Optimize render passes with single quads

cc/output/direct_renderer.h

 // Copyright 2012 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_DIRECT_RENDERER_H_
 #define CC_OUTPUT_DIRECT_RENDERER_H_
 
 #include <unordered_map>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/ca_layer_overlay.h"
 #include "cc/output/overlay_processor.h"
 #include "cc/output/renderer.h"
+#include "cc/quads/tile_draw_quad.h"
 #include "cc/raster/task_graph_runner.h"
 #include "cc/resources/resource_provider.h"
 #include "cc/resources/scoped_resource.h"
 #include "ui/gfx/geometry/quad_f.h"
 
 namespace cc {
 class DrawPolygon;
 class ResourceProvider;
 
 // This is the base class for code shared between the GL and software
 // renderer implementations.  "Direct" refers to the fact that it does not
 // delegate rendering to another compositor.
 class CC_EXPORT DirectRenderer : public Renderer {
  public:
   ~DirectRenderer() override;
 
   void DecideRenderPassAllocationsForFrame(
       const RenderPassList& render_passes_in_draw_order) override;
   bool HasAllocatedResourcesForTesting(RenderPassId id) const override;
   void DrawFrame(RenderPassList* render_passes_in_draw_order,
                  float device_scale_factor,
                  const gfx::Rect& device_viewport_rect,
                  const gfx::Rect& device_clip_rect,
                  bool disable_picture_quad_image_filtering) override;
   virtual void SwapBuffersComplete() {}
 
+  // If a pass contains a single tile draw quad and can be drawn without
+  // a render pass (e.g. applying a filter directly to the tile quad)
+  // return that quad, otherwise return null.
+  virtual const TileDrawQuad* CanPassBeDrawnDirectly(const RenderPass* pass);
+
   struct CC_EXPORT DrawingFrame {
     DrawingFrame();
     ~DrawingFrame();
 
     const RenderPassList* render_passes_in_draw_order;
     const RenderPass* root_render_pass;
     const RenderPass* current_render_pass;
     const ScopedResource* current_texture;
 
     gfx::Rect root_damage_rect;
@@ skipping 93 matching lines @@
 
   virtual void CopyCurrentRenderPassToBitmap(
       DrawingFrame* frame,
       std::unique_ptr<CopyOutputRequest> request) = 0;
 
   // TODO(danakj): Just use a vector of pairs here? Hash map is way overkill.
   std::unordered_map<RenderPassId,
                      std::unique_ptr<ScopedResource>,
                      RenderPassIdHash>
       render_pass_textures_;
+  std::unordered_map<RenderPassId, TileDrawQuad, RenderPassIdHash>
+      render_pass_bypass_quads_;
   OutputSurface* output_surface_;
   ResourceProvider* resource_provider_;
   std::unique_ptr<OverlayProcessor> overlay_processor_;
 
   // For use in coordinate conversion, this stores the output rect, viewport
   // rect (= unflipped version of glViewport rect), the size of target
   // framebuffer, and the current window space viewport. During a draw, this
   // stores the values for the current render pass; in between draws, they
   // retain the values for the root render pass of the last draw.
   gfx::Rect current_draw_rect_;
   gfx::Rect current_viewport_rect_;
   gfx::Size current_surface_size_;
   gfx::Rect current_window_space_viewport_;
 
  private:
   gfx::Size enlarge_pass_texture_amount_;
 
   DISALLOW_COPY_AND_ASSIGN(DirectRenderer);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_DIRECT_RENDERER_H_