glx problem

OpenGL OpenGL: Basic Coding
1

Something odd happens when I try to create a window with the following context:

int dblBuf24[] = {GLX_RGBA, GLX_DOUBLEBUFFER, GLX_RED_SIZE, 8, GL_GREEN_SIZE, 8, GLX_BLUE_SIZE, 8, None};
XVisualInfo *vi = glXChooseVisual(dpy, screen, dblBuf24);
GLXContext context = glXCreateContext(dpy, vi, 0, GL_TRUE);

The resulting window may be different when changing computer. In one I get what I want, on another I get black and white, and on yet another I get truecolor single buffered(the two other was doublebuffered).

Any ideas anyone

2

Hi !

I am assuming that the computers you have tested on have support for the requested context ?, most OpenGL drivers have very limited support for different color depth and resolutions.

Mikael

3

Well, I assumed that when I got an XVisualInfo that was not NULL, the requested context was supported…

I have debugged on all the different computers, and glXChooseVisual(dpy, screen, dblBuf24) allways returns non NULL