XdrawString+double buffer

[Brian Paul]

dragoran wrote:
> Brian Paul wrote:
> 
>> 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 
>> SwapBuffers().
>>
>> Also, you may need a glXWaitGL() call between them.
>>
>> -Brian
>>
>>
> hello
> now I have tryed with
> pglXSwapBuffers(dpy, drawable);
>    glXWaitGL();
>    XDrawString(dpy,drawable, maingc, 20, 50, "test",4);
> the only thing that this causes are lower framerates but teh flickering 
> isn't gone

I guess the only flicker-free solution is to draw the text with OpenGL 
commands prior to SwapBuffers().  Have you tried glWindowPos/glBitmap()?

-Brian