hi :) I was observing X11DRV_SetDeviceClipping when I saw that for painting the borders of a window, 4 clipping rectangles are used at the same time ( one for each border ) This means that the drawing routines have to do useless clipping tests.. What is the purpose of these clipping rectangles ? -- Mark Dufour <[EMAIL PROTECTED]> Kascade <[EMAIL PROTECTED]>