On 08.04.2010, at 18:46, shuiyingzi515 wrote: > Only have one mainbuffer to use, so have no fl_offscreen.
fl_offscreen is a buffer in regular memory. It needs no graphics interface at all. If your machine has RAM, it also has fl_offscreen. > I want to know, it clear all the datas drawed by drawling() when redraw > widget,how to save the drawed datas?? GUI applications are event based. redraw() tells FLTK that you require a redraw. FLTK decides when to call your draw() function. draw() draws into the video memory. Video memory can not always be read (fl_read_image does, but it is not guaranteed to work on screens). That's why we suggest fl_offscreen, which you can always read. Hope this helps, - Matthias _______________________________________________ fltk mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk
