SkBitmapProcShader.h revision 9de5b514d38c5b36066bcdc14fba2f7e5196d372 
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 size_t contextSize() const SK_OVERRIDE;
27
28    static bool CanDo(const SkBitmap&, TileMode tx, TileMode ty);
29
30    SK_TO_STRING_OVERRIDE()
31    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBitmapProcShader)
32
33
34    bool asNewEffect(GrContext*, const SkPaint&, const SkMatrix*, GrColor*, GrEffectRef**)
35            const SK_OVERRIDE;
36
37    class BitmapProcShaderContext : public SkShader::Context {
38    public:
39        // The context takes ownership of the state. It will call its destructor
40        // but will NOT free the memory.
41        BitmapProcShaderContext(const SkBitmapProcShader&, const ContextRec&, SkBitmapProcState*);
42        virtual ~BitmapProcShaderContext();
43
44        virtual void shadeSpan(int x, int y, SkPMColor dstC[], int count) SK_OVERRIDE;
45        virtual ShadeProc asAShadeProc(void** ctx) SK_OVERRIDE;
46        virtual void shadeSpan16(int x, int y, uint16_t dstC[], int count) SK_OVERRIDE;
47
48        virtual uint32_t getFlags() const SK_OVERRIDE { return fFlags; }
49
50    private:
51        SkBitmapProcState*  fState;
52        uint32_t            fFlags;
53
54        typedef SkShader::Context INHERITED;
55    };
56
57protected:
58    SkBitmapProcShader(SkReadBuffer& );
59    virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
60    virtual Context* onCreateContext(const ContextRec&, void* storage) const SK_OVERRIDE;
61
62    SkBitmap    fRawBitmap;   // experimental for RLE encoding
63    uint8_t     fTileModeX, fTileModeY;
64
65private:
66    typedef SkShader INHERITED;
67};
68
69// Commonly used allocator. It currently is only used to allocate up to 3 objects. The total
70// bytes requested is calculated using one of our large shaders, its context size plus the size of
71// an Sk3DBlitter in SkDraw.cpp
72// Note that some contexts may contain other contexts (e.g. for compose shaders), but we've not
73// yet found a situation where the size below isn't big enough.
74typedef SkSmallAllocator<3, 768> SkTBlitterAllocator;
75
76// If alloc is non-NULL, it will be used to allocate the returned SkShader, and MUST outlive
77// the SkShader.
78SkShader* CreateBitmapShader(const SkBitmap& src, SkShader::TileMode, SkShader::TileMode,
79                             const SkMatrix* localMatrix, SkTBlitterAllocator* alloc);
80
81#endif
82