1 files changed, 19 insertions, 1 deletions
diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index 3f96d1c..8aef8b4 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -150,7 +150,25 @@ QGLSignalProxy *QGLSignalProxy::instance()
 class QGLEngineSelector
 {
 public:
-    QGLEngineSelector() : engineType(QPaintEngine::MaxUser) { }
+    QGLEngineSelector() : engineType(QPaintEngine::MaxUser)
+    {
+#ifdef Q_WS_MAC
+        // The ATI X1600 driver for Mac OS X does not support return
+        // values from functions in GLSL. Since working around this in
+        // the GL2 engine would require a big, ugly rewrite, we're
+        // falling back to the GL 1 engine..
+        QGLWidget *tmp = 0;
+        if (!QGLContext::currentContext()) {
+            tmp = new QGLWidget();
+            tmp->makeCurrent();
+        }
+        if (strstr((char *) glGetString(GL_RENDERER), "X1600"))
+            setPreferredPaintEngine(QPaintEngine::OpenGL);
+        if (tmp)
+            delete tmp;
+#endif
+
+    }
 
     void setPreferredPaintEngine(QPaintEngine::Type type) {
         if (type == QPaintEngine::OpenGL || type == QPaintEngine::OpenGL2)