Vulkan support in the Embedder API

ci/licenses_golden/licenses_flutter

@@ -1365,6 +1365,8 @@ FILE: ../../../flutter/shell/platform/embedder/embedder_surface_metal.h
 FILE: ../../../flutter/shell/platform/embedder/embedder_surface_metal.mm
 FILE: ../../../flutter/shell/platform/embedder/embedder_surface_software.cc
 FILE: ../../../flutter/shell/platform/embedder/embedder_surface_software.h
+FILE: ../../../flutter/shell/platform/embedder/embedder_surface_vulkan.cc
+FILE: ../../../flutter/shell/platform/embedder/embedder_surface_vulkan.h
 FILE: ../../../flutter/shell/platform/embedder/embedder_task_runner.cc
 FILE: ../../../flutter/shell/platform/embedder/embedder_task_runner.h
 FILE: ../../../flutter/shell/platform/embedder/embedder_thread_host.cc
@@ -1387,6 +1389,8 @@ FILE: ../../../flutter/shell/platform/embedder/fixtures/scene_without_custom_com
 FILE: ../../../flutter/shell/platform/embedder/fixtures/snapshot_large_scene.png
 FILE: ../../../flutter/shell/platform/embedder/fixtures/verifyb143464703.png
 FILE: ../../../flutter/shell/platform/embedder/fixtures/verifyb143464703_soft_noxform.png
+FILE: ../../../flutter/shell/platform/embedder/fixtures/vk_dpr_noxform.png
+FILE: ../../../flutter/shell/platform/embedder/fixtures/vk_gradient.png
 FILE: ../../../flutter/shell/platform/embedder/platform_view_embedder.cc
 FILE: ../../../flutter/shell/platform/embedder/platform_view_embedder.h
 FILE: ../../../flutter/shell/platform/embedder/test_utils/key_codes.h

shell/gpu/BUILD.gn

@@ -43,8 +43,9 @@ source_set("gpu_surface_vulkan") {
     "gpu_surface_vulkan_delegate.cc",
     "gpu_surface_vulkan_delegate.h",
   ]
-
-  deps = gpu_common_deps + [ "//flutter/vulkan" ]
+  deps = [ "//flutter/shell/platform/embedder:embedder_headers" ]
+  deps += gpu_common_deps
+  public_deps = [ "//flutter/vulkan" ]
 }
 
 source_set("gpu_surface_metal") {

shell/gpu/gpu_surface_metal_delegate.h

@@ -75,14 +75,14 @@ class GPUSurfaceMetalDelegate {
 
   //------------------------------------------------------------------------------
   /// @brief Returns the handle to the MTLTexture to render to. This is only
-  /// called when the specefied render target type is `kMTLTexture`.
+  /// called when the specified render target type is `kMTLTexture`.
   ///
   virtual GPUMTLTextureInfo GetMTLTexture(const SkISize& frame_info) const = 0;
 
   //------------------------------------------------------------------------------
   /// @brief Presents the texture with `texture_id` to the "screen".
   /// `texture_id` corresponds to a texture that has been obtained by an earlier
-  /// call to `GetMTLTexture`. This is only called when the specefied render
+  /// call to `GetMTLTexture`. This is only called when the specified render
   /// target type is `kMTLTexture`.
   ///
   /// @see |GPUSurfaceMetalDelegate::GetMTLTexture|

shell/gpu/gpu_surface_vulkan.cc

@@ -5,68 +5,77 @@
 #include "flutter/shell/gpu/gpu_surface_vulkan.h"
 
 #include "flutter/fml/logging.h"
+#include "fml/trace_event.h"
+#include "include/core/SkSize.h"
+#include "third_party/swiftshader/include/vulkan/vulkan_core.h"
 
 namespace flutter {
 
-GPUSurfaceVulkan::GPUSurfaceVulkan(
-    GPUSurfaceVulkanDelegate* delegate,
-    std::unique_ptr<vulkan::VulkanNativeSurface> native_surface,
-    bool render_to_surface)
-    : GPUSurfaceVulkan(/*context=*/nullptr,
-                       delegate,
-                       std::move(native_surface),
-                       render_to_surface) {}
-
-GPUSurfaceVulkan::GPUSurfaceVulkan(
-    const sk_sp<GrDirectContext>& context,
-    GPUSurfaceVulkanDelegate* delegate,
-    std::unique_ptr<vulkan::VulkanNativeSurface> native_surface,
-    bool render_to_surface)
-    : window_(context,
-              delegate->vk(),
-              std::move(native_surface),
-              render_to_surface),
+GPUSurfaceVulkan::GPUSurfaceVulkan(GPUSurfaceVulkanDelegate* delegate,
+                                   const sk_sp<GrDirectContext>& skia_context,
+                                   bool render_to_surface)
+    : delegate_(delegate),
+      skia_context_(skia_context),
       render_to_surface_(render_to_surface),
       weak_factory_(this) {}
 
 GPUSurfaceVulkan::~GPUSurfaceVulkan() = default;
 
 bool GPUSurfaceVulkan::IsValid() {
-  return window_.IsValid();
+  return skia_context_ != nullptr;
 }
 
 std::unique_ptr<SurfaceFrame> GPUSurfaceVulkan::AcquireFrame(
-    const SkISize& size) {
-  SurfaceFrame::FramebufferInfo framebuffer_info;
-  framebuffer_info.supports_readback = true;
+    const SkISize& frame_size) {
+  if (!IsValid()) {
+    FML_LOG(ERROR) << "Vulkan surface was invalid.";
+    return nullptr;
+  }
+
+  if (frame_size.isEmpty()) {
+    FML_LOG(ERROR) << "Vulkan surface was asked for an empty frame.";
+    return nullptr;
+  }
 
-  // TODO(38466): Refactor GPU surface APIs take into account the fact that an
-  // external view embedder may want to render to the root surface.
   if (!render_to_surface_) {
     return std::make_unique<SurfaceFrame>(
-        nullptr, std::move(framebuffer_info),
+        nullptr, SurfaceFrame::FramebufferInfo(),
         [](const SurfaceFrame& surface_frame, SkCanvas* canvas) {
           return true;
         });
   }
 
-  auto surface = window_.AcquireSurface();
+  FlutterVulkanImage image = delegate_->AcquireImage(frame_size);
+  if (!image.image) {
+    FML_LOG(ERROR) << "Invalid VkImage given by the embedder.";
+    return nullptr;
+  }
 
-  if (surface == nullptr) {
+  sk_sp<SkSurface> surface = CreateSurfaceFromVulkanImage(
+      reinterpret_cast<VkImage>(image.image),
+      static_cast<VkFormat>(image.format), frame_size);
+  if (!surface) {
+    FML_LOG(ERROR) << "Could not create the SkSurface from the Vulkan image.";
     return nullptr;
   }
 
-  SurfaceFrame::SubmitCallback callback =
-      [weak_this = weak_factory_.GetWeakPtr()](const SurfaceFrame&,
-                                               SkCanvas* canvas) -> bool {
-    // Frames are only ever acquired on the raster thread. This is also the
-    // thread on which the weak pointer factory is collected (as this instance
-    // is owned by the rasterizer). So this use of weak pointers is safe.
-    if (canvas == nullptr || !weak_this) {
+  SurfaceFrame::SubmitCallback callback = [image = image, delegate = delegate_](
+                                              const SurfaceFrame&,
+                                              SkCanvas* canvas) -> bool {
+    TRACE_EVENT0("flutter", "GPUSurfaceVulkan::PresentImage");
+    if (canvas == nullptr) {
+      FML_DLOG(ERROR) << "Canvas not available.";
       return false;
     }
-    return weak_this->window_.SwapBuffers();
+
+    canvas->flush();
+
+    return delegate->PresentImage(reinterpret_cast<VkImage>(image.image),
+                                  static_cast<VkFormat>(image.format));
   };
+
+  SurfaceFrame::FramebufferInfo framebuffer_info{.supports_readback = true};
+
   return std::make_unique<SurfaceFrame>(
       std::move(surface), std::move(framebuffer_info), std::move(callback));
 }
@@ -80,7 +89,54 @@ SkMatrix GPUSurfaceVulkan::GetRootTransformation() const {
 }
 
 GrDirectContext* GPUSurfaceVulkan::GetContext() {
-  return window_.GetSkiaGrContext();
+  return skia_context_.get();
+}
+
+sk_sp<SkSurface> GPUSurfaceVulkan::CreateSurfaceFromVulkanImage(
+    const VkImage image,
+    const VkFormat format,
+    const SkISize& size) {
+  GrVkImageInfo image_info = {
+      .fImage = image,
+      .fImageTiling = VK_IMAGE_TILING_OPTIMAL,
+      .fImageLayout = VK_IMAGE_LAYOUT_UNDEFINED,
+      .fFormat = format,
+      .fImageUsageFlags = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT |
+                          VK_IMAGE_USAGE_TRANSFER_SRC_BIT |
+                          VK_IMAGE_USAGE_TRANSFER_DST_BIT |
+                          VK_IMAGE_USAGE_SAMPLED_BIT,
+      .fSampleCount = 1,
+      .fLevelCount = 1,
+  };
+  GrBackendTexture backend_texture(size.width(),   //
+                                   size.height(),  //
+                                   image_info      //
+  );
+
+  SkSurfaceProps surface_properties(0, kUnknown_SkPixelGeometry);
+
+  return SkSurface::MakeFromBackendTexture(
+      skia_context_.get(),          // context
+      backend_texture,              // back-end texture
+      kTopLeft_GrSurfaceOrigin,     // surface origin
+      1,                            // sample count
+      ColorTypeFromFormat(format),  // color type
+      SkColorSpace::MakeSRGB(),     // color space
+      &surface_properties           // surface properties
+  );
+}
+
+SkColorType GPUSurfaceVulkan::ColorTypeFromFormat(const VkFormat format) {
+  switch (format) {
+    case VK_FORMAT_R8G8B8A8_UNORM:
+    case VK_FORMAT_R8G8B8A8_SRGB:
+      return SkColorType::kRGBA_8888_SkColorType;
+    case VK_FORMAT_B8G8R8A8_UNORM:
+    case VK_FORMAT_B8G8R8A8_SRGB:
+      return SkColorType::kBGRA_8888_SkColorType;
+    default:
+      return SkColorType::kUnknown_SkColorType;
+  }
 }
 
 }  // namespace flutter

shell/gpu/gpu_surface_vulkan.h

@@ -11,29 +11,25 @@
 #include "flutter/fml/macros.h"
 #include "flutter/fml/memory/weak_ptr.h"
 #include "flutter/shell/gpu/gpu_surface_vulkan_delegate.h"
+#include "flutter/vulkan/vulkan_backbuffer.h"
 #include "flutter/vulkan/vulkan_native_surface.h"
 #include "flutter/vulkan/vulkan_window.h"
 #include "include/core/SkRefCnt.h"
 
 namespace flutter {
 
+//------------------------------------------------------------------------------
+/// @brief  A GPU surface backed by VkImages provided by a
+///         GPUSurfaceVulkanDelegate.
+///
 class GPUSurfaceVulkan : public Surface {
  public:
-  //------------------------------------------------------------------------------
-  /// @brief      Create a GPUSurfaceVulkan which implicitly creates its own
-  ///             GrDirectContext for Skia.
-  ///
-  GPUSurfaceVulkan(GPUSurfaceVulkanDelegate* delegate,
-                   std::unique_ptr<vulkan::VulkanNativeSurface> native_surface,
-                   bool render_to_surface);
-
   //------------------------------------------------------------------------------
   /// @brief      Create a GPUSurfaceVulkan while letting it reuse an existing
   ///             GrDirectContext.
   ///
-  GPUSurfaceVulkan(const sk_sp<GrDirectContext>& context,
-                   GPUSurfaceVulkanDelegate* delegate,
-                   std::unique_ptr<vulkan::VulkanNativeSurface> native_surface,
+  GPUSurfaceVulkan(GPUSurfaceVulkanDelegate* delegate,
+                   const sk_sp<GrDirectContext>& context,
                    bool render_to_surface);
 
   ~GPUSurfaceVulkan() override;
@@ -50,11 +46,19 @@ class GPUSurfaceVulkan : public Surface {
   // |Surface|
   GrDirectContext* GetContext() override;
 
+  static SkColorType ColorTypeFromFormat(const VkFormat format);
+
  private:
-  vulkan::VulkanWindow window_;
-  const bool render_to_surface_;
+  GPUSurfaceVulkanDelegate* delegate_;
+  sk_sp<GrDirectContext> skia_context_;
+  bool render_to_surface_;
 
   fml::WeakPtrFactory<GPUSurfaceVulkan> weak_factory_;
+
+  sk_sp<SkSurface> CreateSurfaceFromVulkanImage(const VkImage image,
+                                                const VkFormat format,
+                                                const SkISize& size);
+
   FML_DISALLOW_COPY_AND_ASSIGN(GPUSurfaceVulkan);
 };
 

shell/gpu/gpu_surface_vulkan_delegate.h

@@ -6,16 +6,43 @@
 #define FLUTTER_SHELL_GPU_GPU_SURFACE_VULKAN_DELEGATE_H_
 
 #include "flutter/fml/memory/ref_ptr.h"
+#include "flutter/shell/platform/embedder/embedder.h"
+#include "flutter/vulkan/vulkan_device.h"
+#include "flutter/vulkan/vulkan_image.h"
 #include "flutter/vulkan/vulkan_proc_table.h"
+#include "third_party/skia/include/core/SkSize.h"
 
 namespace flutter {
 
+//------------------------------------------------------------------------------
+/// @brief      Interface implemented by all platform surfaces that can present
+///             a Vulkan backing store to the "screen". The GPU surface
+///             abstraction (which abstracts the client rendering API) uses this
+///             delegation pattern to tell the platform surface (which abstracts
+///             how backing stores fulfilled by the selected client rendering
+///             API end up on the "screen" on a particular platform) when the
+///             rasterizer needs to allocate and present the Vulkan backing
+///             store.
+///
+/// @see        |EmbedderSurfaceVulkan|.
+///
 class GPUSurfaceVulkanDelegate {
  public:
-  ~GPUSurfaceVulkanDelegate();
+  virtual ~GPUSurfaceVulkanDelegate();
 
-  // Obtain a reference to the Vulkan implementation's proc table.
-  virtual fml::RefPtr<vulkan::VulkanProcTable> vk() = 0;
+  /// @brief  Obtain a reference to the Vulkan implementation's proc table.
+  ///
+  virtual const vulkan::VulkanProcTable& vk() = 0;
+
+  /// @brief  Called by the engine to fetch a VkImage for writing the next
+  ///         frame.
+  ///
+  virtual FlutterVulkanImage AcquireImage(const SkISize& size) = 0;
+
+  /// @brief  Called by the engine once a frame has been rendered to the image
+  ///         and it's ready to be bound for further reading/writing.
+  ///
+  virtual bool PresentImage(VkImage image, VkFormat format) = 0;
 };
 
 }  // namespace flutter

shell/platform/embedder/BUILD.gn

@@ -109,6 +109,13 @@ template("embedder_source_set") {
       deps += [ "//flutter/shell/platform/darwin/graphics" ]
     }
 
+    if (embedder_enable_vulkan) {
+      sources += [
+        "embedder_surface_vulkan.cc",
+        "embedder_surface_vulkan.h",
+      ]
+    }
+
     public_deps = [ ":embedder_headers" ]
 
     public_configs += [
@@ -168,6 +175,8 @@ test_fixtures("fixtures") {
     "fixtures/dpr_noxform.png",
     "fixtures/dpr_xform.png",
     "fixtures/gradient.png",
+    "fixtures/vk_dpr_noxform.png",
+    "fixtures/vk_gradient.png",
     "fixtures/gradient_metal.png",
     "fixtures/external_texture_metal.png",
     "fixtures/gradient_xform.png",
@@ -250,6 +259,13 @@ if (enable_unittests) {
     }
 
     if (test_enable_vulkan) {
+      sources += [
+        "tests/embedder_test_compositor_vulkan.cc",
+        "tests/embedder_test_compositor_vulkan.h",
+        "tests/embedder_test_context_vulkan.cc",
+        "tests/embedder_test_context_vulkan.h",
+      ]
+
       deps += [
         "//flutter/testing:vulkan",
         "//flutter/vulkan",