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, 7 insertions, 5 deletions

diff --git a/src/opengl/gl2paintengineex/qtriangulator.cpp b/src/opengl/gl2paintengineex/qtriangulator.cpp
index ce917ff..df7cbc2 100644
--- a/src/opengl/gl2paintengineex/qtriangulator.cpp
+++ b/src/opengl/gl2paintengineex/qtriangulator.cpp
@@ -510,6 +510,7 @@ template <class T>
 class QMaxHeap
 {
 public:
+    QMaxHeap() : m_data(0) {}
     inline int size() const {return m_data.size();}
     inline bool empty() const {return m_data.isEmpty();}
     inline bool isEmpty() const {return m_data.isEmpty();}
@@ -1299,7 +1300,8 @@ public:
     class ComplexToSimple
     {
     public:
-        inline ComplexToSimple(QTriangulator *parent) : m_parent(parent) { }
+        inline ComplexToSimple(QTriangulator *parent) : m_parent(parent),
+            m_edges(0), m_events(0), m_splits(0) { }
         void decompose();
     private:
         struct Edge
@@ -1412,7 +1414,7 @@ public:
     class SimpleToMonotone
     {
     public:
-        inline SimpleToMonotone(QTriangulator *parent) : m_parent(parent) { }
+        inline SimpleToMonotone(QTriangulator *parent) : m_parent(parent), m_edges(0), m_upperVertex(0) { }
         void decompose();
     private:
         enum VertexType {MergeVertex, EndVertex, RegularVertex, StartVertex, SplitVertex};
@@ -1486,7 +1488,7 @@ public:
         int m_length;
     };
 
-    inline QTriangulator() { }
+    inline QTriangulator() : m_vertices(0) { }
 
     // Call this only once.
     void initialize(const qreal *polygon, int count, uint hint, const QTransform &matrix);
@@ -2709,7 +2711,7 @@ void QTriangulator::SimpleToMonotone::monotoneDecomposition()
         return;
 
     Q_ASSERT(!m_edgeList.root);
-    QDataBuffer<QPair<int, int> > diagonals;
+    QDataBuffer<QPair<int, int> > diagonals(m_upperVertex.size());
 
     int i = 0;
     for (int index = 1; index < m_edges.size(); ++index) {
@@ -2853,7 +2855,7 @@ bool QTriangulator::SimpleToMonotone::CompareVertices::operator () (int i, int j
 void QTriangulator::MonotoneToTriangles::decompose()
 {
     QVector<quint32> result;
-    QDataBuffer<int> stack;
+    QDataBuffer<int> stack(m_parent->m_indices.size());
     m_first = 0;
     // Require at least three more indices.
     while (m_first + 3 <= m_parent->m_indices.size()) {