skia/ext/analysis_canvas.h

   1 // Copyright (c) 2013 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 SKIA_EXT_ANALYSIS_CANVAS_H_
   6 #define SKIA_EXT_ANALYSIS_CANVAS_H_
   7
   8 #include <list>
   9 #include <set>
  10
  11 #include "base/hash_tables.h"
  12 #include "skia/ext/lazy_pixel_ref.h"
  13 #include "third_party/skia/include/core/SkCanvas.h"
  14 #include "third_party/skia/include/core/SkDevice.h"
  15
  16 namespace skia {
  17
  18 class AnalysisDevice;
  19
  20 // Does not render anything, but gathers statistics about a region
  21 // (specified as a clip rectangle) of an SkPicture as the picture is
  22 // played back through it.
  23 // To use: create a SkBitmap with kNo_Config, create an AnalysisDevice
  24 // using that bitmap, and create an AnalysisCanvas using the device.
  25 // Play a picture into the canvas, and then check isCheap().
  26 class SK_API AnalysisCanvas : public SkCanvas {
  27  public:
  28   typedef std::list<skia::LazyPixelRef*> LazyPixelRefList;
  29
  30   AnalysisCanvas(AnalysisDevice*);
  31   virtual ~AnalysisCanvas();
  32
  33   // Returns true if the estimated cost of drawing is below an
  34   // arbitrary threshold.
  35   bool isCheap() const;
  36   bool getColorIfSolid(SkColor* color) const;
  37   bool isTransparent() const;
  38   bool hasText() const;
  39   void consumeLazyPixelRefs(LazyPixelRefList* pixelRefs);
  40
  41   // Returns the estimated cost of drawing, in arbitrary units.
  42   int getEstimatedCost() const;
  43
  44   virtual bool clipRect(const SkRect& rect,
  45                         SkRegion::Op op = SkRegion::kIntersect_Op,
  46                         bool doAntiAlias = false) OVERRIDE;
  47   virtual bool clipPath(const SkPath& path,
  48                         SkRegion::Op op = SkRegion::kIntersect_Op,
  49                         bool doAntiAlias = false) OVERRIDE;
  50   virtual bool clipRRect(const SkRRect& rrect,
  51                          SkRegion::Op op = SkRegion::kIntersect_Op,
  52                          bool doAntiAlias = false) OVERRIDE;
  53
  54   virtual int saveLayer(const SkRect* bounds, const SkPaint*,
  55                               SkCanvas::SaveFlags flags) OVERRIDE;
  56   virtual int save(SaveFlags flags = kMatrixClip_SaveFlag) OVERRIDE;
  57
  58   virtual void restore() OVERRIDE;
  59
  60  private:
  61   typedef SkCanvas INHERITED;
  62   static const int kNoLayer;
  63
  64   int savedStackSize_;
  65   int forceNotSolidStackLevel_;
  66   int forceNotTransparentStackLevel_;
  67 };
  68
  69 class SK_API AnalysisDevice : public SkDevice {
  70  public:
  71   typedef std::list<skia::LazyPixelRef*> LazyPixelRefList;
  72   typedef base::hash_set<uint32_t> IdSet;
  73
  74   AnalysisDevice(const SkBitmap& bm);
  75   virtual ~AnalysisDevice();
  76
  77   int getEstimatedCost() const;
  78   bool getColorIfSolid(SkColor* color) const;
  79   bool isTransparent() const;
  80   bool hasText() const;
  81   void consumeLazyPixelRefs(LazyPixelRefList* pixelRefs);
  82
  83   void setForceNotSolid(bool flag);
  84   void setForceNotTransparent(bool flag);
  85
  86  protected:
  87   virtual void clear(SkColor color) OVERRIDE;
  88   virtual void drawPaint(const SkDraw&, const SkPaint& paint) OVERRIDE;
  89   virtual void drawPoints(const SkDraw&, SkCanvas::PointMode mode,
  90                           size_t count, const SkPoint[],
  91                           const SkPaint& paint) OVERRIDE;
  92   virtual void drawRect(const SkDraw&, const SkRect& r,
  93                         const SkPaint& paint) OVERRIDE;
  94   virtual void drawOval(const SkDraw&, const SkRect& oval,
  95                         const SkPaint& paint) OVERRIDE;
  96   virtual void drawPath(const SkDraw&, const SkPath& path,
  97                         const SkPaint& paint,
  98                         const SkMatrix* prePathMatrix = NULL,
  99                         bool pathIsMutable = false) OVERRIDE;
 100   virtual void drawBitmap(const SkDraw&, const SkBitmap& bitmap,
 101                           const SkIRect* srcRectOrNull,
 102                           const SkMatrix& matrix, const SkPaint& paint)
 103                           OVERRIDE;
 104   virtual void drawSprite(const SkDraw&, const SkBitmap& bitmap,
 105                           int x, int y, const SkPaint& paint) OVERRIDE;
 106   virtual void drawBitmapRect(const SkDraw&, const SkBitmap&,
 107                               const SkRect* srcOrNull, const SkRect& dst,
 108                               const SkPaint& paint) OVERRIDE;
 109   virtual void drawText(const SkDraw&, const void* text, size_t len,
 110                         SkScalar x, SkScalar y, const SkPaint& paint)
 111                         OVERRIDE;
 112   virtual void drawPosText(const SkDraw& draw, const void* text, size_t len,
 113                            const SkScalar pos[], SkScalar constY,
 114                            int scalarsPerPos, const SkPaint& paint) OVERRIDE;
 115   virtual void drawTextOnPath(const SkDraw&, const void* text, size_t len,
 116                               const SkPath& path, const SkMatrix* matrix,
 117                               const SkPaint& paint) OVERRIDE;
 118 #ifdef SK_BUILD_FOR_ANDROID
 119   virtual void drawPosTextOnPath(const SkDraw& draw, const void* text,
 120                                  size_t len,
 121                                  const SkPoint pos[], const SkPaint& paint,
 122                                  const SkPath& path, const SkMatrix* matrix)
 123                                  OVERRIDE;
 124 #endif
 125   virtual void drawVertices(const SkDraw&, SkCanvas::VertexMode,
 126                             int vertexCount,
 127                             const SkPoint verts[], const SkPoint texs[],
 128                             const SkColor colors[], SkXfermode* xmode,
 129                             const uint16_t indices[], int indexCount,
 130                             const SkPaint& paint) OVERRIDE;
 131   virtual void drawDevice(const SkDraw&, SkDevice*, int x, int y,
 132                           const SkPaint&) OVERRIDE;
 133
 134   int estimatedCost_;
 135
 136  private:
 137
 138   typedef SkDevice INHERITED;
 139
 140   void addPixelRefIfLazy(SkPixelRef* pixelRef);
 141   void addBitmap(const SkBitmap& bitmap);
 142   void addBitmapFromPaint(const SkPaint& paint);
 143
 144   bool isForcedNotSolid_;
 145   bool isForcedNotTransparent_;
 146   bool isSolidColor_;
 147   SkColor color_;
 148   bool isTransparent_;
 149   bool hasText_;
 150   IdSet existingPixelRefIDs_;
 151   LazyPixelRefList lazyPixelRefs_;
 152 };
 153
 154 }  // namespace skia
 155
 156 #endif  // SKIA_EXT_ANALYSIS_CANVAS_H_
 157