cc/playback/picture_pile_impl.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_PLAYBACK_PICTURE_PILE_IMPL_H_
#define CC_PLAYBACK_PICTURE_PILE_IMPL_H_

#include <map>
#include <set>
#include <vector>

#include "base/time/time.h"
#include "cc/base/cc_export.h"
#include "cc/debug/rendering_stats_instrumentation.h"
#include "cc/playback/picture_pile.h"
#include "cc/playback/pixel_ref_map.h"
#include "cc/playback/raster_source.h"
#include "skia/ext/analysis_canvas.h"
#include "skia/ext/refptr.h"

class SkCanvas;
class SkPicture;
class SkPixelRef;

namespace gfx {
class Rect;
}

namespace cc {

class CC_EXPORT PicturePileImpl : public RasterSource {
 public:
  static scoped_refptr<PicturePileImpl> CreateFromPicturePile(
      const PicturePile* other,
      bool can_use_lcd_text);

  // RasterSource overrides. See RasterSource header for full description.
  // When slow-down-raster-scale-factor is set to a value greater than 1, the
  // reported rasterize time (in stats_instrumentation) is the minimum measured
  // value over all runs.
  void PlaybackToCanvas(SkCanvas* canvas,
                        const gfx::Rect& canvas_bitmap_rect,
                        const gfx::Rect& canvas_playback_rect,
                        float contents_scale) const override;
  void PlaybackToSharedCanvas(SkCanvas* canvas,
                              const gfx::Rect& canvas_rect,
                              float contents_scale) const override;
  void PerformSolidColorAnalysis(
      const gfx::Rect& content_rect,
      float contents_scale,
      RasterSource::SolidColorAnalysis* analysis) const override;
  void GatherPixelRefs(const gfx::Rect& content_rect,
                       float contents_scale,
                       std::vector<SkPixelRef*>* pixel_refs) const override;
  bool CoversRect(const gfx::Rect& content_rect,
                  float contents_scale) const override;
  void SetShouldAttemptToUseDistanceFieldText() override;
  bool ShouldAttemptToUseDistanceFieldText() const override;
  gfx::Size GetSize() const override;
  bool IsSolidColor() const override;
  SkColor GetSolidColor() const override;
  bool HasRecordings() const override;
  bool CanUseLCDText() const override;
  scoped_refptr<RasterSource> CreateCloneWithoutLCDText() const override;

  // Tracing functionality.
  void DidBeginTracing() override;
  void AsValueInto(base::trace_event::TracedValue* array) const override;
  skia::RefPtr<SkPicture> GetFlattenedPicture() override;
  size_t GetPictureMemoryUsage() const override;

  // Iterator used to return SkPixelRefs from this picture pile.
  // Public for testing.
  class CC_EXPORT PixelRefIterator {
   public:
    PixelRefIterator(const gfx::Rect& content_rect,
                     float contents_scale,
                     const PicturePileImpl* picture_pile);
    ~PixelRefIterator();

    SkPixelRef* operator->() const { return *pixel_ref_iterator_; }
    SkPixelRef* operator*() const { return *pixel_ref_iterator_; }
    PixelRefIterator& operator++();
    operator bool() const { return pixel_ref_iterator_; }

   private:
    void AdvanceToTilePictureWithPixelRefs();

    const PicturePileImpl* picture_pile_;
    gfx::Rect layer_rect_;
    TilingData::Iterator tile_iterator_;
    PixelRefMap::Iterator pixel_ref_iterator_;
    std::set<const void*> processed_pictures_;
  };

 protected:
  friend class PicturePile;
  friend class PixelRefIterator;

  using PictureMapKey = PicturePile::PictureMapKey;
  using PictureMap = PicturePile::PictureMap;

  PicturePileImpl();
  explicit PicturePileImpl(const PicturePile* other, bool can_use_lcd_text);
  explicit PicturePileImpl(const PicturePileImpl* other, bool can_use_lcd_text);
  ~PicturePileImpl() override;

  int buffer_pixels() const { return tiling_.border_texels(); }

  // These members are const as this raster source may be in use on another
  // thread and so should not be touched after construction.
  const PictureMap picture_map_;
  const TilingData tiling_;
  const SkColor background_color_;
  const bool requires_clear_;
  const bool can_use_lcd_text_;
  const bool is_solid_color_;
  const SkColor solid_color_;
  const gfx::Rect recorded_viewport_;
  const bool has_any_recordings_;
  const bool clear_canvas_with_debug_color_;
  const float min_contents_scale_;
  const int slow_down_raster_scale_factor_for_debug_;
  // TODO(enne/vmiura): this has a read/write race between raster and compositor
  // threads with multi-threaded Ganesh.  Make this const or remove it.
  bool should_attempt_to_use_distance_field_text_;

  size_t picture_memory_usage_;

 private:
  typedef std::map<const Picture*, Region> PictureRegionMap;

  // Called when analyzing a tile. We can use AnalysisCanvas as
  // SkPicture::AbortCallback, which allows us to early out from analysis.
  void RasterForAnalysis(skia::AnalysisCanvas* canvas,
                         const gfx::Rect& canvas_rect,
                         float contents_scale) const;

  void CoalesceRasters(const gfx::Rect& canvas_rect,
                       const gfx::Rect& content_rect,
                       float contents_scale,
                       PictureRegionMap* result) const;

  void RasterCommon(SkCanvas* canvas,
                    SkPicture::AbortCallback* callback,
                    const gfx::Rect& canvas_rect,
                    float contents_scale) const;

  // An internal CanRaster check that goes to the picture_map rather than
  // using the recorded_viewport hint.
  bool CanRasterSlowTileCheck(const gfx::Rect& layer_rect) const;

  gfx::Rect PaddedRect(const PictureMapKey& key) const;

  DISALLOW_COPY_AND_ASSIGN(PicturePileImpl);
};

}  // namespace cc

#endif  // CC_PLAYBACK_PICTURE_PILE_IMPL_H_