void ufoEditorOverlayDraw( ufoEditor editor_instance, ufoProcess process_instance);
This function is optional. If supplied, it will be called during editing and rendering when the viewer window needs updating or a process parameter has changed.
Any graphics drawn in the Open GL overlay plane during editing should be performed within this function. OpenGL projections are set up for projection of the full/master raster resolution coordinate space on the screen.
The UFO library function ufoEditorGetOverlayIndex gets the correct colour index to be used for setting the overlay draw colour in OpenGL. This is necessary as a part of the overlay plane is used for other specific tools.
Autodesk Softimage v7.5