Use the links in the table of contents to the left to access the documentation.
void SetCanvas( CImageCanvas *inCanvas )
This canvas contains the result of the user's drawings.
void SetTemporaryCanvas( CImageCanvas *inCanvas )
The temporary canvas is the one in which e.g. a rectangle is drawn and re-drawn until the mouse is released. It is erased between mouse events, and drawn on top of the actual canvas.