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 "base/basictypes.h"
#include "base/callback.h"
#include "base/containers/scoped_ptr_hash_map.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/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;

  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;
    gfx::Rect device_viewport_rect;
    gfx::Rect device_clip_rect;

    gfx::Transform projection_matrix;
    gfx::Transform window_matrix;

    bool disable_picture_quad_image_filtering;

    OverlayCandidateList overlay_list;
    CALayerOverlayList ca_layer_overlay_list;
  };

  void SetEnlargePassTextureAmountForTesting(const gfx::Vector2d& amount);
  void DoDrawPolygon(const DrawPolygon& poly,
                     DrawingFrame* frame,
                     const gfx::Rect& render_pass_scissor,
                     bool use_render_pass_scissor);

 protected:
  enum SurfaceInitializationMode {
    SURFACE_INITIALIZATION_MODE_PRESERVE,
    SURFACE_INITIALIZATION_MODE_SCISSORED_CLEAR,
    SURFACE_INITIALIZATION_MODE_FULL_SURFACE_CLEAR,
  };

  DirectRenderer(RendererClient* client,
                 const RendererSettings* settings,
                 OutputSurface* output_surface,
                 ResourceProvider* resource_provider);

  static gfx::RectF QuadVertexRect();
  static void QuadRectTransform(gfx::Transform* quad_rect_transform,
                                const gfx::Transform& quad_transform,
                                const gfx::RectF& quad_rect);
  void InitializeViewport(DrawingFrame* frame,
                          const gfx::Rect& draw_rect,
                          const gfx::Rect& viewport_rect,
                          const gfx::Size& surface_size);
  gfx::Rect MoveFromDrawToWindowSpace(const DrawingFrame* frame,
                                      const gfx::Rect& draw_rect) const;

  bool NeedDeviceClip(const DrawingFrame* frame) const;
  gfx::Rect DeviceClipRectInDrawSpace(const DrawingFrame* frame) const;
  gfx::Rect DeviceViewportRectInDrawSpace(const DrawingFrame* frame) const;
  gfx::Rect OutputSurfaceRectInDrawSpace(const DrawingFrame* frame) const;
  static gfx::Rect ComputeScissorRectForRenderPass(const DrawingFrame* frame);
  void SetScissorStateForQuad(const DrawingFrame* frame,
                              const DrawQuad& quad,
                              const gfx::Rect& render_pass_scissor,
                              bool use_render_pass_scissor);
  bool ShouldSkipQuad(const DrawQuad& quad,
                      const gfx::Rect& render_pass_scissor);
  void SetScissorTestRectInDrawSpace(const DrawingFrame* frame,
                                     const gfx::Rect& draw_space_rect);

  static gfx::Size RenderPassTextureSize(const RenderPass* render_pass);

  void FlushPolygons(std::deque<scoped_ptr<DrawPolygon>>* poly_list,
                     DrawingFrame* frame,
                     const gfx::Rect& render_pass_scissor,
                     bool use_render_pass_scissor);
  void DrawRenderPass(DrawingFrame* frame, const RenderPass* render_pass);
  bool UseRenderPass(DrawingFrame* frame, const RenderPass* render_pass);

  virtual void BindFramebufferToOutputSurface(DrawingFrame* frame) = 0;
  virtual bool BindFramebufferToTexture(DrawingFrame* frame,
                                        const ScopedResource* resource,
                                        const gfx::Rect& target_rect) = 0;
  virtual void SetScissorTestRect(const gfx::Rect& scissor_rect) = 0;
  virtual void PrepareSurfaceForPass(
      DrawingFrame* frame,
      SurfaceInitializationMode initialization_mode,
      const gfx::Rect& render_pass_scissor) = 0;
  // clip_region is a (possibly null) pointer to a quad in the same
  // space as the quad. When non-null only the area of the quad that overlaps
  // with clip_region will be drawn.
  virtual void DoDrawQuad(DrawingFrame* frame,
                          const DrawQuad* quad,
                          const gfx::QuadF* clip_region) = 0;
  virtual void BeginDrawingFrame(DrawingFrame* frame) = 0;
  virtual void FinishDrawingFrame(DrawingFrame* frame) = 0;
  virtual void FinishDrawingQuadList();
  virtual bool FlippedFramebuffer(const DrawingFrame* frame) const = 0;
  virtual void EnsureScissorTestEnabled() = 0;
  virtual void EnsureScissorTestDisabled() = 0;
  virtual void DiscardBackbuffer() {}
  virtual void EnsureBackbuffer() {}

  virtual void CopyCurrentRenderPassToBitmap(
      DrawingFrame* frame,
      scoped_ptr<CopyOutputRequest> request) = 0;

  // TODO(danakj): Just use a vector of pairs here? Hash map is way overkill.
  base::ScopedPtrHashMap<RenderPassId, scoped_ptr<ScopedResource>>
      render_pass_textures_;
  OutputSurface* output_surface_;
  ResourceProvider* resource_provider_;
  scoped_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::Vector2d enlarge_pass_texture_amount_;

  DISALLOW_COPY_AND_ASSIGN(DirectRenderer);
};

}  // namespace cc

#endif  // CC_OUTPUT_DIRECT_RENDERER_H_