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      *  k1=k2=k3=0, k4=1.0 results in returning opaque white
22      *  k1=k3=k4=0, k2=1.0 results in returning the src
23      *  k1=k2=k4=0, k3=1.0 results in returning the dst
24      */
25     static SkXfermode* Create(SkScalar k1, SkScalar k2,
26                               SkScalar k3, SkScalar k4,
27                               bool enforcePMColor = true);
28 
29     SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP();
30 
31 private:
32     SkArithmeticMode(); // can't be instantiated
33 };
34 
35 #endif
36