CrossfadeGeneratedImage.cpp [plain text]
#include "config.h"
#include "CrossfadeGeneratedImage.h"
#include "FloatRect.h"
#include "GraphicsContext.h"
#include "ImageBuffer.h"
using namespace std;
namespace WebCore {
CrossfadeGeneratedImage::CrossfadeGeneratedImage(Image* fromImage, Image* toImage, float percentage, IntSize crossfadeSize, const IntSize& size)
: m_fromImage(fromImage)
, m_toImage(toImage)
, m_percentage(percentage)
, m_crossfadeSize(crossfadeSize)
{
m_size = size;
}
void CrossfadeGeneratedImage::drawCrossfade(GraphicsContext* context)
{
float inversePercentage = 1 - m_percentage;
IntSize fromImageSize = m_fromImage->size();
IntSize toImageSize = m_toImage->size();
if (m_fromImage == Image::nullImage() || m_toImage == Image::nullImage())
return;
GraphicsContextStateSaver stateSaver(*context);
context->clip(IntRect(IntPoint(), m_crossfadeSize));
context->beginTransparencyLayer(1);
context->save();
if (m_crossfadeSize != fromImageSize)
context->scale(FloatSize(static_cast<float>(m_crossfadeSize.width()) / fromImageSize.width(),
static_cast<float>(m_crossfadeSize.height()) / fromImageSize.height()));
context->setAlpha(inversePercentage);
context->drawImage(m_fromImage, ColorSpaceDeviceRGB, IntPoint());
context->restore();
context->save();
if (m_crossfadeSize != toImageSize)
context->scale(FloatSize(static_cast<float>(m_crossfadeSize.width()) / toImageSize.width(),
static_cast<float>(m_crossfadeSize.height()) / toImageSize.height()));
context->setAlpha(m_percentage);
context->drawImage(m_toImage, ColorSpaceDeviceRGB, IntPoint(), CompositePlusLighter);
context->restore();
context->endTransparencyLayer();
}
void CrossfadeGeneratedImage::draw(GraphicsContext* context, const FloatRect& dstRect, const FloatRect& srcRect, ColorSpace, CompositeOperator compositeOp)
{
GraphicsContextStateSaver stateSaver(*context);
context->setCompositeOperation(compositeOp);
context->clip(dstRect);
context->translate(dstRect.x(), dstRect.y());
if (dstRect.size() != srcRect.size())
context->scale(FloatSize(dstRect.width() / srcRect.width(), dstRect.height() / srcRect.height()));
context->translate(-srcRect.x(), -srcRect.y());
drawCrossfade(context);
}
void CrossfadeGeneratedImage::drawPattern(GraphicsContext* context, const FloatRect& srcRect, const AffineTransform& patternTransform, const FloatPoint& phase, ColorSpace styleColorSpace, CompositeOperator compositeOp, const FloatRect& dstRect)
{
OwnPtr<ImageBuffer> imageBuffer = ImageBuffer::create(m_size, 1, ColorSpaceDeviceRGB, context->isAcceleratedContext() ? Accelerated : Unaccelerated);
if (!imageBuffer)
return;
GraphicsContext* graphicsContext = imageBuffer->context();
drawCrossfade(graphicsContext);
imageBuffer->drawPattern(context, srcRect, patternTransform, phase, styleColorSpace, compositeOp, dstRect);
}
}