XdrawString+double buffer

Brian Paul brian.paul at tungstengraphics.com
Mon Jul 31 08:40:02 PDT 2006

dragoran wrote:
> Hello
> I am working on a wrapper around glxSwapbuffers. I want to display text 
> in openglapps.
> I have tryed many different things like textures,gldrawpixels, etc. but 
> none of the works in all apps.
> ut2004 does not even like the gldrawpixel version.
> so I tryed using Xdrawstring which works in all of this apps but it 
> flackers because of double buffering.
> how can I avoid this?
> here is my code, it simply displays "test" on the appwindow...
> void glXSwapBuffers(Display* dpy, GLXDrawable drawable) {
> #ifdef DEBUG
>    fprintf(stderr,"about to draw hud ;)\n");
> #endif
>    Colormap cmap;
>    XColor c0, c1;
>    cmap = DefaultColormap(dpy, 0);
>    XAllocNamedColor(dpy, cmap, "red", &c1, &c0);
>    XGCValues values;
>    GC maingc=XCreateGC(dpy, drawable, 0 ,&values);
>    XSetForeground(dpy, maingc, c1.pixel);     XDrawString(dpy,drawable, 
> maingc, 20, 50, "test",4);
>    pglXSwapBuffers(dpy, drawable); }

It might work better to put the XDrawString() call after the 

Also, you may need a glXWaitGL() call between them.


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