> I am using a GL_Window, and I call a function from within handle() that > converts window coordinates to world coordintes, so that I can send world > coordinates to my app for mouse events, etc. However, this conversion > requires knowledge of the opengl viewport parameters. My app includes two > windows with different viewport parameters, and I am finding that > when I call glGetIntegerv(GL_VIEWPORT) from within handle() I do not always > get the correct viewport, even after a call to make_current. > > I have two questions. First, are the viewport parameters part of the opengl > context? I would have thought so, but the scenario above makes it seem like > not. > > My second question is, would it be ok to call make_current() and then set the > viewport as I need it from within handle()? I have seen warnings that only > non-drawing opengl calls should be made from within handle(), and I'm not > sure whether glViewport() counts as a drawing routine or not. > > Thank you for your help.
1. Yes, the viewport is part of the opengl context 2. Yes, it should be ok to get and set the viewport from handle() as long as visible() is true. The behaviour you describe does sound strange. Check all your calls to glViewport() and ortho() Don. _______________________________________________ fltk-opengl mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk-opengl
