SkPictureShader.h revision 001f4ed2fb62ecdc98ce2884d925de11b7516d23 
1/*
2 * Copyright 2014 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef SkPictureShader_DEFINED
9#define SkPictureShader_DEFINED
10
11#include "SkShader.h"
12
13class SkBitmap;
14class SkPicture;
15
16/*
17 * An SkPictureShader can be used to draw SkPicture-based patterns.
18 *
19 * The SkPicture is first rendered into a tile, which is then used to shade the area according
20 * to specified tiling rules.
21 */
22class SkPictureShader : public SkShader {
23public:
24    static SkPictureShader* Create(SkPicture*, TileMode, TileMode);
25    virtual ~SkPictureShader();
26
27    virtual bool validContext(const SkBitmap&, const SkPaint&,
28                              const SkMatrix&, SkMatrix* totalInverse = NULL) const SK_OVERRIDE;
29    virtual SkShader::Context* createContext(const SkBitmap& device, const SkPaint& paint,
30                                             const SkMatrix& matrix, void* storage) const
31            SK_OVERRIDE;
32    virtual size_t contextSize() const SK_OVERRIDE;
33
34    class PictureShaderContext : public SkShader::Context {
35    public:
36        PictureShaderContext(const SkPictureShader& shader, const SkBitmap& device,
37                             const SkPaint& paint, const SkMatrix& matrix,
38                             SkShader* bitmapShader);
39        virtual ~PictureShaderContext();
40
41        virtual uint32_t getFlags() const SK_OVERRIDE;
42
43        virtual ShadeProc asAShadeProc(void** ctx) SK_OVERRIDE;
44        virtual void shadeSpan(int x, int y, SkPMColor dstC[], int count) SK_OVERRIDE;
45        virtual void shadeSpan16(int x, int y, uint16_t dstC[], int count) SK_OVERRIDE;
46
47    private:
48        SkAutoTUnref<SkShader>  fBitmapShader;
49        SkShader::Context*      fBitmapShaderContext;
50        void*                   fBitmapShaderContextStorage;
51
52        typedef SkShader::Context INHERITED;
53    };
54
55    SK_TO_STRING_OVERRIDE()
56    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkPictureShader)
57
58#if SK_SUPPORT_GPU
59    GrEffectRef* asNewEffect(GrContext*, const SkPaint&) const SK_OVERRIDE;
60#endif
61
62protected:
63    SkPictureShader(SkReadBuffer&);
64    virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
65
66private:
67    SkPictureShader(SkPicture*, TileMode, TileMode);
68
69    SkShader* validInternal(const SkBitmap& device, const SkPaint& paint,
70                            const SkMatrix& matrix, SkMatrix* totalInverse) const;
71
72    SkShader* buildBitmapShader(const SkMatrix&) const;
73
74    SkPicture*  fPicture;
75    TileMode    fTmx, fTmy;
76
77    mutable SkMutex                 fCachedBitmapShaderMutex;
78    mutable SkAutoTUnref<SkShader>  fCachedBitmapShader;
79    mutable SkSize                  fCachedTileScale;
80    mutable SkMatrix                fCachedLocalMatrix;
81
82    typedef SkShader INHERITED;
83};
84
85#endif // SkPictureShader_DEFINED
86