ssd@engr.ucf.edu (Steven S. Dick) (01/24/91)
I have an application for which drawing the window is computationally expensive, so I'd like to be able to draw the smallest amount possible--in other words, only the visible portions. Currently, the program triggers off of expose events, and draws each part as it is exposed. Unfortunately, the program must periodically redraw the window from scratch. When this becomes necessary, I have to guess what portions of the window are visible. Is there a way to ask the server what parts of the window are visible? Steve ssd@engr.ucf.edu
marbru@attc.UUCP (Martin Brunecky) (01/26/91)
In article <1991Jan24.140821.19001@osceola.cs.ucf.edu> ssd@engr.ucf.edu (Steven S. Dick) writes: >I have an application for which drawing the window is computationally >expensive, so I'd like to be able to draw the smallest amount >possible--in other words, only the visible portions. > >Is there a way to ask the server what parts of the window are visible? > I don't know about such protocol request (correct me if I am wrong). What you can do, however, is: - kepp track of ALL exposure events SINCE you cleared your window (asking for exposure in clear). This will show you what portions of window are visible. Though some portions may become obscured since the clear, at least you will know what areas NEVER got exposed. - merge expose events where possible (Xt has a mechanism to do that for you, in pure X you can do it yourself). This will help with multiple XExpose events caused by a single event (such as unmap of an obscuring window). -- =*= Opinions presented here are solely of my own and not those of Auto-trol =*= Martin Brunecky {...}sunpeaks!auto-trol!marbru (303) 252-2499 (sometimes also: marbru@auto-trol.COM ) Auto-trol Technology Corp. 12500 North Washington St., Denver, CO 80241-2404