1 /* 2 * Copyright 2011 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef SkArithmeticMode_DEFINED 9 #define SkArithmeticMode_DEFINED 10 11 #include "SkFlattenable.h" 12 #include "SkScalar.h" 13 14 class SkXfermode; 15 16 class SK_API SkArithmeticMode { 17 public: 18 /** 19 * result = clamp[k1 * src * dst + k2 * src + k3 * dst + k4] 20 * 21 * src and dst are treated as being [0.0 .. 1.0]. The polynomial is 22 * evaluated on their unpremultiplied components. 23 * 24 * k1=k2=k3=0, k4=1.0 results in returning opaque white 25 * k1=k3=k4=0, k2=1.0 results in returning the src 26 * k1=k2=k4=0, k3=1.0 results in returning the dst 27 */ 28 static SkXfermode* Create(SkScalar k1, SkScalar k2, 29 SkScalar k3, SkScalar k4, 30 bool enforcePMColor = true); 31 32 SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP(); 33 34 private: 35 SkArithmeticMode(); // can't be instantiated 36 }; 37 38 #endif 39
