#include "config.h"
#if ENABLE(FILTERS)
#include "FEBlend.h"
#include "CanvasPixelArray.h"
#include "Filter.h"
#include "FloatPoint.h"
#include "GraphicsContext.h"
#include "ImageData.h"
typedef unsigned char (*BlendType)(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB);
namespace WebCore {
FEBlend::FEBlend(FilterEffect* in, FilterEffect* in2, BlendModeType mode)
: FilterEffect()
, m_in(in)
, m_in2(in2)
, m_mode(mode)
{
}
PassRefPtr<FEBlend> FEBlend::create(FilterEffect* in, FilterEffect* in2, BlendModeType mode)
{
return adoptRef(new FEBlend(in, in2, mode));
}
FilterEffect* FEBlend::in2() const
{
return m_in2.get();
}
void FEBlend::setIn2(FilterEffect* in2)
{
m_in2 = in2;
}
BlendModeType FEBlend::blendMode() const
{
return m_mode;
}
void FEBlend::setBlendMode(BlendModeType mode)
{
m_mode = mode;
}
static unsigned char unknown(unsigned char, unsigned char, unsigned char, unsigned char)
{
return 0;
}
static unsigned char normal(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char)
{
return (((255 - alphaA) * colorB + colorA * 255) / 255);
}
static unsigned char multiply(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB)
{
return (((255 - alphaA) * colorB + (255 - alphaB + colorB) * colorA) / 255);
}
static unsigned char screen(unsigned char colorA, unsigned char colorB, unsigned char, unsigned char)
{
return (((colorB + colorA) * 255 - colorA * colorB) / 255);
}
static unsigned char darken(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB)
{
return ((std::min((255 - alphaA) * colorB + colorA * 255, (255 - alphaB) * colorA + colorB * 255)) / 255);
}
static unsigned char lighten(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB)
{
return ((std::max((255 - alphaA) * colorB + colorA * 255, (255 - alphaB) * colorA + colorB * 255)) / 255);
}
void FEBlend::apply(Filter* filter)
{
m_in->apply(filter);
m_in2->apply(filter);
if (!m_in->resultImage() || !m_in2->resultImage())
return;
if (m_mode == FEBLEND_MODE_UNKNOWN)
return;
if (!getEffectContext())
return;
IntRect effectADrawingRect = calculateDrawingIntRect(m_in->scaledSubRegion());
RefPtr<CanvasPixelArray> srcPixelArrayA(m_in->resultImage()->getPremultipliedImageData(effectADrawingRect)->data());
IntRect effectBDrawingRect = calculateDrawingIntRect(m_in2->scaledSubRegion());
RefPtr<CanvasPixelArray> srcPixelArrayB(m_in2->resultImage()->getPremultipliedImageData(effectBDrawingRect)->data());
IntRect imageRect(IntPoint(), resultImage()->size());
RefPtr<ImageData> imageData = ImageData::create(imageRect.width(), imageRect.height());
static const BlendType callEffect[] = {unknown, normal, multiply, screen, darken, lighten};
ASSERT(srcPixelArrayA->length() == srcPixelArrayB->length());
for (unsigned pixelOffset = 0; pixelOffset < srcPixelArrayA->length(); pixelOffset += 4) {
unsigned char alphaA = srcPixelArrayA->get(pixelOffset + 3);
unsigned char alphaB = srcPixelArrayB->get(pixelOffset + 3);
for (unsigned channel = 0; channel < 3; ++channel) {
unsigned char colorA = srcPixelArrayA->get(pixelOffset + channel);
unsigned char colorB = srcPixelArrayB->get(pixelOffset + channel);
unsigned char result = (*callEffect[m_mode])(colorA, colorB, alphaA, alphaB);
imageData->data()->set(pixelOffset + channel, result);
}
unsigned char alphaR = 255 - ((255 - alphaA) * (255 - alphaB)) / 255;
imageData->data()->set(pixelOffset + 3, alphaR);
}
resultImage()->putPremultipliedImageData(imageData.get(), imageRect, IntPoint());
}
void FEBlend::dump()
{
}
}
#endif // ENABLE(FILTERS)