If auto_render is TRUE the render signal will be
emitted every time the widget draws. This is the default and is
useful if drawing the widget is faster.
If auto_render is FALSE the data from previous rendering is kept
around and will be used for drawing the widget the next time,
unless the window is resized. In order to force a rendering
gtk_gl_area_queue_render() must be called. This mode is useful when
the scene changes seldomly, but takes a long time to redraw.
If auto_render is TRUE the render signal will be emitted every time the widget draws. This is the default and is useful if drawing the widget is faster.
If auto_render is FALSE the data from previous rendering is kept around and will be used for drawing the widget the next time, unless the window is resized. In order to force a rendering gtk_gl_area_queue_render() must be called. This mode is useful when the scene changes seldomly, but takes a long time to redraw.