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, 15 insertions, 8 deletions

diff --git a/src/gui/painting/qpathclipper.cpp b/src/gui/painting/qpathclipper.cpp
index c910024679..78553c9b5c 100644
--- a/src/gui/painting/qpathclipper.cpp
+++ b/src/gui/painting/qpathclipper.cpp
@@ -278,7 +278,8 @@ private:
 };
 
 SegmentTree::SegmentTree(QPathSegments &segments)
-    : m_segments(segments)
+    : m_segments(segments),
+      m_intersections(0)
 {
     m_bounds.x1 = qt_inf();
     m_bounds.y1 = qt_inf();
@@ -806,7 +807,7 @@ void QWingedEdge::intersectAndAdd()
     for (int i = 0; i < m_segments.points(); ++i)
         addVertex(m_segments.pointAt(i));
 
-    QDataBuffer<QPathSegments::Intersection> intersections;
+    QDataBuffer<QPathSegments::Intersection> intersections(m_segments.segments());
     for (int i = 0; i < m_segments.segments(); ++i) {
         intersections.reset();
 
@@ -857,11 +858,17 @@ void QWingedEdge::intersectAndAdd()
     }
 }
 
-QWingedEdge::QWingedEdge()
+QWingedEdge::QWingedEdge() :
+    m_edges(0),
+    m_vertices(0),
+    m_segments(0)
 {
 }
 
-QWingedEdge::QWingedEdge(const QPainterPath &subject, const QPainterPath &clip)
+QWingedEdge::QWingedEdge(const QPainterPath &subject, const QPainterPath &clip) :
+    m_edges(subject.length()),
+    m_vertices(subject.length()),
+    m_segments(subject.length())
 {
     m_segments.setPath(subject);
     m_segments.addPath(clip);
@@ -1414,9 +1421,9 @@ bool QPathClipper::intersect()
     else if (clipIsRect)
         return subjectPath.intersects(r2);
 
-    QPathSegments a;
+    QPathSegments a(subjectPath.length());
     a.setPath(subjectPath);
-    QPathSegments b;
+    QPathSegments b(clipPath.length());
     b.setPath(clipPath);
 
     QIntersectionFinder finder;
@@ -1459,9 +1466,9 @@ bool QPathClipper::contains()
     if (clipIsRect)
         return subjectPath.contains(r2);
 
-    QPathSegments a;
+    QPathSegments a(subjectPath.length());
     a.setPath(subjectPath);
-    QPathSegments b;
+    QPathSegments b(clipPath.length());
     b.setPath(clipPath);
 
     QIntersectionFinder finder;