comparison panner.cpp @ 48:996b3c4037ef

* Add IndirectPainting opt flag, makes a big difference to rendering Panner; rename project

     m_clicked(false)
 {
 //    setViewport(new QGLWidget());
     setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
     setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
-    setOptimizationFlags(QGraphicsView::DontSavePainterState);
+    setOptimizationFlags(QGraphicsView::DontSavePainterState |
+                         QGraphicsView::IndirectPainting);
     setMouseTracking(true);
     setInteractive(false);
 }
 
 void

 Panner::drawItems(QPainter *painter, int numItems,
                   QGraphicsItem *items[],
                   const QStyleOptionGraphicsItem options[])
 {
     if (m_cache.size() != viewport()->size()) {
+
+    std::cerr << "Panner: recreating cache" << std::endl;
 
         QGraphicsScene *s = scene();
         if (!s) return;
         PannerScene *ps = static_cast<PannerScene *>(s);