diff options
| -rw-r--r-- | Source/WebCore/platform/graphics/qt/ImageQt.cpp | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/Source/WebCore/platform/graphics/qt/ImageQt.cpp b/Source/WebCore/platform/graphics/qt/ImageQt.cpp index 83692fdae..0c66fe5fb 100644 --- a/Source/WebCore/platform/graphics/qt/ImageQt.cpp +++ b/Source/WebCore/platform/graphics/qt/ImageQt.cpp @@ -47,7 +47,9 @@ #include <QImageReader> #include <QPainter> #include <QPixmap> +#include <QPixmapCache> #include <QTransform> +#include <private/qhexstring_p.h> #include <math.h> @@ -245,6 +247,7 @@ void BitmapImage::draw(GraphicsContext* ctxt, const FloatRect& dst, QPixmap* image = nativeImageForCurrentFrame(); if (!image) return; + QPixmap prescaled; if (mayFillWithSolidColor()) { fillWithSolidColor(ctxt, normalizedDst, solidColor(), styleColorSpace, op); @@ -255,6 +258,37 @@ void BitmapImage::draw(GraphicsContext* ctxt, const FloatRect& dst, normalizedSrc = adjustSourceRectForDownSampling(normalizedSrc, image->size()); #endif + QPainter* painter = ctxt->platformContext(); + // The quality of down scaling at 0.5x and below in QPainter is not very good + // due only using bilinear sampling, so for high quality scaling we need to + // perform scaling ourselves. +#if QT_VERSION >= QT_VERSION_CHECK(5, 1, 0) + const float pixelRatio = painter->device()->devicePixelRatio(); +#else + const float pixelRatio = 1; +#endif + if (painter->renderHints() & QPainter::SmoothPixmapTransform + && (normalizedDst.width() * 2 * pixelRatio < normalizedSrc.width() + || normalizedDst.height() * 2 * pixelRatio < normalizedSrc.height())) { + // This may not work right with subpixel positions, but that can not currently happen. + QRect pixelSrc = normalizedSrc.toRect(); + QSize scaledSize(normalizedDst.width() * pixelRatio, normalizedDst.height() * pixelRatio); + QString key = QStringLiteral("qtwebkit_prescaled_") + % HexString<qint64>(image->cacheKey()) + % HexString<int>(pixelSrc.x()) % HexString<int>(pixelSrc.y()) + % HexString<int>(pixelSrc.width()) % HexString<int>(pixelSrc.height()) + % HexString<int>(scaledSize.width()) % HexString<int>(scaledSize.height()); + if (!QPixmapCache::find(key, &prescaled)) { + if (pixelSrc != image->rect()) + prescaled = image->copy(pixelSrc).scaled(scaledSize, Qt::IgnoreAspectRatio, Qt::SmoothTransformation); + else + prescaled = image->scaled(scaledSize, Qt::IgnoreAspectRatio, Qt::SmoothTransformation); + QPixmapCache::insert(key, prescaled); + } + normalizedSrc = QRectF(QPointF(), prescaled.size()); + image = &prescaled; + } + CompositeOperator previousOperator = ctxt->compositeOperation(); ctxt->setCompositeOperation(!image->hasAlpha() && op == CompositeSourceOver ? CompositeCopy : op); |