michael@0: 
michael@0: /*
michael@0:  * Copyright 2006 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #ifndef SkComposeShader_DEFINED
michael@0: #define SkComposeShader_DEFINED
michael@0: 
michael@0: #include "SkShader.h"
michael@0: 
michael@0: class SkXfermode;
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: /** \class SkComposeShader
michael@0:     This subclass of shader returns the coposition of two other shaders, combined by
michael@0:     a xfermode.
michael@0: */
michael@0: class SK_API SkComposeShader : public SkShader {
michael@0: public:
michael@0:     /** Create a new compose shader, given shaders A, B, and a combining xfermode mode.
michael@0:         When the xfermode is called, it will be given the result from shader A as its
michael@0:         "dst", and the result of from shader B as its "src".
michael@0:         mode->xfer32(sA_result, sB_result, ...)
michael@0:         @param shaderA  The colors from this shader are seen as the "dst" by the xfermode
michael@0:         @param shaderB  The colors from this shader are seen as the "src" by the xfermode
michael@0:         @param mode     The xfermode that combines the colors from the two shaders. If mode
michael@0:                         is null, then SRC_OVER is assumed.
michael@0:     */
michael@0:     SkComposeShader(SkShader* sA, SkShader* sB, SkXfermode* mode = NULL);
michael@0:     virtual ~SkComposeShader();
michael@0: 
michael@0:     virtual bool setContext(const SkBitmap&, const SkPaint&,
michael@0:                             const SkMatrix&) SK_OVERRIDE;
michael@0:     virtual void endContext() SK_OVERRIDE;
michael@0:     virtual void shadeSpan(int x, int y, SkPMColor[], int count) SK_OVERRIDE;
michael@0: 
michael@0:     SK_TO_STRING_OVERRIDE()
michael@0:     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkComposeShader)
michael@0: 
michael@0: protected:
michael@0:     SkComposeShader(SkReadBuffer& );
michael@0:     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
michael@0: 
michael@0: private:
michael@0: 
michael@0:     SkShader*   fShaderA;
michael@0:     SkShader*   fShaderB;
michael@0:     SkXfermode* fMode;
michael@0: 
michael@0:     typedef SkShader INHERITED;
michael@0: };
michael@0: 
michael@0: #endif