void ClearRectangleOnBackground(Bitmap *, int, int, int, int);
void BlitBitmapMasked(Bitmap *, Bitmap *, int, int, int, int, int, int);
boolean DrawingDeactivatedField(void);
-boolean DrawingDeactivated(int, int, int, int);
+boolean DrawingDeactivated(int, int);
boolean DrawingOnBackground(int, int);
boolean DrawingAreaChanged(void);
void BlitBitmapOnBackground(Bitmap *, Bitmap *, int, int, int, int, int, int);