CrossfadeGeneratedImage.cpp [plain text]
#include "config.h"
#include "CrossfadeGeneratedImage.h"
#include "FloatRect.h"
#include "GraphicsContext.h"
#include "ImageBuffer.h"
#include <wtf/text/TextStream.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);
CompositeOperator drawImageOperation = operation;
if (useTransparencyLayer) {
context.setCompositeOperation(operation);
context.beginTransparencyLayer(opacity);
drawImageOperation = CompositeSourceOver;
} else
context.setAlpha(opacity);
if (targetSize != imageSize)
context.scale(targetSize / imageSize);
context.drawImage(image, IntPoint(), ImagePaintingOptions(drawImageOperation));
if (useTransparencyLayer)
context.endTransparencyLayer();
}
void CrossfadeGeneratedImage::drawCrossfade(GraphicsContext& context)
{
if (m_fromImage.ptr() == &Image::nullImage() || m_toImage.ptr() == &Image::nullImage())
return;
GraphicsContextStateSaver stateSaver(context);
context.clip(FloatRect(FloatPoint(), m_crossfadeSize));
context.beginTransparencyLayer(1);
drawCrossfadeSubimage(context, m_fromImage.get(), CompositeSourceOver, 1 - m_percentage, m_crossfadeSize);
drawCrossfadeSubimage(context, m_toImage.get(), CompositePlusLighter, m_percentage, m_crossfadeSize);
context.endTransparencyLayer();
}
ImageDrawResult CrossfadeGeneratedImage::draw(GraphicsContext& context, const FloatRect& dstRect, const FloatRect& srcRect, CompositeOperator compositeOp, BlendMode blendMode, DecodingMode, ImageOrientationDescription)
{
GraphicsContextStateSaver stateSaver(context);
context.setCompositeOperation(compositeOp, blendMode);
context.clip(dstRect);
context.translate(dstRect.location());
if (dstRect.size() != srcRect.size())
context.scale(dstRect.size() / srcRect.size());
context.translate(-srcRect.location());
drawCrossfade(context);
return ImageDrawResult::DidDraw;
}
void CrossfadeGeneratedImage::drawPattern(GraphicsContext& context, const FloatRect& dstRect, const FloatRect& srcRect, const AffineTransform& patternTransform, const FloatPoint& phase, const FloatSize& spacing, CompositeOperator compositeOp, BlendMode blendMode)
{
std::unique_ptr<ImageBuffer> imageBuffer = ImageBuffer::create(size(), context.renderingMode());
if (!imageBuffer)
return;
GraphicsContext& graphicsContext = imageBuffer->context();
drawCrossfade(graphicsContext);
imageBuffer->drawPattern(context, dstRect, srcRect, patternTransform, phase, spacing, compositeOp, blendMode);
}
void CrossfadeGeneratedImage::dump(TextStream& ts) const
{
GeneratedImage::dump(ts);
ts.dumpProperty("from-image", m_fromImage.get());
ts.dumpProperty("to-image", m_toImage.get());
ts.dumpProperty("percentage", m_percentage);
}
}