[Impeller] add experimental canvas support to screenshotter.

impeller/golden_tests/golden_playground_test_mac.cc

@@ -6,6 +6,7 @@
 #include <filesystem>
 #include <memory>
 
+#include "display_list/display_list.h"
 #include "flutter/impeller/golden_tests/golden_playground_test.h"
 
 #include "flutter/impeller/aiks/picture.h"
@@ -14,6 +15,7 @@
 #include "flutter/impeller/golden_tests/vulkan_screenshotter.h"
 #include "flutter/third_party/abseil-cpp/absl/base/no_destructor.h"
 #include "fml/closure.h"
+#include "impeller/aiks/aiks_context.h"
 #include "impeller/display_list/dl_dispatcher.h"
 #include "impeller/display_list/dl_image_impeller.h"
 #include "impeller/typographer/backends/skia/typographer_context_skia.h"
@@ -22,6 +24,8 @@
 #define GLFW_INCLUDE_NONE
 #include "third_party/glfw/include/GLFW/glfw3.h"
 
+#define EXPERIMENTAL_CANVAS false
+
 namespace impeller {
 
 namespace {
@@ -55,6 +59,56 @@ const std::unique_ptr<PlaygroundImpl>& GetSharedVulkanPlayground(
     return *vulkan_playground;
   }
 }
+
+#if EXPERIMENTAL_CANVAS
+std::shared_ptr<Texture> DisplayListToTexture(
+    sk_sp<flutter::DisplayList>& display_list,
+    ISize size,
+    AiksContext& context) {
+  // Do not use the render target cache as the lifecycle of this texture
+  // will outlive a particular frame.
+  impeller::RenderTargetAllocator render_target_allocator =
+      impeller::RenderTargetAllocator(
+          context.GetContext()->GetResourceAllocator());
+  impeller::RenderTarget target;
+  if (context.GetContext()->GetCapabilities()->SupportsOffscreenMSAA()) {
+    target = render_target_allocator.CreateOffscreenMSAA(
+        *context.GetContext(),  // context
+        size,                   // size
+        /*mip_count=*/1,
+        "Picture Snapshot MSAA",  // label
+        impeller::RenderTarget::
+            kDefaultColorAttachmentConfigMSAA  // color_attachment_config
+    );
+  } else {
+    target = render_target_allocator.CreateOffscreen(
+        *context.GetContext(),  // context
+        size,                   // size
+        /*mip_count=*/1,
+        "Picture Snapshot",  // label
+        impeller::RenderTarget::
+            kDefaultColorAttachmentConfig  // color_attachment_config
+    );
+  }
+
+  impeller::TextFrameDispatcher collector(context.GetContentContext(),
+                                          impeller::Matrix());
+  display_list->Dispatch(
+      collector, SkIRect::MakeSize(SkISize::Make(size.width, size.height)));
+  impeller::ExperimentalDlDispatcher impeller_dispatcher(
+      context.GetContentContext(), target,
+      display_list->root_has_backdrop_filter(),
+      display_list->max_root_blend_mode(), impeller::IRect::MakeSize(size));
+  display_list->Dispatch(impeller_dispatcher, SkIRect::MakeSize(SkISize::Make(
+                                                  size.width, size.height)));
+  impeller_dispatcher.FinishRecording();
+
+  context.GetContentContext().GetLazyGlyphAtlas()->ResetTextFrames();
+
+  return target.GetRenderTargetTexture();
+}
+#endif  // EXPERIMENTAL_CANVAS
+
 }  // namespace
 
 #define IMP_AIKSTEST(name)                         \
@@ -214,8 +268,16 @@ bool GoldenPlaygroundTest::OpenPlaygroundHere(
     const AiksDlPlaygroundCallback& callback) {
   AiksContext renderer(GetContext(), typographer_context_);
 
-  std::optional<Picture> picture;
   std::unique_ptr<testing::Screenshot> screenshot;
+#if EXPERIMENTAL_CANVAS
+  for (int i = 0; i < 2; ++i) {
+    auto display_list = callback();
+    auto texture =
+        DisplayListToTexture(display_list, pimpl_->window_size, renderer);
+    screenshot = pimpl_->screenshotter->MakeScreenshot(renderer, texture);
+  }
+#else
+  std::optional<Picture> picture;
   for (int i = 0; i < 2; ++i) {
     auto display_list = callback();
     DlDispatcher dispatcher;
@@ -225,7 +287,7 @@ bool GoldenPlaygroundTest::OpenPlaygroundHere(
     screenshot = pimpl_->screenshotter->MakeScreenshot(renderer, picture,
                                                        pimpl_->window_size);
   }
-
+#endif  // EXPERIMENTAL_CANVAS
   return SaveScreenshot(std::move(screenshot));
 }
 
@@ -250,10 +312,7 @@ bool GoldenPlaygroundTest::OpenPlaygroundHere(
 
 bool GoldenPlaygroundTest::OpenPlaygroundHere(
     const sk_sp<flutter::DisplayList>& list) {
-  DlDispatcher dispatcher;
-  list->Dispatch(dispatcher);
-  Picture picture = dispatcher.EndRecordingAsPicture();
-  return OpenPlaygroundHere(std::move(picture));
+  return OpenPlaygroundHere([&list]() { return list; });
 }
 
 bool GoldenPlaygroundTest::ImGuiBegin(const char* name,

impeller/golden_tests/metal_screenshotter.h

@@ -25,6 +25,10 @@ class MetalScreenshotter : public Screenshotter {
       const ISize& size = {300, 300},
       bool scale_content = true) override;
 
+  std::unique_ptr<Screenshot> MakeScreenshot(
+      AiksContext& aiks_context,
+      const std::shared_ptr<Texture> texture) override;
+
   PlaygroundImpl& GetPlayground() override { return *playground_; }
 
  private:

impeller/golden_tests/metal_screenshotter.mm

@@ -31,6 +31,12 @@
       aiks_context,
       ISize(size.width * content_scale.x, size.height * content_scale.y));
   std::shared_ptr<Texture> texture = image->GetTexture();
+  return MakeScreenshot(aiks_context, texture);
+}
+
+std::unique_ptr<Screenshot> MetalScreenshotter::MakeScreenshot(
+    AiksContext& aiks_context,
+    const std::shared_ptr<Texture> texture) {
   id<MTLTexture> metal_texture =
       std::static_pointer_cast<TextureMTL>(texture)->GetMTLTexture();
 

impeller/golden_tests/screenshotter.h

@@ -24,6 +24,10 @@ class Screenshotter {
       const ISize& size = {300, 300},
       bool scale_content = true) = 0;
 
+  virtual std::unique_ptr<Screenshot> MakeScreenshot(
+      AiksContext& aiks_context,
+      const std::shared_ptr<Texture> texture) = 0;
+
   virtual PlaygroundImpl& GetPlayground() = 0;
 };
 

impeller/golden_tests/vulkan_screenshotter.h

@@ -26,6 +26,10 @@ class VulkanScreenshotter : public Screenshotter {
       const ISize& size = {300, 300},
       bool scale_content = true) override;
 
+  std::unique_ptr<Screenshot> MakeScreenshot(
+      AiksContext& aiks_context,
+      const std::shared_ptr<Texture> texture) override;
+
   PlaygroundImpl& GetPlayground() override { return *playground_; }
 
  private:

impeller/golden_tests/vulkan_screenshotter.mm

@@ -120,5 +120,11 @@ CGImagePtr flipped_image(CGBitmapContextCreateImage(flipped_context.get()),
   return ReadTexture(aiks_context.GetContext(), texture);
 }
 
+std::unique_ptr<Screenshot> VulkanScreenshotter::MakeScreenshot(
+    AiksContext& aiks_context,
+    const std::shared_ptr<Texture> texture) {
+  return ReadTexture(aiks_context.GetContext(), texture);
+}
+
 }  // namespace testing
 }  // namespace impeller