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/lazy_instance.h"
  15 #include "base/logging.h"
  16 #include "base/memory/ref_counted.h"
  17 #include "base/memory/scoped_ptr.h"
  18 #include "base/trace_event/trace_event.h"
  19 #include "cc/base/cc_export.h"
  20 #include "cc/base/region.h"
  21 #include "cc/resources/recording_source.h"
  22 #include "skia/ext/refptr.h"
  23 #include "third_party/skia/include/core/SkPicture.h"
  24 #include "ui/gfx/geometry/rect.h"
  25
  26 class SkDrawPictureCallback;
  27 class SkPixelRef;
  28
  29 namespace base {
  30 class Value;
  31 }
  32
  33 namespace skia {
  34 class AnalysisCanvas;
  35 }
  36
  37 namespace cc {
  38
  39 class ContentLayerClient;
  40
  41 class CC_EXPORT Picture
  42     : public base::RefCountedThreadSafe<Picture> {
  43  public:
  44   typedef std::pair<int, int> PixelRefMapKey;
  45   typedef std::vector<SkPixelRef*> PixelRefs;
  46   typedef base::hash_map<PixelRefMapKey, PixelRefs> PixelRefMap;
  47
  48   static scoped_refptr<Picture> Create(
  49       const gfx::Rect& layer_rect,
  50       ContentLayerClient* client,
  51       const gfx::Size& tile_grid_size,
  52       bool gather_pixels_refs,
  53       RecordingSource::RecordingMode recording_mode);
  54   static scoped_refptr<Picture> CreateFromValue(const base::Value* value);
  55   static scoped_refptr<Picture> CreateFromSkpValue(const base::Value* value);
  56
  57   gfx::Rect LayerRect() const { return layer_rect_; }
  58
  59   // Has Record() been called yet?
  60   bool HasRecording() const { return picture_.get() != NULL; }
  61
  62   bool IsSuitableForGpuRasterization(const char** reason) const;
  63   int ApproximateOpCount() const;
  64   size_t ApproximateMemoryUsage() const;
  65
  66   bool HasText() const;
  67
  68   // Apply this scale and raster the negated region into the canvas.
  69   // |negated_content_region| specifies the region to be clipped out of the
  70   // raster operation, i.e., the parts of the canvas which will not get drawn
  71   // to.
  72   int Raster(SkCanvas* canvas,
  73              SkDrawPictureCallback* callback,
  74              const Region& negated_content_region,
  75              float contents_scale) const;
  76
  77   // Draw the picture directly into the given canvas, without applying any
  78   // clip/scale/layer transformations.
  79   void Replay(SkCanvas* canvas);
  80
  81   scoped_ptr<base::Value> AsValue() const;
  82
  83   // This iterator imprecisely returns the set of pixel refs that are needed to
  84   // raster this layer rect from this picture.  Internally, pixel refs are
  85   // clumped into tile grid buckets, so there may be false positives.
  86   class CC_EXPORT PixelRefIterator {
  87    public:
  88     PixelRefIterator();
  89     PixelRefIterator(const gfx::Rect& layer_rect, const Picture* picture);
  90     ~PixelRefIterator();
  91
  92     SkPixelRef* operator->() const {
  93       DCHECK_LT(current_index_, current_pixel_refs_->size());
  94       return (*current_pixel_refs_)[current_index_];
  95     }
  96
  97     SkPixelRef* operator*() const {
  98       DCHECK_LT(current_index_, current_pixel_refs_->size());
  99       return (*current_pixel_refs_)[current_index_];
 100     }
 101
 102     PixelRefIterator& operator++();
 103     operator bool() const {
 104       return current_index_ < current_pixel_refs_->size();
 105     }
 106
 107    private:
 108     static base::LazyInstance<PixelRefs> empty_pixel_refs_;
 109     const Picture* picture_;
 110     const PixelRefs* current_pixel_refs_;
 111     unsigned current_index_;
 112
 113     gfx::Point min_point_;
 114     gfx::Point max_point_;
 115     int current_x_;
 116     int current_y_;
 117   };
 118
 119   void EmitTraceSnapshot() const;
 120   void EmitTraceSnapshotAlias(Picture* original) const;
 121
 122   bool WillPlayBackBitmaps() const { return picture_->willPlayBackBitmaps(); }
 123
 124  private:
 125   explicit Picture(const gfx::Rect& layer_rect);
 126   // This constructor assumes SkPicture is already ref'd and transfers
 127   // ownership to this picture.
 128   Picture(const skia::RefPtr<SkPicture>&,
 129           const gfx::Rect& layer_rect,
 130           const PixelRefMap& pixel_refs);
 131   // This constructor will call AdoptRef on the SkPicture.
 132   Picture(SkPicture*, const gfx::Rect& layer_rect);
 133   ~Picture();
 134
 135   // Record a paint operation. To be able to safely use this SkPicture for
 136   // playback on a different thread this can only be called once.
 137   void Record(ContentLayerClient* client,
 138               const gfx::Size& tile_grid_size,
 139               RecordingSource::RecordingMode recording_mode);
 140
 141   // Gather pixel refs from recording.
 142   void GatherPixelRefs(const gfx::Size& tile_grid_info);
 143
 144   gfx::Rect layer_rect_;
 145   skia::RefPtr<SkPicture> picture_;
 146
 147   PixelRefMap pixel_refs_;
 148   gfx::Point min_pixel_cell_;
 149   gfx::Point max_pixel_cell_;
 150   gfx::Size cell_size_;
 151
 152   scoped_refptr<base::debug::ConvertableToTraceFormat>
 153     AsTraceableRasterData(float scale) const;
 154   scoped_refptr<base::debug::ConvertableToTraceFormat>
 155     AsTraceableRecordData() const;
 156
 157   friend class base::RefCountedThreadSafe<Picture>;
 158   friend class PixelRefIterator;
 159   DISALLOW_COPY_AND_ASSIGN(Picture);
 160 };
 161
 162 }  // namespace cc
 163
 164 #endif  // CC_RESOURCES_PICTURE_H_