CrossfadeGeneratedImage.cpp [plain text]
#include "config.h"
#include "CrossfadeGeneratedImage.h"
#include "FloatRect.h"
#include "GraphicsContext.h"
#include "ImageBuffer.h"
namespace WebCore {
CrossfadeGeneratedImage::CrossfadeGeneratedImage(Image* fromImage, Image* toImage, float percentage, const FloatSize& crossfadeSize, const FloatSize& size)
: m_fromImage(fromImage)
, m_toImage(toImage)
, m_percentage(percentage)
, m_crossfadeSize(crossfadeSize)
{
setContainerSize(size);
}
static void drawCrossfadeSubimage(GraphicsContext* context, Image* image, CompositeOperator operation, float opacity, const FloatSize& targetSize)
{
FloatSize imageSize = image->size();
bool useTransparencyLayer = image->isSVGImage();
GraphicsContextStateSaver stateSaver(*context);
context->setCompositeOperation(operation);
if (useTransparencyLayer)
context->beginTransparencyLayer(opacity);
else
context->setAlpha(opacity);
if (targetSize != imageSize)
context->scale(FloatSize(targetSize.width() / imageSize.width(), targetSize.height() / imageSize.height()));
context->drawImage(image, ColorSpaceDeviceRGB, IntPoint());
if (useTransparencyLayer)
context->endTransparencyLayer();
}
void CrossfadeGeneratedImage::drawCrossfade(GraphicsContext* context)
{
if (m_fromImage == Image::nullImage() || m_toImage == Image::nullImage())
return;
GraphicsContextStateSaver stateSaver(*context);
context->clip(FloatRect(FloatPoint(), m_crossfadeSize));
context->beginTransparencyLayer(1);
drawCrossfadeSubimage(context, m_fromImage, CompositeSourceOver, 1 - m_percentage, m_crossfadeSize);
drawCrossfadeSubimage(context, m_toImage, CompositePlusLighter, m_percentage, m_crossfadeSize);
context->endTransparencyLayer();
}
void CrossfadeGeneratedImage::draw(GraphicsContext* context, const FloatRect& dstRect, const FloatRect& srcRect, ColorSpace, CompositeOperator compositeOp, BlendMode blendMode, ImageOrientationDescription)
{
GraphicsContextStateSaver stateSaver(*context);
context->setCompositeOperation(compositeOp, blendMode);
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, BlendMode blendMode)
{
std::unique_ptr<ImageBuffer> imageBuffer = ImageBuffer::create(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, blendMode);
}
}