Re: XForms: XForms 0.89, Mesa 3.0, Multiple GL Canvases?

From: Steve Lamont (
Date: Sun Jan 30 2000 - 19:46:45 EST

  • Next message: Matthew J. Sheats: "Re: XForms: XForms 0.89, Mesa 3.0, Multiple GL Canvases?"

    # To subscribers of the xforms list from (Steve Lamont) :

    > I cannot make a simple program work with multiple canvases. Either
    > only one canvas displays (usually the last one drawn to), or neither of
    > them does.
    > I'm doing something along the lines of:
    > glXMakeCurrent( fl_get_display(), fl_get_canvas_id( canvas1
    > ),
    > fl_get_glcanvas_context( canvas1 ) );
    > < .. GL CODE HERE .. >
    > glXSwapBuffers ( fl_get_display(), glXGetCurrentDrawable ( ) );
    > I use something similar in each Expose callback.. and both callbacks
    > are called, but only the second one produces a picture. Is this
    > something I"m doing or a problem with Mesa perhaps? Or maybe glX? I'm
    > out of ideas.

    Dunno. Mesa is a pretty close approximation of OpenGL and if things
    are as you say, it should work. I have applications which I used to
    run under Mesa with multiple windows and multiple `GLXContext's and
    they worked just fine.

    It's possible that somehow Mesa and your app are mutually confused as
    to what the current Drawable is for some reason. You might try

        glXSwapBuffers( fl_get_display(), FL_ObjWin( canvas ) );

    rather than what you show. That may help.

    If you can reduce the problem to a simple example, you might post it
    and let the list take a look.

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