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 "cc/base/cc_export.h"
  20 #include "cc/base/region.h"
  21 #include "skia/ext/refptr.h"
  22 #include "third_party/skia/include/core/SkBBHFactory.h"
  23 #include "third_party/skia/include/core/SkPicture.h"
  24 #include "ui/gfx/geometry/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   enum RecordingMode {
  48     RECORD_NORMALLY,
  49     RECORD_WITH_SK_NULL_CANVAS,
  50     RECORD_WITH_PAINTING_DISABLED,
  51     RECORDING_MODE_COUNT,  // Must be the last entry.
  52   };
  53
  54   static scoped_refptr<Picture> Create(
  55       const gfx::Rect& layer_rect,
  56       ContentLayerClient* client,
  57       const SkTileGridFactory::TileGridInfo& tile_grid_info,
  58       bool gather_pixels_refs,
  59       RecordingMode recording_mode);
  60   static scoped_refptr<Picture> CreateFromValue(const base::Value* value);
  61   static scoped_refptr<Picture> CreateFromSkpValue(const base::Value* value);
  62
  63   gfx::Rect LayerRect() const { return layer_rect_; }
  64
  65   // Has Record() been called yet?
  66   bool HasRecording() const { return picture_.get() != NULL; }
  67
  68   bool IsSuitableForGpuRasterization() const;
  69   int ApproximateOpCount() const;
  70
  71   bool HasText() const;
  72
  73   // Apply this scale and raster the negated region into the canvas.
  74   // |negated_content_region| specifies the region to be clipped out of the
  75   // raster operation, i.e., the parts of the canvas which will not get drawn
  76   // to.
  77   int Raster(SkCanvas* canvas,
  78              SkDrawPictureCallback* callback,
  79              const Region& negated_content_region,
  80              float contents_scale) const;
  81
  82   // Draw the picture directly into the given canvas, without applying any
  83   // clip/scale/layer transformations.
  84   void Replay(SkCanvas* canvas);
  85
  86   scoped_ptr<base::Value> AsValue() const;
  87
  88   // This iterator imprecisely returns the set of pixel refs that are needed to
  89   // raster this layer rect from this picture.  Internally, pixel refs are
  90   // clumped into tile grid buckets, so there may be false positives.
  91   class CC_EXPORT PixelRefIterator {
  92    public:
  93     PixelRefIterator();
  94     PixelRefIterator(const gfx::Rect& layer_rect, const Picture* picture);
  95     ~PixelRefIterator();
  96
  97     SkPixelRef* operator->() const {
  98       DCHECK_LT(current_index_, current_pixel_refs_->size());
  99       return (*current_pixel_refs_)[current_index_];
 100     }
 101
 102     SkPixelRef* operator*() const {
 103       DCHECK_LT(current_index_, current_pixel_refs_->size());
 104       return (*current_pixel_refs_)[current_index_];
 105     }
 106
 107     PixelRefIterator& operator++();
 108     operator bool() const {
 109       return current_index_ < current_pixel_refs_->size();
 110     }
 111
 112    private:
 113     static base::LazyInstance<PixelRefs> empty_pixel_refs_;
 114     const Picture* picture_;
 115     const PixelRefs* current_pixel_refs_;
 116     unsigned current_index_;
 117
 118     gfx::Point min_point_;
 119     gfx::Point max_point_;
 120     int current_x_;
 121     int current_y_;
 122   };
 123
 124   void EmitTraceSnapshot() const;
 125   void EmitTraceSnapshotAlias(Picture* original) const;
 126
 127   bool WillPlayBackBitmaps() const { return picture_->willPlayBackBitmaps(); }
 128
 129  private:
 130   explicit Picture(const gfx::Rect& layer_rect);
 131   // This constructor assumes SkPicture is already ref'd and transfers
 132   // ownership to this picture.
 133   Picture(const skia::RefPtr<SkPicture>&,
 134           const gfx::Rect& layer_rect,
 135           const PixelRefMap& pixel_refs);
 136   // This constructor will call AdoptRef on the SkPicture.
 137   Picture(SkPicture*, const gfx::Rect& layer_rect);
 138   ~Picture();
 139
 140   // Record a paint operation. To be able to safely use this SkPicture for
 141   // playback on a different thread this can only be called once.
 142   void Record(ContentLayerClient* client,
 143               const SkTileGridFactory::TileGridInfo& tile_grid_info,
 144               RecordingMode recording_mode);
 145
 146   // Gather pixel refs from recording.
 147   void GatherPixelRefs(const SkTileGridFactory::TileGridInfo& tile_grid_info);
 148
 149   gfx::Rect layer_rect_;
 150   skia::RefPtr<SkPicture> picture_;
 151
 152   PixelRefMap pixel_refs_;
 153   gfx::Point min_pixel_cell_;
 154   gfx::Point max_pixel_cell_;
 155   gfx::Size cell_size_;
 156
 157   scoped_refptr<base::debug::ConvertableToTraceFormat>
 158     AsTraceableRasterData(float scale) const;
 159   scoped_refptr<base::debug::ConvertableToTraceFormat>
 160     AsTraceableRecordData() const;
 161
 162   friend class base::RefCountedThreadSafe<Picture>;
 163   friend class PixelRefIterator;
 164   DISALLOW_COPY_AND_ASSIGN(Picture);
 165 };
 166
 167 }  // namespace cc
 168
 169 #endif  // CC_RESOURCES_PICTURE_H_