cc: Make async readback path use async glRreadPixels.

cc/output/gl_renderer.h

 // Copyright 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_OUTPUT_GL_RENDERER_H_
 #define CC_OUTPUT_GL_RENDERER_H_
 
+#include "base/cancelable_callback.h"
 #include "cc/base/cc_export.h"
+#include "cc/base/scoped_ptr_vector.h"
 #include "cc/output/direct_renderer.h"
 #include "cc/output/gl_renderer_draw_cache.h"
 #include "cc/output/renderer.h"
 #include "cc/quads/checkerboard_draw_quad.h"
 #include "cc/quads/debug_border_draw_quad.h"
 #include "cc/quads/io_surface_draw_quad.h"
 #include "cc/quads/render_pass_draw_quad.h"
 #include "cc/quads/solid_color_draw_quad.h"
 #include "cc/quads/tile_draw_quad.h"
 #include "cc/quads/yuv_video_draw_quad.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsMemoryAllocation.h"
 #include "ui/gfx/quad_f.h"
 
+class SkBitmap;
+
 namespace cc {
 
 class GLRendererShaderTest;
 class OutputSurface;
 class PictureDrawQuad;
 class ScopedResource;
 class StreamVideoDrawQuad;
 class TextureDrawQuad;
 class GeometryBinding;
 class ScopedEnsureFramebufferAllocation;
@@ skipping 47 matching lines @@
              int highp_threshold_min);
 
   bool IsBackbufferDiscarded() const { return is_backbuffer_discarded_; }
   bool Initialize();
 
   const gfx::QuadF& SharedGeometryQuad() const { return shared_geometry_quad_; }
   const GeometryBinding* SharedGeometry() const {
     return shared_geometry_.get();
   }
 
+  void GetFramebufferPixels(gfx::Rect rect, CopyRenderPassCallback callback);

[piman, 2013/04/27 00:42:25]

nit: can we avoid overloading? Especially if one is virtual it becomes super
confusing.

[danakj, 2013/04/29 14:59:05]

Oh gosh, yes you're right. Renamed back to GetFramebufferPixelsAsync() as I had
done at first..

   bool GetFramebufferTexture(ScopedResource* resource, gfx::Rect device_rect);
   void ReleaseRenderPassTextures();
 
   virtual void BindFramebufferToOutputSurface(DrawingFrame* frame) OVERRIDE;
   virtual bool BindFramebufferToTexture(DrawingFrame* frame,
                                         const ScopedResource* resource,
                                         gfx::Rect framebuffer_rect) OVERRIDE;
   virtual void SetDrawViewportSize(gfx::Size viewport_size) OVERRIDE;
   virtual void SetScissorTestRect(gfx::Rect scissor_rect) OVERRIDE;
   virtual void ClearFramebuffer(DrawingFrame* frame) OVERRIDE;
   virtual void DoDrawQuad(DrawingFrame* frame, const class DrawQuad*) OVERRIDE;
   virtual void BeginDrawingFrame(DrawingFrame* frame) OVERRIDE;
   virtual void FinishDrawingFrame(DrawingFrame* frame) OVERRIDE;
   virtual bool FlippedFramebuffer() const OVERRIDE;
   virtual void EnsureScissorTestEnabled() OVERRIDE;
   virtual void EnsureScissorTestDisabled() OVERRIDE;
-  virtual void CopyCurrentRenderPassToBitmap(DrawingFrame* frame,
-                                             SkBitmap* bitmap) OVERRIDE;
+  virtual void CopyCurrentRenderPassToBitmap(
+      DrawingFrame* frame,
+      const CopyRenderPassCallback& callback) OVERRIDE;
   virtual void FinishDrawingQuadList() OVERRIDE;
 
  private:
   friend class GLRendererShaderPixelTest;
   friend class GLRendererShaderTest;
 
   static void ToGLMatrix(float* gl_matrix, const gfx::Transform& transform);
   static ManagedMemoryPolicy::PriorityCutoff PriorityCutoff(
       WebKit::WebGraphicsMemoryAllocation::PriorityCutoff priority_cutoff);
 
@@ skipping 54 matching lines @@
 
   bool UseScopedTexture(DrawingFrame* frame,
                         const ScopedResource* resource,
                         gfx::Rect viewport_rect);
 
   bool MakeContextCurrent();
 
   bool InitializeSharedObjects();
   void CleanupSharedObjects();
 
+  typedef base::Callback<void(bool success)>
+      AsyncGetFramebufferPixelsCleanupCallback;
+  void DoGetFramebufferPixels(
+      uint8* pixels,
+      gfx::Rect rect,
+      const AsyncGetFramebufferPixelsCleanupCallback& cleanup_callback);
+  void FinishedReadback(
+      const AsyncGetFramebufferPixelsCleanupCallback& cleanup_callback,
+      unsigned source_buffer,
+      scoped_ptr<uint8[]> sync_pixels,
+      uint8_t* dest_pixels,
+      gfx::Size size,
+      unsigned sync_point);
+  void PassOnSkBitmap(
+      scoped_ptr<SkBitmap> bitmap,
+      scoped_ptr<SkAutoLockPixels> lock,
+      const CopyRenderPassCallback& callback,
+      bool success);
+
   // WebKit::
   // WebGraphicsContext3D::WebGraphicsMemoryAllocationChangedCallbackCHROMIUM
   // implementation.
   virtual void onMemoryAllocationChanged(
       WebKit::WebGraphicsMemoryAllocation allocation) OVERRIDE;
   void DiscardBackbuffer();
   void EnsureBackbuffer();
   void EnforceMemoryPolicy();
 
   RendererCapabilities capabilities_;
@@ skipping 179 matching lines @@
   bool is_backbuffer_discarded_;
   bool discard_backbuffer_when_not_visible_;
   bool is_using_bind_uniform_;
   bool visible_;
   bool is_scissor_enabled_;
   bool blend_shadow_;
   unsigned program_shadow_;
   TexturedQuadDrawCache draw_cache_;
   int highp_threshold_min_;
 
+  struct PendingAsyncReadPixels;
+  ScopedPtrVector<PendingAsyncReadPixels> pending_async_read_pixels_;
+
   scoped_ptr<ResourceProvider::ScopedWriteLockGL> current_framebuffer_lock_;
 
   scoped_refptr<ResourceProvider::Fence> last_swap_fence_;
 
   SkBitmap on_demand_tile_raster_bitmap_;
   ResourceProvider::ResourceId on_demand_tile_raster_resource_id_;
 
   DISALLOW_COPY_AND_ASSIGN(GLRenderer);
 };
 
 // Setting DEBUG_GL_CALLS to 1 will call glGetError() after almost every GL
 // call made by the compositor. Useful for debugging rendering issues but
 // will significantly degrade performance.
 #define DEBUG_GL_CALLS 0
 
 #if DEBUG_GL_CALLS && !defined(NDEBUG)
 #define GLC(context, x)                                                        \
   (x, GLRenderer::DebugGLCall(&* context, #x, __FILE__, __LINE__))
 #else
 #define GLC(context, x) (x)
 #endif
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_GL_RENDERER_H_