External Texture implementation for Vulkan

Add support for the new createTextureExternalImage2R
API instead of createTextureExternalImageR.

Add the support to import AHardwareBuffer objects
into Vulkan in Android.

Author: rafadevai

filament/backend/CMakeLists.txt

@@ -233,7 +233,10 @@ if (FILAMENT_SUPPORTS_VULKAN)
     elseif (APPLE OR IOS)
         list(APPEND SRCS src/vulkan/platform/VulkanPlatformApple.mm)
     elseif (ANDROID)
-        list(APPEND SRCS src/vulkan/platform/VulkanPlatformAndroid.cpp)
+        list(APPEND SRCS
+            include/backend/platforms/VulkanPlatformAndroid.h
+            src/vulkan/platform/VulkanPlatformAndroid.cpp
+        )
     endif()
 endif()
 

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

@@ -347,18 +347,20 @@ class VulkanPlatform : public Platform, utils::PrivateImplementation<VulkanPlatf
          */
         uint32_t memoryTypeBits;
     };
-    virtual ExternalImageMetadata getExternalImageMetadata(void* externalImage);
+    virtual ExternalImageMetadata getExternalImageMetadata(ExternalImageHandleRef externalImage);
 
     using ImageData = std::pair<VkImage, VkDeviceMemory>;
-    virtual ImageData createExternalImage(void* externalImage,
+    virtual ImageData createExternalImageData(ExternalImageHandleRef externalImage,
             const ExternalImageMetadata& metadata);
 
 private:
     static ExtensionSet getSwapchainInstanceExtensions();
-    static ExternalImageMetadata getExternalImageMetadataImpl(void* externalImage,
+
+    static ExternalImageMetadata getExternalImageMetadataImpl(ExternalImageHandleRef externalImage,
             VkDevice device);
-    static ImageData createExternalImageImpl(void* externalImage, VkDevice device,
-            const VkAllocationCallbacks* allocator, const ExternalImageMetadata& metadata);
+
+    static ImageData createExternalImageDataImpl(ExternalImageHandleRef externalImage,
+            VkDevice device, const ExternalImageMetadata& metadata);
 
     // Platform dependent helper methods
     using SurfaceBundle = std::tuple<VkSurfaceKHR, VkExtent2D>;

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

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2025 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAMENT_BACKEND_PLATFORMS_VULKAN_PLATFORM_ANDROID_H
+#define TNT_FILAMENT_BACKEND_PLATFORMS_VULKAN_PLATFORM_ANDROID_H
+
+#include <backend/Platform.h>
+
+#include <android/hardware_buffer.h>
+
+namespace filament::backend::fvkandroid {
+
+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;
+};
+
+Platform::ExternalImageHandle UTILS_PUBLIC createExternalImage(
+    AHardwareBuffer const *buffer, bool sRGB) noexcept;
+
+} // namespace filament::backend::fvkandroid
+
+#endif // TNT_FILAMENT_BACKEND_PLATFORMS_VULKAN_PLATFORM_ANDROID_H

filament/backend/src/vulkan/VulkanDriver.cpp

@@ -560,14 +560,6 @@ void VulkanDriver::createTextureExternalImage2R(Handle<HwTexture> th,
         Platform::ExternalImageHandleRef externalImage) {
     FVK_SYSTRACE_SCOPE();
 
-    // FIXME: implement createTextureExternalImage2R
-}
-
-void VulkanDriver::createTextureExternalImageR(Handle<HwTexture> th, backend::SamplerType target,
-        backend::TextureFormat format, uint32_t width, uint32_t height, backend::TextureUsage usage,
-        void* externalImage) {
-    FVK_SYSTRACE_SCOPE();
-
     const auto& metadata = mPlatform->getExternalImageMetadata(externalImage);
     if (metadata.isProtected) {
         usage |= backend::TextureUsage::PROTECTED;
@@ -577,15 +569,23 @@ void VulkanDriver::createTextureExternalImageR(Handle<HwTexture> th, backend::Sa
     assert_invariant(height == metadata.height);
     assert_invariant(fvkutils::getVkFormat(format) == metadata.format);
 
-    const auto& data = mPlatform->createExternalImage(externalImage, metadata);
+    const auto& data = mPlatform->createExternalImageData(externalImage, metadata);
 
-    auto texture = resource_ptr<VulkanTexture>::make(&mResourceManager, th, mPlatform->getDevice(),
-        mAllocator, &mResourceManager, &mCommands, data.first, data.second, metadata.format,
-        1, metadata.width, metadata.height, /*depth=*/1, usage, mStagePool);
+    auto texture = resource_ptr<VulkanTexture>::make(&mResourceManager, th,
+            mPlatform->getDevice(), mAllocator, &mResourceManager, &mCommands, data.first, data.second, metadata.format,
+            1, metadata.width, metadata.height, /*depth=*/1, usage, mStagePool);
 
     texture.inc();
 }
 
+void VulkanDriver::createTextureExternalImageR(Handle<HwTexture> th, backend::SamplerType target,
+        backend::TextureFormat format, uint32_t width, uint32_t height, backend::TextureUsage usage,
+        void* externalImage) {
+    FVK_SYSTRACE_SCOPE();
+
+    // not supported in this backend
+}
+
 void VulkanDriver::createTextureExternalImagePlaneR(Handle<HwTexture> th,
         backend::TextureFormat format, uint32_t width, uint32_t height, backend::TextureUsage usage,
         void* image, uint32_t plane) {

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

@@ -978,13 +978,13 @@ VkQueue VulkanPlatform::getProtectedGraphicsQueue() const noexcept {
 }
 
 VulkanPlatform::ExternalImageMetadata VulkanPlatform::getExternalImageMetadata(
-        void* externalImage) {
+        ExternalImageHandleRef externalImage) {
     return getExternalImageMetadataImpl(externalImage, mImpl->mDevice);
 }
 
-VulkanPlatform::ImageData VulkanPlatform::createExternalImage(void* externalImage,
-            const ExternalImageMetadata& metadata) {
-    return createExternalImageImpl(externalImage, mImpl->mDevice, nullptr, metadata);
+VulkanPlatform::ImageData VulkanPlatform::createExternalImageData(
+        ExternalImageHandleRef externalImage, const ExternalImageMetadata& metadata) {
+    return createExternalImageDataImpl(externalImage, mImpl->mDevice, metadata);
 }
 
 #undef SWAPCHAIN_RET_FUNC