On 23.01.2011, at 05:05, james wrote: > Heya! > So I have a Fl_Box inside of a Fl_Scroll. > I'm taking over the draw() of my box, and when I scroll around by clicking > and dragging on the nobs, my draw function can only draw on the newly exposed > pixels. It simply blits the pixels that are still on the screen over to their > new position. > > How can I eliminate this buffer that exists?
Well, the draw() function as it is called by Fl_Scroll is optimized so it doesn't need to redraw the entire area, but simply moves pixels around that are still on the screen. This is achieved - among other things - by clipping out the are of the widget that was preserved. This works for 99.9% of all cases. If you really need to draw a different widget during a scroll event, you can use fl_push_no_clip(); draw stuff; fl_pop_clip(); to draw into the the entire window. Careful though: this will also draw over the borders of Fl_Scroll. <http://www.fltk.org/doc-1.3/drawing.html#ssect_Clipping> Check src/Fl_Scroll.cxx draw() and draw_clip() for details - Matthias _______________________________________________ fltk mailing list fltk@easysw.com http://lists.easysw.com/mailman/listinfo/fltk
