blob: d73ecf4c5771bd425d6104ec2a51a86c700ec6f1 [file] [log] [blame]
/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkLerpXfermode.h"
#include "SkColorPriv.h"
#include "SkFlattenableBuffers.h"
#include "SkString.h"
SkXfermode* SkLerpXfermode::Create(SkScalar scale) {
int scale256 = SkScalarRoundToInt(scale * 256);
if (scale256 >= 256) {
return SkXfermode::Create(SkXfermode::kSrc_Mode);
} else if (scale256 <= 0) {
return SkXfermode::Create(SkXfermode::kDst_Mode);
}
return SkNEW_ARGS(SkLerpXfermode, (scale256));
}
SkLerpXfermode::SkLerpXfermode(unsigned scale256) : fScale256(scale256) {}
SkLerpXfermode::SkLerpXfermode(SkFlattenableReadBuffer& buffer)
: INHERITED(buffer) {
fScale256 = buffer.readUInt();
}
void SkLerpXfermode::flatten(SkFlattenableWriteBuffer& buffer) const {
this->INHERITED::flatten(buffer);
buffer.writeUInt(fScale256);
}
void SkLerpXfermode::xfer32(SkPMColor dst[], const SkPMColor src[], int count,
const SkAlpha aa[]) const {
const int scale = fScale256;
if (aa) {
for (int i = 0; i < count; ++i) {
unsigned a = aa[i];
if (a) {
SkPMColor dstC = dst[i];
SkPMColor resC = SkFastFourByteInterp256(src[i], dstC, scale);
if (a < 255) {
resC = SkFastFourByteInterp256(resC, dstC, a + (a >> 7));
}
dst[i] = resC;
}
}
} else {
for (int i = 0; i < count; ++i) {
dst[i] = SkFastFourByteInterp256(src[i], dst[i], scale);
}
}
}
void SkLerpXfermode::xfer16(uint16_t dst[], const SkPMColor src[], int count,
const SkAlpha aa[]) const {
const int scale = fScale256;
if (aa) {
for (int i = 0; i < count; ++i) {
unsigned a = aa[i];
if (a) {
SkPMColor dstC = SkPixel16ToPixel32(dst[i]);
SkPMColor resC = SkFastFourByteInterp256(src[i], dstC, scale);
if (a < 255) {
resC = SkFastFourByteInterp256(resC, dstC, a + (a >> 7));
}
dst[i] = SkPixel32ToPixel16(resC);
}
}
} else {
for (int i = 0; i < count; ++i) {
SkPMColor dstC = SkPixel16ToPixel32(dst[i]);
SkPMColor resC = SkFastFourByteInterp256(src[i], dstC, scale);
dst[i] = SkPixel32ToPixel16(resC);
}
}
}
void SkLerpXfermode::xferA8(SkAlpha dst[], const SkPMColor src[], int count,
const SkAlpha aa[]) const {
const int scale = fScale256;
if (aa) {
for (int i = 0; i < count; ++i) {
unsigned a = aa[i];
if (a) {
unsigned dstA = dst[i];
unsigned resA = SkAlphaBlend(SkGetPackedA32(src[i]), dstA, scale);
if (a < 255) {
resA = SkAlphaBlend(resA, dstA, a + (a >> 7));
}
dst[i] = resA;
}
}
} else {
for (int i = 0; i < count; ++i) {
dst[i] = SkAlphaBlend(SkGetPackedA32(src[i]), dst[i], scale);
}
}
}
#ifdef SK_DEVELOPER
void SkLerpXfermode::toString(SkString* str) const {
str->printf("SkLerpXfermode: scale: %g", fScale256 / 256.0);
}
#endif