void ClearRectangleOnBackground(Bitmap *, int, int, int, int);
void BlitBitmapMasked(Bitmap *, Bitmap *, int, int, int, int, int, int);
boolean DrawingDeactivatedField(void);
void ClearRectangleOnBackground(Bitmap *, int, int, int, int);
void BlitBitmapMasked(Bitmap *, Bitmap *, int, int, int, int, int, int);
boolean DrawingDeactivatedField(void);