static inline void setPixelPremultipliedRGBA(ImageFrame::PixelData* dest, png_bytep pixel, unsigned char& nonTrivialAlphaMask)
{
unsigned char a = pixel[3];
unsigned char r = fastDivideBy255(pixel[0] * a);
unsigned char g = fastDivideBy255(pixel[1] * a);
unsigned char b = fastDivideBy255(pixel[2] * a);
*dest = a << 24 | r << 16 | g << 8 | b;
nonTrivialAlphaMask |= (255 - a);
}
RGBA32 premultipliedARGBFromColor(const Color& color)
{
unsigned pixelColor;
unsigned alpha = color.alpha();
if (alpha < 255) {
pixelColor = Color::createUnchecked(
fastDivideBy255(color.red() * alpha + 254),
fastDivideBy255(color.green() * alpha + 254),
fastDivideBy255(color.blue() * alpha + 254),
alpha).rgb();
} else
pixelColor = color.rgb();
return pixelColor;
}
static void platformApply(unsigned char* sourcePixelA, unsigned char* sourcePixelB,
unsigned char* destinationPixel, unsigned pixelArrayLength)
{
unsigned len = pixelArrayLength / 4;
for (unsigned pixelOffset = 0; pixelOffset < len; pixelOffset++) {
unsigned char alphaA = sourcePixelA[3];
unsigned char alphaB = sourcePixelB[3];
destinationPixel[0] = BlendFunction(sourcePixelA[0], sourcePixelB[0], alphaA, alphaB);
destinationPixel[1] = BlendFunction(sourcePixelA[1], sourcePixelB[1], alphaA, alphaB);
destinationPixel[2] = BlendFunction(sourcePixelA[2], sourcePixelB[2], alphaA, alphaB);
destinationPixel[3] = 255 - fastDivideBy255((255 - alphaA) * (255 - alphaB));
sourcePixelA += 4;
sourcePixelB += 4;
destinationPixel += 4;
}
}
inline unsigned char feBlendLighten(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB)
{
return fastDivideBy255(std::max((255 - alphaA) * colorB + colorA * 255, (255 - alphaB) * colorA + colorB * 255));
}
inline unsigned char feBlendScreen(unsigned char colorA, unsigned char colorB, unsigned char, unsigned char)
{
return fastDivideBy255((colorB + colorA) * 255 - colorA * colorB);
}
inline unsigned char feBlendMultiply(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB)
{
return fastDivideBy255((255 - alphaA) * colorB + (255 - alphaB + colorB) * colorA);
}
inline unsigned char feBlendNormal(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char)
{
return fastDivideBy255((255 - alphaA) * colorB + colorA * 255);
}
