1 /* 2 * Copyright (C) 2006 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef SkComposeShader_DEFINED 18 #define SkComposeShader_DEFINED 19 20 #include "SkShader.h" 21 22 class SkXfermode; 23 24 /////////////////////////////////////////////////////////////////////////////////////////// 25 26 /** \class SkComposeShader 27 This subclass of shader returns the coposition of two other shaders, combined by 28 a xfermode. 29 */ 30 class SkComposeShader : public SkShader { 31 public: 32 /** Create a new compose shader, given shaders A, B, and a combining xfermode mode. 33 When the xfermode is called, it will be given the result from shader A as its 34 "dst", and the result of from shader B as its "src". 35 mode->xfer32(sA_result, sB_result, ...) 36 @param shaderA The colors from this shader are seen as the "dst" by the xfermode 37 @param shaderB The colors from this shader are seen as the "src" by the xfermode 38 @param mode The xfermode that combines the colors from the two shaders. If mode 39 is null, then SRC_OVER is assumed. 40 */ 41 SkComposeShader(SkShader* sA, SkShader* sB, SkXfermode* mode = NULL); 42 virtual ~SkComposeShader(); 43 44 // override 45 virtual bool setContext(const SkBitmap& device, const SkPaint& paint, const SkMatrix& matrix); 46 virtual void shadeSpan(int x, int y, SkPMColor result[], int count); 47 virtual void beginSession(); 48 virtual void endSession(); 49 50 protected: 51 SkComposeShader(SkFlattenableReadBuffer& ); 52 virtual void flatten(SkFlattenableWriteBuffer& ); getFactory()53 virtual Factory getFactory() { return CreateProc; } 54 55 private: CreateProc(SkFlattenableReadBuffer & buffer)56 static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer) { 57 return SkNEW_ARGS(SkComposeShader, (buffer)); } 58 59 SkShader* fShaderA; 60 SkShader* fShaderB; 61 SkXfermode* fMode; 62 63 typedef SkShader INHERITED; 64 }; 65 66 #endif 67