SkBitmapProcShader.h revision 9c9005a347e9996f357bd79591bd34f74f8bbc66 
1
2/*
3 * Copyright 2006 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef SkBitmapProcShader_DEFINED
11#define SkBitmapProcShader_DEFINED
12
13#include "SkShader.h"
14#include "SkBitmapProcState.h"
15#include "SkSmallAllocator.h"
16
17class SkBitmapProcShader : public SkShader {
18public:
19    SkBitmapProcShader(const SkBitmap& src, TileMode tx, TileMode ty,
20                       const SkMatrix* localMatrix = NULL);
21
22    // overrides from SkShader
23    virtual bool isOpaque() const SK_OVERRIDE;
24    virtual BitmapType asABitmap(SkBitmap*, SkMatrix*, TileMode*) const SK_OVERRIDE;
25
26    virtual bool validContext(const SkBitmap& device,
27                              const SkPaint& paint,
28                              const SkMatrix& matrix,
29                              SkMatrix* totalInverse = NULL) const SK_OVERRIDE;
30    virtual SkShader::Context* createContext(const SkBitmap&, const SkPaint&,
31                                             const SkMatrix&, void* storage) const SK_OVERRIDE;
32    virtual size_t contextSize() const SK_OVERRIDE;
33
34    static bool CanDo(const SkBitmap&, TileMode tx, TileMode ty);
35
36    SK_TO_STRING_OVERRIDE()
37    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBitmapProcShader)
38
39#if SK_SUPPORT_GPU
40    GrEffectRef* asNewEffect(GrContext*, const SkPaint&) const SK_OVERRIDE;
41#endif
42
43    class BitmapProcShaderContext : public SkShader::Context {
44    public:
45        // The context takes ownership of the state. It will call its destructor
46        // but will NOT free the memory.
47        BitmapProcShaderContext(const SkBitmapProcShader& shader,
48                                const SkBitmap& device,
49                                const SkPaint& paint,
50                                const SkMatrix& matrix,
51                                SkBitmapProcState* state);
52        virtual ~BitmapProcShaderContext();
53
54        virtual void shadeSpan(int x, int y, SkPMColor dstC[], int count) SK_OVERRIDE;
55        virtual ShadeProc asAShadeProc(void** ctx) SK_OVERRIDE;
56        virtual void shadeSpan16(int x, int y, uint16_t dstC[], int count) SK_OVERRIDE;
57
58        virtual uint32_t getFlags() const SK_OVERRIDE { return fFlags; }
59
60    private:
61        SkBitmapProcState*  fState;
62        uint32_t            fFlags;
63
64        typedef SkShader::Context INHERITED;
65    };
66
67protected:
68    SkBitmapProcShader(SkReadBuffer& );
69    virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
70
71    SkBitmap    fRawBitmap;   // experimental for RLE encoding
72    uint8_t     fTileModeX, fTileModeY;
73
74private:
75    bool validInternal(const SkBitmap& device, const SkPaint& paint,
76                       const SkMatrix& matrix, SkMatrix* totalInverse,
77                       SkBitmapProcState* state) const;
78
79    typedef SkShader INHERITED;
80};
81
82// Commonly used allocator. It currently is only used to allocate up to 3 objects. The total
83// bytes requested is calculated using one of our large shaders, its context size plus the size of
84// an Sk3DBlitter in SkDraw.cpp
85// Note that some contexts may contain other contexts (e.g. for compose shaders), but we've not
86// yet found a situation where the size below isn't big enough.
87typedef SkSmallAllocator<3, sizeof(SkBitmapProcShader) +
88                            sizeof(SkBitmapProcShader::BitmapProcShaderContext) +
89                            sizeof(SkBitmapProcState) +
90                            sizeof(void*) * 2> SkTBlitterAllocator;
91
92// If alloc is non-NULL, it will be used to allocate the returned SkShader, and MUST outlive
93// the SkShader.
94SkShader* CreateBitmapShader(const SkBitmap& src, SkShader::TileMode, SkShader::TileMode,
95                             const SkMatrix* localMatrix, SkTBlitterAllocator* alloc);
96
97#endif
98