#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <GL/glx.h>

int main()
{
	Display *dpy;
	unsigned long mask;
	int scn_id;
	int attrib [] = { GLX_RGBA,
	    GLX_RED_SIZE, 1,
	    GLX_GREEN_SIZE, 1,
	    GLX_BLUE_SIZE, 1,
	    GLX_DOUBLEBUFFER,
	    None };
	XVisualInfo *visinfo;
	XSetWindowAttributes attr;
	int dwidth=1024;
	int dheight=1024;

	if(!(dpy = XOpenDisplay(NULL)))
		return(1);

	Window rwin = DefaultRootWindow(dpy);
	scn_id = DefaultScreen(dpy);
	visinfo = glXChooseVisual(dpy, scn_id, attrib);
	memset(&attr, 0, sizeof(XSetWindowAttributes));
	Window win = XCreateWindow(dpy, rwin,
	    0, 0, dwidth, dheight,
	    0, visinfo->depth, InputOutput,
	    visinfo->visual, mask, &attr );
	XSync(dpy, True);

	GLXContext ctx = glXCreateContext(dpy, visinfo, NULL, GL_TRUE);
	XSync(dpy, False);
	if(!ctx) {
		fprintf(stderr, "[video-gl] Error: glXCreateContext failed\n");
		printf("[video-gl] Error: glXCreateContext failed");
		exit(1);
	}

	fprintf(stderr, "[video-gl]: Create Context: Direct Rendering: %s\n",
	    (glXIsDirect(dpy, ctx)) ? "YES :-)" : "NO :-((");

	glXMakeCurrent(dpy, win, ctx);

	fprintf(stderr, "[video-gl]: OpenGL Vendor : %s\n", glGetString(GL_VENDOR));
	fprintf(stderr, "[video-gl]: OpenGL Renderer: %s\n",
	    glGetString(GL_RENDERER));
	fprintf(stderr, "[video-gl]: OpenGL Version : %s\n", glGetString(GL_VERSION));
	fprintf(stderr, "[video-gl]: Direct Rendering: %s\n",
	    (glXIsDirect(dpy, ctx)) ? "YES :-)" : "NO :-((");

	return(0);
}