Avoid many unnecessary allocations, so so that paint engines attached to pixmaps

do not consume excessive amounts of memory, and so can still be reasonably kept
cached with the pixmap.
Saves 8K for every pixmaps drawn to on raster paint engine. Saves about 2K for other graphicssystems.

Task-number: QTBUG-10215
Reviewed-by: Gunnar

1 files changed, 2 insertions, 1 deletions

diff --git a/src/gui/painting/qpaintengineex.cpp b/src/gui/painting/qpaintengineex.cpp
index a78cafb..fda937e 100644
--- a/src/gui/painting/qpaintengineex.cpp
+++ b/src/gui/painting/qpaintengineex.cpp
@@ -149,6 +149,7 @@ QDebug Q_GUI_EXPORT &operator<<(QDebug &s, const QVectorPath &path)
 
 
 struct StrokeHandler {
+    StrokeHandler(int reserve) : pts(reserve), types(reserve) {}
     QDataBuffer<qreal> pts;
     QDataBuffer<QPainterPath::ElementType> types;
 };
@@ -394,7 +395,7 @@ void QPaintEngineEx::stroke(const QVectorPath &path, const QPen &pen)
         return;
 
     if (!d->strokeHandler) {
-        d->strokeHandler = new StrokeHandler;
+        d->strokeHandler = new StrokeHandler(path.elementCount()+4);
         d->stroker.setMoveToHook(qpaintengineex_moveTo);
         d->stroker.setLineToHook(qpaintengineex_lineTo);
         d->stroker.setCubicToHook(qpaintengineex_cubicTo);