skia2/include/effects/SkArithmeticMode.h

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/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkArithmeticMode_DEFINED
#define SkArithmeticMode_DEFINED
#include "SkFlattenable.h"
#include "SkScalar.h"
class SkXfermode;
class SK_API SkArithmeticMode {
public:
/**
* result = clamp[k1 * src * dst + k2 * src + k3 * dst + k4]
*
* src and dst are treated as being [0.0 .. 1.0]. The polynomial is
* evaluated on their unpremultiplied components.
*
* k1=k2=k3=0, k4=1.0 results in returning opaque white
* k1=k3=k4=0, k2=1.0 results in returning the src
* k1=k2=k4=0, k3=1.0 results in returning the dst
*/
static SkXfermode* Create(SkScalar k1, SkScalar k2,
SkScalar k3, SkScalar k4,
bool enforcePMColor = true);
SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP();
private:
SkArithmeticMode(); // can't be instantiated
};
#endif