Improve performance of QStaticText on OpenGL by caching data on GPU

There's a big improvement to be seen in the OpenGL engine by caching
the vertex data for the QStaticText in VBOs. In order to have the
buffers properly disposed, I've implemented a userdata concept for
QStaticTextItem. By default, the optimizations will be turned off, and
can be turned on by using the useBackendOptimizations flag.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 54eed03..521072f 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -5800,6 +5800,7 @@ void QPainter::drawStaticText(const QPointF &position, const QStaticText &static
                 textItem->glyphPositions[i].x += fx - oldX;
                 textItem->glyphPositions[i].y += fy - oldY;
             }
+            textItem->userDataNeedsUpdate = true;
         }
 
         staticText_d->position = transformedPosition;