On 10 Apr 2010, at 15:05, nigo wrote: > Hi, > > is it possible to draw the contents of a widget hierarchy ito a > memory buffer? > Grabbing screen contents after normal redraw is not good enough due > to potential overlapping windows over the area.
Yes, it is. I was going to post some simplified example code, but the I remembered the example was made up for this STR anyway... http://www.fltk.org/str.php?L2257 So the code that's there "offscreen-grab.cxx" shows how to redirect drawing of the widget hierarchy on a group, such that it is stored in an offscreen memory buffer, from which it can safely be read back without having to worry about being overlaid by other windows. In fact, for simplicity, this example *always* draws into the offscreen, then blits the interesting bit from the offscreen back onto the real screen, but in practice what you would probably do is *usually* draw direct to the real screen, and only during your effect would you redirect via the offscreen. Also, note that with fltk-1.3 on OSX, at present, reading back from the offscreen can be a little bit hosed. Works fine on X11 and win32 though, and fltk-1.1 works fine, and AFAIK fltk2 works fine. What fltk version, host, etc are you targeting? -- Ian _______________________________________________ fltk mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk
