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 SkComposeShader_DEFINED
11 : #define SkComposeShader_DEFINED
12 :
13 : #include "SkShader.h"
14 :
15 : class SkXfermode;
16 :
17 : ///////////////////////////////////////////////////////////////////////////////////////////
18 :
19 : /** \class SkComposeShader
20 : This subclass of shader returns the coposition of two other shaders, combined by
21 : a xfermode.
22 : */
23 : class SK_API SkComposeShader : public SkShader {
24 : public:
25 : /** Create a new compose shader, given shaders A, B, and a combining xfermode mode.
26 : When the xfermode is called, it will be given the result from shader A as its
27 : "dst", and the result of from shader B as its "src".
28 : mode->xfer32(sA_result, sB_result, ...)
29 : @param shaderA The colors from this shader are seen as the "dst" by the xfermode
30 : @param shaderB The colors from this shader are seen as the "src" by the xfermode
31 : @param mode The xfermode that combines the colors from the two shaders. If mode
32 : is null, then SRC_OVER is assumed.
33 : */
34 : SkComposeShader(SkShader* sA, SkShader* sB, SkXfermode* mode = NULL);
35 : virtual ~SkComposeShader();
36 :
37 : // override
38 : virtual bool setContext(const SkBitmap& device, const SkPaint& paint, const SkMatrix& matrix);
39 : virtual void shadeSpan(int x, int y, SkPMColor result[], int count);
40 : virtual void beginSession();
41 : virtual void endSession();
42 :
43 : protected:
44 : SkComposeShader(SkFlattenableReadBuffer& );
45 : virtual void flatten(SkFlattenableWriteBuffer& );
46 0 : virtual Factory getFactory() { return CreateProc; }
47 :
48 : private:
49 0 : static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer) {
50 0 : return SkNEW_ARGS(SkComposeShader, (buffer)); }
51 :
52 : SkShader* fShaderA;
53 : SkShader* fShaderB;
54 : SkXfermode* fMode;
55 :
56 : typedef SkShader INHERITED;
57 : };
58 :
59 : #endif
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