Hello, i am seeing some behaviour in my app that i don't understand: i have an application with several tabs in a notebook, each containing an individual drawing area (one tab contains two and three panes of drawing areas). there are several different possible drawing combinations per drawing area, so to avoid having to redraw only when a combination is chosen, i am maintaining as many pixmap backing stores necessary to avoid redrawina a pixmap when it's already been previously drawn. and this all works nifty, no problems. my problem can be described by the following sequence: -) in the normal course of using the app, i generate, say, 10-15 drawing events; -) at some point, when switching between two pixmaps that have previously been drawn (thus, my pixmap expose event must simply draw the current pixmap to the screen), there is a rather visible delay (~1 second) between old and new pixmap, event though no drawing occurs (except in the expose event drawing the entire new pixmap to the screen). observations: -) i have noticed that this only happens when some particular pixmap is being displayed. -) e.g.: switching between the same two pixmaps, one is drawn delayed, the other is drawn instantaneously. -) and, the same behaviour occurs when i partially obscure the drawing with another window: one pixmap is redrawn delayed, while the other is redrawn instantaneously (thus, demonstrating that it solely related to expose event delivery). (btw, using the same two pixmaps from previous example.) -) i have used the ubiquitous printf() inside the expose event to also demonstrate that the delay occurs before the expose event is drawn. once the expose event is called, the drawing of the pixmap to the screen is instantaneous. and i've just realized something i think that's important. this behaviour is seen only after i have generated a pixmap containing more than the two colors i have setup for fg and bg. (in fact, if i reset all my pixmap backing stores to nothing and start drawing from the beginning, the delay goes away.) is there something important (requiring a lot of time) in the background when dealing with multiple pixmaps having been generated with different colour maps? (i'm guessing here, don't shoot me...) or is there something else going on that i don't understand? is there something relevant to know about how colourmaps are managed in the background, and then be able to program in consideration of in the foreground (my program)? any thoughts/ideas would be greatly appreciated. i'm striving to write an efficient program by never redrawing pixmaps that have already been drawn, and ironically enough, a configure event (drawing from scratch) is quicker than the expose event (with delay). or is this all related to my Xserver or machine (linux)? thanks in advance, richard boaz _______________________________________________ gtk-list@xxxxxxxxx http://mail.gnome.org/mailman/listinfo/gtk-list
