Improved performance in raster window surface for 16-bit displays.

Greatly improves performance in flush() for the non-MITSHM case on
16-bit displays. Instead of converting the whole image to a pixmap only
convert the sub-rect that's needed.

Reviewed-by: Gunnar

1 files changed, 5 insertions, 2 deletions

diff --git a/src/gui/painting/qwindowsurface_raster.cpp b/src/gui/painting/qwindowsurface_raster.cpp
index 592b34c..2f7e879 100644
--- a/src/gui/painting/qwindowsurface_raster.cpp
+++ b/src/gui/painting/qwindowsurface_raster.cpp
@@ -219,11 +219,14 @@ void QRasterWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoi
         const QImage &src = d->image->image;
         br = br.intersected(src.rect());
         if (src.format() != QImage::Format_RGB32 || widget->x11Info().depth() < 24) {
+            Q_ASSERT(src.depth() >= 16);
+            const QImage sub_src(src.scanLine(br.y()) + br.x() * (uint(src.depth()) / 8),
+                                 br.width(), br.height(), src.bytesPerLine(), src.format());
             QX11PixmapData *data = new QX11PixmapData(QPixmapData::PixmapType);
             data->xinfo = widget->x11Info();
-            data->fromImage(src, Qt::AutoColor);
+            data->fromImage(sub_src, Qt::NoOpaqueDetection);
             QPixmap pm = QPixmap(data);
-            XCopyArea(X11->display, pm.handle(), widget->handle(), d_ptr->gc, br.x() , br.y() , br.width(), br.height(), wbr.x(), wbr.y());
+            XCopyArea(X11->display, pm.handle(), widget->handle(), d_ptr->gc, 0 , 0 , br.width(), br.height(), wbr.x(), wbr.y());
         } else {
             // qpaintengine_x11.cpp
             extern void qt_x11_drawImage(const QRect &rect, const QPoint &pos, const QImage &image, Drawable hd, GC gc, Display *dpy, Visual *visual, int depth);