Made the opengl/overpainting example work with the GL 2 engine.

Since the GL 2 engine can't set/unset every single GL state that
a user might possibly change, we have to make a rule that if something
is changed from its default state, it needs to be reset before
the GL 2 engine can draw correctly.

Reviewed-by: Samuel

2 files changed, 9 insertions, 3 deletions

diff --git a/doc/src/examples/overpainting.qdoc b/doc/src/examples/overpainting.qdoc
index 91100c0..b19b503 100644
--- a/doc/src/examples/overpainting.qdoc
+++ b/doc/src/examples/overpainting.qdoc
@@ -159,9 +159,10 @@
 
     \snippet examples/opengl/overpainting/glwidget.cpp 7
 
-    Once the list containing the object has been executed, the matrix stack
-    needs to be restored to its original state at the start of this function
-    before we can begin overpainting:
+    Once the list containing the object has been executed, the GL
+    states we changed and the matrix stack needs to be restored to its
+    original state at the start of this function before we can begin
+    overpainting:
 
     \snippet examples/opengl/overpainting/glwidget.cpp 8
 
diff --git a/examples/opengl/overpainting/glwidget.cpp b/examples/opengl/overpainting/glwidget.cpp
index a6e6195..cad591f 100644
--- a/examples/opengl/overpainting/glwidget.cpp
+++ b/examples/opengl/overpainting/glwidget.cpp
@@ -166,6 +166,11 @@ void GLWidget::paintEvent(QPaintEvent *event)
 //! [7]
 
 //! [8]
+    glShadeModel(GL_FLAT);
+    glDisable(GL_CULL_FACE);
+    glDisable(GL_DEPTH_TEST);
+    glDisable(GL_LIGHTING);
+
     glMatrixMode(GL_MODELVIEW);
     glPopMatrix();
 //! [8]