Added a public function to enforce usage og the old GL engine.

Some applications that uses a mix of OpenGL and QPainter code may
not work correctly with the new GL 2 engine (e.g. the composition demo).
The same is most likely also true for user apps, therefore we need
a way to enforce the usage of the old GL 1 engine for the sake of
compatibility.

Task-number: 260872
Reviewed-by: Samuel

1 files changed, 6 insertions, 0 deletions

diff --git a/demos/composition/main.cpp b/demos/composition/main.cpp
index 3a959a9..fe142ad 100644
--- a/demos/composition/main.cpp
+++ b/demos/composition/main.cpp
@@ -42,11 +42,17 @@
 #include "composition.h"
 
 #include <QApplication>
+#ifdef QT_OPENGL_SUPPORT
+#include <QtOpenGL>
+#endif
 
 int main(int argc, char **argv)
 {
  //   Q_INIT_RESOURCE(deform);
 
+#ifdef QT_OPENGL_SUPPORT
+    QGL::setPreferredPaintEngine(QPaintEngine::OpenGL);
+#endif
     QApplication app(argc, argv);
 
     CompositionWidget compWidget(0);