Complete a programmatic painting operation and enact the changes (i.e. to mimic a user painting operation with your own code).
Result is the area that was painted (in screen coordinates).
Normally, painting operations are performed by the user via miBrushTool, but it can be performed with code using:
1. Set the size and color of the brush
2. Start painting using StartPainting
3. Add extra points to the painting operation using AddToPainting (Optional)
4. Enact the painting changes using EndPainting