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      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 "third_party/skia/include/record/SkRecording.h"
     25 #include "ui/gfx/rect.h"
     26 
     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   enum RecordingMode {
     49     RECORD_NORMALLY,
     50     RECORD_WITH_SK_NULL_CANVAS,
     51     RECORD_WITH_PAINTING_DISABLED,
     52     RECORD_WITH_SKRECORD,
     53     RECORDING_MODE_COUNT,  // Must be the last entry.
     54   };
     55 
     56   static scoped_refptr<Picture> Create(
     57       const gfx::Rect& layer_rect,
     58       ContentLayerClient* client,
     59       const SkTileGridFactory::TileGridInfo& tile_grid_info,
     60       bool gather_pixels_refs,
     61       RecordingMode recording_mode);
     62   static scoped_refptr<Picture> CreateFromValue(const base::Value* value);
     63   static scoped_refptr<Picture> CreateFromSkpValue(const base::Value* value);
     64 
     65   gfx::Rect LayerRect() const { return layer_rect_; }
     66 
     67   // Has Record() been called yet?
     68   bool HasRecording() const { return picture_.get() != NULL; }
     69 
     70   bool IsSuitableForGpuRasterization() const;
     71   int ApproximateOpCount() const;
     72 
     73   bool HasText() const;
     74 
     75   // Apply this scale and raster the negated region into the canvas.
     76   // |negated_content_region| specifies the region to be clipped out of the
     77   // raster operation, i.e., the parts of the canvas which will not get drawn
     78   // to.
     79   int Raster(SkCanvas* canvas,
     80              SkDrawPictureCallback* callback,
     81              const Region& negated_content_region,
     82              float contents_scale) const;
     83 
     84   // Draw the picture directly into the given canvas, without applying any
     85   // clip/scale/layer transformations.
     86   void Replay(SkCanvas* canvas);
     87 
     88   scoped_ptr<base::Value> AsValue() const;
     89 
     90   // This iterator imprecisely returns the set of pixel refs that are needed to
     91   // raster this layer rect from this picture.  Internally, pixel refs are
     92   // clumped into tile grid buckets, so there may be false positives.
     93   class CC_EXPORT PixelRefIterator {
     94    public:
     95     PixelRefIterator();
     96     PixelRefIterator(const gfx::Rect& layer_rect, const Picture* picture);
     97     ~PixelRefIterator();
     98 
     99     SkPixelRef* operator->() const {
    100       DCHECK_LT(current_index_, current_pixel_refs_->size());
    101       return (*current_pixel_refs_)[current_index_];
    102     }
    103 
    104     SkPixelRef* operator*() const {
    105       DCHECK_LT(current_index_, current_pixel_refs_->size());
    106       return (*current_pixel_refs_)[current_index_];
    107     }
    108 
    109     PixelRefIterator& operator++();
    110     operator bool() const {
    111       return current_index_ < current_pixel_refs_->size();
    112     }
    113 
    114    private:
    115     static base::LazyInstance<PixelRefs> empty_pixel_refs_;
    116     const Picture* picture_;
    117     const PixelRefs* current_pixel_refs_;
    118     unsigned current_index_;
    119 
    120     gfx::Point min_point_;
    121     gfx::Point max_point_;
    122     int current_x_;
    123     int current_y_;
    124   };
    125 
    126   void EmitTraceSnapshot() const;
    127   void EmitTraceSnapshotAlias(Picture* original) const;
    128 
    129   bool WillPlayBackBitmaps() const { return picture_->willPlayBackBitmaps(); }
    130 
    131  private:
    132   explicit Picture(const gfx::Rect& layer_rect);
    133   // This constructor assumes SkPicture is already ref'd and transfers
    134   // ownership to this picture.
    135   Picture(const skia::RefPtr<SkPicture>&,
    136           const gfx::Rect& layer_rect,
    137           const PixelRefMap& pixel_refs);
    138   // This constructor will call AdoptRef on the SkPicture.
    139   Picture(SkPicture*, const gfx::Rect& layer_rect);
    140   ~Picture();
    141 
    142   // Record a paint operation. To be able to safely use this SkPicture for
    143   // playback on a different thread this can only be called once.
    144   void Record(ContentLayerClient* client,
    145               const SkTileGridFactory::TileGridInfo& tile_grid_info,
    146               RecordingMode recording_mode);
    147 
    148   // Gather pixel refs from recording.
    149   void GatherPixelRefs(const SkTileGridFactory::TileGridInfo& tile_grid_info);
    150 
    151   gfx::Rect layer_rect_;
    152   skia::RefPtr<SkPicture> picture_;
    153   scoped_ptr<const EXPERIMENTAL::SkPlayback> playback_;
    154 
    155   PixelRefMap pixel_refs_;
    156   gfx::Point min_pixel_cell_;
    157   gfx::Point max_pixel_cell_;
    158   gfx::Size cell_size_;
    159 
    160   scoped_refptr<base::debug::ConvertableToTraceFormat>
    161     AsTraceableRasterData(float scale) const;
    162   scoped_refptr<base::debug::ConvertableToTraceFormat>
    163     AsTraceableRecordData() const;
    164 
    165   friend class base::RefCountedThreadSafe<Picture>;
    166   friend class PixelRefIterator;
    167   DISALLOW_COPY_AND_ASSIGN(Picture);
    168 };
    169 
    170 }  // namespace cc
    171 
    172 #endif  // CC_RESOURCES_PICTURE_H_
    173