Mozart: Improve internal scene graph representation.

services/gfx/compositor/render/render_layer.h

-// Copyright 2015 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 SERVICES_GFX_COMPOSITOR_RENDER_RENDER_LAYER_H_
-#define SERVICES_GFX_COMPOSITOR_RENDER_RENDER_LAYER_H_
-
-#include <memory>
-#include <vector>
-
-#include "base/macros.h"
-#include "services/gfx/compositor/render/render_image.h"
-#include "skia/ext/refptr.h"
-#include "third_party/skia/include/core/SkMatrix.h"
-#include "third_party/skia/include/core/SkPaint.h"
-#include "third_party/skia/include/core/SkPath.h"
-#include "third_party/skia/include/core/SkPictureRecorder.h"
-#include "third_party/skia/include/core/SkRRect.h"
-#include "third_party/skia/include/core/SkRect.h"
-
-class SkCanvas;
-class SkPicture;
-
-namespace compositor {
-
-class RenderCommand;
-
-// Describes a sequence of drawing commands to be evaluated as a single pass.
-// Layers are introduced into the render frame at points where blending must
-// occur or where portions of a scene graph may be drawn once into a temporary
-// buffer and used many times.
-//
-// Render objects are thread-safe, immutable, and reference counted via
-// std::shared_ptr.  They have no direct references to the scene graph.
-class RenderLayer {
- public:
-  ~RenderLayer();
-  explicit RenderLayer(const skia::RefPtr<SkPicture>& picture);
-
-  // Gets the underlying picture to rasterize.
-  const skia::RefPtr<SkPicture>& picture() const { return picture_; }
-
- private:
-  friend class RenderLayerBuilder;
-
-  // TODO: store auxiliary information required for hit testing
-  skia::RefPtr<SkPicture> picture_;
-
-  DISALLOW_COPY_AND_ASSIGN(RenderLayer);
-};
-
-// Builder for render layers.
-class RenderLayerBuilder {
- public:
-  // Creates a layer builder with an optional |cull_rect| to cull recorded
-  // geometry information.
-  RenderLayerBuilder();
-  explicit RenderLayerBuilder(const SkRect* cull_rect);
-  ~RenderLayerBuilder();
-
-  // Pushes information about a scene onto the stack.
-  void PushScene(uint32_t scene_token, uint32_t version);
-
-  // Pops a scene off the stack.
-  void PopScene();
-
-  // Pushes information about a node onto the stack.
-  void PushNode(uint32_t node_id, uint32_t hit_id);
-
-  // Pops a node off the stack.
-  void PopNode();
-
-  // Applies a transformation matrix to the node.
-  void ApplyTransform(const SkMatrix& content_transform);
-
-  // Applies a clip to the node.
-  void ApplyClip(const SkRect& content_clip);
-
-  // Inserts a command to draw a rectangle.
-  void DrawRect(const SkRect& content_rect, const SkPaint& paint);
-
-  // Inserts a command to draw an image.
-  void DrawImage(const std::shared_ptr<RenderImage>& image,
-                 const SkRect& content_rect,
-                 const SkRect& image_rect,
-                 const SkPaint& paint);
-
-  // Inserts a command to draw an in-place layer.
-  void DrawLayer(const std::shared_ptr<RenderLayer>& layer);
-
-  // Inserts a command to draw a saved layer.
-  void DrawSavedLayer(const std::shared_ptr<RenderLayer>& layer,
-                      const SkRect& content_rect,
-                      const SkPaint& paint);
-
-  // Returns the layer which was built.
-  std::shared_ptr<RenderLayer> Build();
-
- private:
-  SkPictureRecorder recorder_;
-  SkCanvas* canvas_;
-
-  DISALLOW_COPY_AND_ASSIGN(RenderLayerBuilder);
-};
-
-}  // namespace compositor
-
-#endif  // SERVICES_GFX_COMPOSITOR_RENDER_RENDER_LAYER_H_