Optimized sub-rect copying / painting of QPixmaps.

Prevented downloading of the whole XImage by introducing new
QPixmapData::toImage() overload taking a sub-rect. Also avoid an
additional copy by simply taking ownership of the XImage data when
the XImage format matches the QImage format.

Reviewed-by: Trond

1 files changed, 5 insertions, 3 deletions

diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp
index 94e5cbc..84b36c7 100644
--- a/src/gui/painting/qpaintengine_raster.cpp
+++ b/src/gui/painting/qpaintengine_raster.cpp
@@ -2419,7 +2419,9 @@ void QRasterPaintEngine::drawPixmap(const QRectF &r, const QPixmap &pixmap, cons
             drawImage(r, image, sr);
         }
     } else {
-        const QImage image = pixmap.toImage();
+        QRect clippedSource = sr.toAlignedRect().intersected(pixmap.rect());
+        const QImage image = pd->toImage(clippedSource);
+        QRectF translatedSource = sr.translated(-clippedSource.topLeft());
         if (image.depth() == 1) {
             Q_D(QRasterPaintEngine);
             QRasterPaintEngineState *s = state();
@@ -2430,10 +2432,10 @@ void QRasterPaintEngine::drawPixmap(const QRectF &r, const QPixmap &pixmap, cons
                 drawBitmap(r.topLeft() + QPointF(s->matrix.dx(), s->matrix.dy()), image, &s->penData);
                 return;
             } else {
-                drawImage(r, d->rasterBuffer->colorizeBitmap(image, s->pen.color()), sr);
+                drawImage(r, d->rasterBuffer->colorizeBitmap(image, s->pen.color()), translatedSource);
             }
         } else {
-            drawImage(r, image, sr);
+            drawImage(r, image, translatedSource);
         }
     }
 }