src/cc/resources/picture.h

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CC_RESOURCES_PICTURE_H_
   6 #define CC_RESOURCES_PICTURE_H_
   7
   8 #include <string>
   9 #include <utility>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/containers/hash_tables.h"
  14 #include "base/debug/trace_event.h"
  15 #include "base/lazy_instance.h"
  16 #include "base/logging.h"
  17 #include "base/memory/ref_counted.h"
  18 #include "base/memory/scoped_ptr.h"
  19 #include "base/threading/thread_checker.h"
  20 #include "cc/base/cc_export.h"
  21 #include "cc/base/region.h"
  22 #include "skia/ext/refptr.h"
  23 #include "third_party/skia/include/core/SkTileGridPicture.h"
  24 #include "ui/gfx/rect.h"
  25
  26 class SkPixelRef;
  27
  28 namespace base {
  29 class Value;
  30 }
  31
  32 namespace skia {
  33 class AnalysisCanvas;
  34 }
  35
  36 namespace cc {
  37
  38 class ContentLayerClient;
  39
  40 class CC_EXPORT Picture
  41     : public base::RefCountedThreadSafe<Picture> {
  42  public:
  43   typedef std::pair<int, int> PixelRefMapKey;
  44   typedef std::vector<SkPixelRef*> PixelRefs;
  45   typedef base::hash_map<PixelRefMapKey, PixelRefs> PixelRefMap;
  46
  47   static scoped_refptr<Picture> Create(
  48       const gfx::Rect& layer_rect,
  49       ContentLayerClient* client,
  50       const SkTileGridPicture::TileGridInfo& tile_grid_info,
  51       bool gather_pixels_refs,
  52       int num_raster_threads);
  53   static scoped_refptr<Picture> CreateFromValue(const base::Value* value);
  54   static scoped_refptr<Picture> CreateFromSkpValue(const base::Value* value);
  55
  56   gfx::Rect LayerRect() const { return layer_rect_; }
  57   gfx::Rect OpaqueRect() const { return opaque_rect_; }
  58
  59   // Get thread-safe clone for rasterizing with on a specific thread.
  60   Picture* GetCloneForDrawingOnThread(unsigned thread_index);
  61
  62   // Has Record() been called yet?
  63   bool HasRecording() const { return picture_.get() != NULL; }
  64
  65   // Apply this scale and raster the negated region into the canvas. See comment
  66   // in PicturePileImpl::RasterCommon for explanation on negated content region.
  67   int Raster(SkCanvas* canvas,
  68              SkDrawPictureCallback* callback,
  69              const Region& negated_content_region,
  70              float contents_scale);
  71
  72   // Draw the picture directly into the given canvas, without applying any
  73   // clip/scale/layer transformations.
  74   void Replay(SkCanvas* canvas);
  75
  76   scoped_ptr<base::Value> AsValue() const;
  77
  78   class CC_EXPORT PixelRefIterator {
  79    public:
  80     PixelRefIterator();
  81     PixelRefIterator(const gfx::Rect& layer_rect, const Picture* picture);
  82     ~PixelRefIterator();
  83
  84     SkPixelRef* operator->() const {
  85       DCHECK_LT(current_index_, current_pixel_refs_->size());
  86       return (*current_pixel_refs_)[current_index_];
  87     }
  88
  89     SkPixelRef* operator*() const {
  90       DCHECK_LT(current_index_, current_pixel_refs_->size());
  91       return (*current_pixel_refs_)[current_index_];
  92     }
  93
  94     PixelRefIterator& operator++();
  95     operator bool() const {
  96       return current_index_ < current_pixel_refs_->size();
  97     }
  98
  99    private:
 100     static base::LazyInstance<PixelRefs> empty_pixel_refs_;
 101     const Picture* picture_;
 102     const PixelRefs* current_pixel_refs_;
 103     unsigned current_index_;
 104
 105     gfx::Point min_point_;
 106     gfx::Point max_point_;
 107     int current_x_;
 108     int current_y_;
 109   };
 110
 111   void EmitTraceSnapshot() const;
 112   void EmitTraceSnapshotAlias(Picture* original) const;
 113
 114   bool WillPlayBackBitmaps() const { return picture_->willPlayBackBitmaps(); }
 115
 116  private:
 117   explicit Picture(const gfx::Rect& layer_rect);
 118   // This constructor assumes SkPicture is already ref'd and transfers
 119   // ownership to this picture.
 120   Picture(const skia::RefPtr<SkPicture>&,
 121           const gfx::Rect& layer_rect,
 122           const gfx::Rect& opaque_rect,
 123           const PixelRefMap& pixel_refs);
 124   // This constructor will call AdoptRef on the SkPicture.
 125   Picture(SkPicture*,
 126           const gfx::Rect& layer_rect,
 127           const gfx::Rect& opaque_rect);
 128   ~Picture();
 129
 130   // Make thread-safe clones for rasterizing with.
 131   void CloneForDrawing(int num_threads);
 132
 133   // Record a paint operation. To be able to safely use this SkPicture for
 134   // playback on a different thread this can only be called once.
 135   void Record(ContentLayerClient* client,
 136               const SkTileGridPicture::TileGridInfo& tile_grid_info);
 137
 138   // Gather pixel refs from recording.
 139   void GatherPixelRefs(const SkTileGridPicture::TileGridInfo& tile_grid_info);
 140
 141   gfx::Rect layer_rect_;
 142   gfx::Rect opaque_rect_;
 143   skia::RefPtr<SkPicture> picture_;
 144
 145   typedef std::vector<scoped_refptr<Picture> > PictureVector;
 146   PictureVector clones_;
 147
 148   PixelRefMap pixel_refs_;
 149   gfx::Point min_pixel_cell_;
 150   gfx::Point max_pixel_cell_;
 151   gfx::Size cell_size_;
 152
 153   scoped_refptr<base::debug::ConvertableToTraceFormat>
 154     AsTraceableRasterData(float scale) const;
 155   scoped_refptr<base::debug::ConvertableToTraceFormat>
 156     AsTraceableRecordData() const;
 157
 158   base::ThreadChecker raster_thread_checker_;
 159
 160   friend class base::RefCountedThreadSafe<Picture>;
 161   friend class PixelRefIterator;
 162   DISALLOW_COPY_AND_ASSIGN(Picture);
 163 };
 164
 165 }  // namespace cc
 166
 167 #endif  // CC_RESOURCES_PICTURE_H_