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/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkAvoidXfermode_DEFINED
#define SkAvoidXfermode_DEFINED
#include "SkColor.h"
#include "SkTypes.h"
#include "SkXfermode.h"
/** \class AvoidXfermode
This xfermode will draw the src everywhere except on top of the specified
color.
*/
class SkAvoidXfermode : public SkXfermode {
public:
enum Mode {
kAvoidColor_Mode, //!< draw everywhere except on the opColor
kTargetColor_Mode //!< draw only on top of the opColor
};
/** This xfermode draws, or doesn't draw, based on the destination's
distance from an op-color.
There are two modes, and each mode interprets a tolerance value.
Avoid: In this mode, drawing is allowed only on destination pixels that
are different from the op-color.
Tolerance near 0: avoid any colors even remotely similar to the op-color
Tolerance near 255: avoid only colors nearly identical to the op-color
Target: In this mode, drawing only occurs on destination pixels that
are similar to the op-color
Tolerance near 0: draw only on colors that are nearly identical to the op-color
Tolerance near 255: draw on any colors even remotely similar to the op-color
*/
static SkAvoidXfermode* Create(SkColor opColor, U8CPU tolerance, Mode mode) {
return new SkAvoidXfermode(opColor, tolerance, mode);
}
// overrides from SkXfermode
void xfer32(SkPMColor dst[], const SkPMColor src[], int count,
const SkAlpha aa[]) const override;
void xfer16(uint16_t dst[], const SkPMColor src[], int count,
const SkAlpha aa[]) const override;
void xferA8(SkAlpha dst[], const SkPMColor src[], int count,
const SkAlpha aa[]) const override;
SK_TO_STRING_OVERRIDE()
SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(AvoidXfermode)
protected:
SkAvoidXfermode(SkColor opColor, U8CPU tolerance, Mode mode);
void flatten(SkWriteBuffer&) const override;
private:
SkColor fOpColor;
uint32_t fDistMul; // x.14 cached from fTolerance
uint8_t fTolerance;
Mode fMode;
typedef SkXfermode INHERITED;
};
#endif