <cstdint>
 
 namespace filament::backend {
 
-class WebGPUSwapChain final : public Platform::SwapChain, HwSwapChain {
+class WebGPUSwapChain : public Platform::SwapChain {
 public:
-    WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Extent2D const& surfaceSize,
-            wgpu::Adapter& adapter, wgpu::Device& device, uint64_t flags);
+    WebGPUSwapChain(wgpu::Surface&& surface, wgpu::Adapter& adapter, wgpu::Device& device,
+            uint64_t flags);
     ~WebGPUSwapChain();
 
-    wgpu::TextureView getCurrentSurfaceTextureView(wgpu::Extent2D const&);
-
-    void present();
+    void GetCurrentTexture(uint32_t width, uint32_t height, wgpu::SurfaceTexture*);
 
 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

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

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

@@ -24,8 +24,21 @@
 #include <cstdint>
 
 // Platform specific includes and defines
-#include <Cocoa/Cocoa.h>
-#import <QuartzCore/CAMetalLayer.h>
+#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
@@ -33,19 +46,14 @@
 
 namespace filament::backend {
 
-wgpu::Extent2D WebGPUPlatform::getSurfaceExtent(void* nativeWindow) const {
-    // Both IOS and MacOS expects CAMetalLayer.
-    CAMetalLayer* metalLayer = (__bridge CAMetalLayer*) nativeWindow;
-    return wgpu::Extent2D{
-        .width = static_cast<uint32_t>(metalLayer.drawableSize.width),
-        .height = static_cast<uint32_t>(metalLayer.drawableSize.height)
-    };
-}
-
 wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t /*flags*/) {
     wgpu::Surface surface = nullptr;
-    // Both IOS and MacOS expects CAMetalLayer.
-    CAMetalLayer* metalLayer = (__bridge CAMetalLayer*) nativeWindow;
+#if defined(__APPLE__)
+    auto nsView = (__bridge NSView*) nativeWindow;
+    FILAMENT_CHECK_POSTCONDITION(nsView) << "Unable to obtain Metal-backed NSView.";
+    [nsView setWantsLayer:YES];
+    id metalLayer = [CAMetalLayer layer];
+    [nsView setLayer:metalLayer];
     wgpu::SurfaceSourceMetalLayer surfaceSourceMetalLayer{};
     surfaceSourceMetalLayer.layer = (__bridge void*) metalLayer;
     wgpu::SurfaceDescriptor surfaceDescriptor = {
@@ -54,6 +62,19 @@ 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

@@ -79,74 +79,6 @@
 
 namespace filament::backend {
 
-wgpu::Extent2D WebGPUPlatform::getSurfaceExtent(void* nativeWindow) const {
-    auto surfaceExtent = wgpu::Extent2D{};
-#if defined(__linux__) && defined(FILAMENT_SUPPORTS_WAYLAND)
-    wl* ptrval = reinterpret_cast<wl*>(nativeWindow);
-    surfaceExtent.width = ptrval->width;
-    surfaceExtent.height = ptrval->height;
-    FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-            << "Unable to get window size for Linux Wayland-backed surface.";
-#elif defined(LINUX_OR_FREEBSD) && defined(FILAMENT_SUPPORTS_X11)
-    if (g_x11.library == nullptr) {
-        g_x11.library = dlopen(LIBRARY_X11, RTLD_LOCAL | RTLD_NOW);
-        FILAMENT_CHECK_PRECONDITION(g_x11.library) << "Unable to open X11 library.";
-        #if defined(FILAMENT_SUPPORTS_XCB)
-            g_x11.xcbConnect = (XCB_CONNECT) dlsym(g_x11.library, "xcb_connect");
-            int screen = 0;
-            g_x11.connection = g_x11.xcbConnect(nullptr, &screen);
-        #endif
-        #if defined(FILAMENT_SUPPORTS_XLIB)
-            g_x11.openDisplay = (X11_OPEN_DISPLAY) dlsym(g_x11.library, "XOpenDisplay");
-            g_x11.display = g_x11.openDisplay(NULL);
-            FILAMENT_CHECK_PRECONDITION(g_x11.display) << "Unable to open X11 display.";
-        #endif
-    }
-    #if defined(FILAMENT_SUPPORTS_XCB) || defined(FILAMENT_SUPPORTS_XLIB)
-        bool useXcb = false;
-    #endif
-    #if defined(FILAMENT_SUPPORTS_XCB)
-        #if defined(FILAMENT_SUPPORTS_XLIB)
-            useXcb = (SWAP_CHAIN_CONFIG_ENABLE_XCB) != 0;
-        #else
-            useXcb = true;
-        #endif
-        if (useXcb) {
-            const xcb_setup_t* setup = xcb_get_setup(g_x11.connection);
-            xcb_screen_iterator_t screen_iter = xcb_setup_roots_iterator(setup);
-            xcb_screen_t* screen = screen_iter.data;
-            surfaceExtent.width = static_cast<uint32_t>(screen->width_in_pixels);
-            surfaceExtent.height = static_cast<uint32_t>(screen->height_in_pixels);
-            FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-                    << "Unable to get window surface size for Linux (or FreeBSD) "
-                       "XCB-backed surface.";
-        }
-    #endif
-    #if defined(FILAMENT_SUPPORTS_XLIB)
-        if (!useXcb) {
-            int screenNumber = DefaultScreen(g_x11.display);
-            Screen* screen = ScreenOfDisplay(g_x11.display, screenNumber);
-            surfaceExtent.width = static_cast<uint32_t>(WidthOfScreen(screen));
-            surfaceExtent.height = static_cast<uint32_t>(HeightOfScreen(screen));
-            FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-                    << "Unable to get window surface size for Linux (or FreeBSD) "
-                       "XLib-backed surface.";
-        }
-    #endif
-    FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-            << "Cannot get window surface size for X11 surface for Linux (or FreeBSD) OS "
-               "(not built with support for XCB or XLIB?)";
-#elif defined(__linux__)
-    FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-            << "Cannot get window surface size for Linux (or FreeBSD) OS "
-               "(not built with support for Wayland or X11?)";
-#else
-    FILAMENT_CHECK_POSTCONDITION(surfaceExtent.width != 0 && surfaceExtent.height != 0)
-            << "Not a supported (Linux) OS + WebGPU platform";
-#endif
-    return surfaceExtent;
-}
-
 wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t flags) {
     wgpu::Surface surface = nullptr;
 #if defined(__linux__) && defined(FILAMENT_SUPPORTS_WAYLAND)

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

@@ -30,16 +30,6 @@
 
 namespace filament::backend {
 
-wgpu::Extent2D WebGPUPlatform::getSurfaceExtent(void* nativeWindow) const {
-    HWND window = static_cast<HWND>(nativeWindow);
-    RECT windowRect;
-    GetWindowRect(window, &windowRect);
-    return wgpu::Extent2D{
-        .width = static_cast<uint32_t>(windowRect.right - windowRect.left),
-        .height = static_cast<uint32_t>(windowRect.bottom - windowRect.top)
-    };
-}
-
 wgpu::Surface WebGPUPlatform::createSurface(void* nativeWindow, uint64_t /*flags*/) {
     // TODO verify this is necessary for Dawn implementation as well:
     // On (at least) NVIDIA drivers, the Vulkan implementation (specifically the call to

filament/backend/test/BackendTest.cpp

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

filament/backend/test/BackendTest.h

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

filament/backend/test/ImageExpectations.cpp

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

filament/backend/test/ImageExpectations.h

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

filament/backend/test/PlatformRunner.cpp

@@ -1,60 +0,0 @@
-/*
- * Copyright (C) 2019 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "PlatformRunner.h"
-
-namespace utils {
-
-template<>
-CString to_string<test::Backend>(test::Backend backend) noexcept {
-    switch (backend) {
-        case test::Backend::OPENGL: {
-            return "OpenGL";
-        }
-        case test::Backend::VULKAN: {
-            return "Vulkan";
-        }
-        case test::Backend::METAL: {
-            return "Metal";
-        }
-        case test::Backend::WEBGPU: {
-            return "WebGPU";
-        }
-        case test::Backend::NOOP:
-        default: {
-            return "No-op";
-        }
-    }
-}
-
-template<>
-CString to_string(test::OperatingSystem os) noexcept {
-    switch (os) {
-        case test::OperatingSystem::LINUX: {
-            return "Linux";
-        }
-        case test::OperatingSystem::APPLE: {
-            return "Apple";
-        }
-        case test::OperatingSystem::OTHER:
-        default: {
-            return "Other";
-        }
-    }
-}
-
-} // namespace utils
-

filament/backend/test/PlatformRunner.h

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

filament/backend/test/Skip.cpp

@@ -1,96 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "Skip.h"
-
-#include <sstream>
-
-namespace test {
-
-SkipEnvironment::SkipEnvironment(test::Backend backend) : backend(backend) {}
-SkipEnvironment::SkipEnvironment(test::OperatingSystem os) : os(os) {}
-SkipEnvironment::SkipEnvironment(test::OperatingSystem os, test::Backend backend)
-    : backend(backend),
-      os(os) {}
-
-bool SkipEnvironment::matches() {
-    bool backendMatches = !backend.has_value() || *backend == BackendTest::sBackend;
-    bool osMatches = !os.has_value() || *os == BackendTest::sOperatingSystem;
-    bool isMobileMatches = !isMobile.has_value() || *isMobile == BackendTest::sIsMobilePlatform;
-    return backendMatches && osMatches && isMobileMatches;
-}
-
-std::string SkipEnvironment::describe() {
-    std::stringstream result;
-    if (matches()) {
-        result << "environment matches because " << describe_actual_environment() << ".";
-    } else {
-        result << "environment does not match because " << describe_requirements() << " but "
-               << describe_actual_environment() << ".";
-    }
-    return result.str();
-}
-
-std::string SkipEnvironment::describe_actual_environment() {
-    bool resultWritten = false;
-    std::stringstream reality;
-    if (backend.has_value()) {
-        reality << "backend was " << utils::to_string(BackendTest::sBackend).c_str();
-        resultWritten = true;
-    }
-    if (os.has_value()) {
-        if (resultWritten) {
-            reality << ", and ";
-        }
-        reality << "operating system was "
-                << utils::to_string(BackendTest::sOperatingSystem).c_str();
-        resultWritten = true;
-    }
-    if (isMobile.has_value()) {
-        if (resultWritten) {
-            reality << ", and ";
-        }
-        reality << "device " << (BackendTest::sIsMobilePlatform ? "was" : "was not") << " mobile";
-        resultWritten = true;
-    }
-    return reality.str();
-}
-
-std::string SkipEnvironment::describe_requirements() {
-    bool resultWritten = false;
-    std::stringstream requirement;
-    if (backend.has_value()) {
-        requirement << "backend needs to be " << utils::to_string(*backend).c_str();
-        resultWritten = true;
-    }
-    if (os.has_value()) {
-        if (resultWritten) {
-            requirement << ", and ";
-        }
-        requirement << "operating system needs to be " << utils::to_string(*os).c_str();
-        resultWritten = true;
-    }
-    if (isMobile.has_value() && BackendTest::sIsMobilePlatform != isMobile) {
-        if (resultWritten) {
-            requirement << ", and ";
-        }
-        requirement << "device needs to " << (*isMobile ? "be" : "not be") << " mobile";
-        resultWritten = true;
-    }
-    return requirement.str();
-}
-
-} // namespace test

filament/backend/test/Skip.h

@@ -1,55 +0,0 @@
-/*
- * Copyright (C) 2025 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef TNT_SKIP_H
-#define TNT_SKIP_H
-
-#include <gtest/gtest.h>
-#include "BackendTest.h"
-
-// skipEnvironment must be a test::SkipEnvironment
-#define SKIP_IF(skipEnvironment)                                                                   \
-do {                                                                                               \
-    SkipEnvironment skip(skipEnvironment);                                                         \
-    if (skip.matches()) {                                                                          \
-        GTEST_SKIP() << "Skipping test as the " << skip.describe();                                \
-    }                                                                                              \
-} while (false)
-
-namespace test {
-
-struct SkipEnvironment {
-    SkipEnvironment(const SkipEnvironment&) = default;
-    explicit SkipEnvironment(test::Backend backend);
-    explicit SkipEnvironment(test::OperatingSystem os);
-    SkipEnvironment(test::OperatingSystem os, test::Backend backend);
-
-    std::optional<test::Backend> backend;
-    std::optional<test::OperatingSystem> os;
-    std::optional<bool> isMobile;
-
-    bool matches();
-    // Describes the current state of either matching or mismatching.
-    std::string describe();
-    // Describe all the non-null requirements.
-    std::string describe_requirements();
-    // Describes the environment's status for all the attributes that are non-null.
-    std::string describe_actual_environment();
-};
-
-} // namespace test
-
-#endif// TNT_SKIP_H

filament/backend/test/linux_runner.cpp

@@ -51,6 +51,6 @@ int main(int argc, char* argv[]) {
         return 1;
     }
 
-    test::initTests(backend, test::OperatingSystem::LINUX, false, argc, argv);
+    test::initTests(backend, false, argc, argv);
     return test::runTests();
 }

filament/backend/test/mac_runner.mm

@@ -98,7 +98,7 @@ test::NativeView getNativeView() {
 
 int main(int argc, char* argv[]) {
     auto backend = test::parseArgumentsForBackend(argc, argv);
-    test::initTests(backend, test::OperatingSystem::APPLE, false, argc, argv);
+    test::initTests(backend, false, argc, argv);
     AppDelegate* delegate = [AppDelegate new];
     delegate.backend = backend;
     NSApplication* app = [NSApplication sharedApplication];

filament/backend/test/test_Blit.cpp

@@ -197,10 +197,16 @@ TEST_F(BlitTest, ColorMagnify) {
     }
 
     {
-        RenderFrame frame(api);
-        EXPECT_IMAGE(dstRenderTargets[0], getExpectations(),
-                ScreenshotParams(kDstTexWidth, kDstTexHeight, "ColorMagnify", 0x410bdd31));
-        api.commit(swapChain);
+        ImageExpectations expectations(api);
+
+        {
+            RenderFrame frame(api);
+            EXPECT_IMAGE(dstRenderTargets[0], expectations,
+                    ScreenshotParams(kDstTexWidth, kDstTexHeight, "ColorMagnify", 0x410bdd31));
+            api.commit(swapChain);
+        }
+
+        flushAndWait();
     }
 }
 
@@ -254,8 +260,14 @@ TEST_F(BlitTest, ColorMinify) {
             { 0, 0, kSrcTexWidth >> srcLevel, kSrcTexHeight >> srcLevel },
             SamplerMagFilter::LINEAR);
 
-    EXPECT_IMAGE(dstRenderTargets[0], getExpectations(),
-            ScreenshotParams(kDstTexWidth, kDstTexHeight, "ColorMinify", 0xf3d9c53f));
+    {
+        ImageExpectations expectations(api);
+
+        EXPECT_IMAGE(dstRenderTargets[0], expectations,
+                ScreenshotParams(kDstTexWidth, kDstTexHeight, "ColorMinify", 0xf3d9c53f));
+
+        flushAndWait();
+    }
 }
 
 TEST_F(BlitTest, ColorResolve) {
@@ -339,8 +351,14 @@ TEST_F(BlitTest, ColorResolve) {
             srcRenderTarget, { 0, 0, kSrcTexWidth, kSrcTexHeight },
             SamplerMagFilter::NEAREST);
 
-    EXPECT_IMAGE(dstRenderTarget, getExpectations(),
-            ScreenshotParams(kDstTexWidth, kDstTexHeight, "ColorResolve", 0xebfac2ef));
+    {
+        ImageExpectations expectations(api);
+
+        EXPECT_IMAGE(dstRenderTarget, expectations,
+                ScreenshotParams(kDstTexWidth, kDstTexHeight, "ColorResolve", 0xebfac2ef));
+
+        flushAndWait();
+    }
 }
 
 TEST_F(BlitTest, Blit2DTextureArray) {
@@ -405,11 +423,17 @@ TEST_F(BlitTest, Blit2DTextureArray) {
     }
 
     {
-        RenderFrame frame(api);
-        EXPECT_IMAGE(dstRenderTarget, getExpectations(),
-                ScreenshotParams(kDstTexWidth, kDstTexHeight, "Blit2DTextureArray",
-                        0x8de7d55b));
-        api.commit(swapChain);
+        ImageExpectations expectations(api);
+
+        {
+            RenderFrame frame(api);
+            EXPECT_IMAGE(dstRenderTarget, expectations,
+                    ScreenshotParams(kDstTexWidth, kDstTexHeight, "Blit2DTextureArray",
+                            0x8de7d55b));
+            api.commit(swapChain);
+        }
+
+        flushAndWait();
     }
 }
 
@@ -479,12 +503,18 @@ TEST_F(BlitTest, BlitRegion) {
     }
 
     {
-        RenderFrame frame(api);
-        // TODO: for some reason, this test has very, very slight (as in one pixel) differences
-        // between OpenGL and Metal. So disable golden checking for now.
-        // EXPECT_IMAGE(dstRenderTarget, expectations, ScreenshotParams(kDstTexWidth,
-        //         kDstTexHeight, "BlitRegion", 0x74fa34ed));
-        api.commit(swapChain);
+        ImageExpectations expectations(api);
+
+        {
+            RenderFrame frame(api);
+            // TODO: for some reason, this test has very, very slight (as in one pixel) differences
+            // between OpenGL and Metal. So disable golden checking for now.
+            // EXPECT_IMAGE(dstRenderTarget, expectations, ScreenshotParams(kDstTexWidth,
+            //         kDstTexHeight, "BlitRegion", 0x74fa34ed));
+            api.commit(swapChain);
+        }
+
+        flushAndWait();
     }
 }
 
@@ -537,19 +567,25 @@ TEST_F(BlitTest, BlitRegionToSwapChain) {
     };
 
     {
-        RenderFrame frame(api);
+        ImageExpectations expectations(api);
+        {
+            {
+                RenderFrame frame(api);
 
-        api.blitDEPRECATED(TargetBufferFlags::COLOR0, dstRenderTarget,
-                dstRect, srcRenderTargets[srcLevel],
-                srcRect, SamplerMagFilter::LINEAR);
+                api.blitDEPRECATED(TargetBufferFlags::COLOR0, dstRenderTarget,
+                        dstRect, srcRenderTargets[srcLevel],
+                        srcRect, SamplerMagFilter::LINEAR);
 
-        api.commit(swapChain);
+                api.commit(swapChain);
+            }
+
+            // TODO: for some reason, this test has been disabled. It needs to be tested on all
+            // machines.
+            // EXPECT_IMAGE(dstRenderTarget, expectations,
+            //         ScreenshotParams(kDstTexWidth, kDstTexHeight, "BlitRegionToSwapChain", 0x0));
+        }
+        flushAndWait();
     }
-
-    // TODO: for some reason, this test has been disabled. It needs to be tested on all
-    // machines.
-    // EXPECT_IMAGE(dstRenderTarget, expectations,
-    //         ScreenshotParams(kDstTexWidth, kDstTexHeight, "BlitRegionToSwapChain", 0x0));
 }
 
 } // namespace test

filament/backend/test/test_BufferUpdates.cpp

@@ -16,7 +16,6 @@
 
 #include "BackendTest.h"
 
-#include "ImageExpectations.h"
 #include "Lifetimes.h"
 #include "Shader.h"
 #include "SharedShaders.h"
@@ -221,9 +220,9 @@ TEST_F(BufferUpdatesTest, BufferObjectUpdateWithOffset) {
     renderTriangle({{ DescriptorSetLayoutHandle{}, shader.getDescriptorSetLayout() }},
             renderTarget, swapChain, shader.getProgram(), params);
 
-
-    EXPECT_IMAGE(renderTarget, getExpectations(),
-            ScreenshotParams(512, 512, "BufferObjectUpdateWithOffset", 91322442));
+    static const uint32_t expectedHash = 91322442;
+    readPixelsAndAssertHash(
+            "BufferObjectUpdateWithOffset", 512, 512, renderTarget, expectedHash, true);
 
     api.flush();
     api.commit(swapChain);

filament/backend/test/test_Callbacks.cpp

@@ -17,7 +17,6 @@
 #include "BackendTest.h"
 
 #include "Lifetimes.h"
-#include "Skip.h"
 
 using namespace filament;
 using namespace filament::backend;
@@ -25,8 +24,6 @@ using namespace filament::backend;
 namespace test {
 
 TEST_F(BackendTest, FrameScheduledCallback) {
-    SKIP_IF(SkipEnvironment(OperatingSystem::APPLE, Backend::OPENGL));
-
     auto& api = getDriverApi();
     Cleanup cleanup(api);
 
@@ -84,8 +81,6 @@ TEST_F(BackendTest, FrameScheduledCallback) {
 }
 
 TEST_F(BackendTest, FrameCompletedCallback) {
-    SKIP_IF(SkipEnvironment(OperatingSystem::APPLE, Backend::OPENGL));
-
     auto& api = getDriverApi();
     Cleanup cleanup(api);
 

filament/backend/test/test_FeedbackLoops.cpp

@@ -71,6 +71,8 @@ void main() {
     fragColor = textureLod(test_tex, uv, params.sourceLevel);
 })";
 
+static uint32_t sPixelHashResult = 0;
+
 // Selecting a NPOT texture size seems to exacerbate the bug seen with Intel GPU's.
 // Note that Filament uses a higher precision format (R11F_G11F_B10F) but this does not seem
 // necessary to trigger the bug.
@@ -94,6 +96,25 @@ struct MaterialParams {
     float unused;
 };
 
+static void dumpScreenshot(DriverApi& dapi, Handle<HwRenderTarget> rt) {
+    const size_t size = kTexWidth * kTexHeight * 4;
+    void* buffer = calloc(1, size);
+    auto cb = [](void* buffer, size_t size, void* user) {
+        int w = kTexWidth, h = kTexHeight;
+        const uint32_t* texels = (uint32_t*) buffer;
+        sPixelHashResult = utils::hash::murmur3(texels, size / 4, 0);
+#ifndef FILAMENT_IOS
+        LinearImage image(w, h, 4);
+        image = toLinearWithAlpha<uint8_t>(w, h, w * 4, (uint8_t*) buffer);
+        std::ofstream pngstrm("feedback.png", std::ios::binary | std::ios::trunc);
+        ImageEncoder::encode(pngstrm, ImageEncoder::Format::PNG, image, "", "feedback.png");
+#endif
+        free(buffer);
+    };
+    PixelBufferDescriptor pb(buffer, size, PixelDataFormat::RGBA, PixelDataType::UBYTE, cb);
+    dapi.readPixels(rt, 0, 0, kTexWidth, kTexHeight, std::move(pb));
+}
+
 // TODO: This test needs work to get Metal and OpenGL to agree on results.
 // The problems are caused by both uploading and rendering into the same texture, since the OpenGL
 // backend's readPixels does not work correctly with textures that have image data uploaded.
@@ -238,8 +259,7 @@ TEST_F(BackendTest, FeedbackLoops) {
             // NOTE: Calling glReadPixels on any miplevel other than the base level
             // seems to be un-reliable on some GPU's.
             if (frame == kNumFrames - 1) {
-                EXPECT_IMAGE(renderTargets[0], getExpectations(),
-                        ScreenshotParams(kTexWidth, kTexHeight, "FeedbackLoops", 0x70695aa1));
+                dumpScreenshot(api, renderTargets[0]);
             }
 
             api.flush();
@@ -250,6 +270,10 @@ TEST_F(BackendTest, FeedbackLoops) {
             getDriver().purge();
         }
     }
+
+    const uint32_t expected = 0x70695aa1;
+    printf("Computed hash is 0x%8.8x, Expected 0x%8.8x\n", sPixelHashResult, expected);
+    EXPECT_TRUE(sPixelHashResult == expected);
 }
 
 } // namespace test

filament/backend/test/test_LoadImage.cpp

@@ -246,42 +246,42 @@ TEST_F(LoadImageTest, UpdateImage2D) {
     std::vector<TestCase> testCases;
 
     // Test basic upload.
-    testCases.emplace_back("RGBA UBYTE to RGBA8", PixelDataFormat::RGBA, PixelDataType::UBYTE, TextureFormat::RGBA8);
+    testCases.emplace_back("RGBA, UBYTE -> RGBA8", PixelDataFormat::RGBA, PixelDataType::UBYTE, TextureFormat::RGBA8);
 
     // Test format conversion.
     // TODO: Vulkan crashes with `Texture at colorAttachment[0] has usage (0x01) which doesn't specify MTLTextureUsageRenderTarget (0x04)'
-    testCases.emplace_back("RGBA FLOAT to RGBA16F", PixelDataFormat::RGBA, PixelDataType::FLOAT, TextureFormat::RGBA16F);
+    testCases.emplace_back("RGBA, FLOAT -> RGBA16F", PixelDataFormat::RGBA, PixelDataType::FLOAT, TextureFormat::RGBA16F);
 
     // Test texture formats not all backends support natively.
     // TODO: Vulkan crashes with "VK_FORMAT_R32G32B32_SFLOAT is not supported"
-    testCases.emplace_back("RGB FLOAT to RGB32F", PixelDataFormat::RGB, PixelDataType::FLOAT, TextureFormat::RGB32F);
-    testCases.emplace_back("RGB FLOAT to RGB16F", PixelDataFormat::RGB, PixelDataType::FLOAT, TextureFormat::RGB16F);
+    testCases.emplace_back("RGB, FLOAT -> RGB32F", PixelDataFormat::RGB, PixelDataType::FLOAT, TextureFormat::RGB32F);
+    testCases.emplace_back("RGB, FLOAT -> RGB16F", PixelDataFormat::RGB, PixelDataType::FLOAT, TextureFormat::RGB16F);
 
     // Test packed format uploads.
     // TODO: Vulkan crashes with "Texture at colorAttachment[0] has usage (0x01) which doesn't specify MTLTextureUsageRenderTarget (0x04)"
-    testCases.emplace_back("RGBA UINT_2_10_10_10_REV to RGB10_A2", PixelDataFormat::RGBA, PixelDataType::UINT_2_10_10_10_REV, TextureFormat::RGB10_A2);
-    testCases.emplace_back("RGB UINT_10F_11F_11F_REV to R11F_G11F_B10F", PixelDataFormat::RGB, PixelDataType::UINT_10F_11F_11F_REV, TextureFormat::R11F_G11F_B10F);
-    testCases.emplace_back("RGB HALF to R11F_G11F_B10F", PixelDataFormat::RGB, PixelDataType::HALF, TextureFormat::R11F_G11F_B10F);
+    testCases.emplace_back("RGBA, UINT_2_10_10_10_REV -> RGB10_A2", PixelDataFormat::RGBA, PixelDataType::UINT_2_10_10_10_REV, TextureFormat::RGB10_A2);
+    testCases.emplace_back("RGB, UINT_10F_11F_11F_REV -> R11F_G11F_B10F", PixelDataFormat::RGB, PixelDataType::UINT_10F_11F_11F_REV, TextureFormat::R11F_G11F_B10F);
+    testCases.emplace_back("RGB, HALF -> R11F_G11F_B10F", PixelDataFormat::RGB, PixelDataType::HALF, TextureFormat::R11F_G11F_B10F);
 
     // Test integer format uploads.
     // TODO: These cases fail on OpenGL and Vulkan.
     // TODO: These cases now also fail on Metal, but at some point previously worked.
-     testCases.emplace_back("RGB_INTEGER UBYTE to RGB8UI", PixelDataFormat::RGB_INTEGER, PixelDataType::UBYTE, TextureFormat::RGB8UI);
-     testCases.emplace_back("RGB_INTEGER USHORT to RGB16UI", PixelDataFormat::RGB_INTEGER, PixelDataType::USHORT, TextureFormat::RGB16UI);
-     testCases.emplace_back("RGB_INTEGER INT to RGB32I", PixelDataFormat::RGB_INTEGER, PixelDataType::INT, TextureFormat::RGB32I);
+     testCases.emplace_back("RGB_INTEGER, UBYTE -> RGB8UI", PixelDataFormat::RGB_INTEGER, PixelDataType::UBYTE, TextureFormat::RGB8UI);
+     testCases.emplace_back("RGB_INTEGER, USHORT -> RGB16UI", PixelDataFormat::RGB_INTEGER, PixelDataType::USHORT, TextureFormat::RGB16UI);
+     testCases.emplace_back("RGB_INTEGER, INT -> RGB32I", PixelDataFormat::RGB_INTEGER, PixelDataType::INT, TextureFormat::RGB32I);
 
     // Test uploads with buffer padding.
     // TODO: Vulkan crashes with "Assertion failed: (offset + size <= allocationSize)"
-    testCases.emplace_back("RGBA UBYTE to RGBA8 (with buffer padding)", PixelDataFormat::RGBA, PixelDataType::UBYTE, TextureFormat::RGBA8, 64u);
-    testCases.emplace_back("RGBA FLOAT to RGBA16F (with buffer padding)", PixelDataFormat::RGBA, PixelDataType::FLOAT, TextureFormat::RGBA16F, 64u);
-    testCases.emplace_back("RGB FLOAT to RGB32F (with buffer padding)", PixelDataFormat::RGB, PixelDataType::FLOAT, TextureFormat::RGB32F, 64u);
+    testCases.emplace_back("RGBA, UBYTE -> RGBA8 (with buffer padding)", PixelDataFormat::RGBA, PixelDataType::UBYTE, TextureFormat::RGBA8, 64u);
+    testCases.emplace_back("RGBA, FLOAT -> RGBA16F (with buffer padding)", PixelDataFormat::RGBA, PixelDataType::FLOAT, TextureFormat::RGBA16F, 64u);
+    testCases.emplace_back("RGB, FLOAT -> RGB32F (with buffer padding)", PixelDataFormat::RGB, PixelDataType::FLOAT, TextureFormat::RGB32F, 64u);
 
     // Upload subregions separately.
     // TODO: Vulkan crashes with "Offsets not yet supported"
-    testCases.emplace_back("RGBA UBYTE to RGBA8 (subregions)", PixelDataFormat::RGBA, PixelDataType::UBYTE, TextureFormat::RGBA8, 0u, true);
-    testCases.emplace_back("RGBA FLOAT to RGBA16F (subregions)", PixelDataFormat::RGBA, PixelDataType::FLOAT, TextureFormat::RGBA16F, 0u, true);
-    testCases.emplace_back("RGBA UBYTE to RGBA8 (subregions and buffer padding)", PixelDataFormat::RGBA, PixelDataType::UBYTE, TextureFormat::RGBA8, 64u, true);
-    testCases.emplace_back("RGB FLOAT to RGB32F (subregions and buffer padding)", PixelDataFormat::RGB, PixelDataType::FLOAT, TextureFormat::RGB32F, 64u, true);
+    testCases.emplace_back("RGBA, UBYTE -> RGBA8 (subregions)", PixelDataFormat::RGBA, PixelDataType::UBYTE, TextureFormat::RGBA8, 0u, true);
+    testCases.emplace_back("RGBA, FLOAT -> RGBA16F (subregions)", PixelDataFormat::RGBA, PixelDataType::FLOAT, TextureFormat::RGBA16F, 0u, true);
+    testCases.emplace_back("RGBA, UBYTE -> RGBA8 (subregions, buffer padding)", PixelDataFormat::RGBA, PixelDataType::UBYTE, TextureFormat::RGBA8, 64u, true);
+    testCases.emplace_back("RGB, FLOAT -> RGB32F (subregions, buffer padding)", PixelDataFormat::RGB, PixelDataType::FLOAT, TextureFormat::RGB32F, 64u, true);
 
     auto& api = getDriverApi();
 
@@ -339,14 +339,16 @@ TEST_F(LoadImageTest, UpdateImage2D) {
         renderTriangle({{ DescriptorSetLayoutHandle{}, shader.getDescriptorSetLayout() }},
                 defaultRenderTarget, swapChain, shader.getProgram());
 
-        EXPECT_IMAGE(defaultRenderTarget, getExpectations(),
-                ScreenshotParams(512, 512, t.name, expectedHash));
+        readPixelsAndAssertHash(t.name, 512, 512, defaultRenderTarget, expectedHash);
 
         api.commit(swapChain);
         api.endFrame(0);
     }
 
+    api.finish();
     api.stopCapture();
+
+    flushAndWait();
 }
 
 TEST_F(LoadImageTest, UpdateImageSRGB) {
@@ -370,7 +372,7 @@ TEST_F(LoadImageTest, UpdateImageSRGB) {
             getSamplerTypeName(textureFormat), fragmentTemplate);
     Shader shader(api, cleanup, ShaderConfig{
         .vertexShader = mVertexShader, .fragmentShader = fragment, .uniforms = {{
-            "test_tex", DescriptorType::SAMPLER, samplerInfo
+            "text_tex", DescriptorType::SAMPLER, samplerInfo
     }}});
 
     // Create a texture.
@@ -414,12 +416,15 @@ TEST_F(LoadImageTest, UpdateImageSRGB) {
     renderTriangle({{ DescriptorSetLayoutHandle{}, shader.getDescriptorSetLayout() }},
             defaultRenderTarget, swapChain, shader.getProgram());
 
-    EXPECT_IMAGE(defaultRenderTarget, getExpectations(),
-            ScreenshotParams(512, 512, "UpdateImageSRGB", 359858623));
+    static const uint32_t expectedHash = 359858623;
+    readPixelsAndAssertHash("UpdateImageSRGB", 512, 512, defaultRenderTarget, expectedHash);
 
+    api.flush();
     api.commit(swapChain);
     api.endFrame(0);
 
+    // This ensures all driver commands have finished before exiting the test.
+    api.finish();
     api.stopCapture();
 }
 
@@ -473,12 +478,15 @@ TEST_F(LoadImageTest, UpdateImageMipLevel) {
     renderTriangle({{ DescriptorSetLayoutHandle{}, shader.getDescriptorSetLayout() }},
             defaultRenderTarget, swapChain, shader.getProgram());
 
-    EXPECT_IMAGE(defaultRenderTarget, getExpectations(),
-            ScreenshotParams(512, 512, "UpdateImageMipLevel", 3644679986));
+    static const uint32_t expectedHash = 3644679986;
+    readPixelsAndAssertHash("UpdateImageMipLevel", 512, 512, defaultRenderTarget, expectedHash);
 
+    api.flush();
     api.commit(swapChain);
     api.endFrame(0);
 
+    // This ensures all driver commands have finished before exiting the test.
+    api.finish();
     api.stopCapture();
 }
 
@@ -530,24 +538,29 @@ TEST_F(LoadImageTest, UpdateImage3D) {
 
     api.update3DImage(texture, 0, 0, 0, 0, 512, 512, 4, std::move(descriptor));
 
-    {
-        RenderFrame frame(api);
+    api.beginFrame(0, 0, 0);
 
-        // Update samplers.
-        DescriptorSetHandle descriptorSet = shader.createDescriptorSet(api);
-        api.updateDescriptorSetTexture(descriptorSet, 0, texture,
-                { .filterMag = SamplerMagFilter::LINEAR,
-                    .filterMin = SamplerMinFilter::LINEAR_MIPMAP_NEAREST });
+    // Update samplers.
+    DescriptorSetHandle  descriptorSet = shader.createDescriptorSet(api);
+    api.updateDescriptorSetTexture(descriptorSet, 0, texture, {
+            .filterMag = SamplerMagFilter::LINEAR,
+            .filterMin = SamplerMinFilter::LINEAR_MIPMAP_NEAREST
+    });
 
-        api.bindDescriptorSet(descriptorSet, 1, {});
+    api.bindDescriptorSet(descriptorSet, 1, {});
 
-        renderTriangle({ { DescriptorSetLayoutHandle{}, shader.getDescriptorSetLayout() } },
-                defaultRenderTarget, swapChain, shader.getProgram());
+    renderTriangle({{ DescriptorSetLayoutHandle{}, shader.getDescriptorSetLayout() }},
+            defaultRenderTarget, swapChain, shader.getProgram());
 
-        EXPECT_IMAGE(defaultRenderTarget, getExpectations(),
-                ScreenshotParams(512, 512, "UpdateImage3D", 3644679986));
-    }
+    static const uint32_t expectedHash = 3644679986;
+    readPixelsAndAssertHash("UpdateImage3D", 512, 512, defaultRenderTarget, expectedHash);
 
+    api.flush();
+    api.commit(swapChain);
+    api.endFrame(0);
+
+    // This ensures all driver commands have finished before exiting the test.
+    api.finish();
     api.stopCapture();
 }
 

filament/backend/test/test_PushConstants.cpp

@@ -16,10 +16,8 @@
 
 #include "BackendTest.h"
 
-#include "ImageExpectations.h"
 #include "Lifetimes.h"
 #include "ShaderGenerator.h"
-#include "Skip.h"
 #include "TrianglePrimitive.h"
 
 #include <utils/Hash.h>
@@ -80,8 +78,6 @@ void main() {
 })";
 
 TEST_F(BackendTest, PushConstants) {
-    SKIP_IF(SkipEnvironment(OperatingSystem::APPLE, Backend::OPENGL));
-
     auto& api = getDriverApi();
 
     api.startCapture(0);
@@ -152,14 +148,19 @@ TEST_F(BackendTest, PushConstants) {
 
         api.endRenderPass();
 
-        EXPECT_IMAGE(renderTarget, getExpectations(),
-                ScreenshotParams(512, 512, "pushConstants", 1957275826));
+        readPixelsAndAssertHash("pushConstants", 512, 512, renderTarget, 1957275826, true);
 
         api.commit(swapChain);
         api.endFrame(0);
     }
 
     api.stopCapture(0);
+
+    // Wait for the ReadPixels result to come back.
+    api.finish();
+
+    executeCommands();
+    getDriver().purge();
 }
 
 } // namespace test

filament/backend/test/test_RenderExternalImage.cpp

@@ -16,7 +16,6 @@
 
 #include "BackendTest.h"
 
-#include "ImageExpectations.h"
 #include "Lifetimes.h"
 #include "Shader.h"
 #include "SharedShaders.h"
@@ -201,16 +200,17 @@ TEST_F(BackendTest, RenderExternalImage) {
     api.draw(state, triangle.getRenderPrimitive(), 0, 3, 1);
     api.endRenderPass();
 
+    readPixelsAndAssertHash("RenderExternalImage", 512, 512, defaultRenderTarget, 267229901, true);
+
     api.flush();
     api.commit(swapChain);
     api.endFrame(0);
-    EXPECT_IMAGE(defaultRenderTarget, getExpectations(),
-            ScreenshotParams(512, 512, "RenderExternalImage", 267229901));
 
     api.stopCapture(0);
-    api.finish();
-    flushAndWait();
 
+    api.finish();
+
+    executeCommands();
 }
 
 } // namespace test

filament/backend/test/test_Scissor.cpp

@@ -16,7 +16,6 @@
 
 #include "BackendTest.h"
 
-#include "ImageExpectations.h"
 #include "Lifetimes.h"
 #include "Shader.h"
 #include "SharedShaders.h"
@@ -131,14 +130,20 @@ TEST_F(BackendTest, ScissorViewportRegion) {
         api.draw(ps, triangle.getRenderPrimitive(), 0, 3, 1);
         api.endRenderPass();
 
-        EXPECT_IMAGE(fullRenderTarget, getExpectations(),
-                ScreenshotParams(kSrcTexWidth >> 1, kSrcTexHeight >> 1, "scissor", 0xAB3D1C53));
+        readPixelsAndAssertHash("scissor", kSrcTexWidth >> 1, kSrcTexHeight >> 1, fullRenderTarget,
+                0xAB3D1C53, true);
 
         api.commit(swapChain);
         api.endFrame(0);
 
         api.stopCapture(0);
     }
+
+    // Wait for the ReadPixels result to come back.
+    api.finish();
+
+    executeCommands();
+    getDriver().purge();
 }
 
 // Verify that a negative Viewport origin works with scissor.
@@ -221,14 +226,20 @@ TEST_F(BackendTest, ScissorViewportEdgeCases) {
         api.draw(ps, triangle.getRenderPrimitive(), 0, 3, 1);
         api.endRenderPass();
 
-        EXPECT_IMAGE(renderTarget, getExpectations(),
-                ScreenshotParams(512, 512, "ScissorViewportEdgeCases", 0x6BF00F31));
+        readPixelsAndAssertHash(
+                "ScissorViewportEdgeCases", 512, 512, renderTarget, 0x6BF00F31, true);
 
         api.commit(swapChain);
         api.endFrame(0);
 
         api.stopCapture(0);
     }
+
+    // Wait for the ReadPixels result to come back.
+    api.finish();
+
+    executeCommands();
+    getDriver().purge();
 }
 
 } // namespace test

filament/backend/test/test_StencilBuffer.cpp

@@ -16,7 +16,6 @@
 
 #include "BackendTest.h"
 
-#include "ImageExpectations.h"
 #include "Lifetimes.h"
 #include "Shader.h"
 #include "SharedShaders.h"
@@ -130,8 +129,7 @@ TEST_F(BasicStencilBufferTest, StencilBuffer) {
 
     RunTest(renderTarget);
 
-    EXPECT_IMAGE(renderTarget, getExpectations(),
-            ScreenshotParams(512, 512, "StencilBuffer", 0x3B1AEF0F));
+    readPixelsAndAssertHash("StencilBuffer", 512, 512, renderTarget, 0x3B1AEF0F, true);
 
     flushAndWait();
     getDriver().purge();
@@ -153,8 +151,7 @@ TEST_F(BasicStencilBufferTest, DepthAndStencilBuffer) {
 
     RunTest(renderTarget);
 
-    EXPECT_IMAGE(renderTarget, getExpectations(),
-            ScreenshotParams(512, 512, "DepthAndStencilBuffer", 0x3B1AEF0F));
+    readPixelsAndAssertHash("DepthAndStencilBuffer", 512, 512, renderTarget, 0x3B1AEF0F, true);
 
     flushAndWait();
     getDriver().purge();
@@ -236,8 +233,7 @@ TEST_F(BasicStencilBufferTest, StencilBufferMSAA) {
     api.stopCapture(0);
     api.endFrame(0);
 
-    EXPECT_IMAGE(renderTarget1, getExpectations(),
-            ScreenshotParams(512, 512, "StencilBufferAutoResolve", 0x6CEFAC8F));
+    readPixelsAndAssertHash("StencilBufferAutoResolve", 512, 512, renderTarget1, 0x6CEFAC8F, true);
 
     flushAndWait();
     getDriver().purge();

filament/include/filament/Engine.h

@@ -317,6 +317,15 @@ public:
          */
         size_t metalUploadBufferSizeBytes = 512 * 1024;
 
+        /**
+         * The action to take if a Drawable cannot be acquired.
+         *
+         * Each frame rendered requires a CAMetalDrawable texture, which is
+         * presented on-screen at the completion of each frame. These are
+         * limited and provided round-robin style by the system.
+         */
+        bool metalDisablePanicOnDrawableFailure = false;
+
         /**
          * Set to `true` to forcibly disable parallel shader compilation in the backend.
          * Currently only honored by the GL and Metal backends.