don't set composition mode to source when painting the bottow layer

Doing so kills performance on the painting benchmark

2 files changed, 0 insertions, 6 deletions

diff --git a/src/plugins/graphicssystems/fb_base/fb_base.cpp b/src/plugins/graphicssystems/fb_base/fb_base.cpp
index c1ce817..d30746a 100644
--- a/src/plugins/graphicssystems/fb_base/fb_base.cpp
+++ b/src/plugins/graphicssystems/fb_base/fb_base.cpp
@@ -189,9 +189,7 @@ QRegion QGraphicsSystemFbScreen::doRedraw()
             foreach (QRect rect, intersect.rects()) {
                 bool firstLayer = true;
                 if (layer == -1) {
-                    compositePainter->setCompositionMode(QPainter::CompositionMode_Source);
                     compositePainter->fillRect(rect, Qt::black);
-                    compositePainter->setCompositionMode(QPainter::CompositionMode_SourceOver);
                     firstLayer = false;
                     layer = windowStack.size() - 1;
                 }
@@ -204,12 +202,9 @@ QRegion QGraphicsSystemFbScreen::doRedraw()
                     QRect windowRect = windowStack[layerIndex]->geometry();
                     QRect windowIntersect = rect.translated(-windowRect.left(),
                                                                  -windowRect.top());
-                    if (firstLayer)
-                        compositePainter->setCompositionMode(QPainter::CompositionMode_Source);
                     compositePainter->drawImage(rect, windowStack[layerIndex]->image(),
                                                 windowIntersect);
                     if (firstLayer) {
-                        compositePainter->setCompositionMode(QPainter::CompositionMode_SourceOver);
                         firstLayer = false;
                     }
                 }
diff --git a/src/plugins/graphicssystems/linuxfb/qgraphicssystem_linuxfb.cpp b/src/plugins/graphicssystems/linuxfb/qgraphicssystem_linuxfb.cpp
index 21a5da3..44960bb 100644
--- a/src/plugins/graphicssystems/linuxfb/qgraphicssystem_linuxfb.cpp
+++ b/src/plugins/graphicssystems/linuxfb/qgraphicssystem_linuxfb.cpp
@@ -846,7 +846,6 @@ QRegion QLinuxFbGraphicsSystemScreen::doRedraw()
 
     if (!compositePainter) {
         compositePainter = new QPainter(mFbScreenImage);
-        compositePainter->setCompositionMode(QPainter::CompositionMode_Source);
     }
 
     QVector<QRect> rects = touched.rects();