#include <stdio.h>
#include <stdlib.h>
#if 0
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <stdarg.h>
#include <unistd.h>
#include <signal.h>
#include <strings.h>
#include <sys/wait.h>
#endif

#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#if 0
#include <X11/Xatom.h>
#include <X11/Xresource.h>
#include <X11/extensions/shape.h>
#endif

#include <GL/glx.h>

extern const char *__progname;

#define UNUSED __attribute__((__unused__))

typedef struct attr ATTR;

struct attr {
  int attrib;
  const char *name;
  } ;

static Display *disp;
static int nvi;
static XVisualInfo *vi;
static ATTR attribs[]
 = {
#define INITATTR(x) { x, #x }
     INITATTR(GLX_USE_GL),
     INITATTR(GLX_BUFFER_SIZE),
     INITATTR(GLX_LEVEL),
     INITATTR(GLX_RGBA),
     INITATTR(GLX_DOUBLEBUFFER),
     INITATTR(GLX_STEREO),
     INITATTR(GLX_AUX_BUFFERS),
     INITATTR(GLX_RED_SIZE),
     INITATTR(GLX_GREEN_SIZE),
     INITATTR(GLX_BLUE_SIZE),
     INITATTR(GLX_ALPHA_SIZE),
     INITATTR(GLX_DEPTH_SIZE),
     INITATTR(GLX_STENCIL_SIZE),
     INITATTR(GLX_ACCUM_RED_SIZE),
     INITATTR(GLX_ACCUM_GREEN_SIZE),
     INITATTR(GLX_ACCUM_BLUE_SIZE),
     INITATTR(GLX_ACCUM_ALPHA_SIZE) };
static int nattribs = sizeof(attribs) / sizeof(attribs[0]);

static const char *classname(int cl)
{
 static char *badbuf = 0;

 switch (cl)
  { case StaticGray:  return("StaticGray");  break;
    case GrayScale:   return("GrayScale");   break;
    case StaticColor: return("StaticColor"); break;
    case PseudoColor: return("PseudoColor"); break;
    case TrueColor:   return("TrueColor");   break;
    case DirectColor: return("DirectColor"); break;
  }
 free(badbuf);
 asprintf(&badbuf,"?%d",cl);
 return(badbuf);
}

int main(void);
int main(void)
{
 int i;
 int e;
 int value;
 int j;

 disp = XOpenDisplay(0);
 if (disp == 0)
  { fprintf(stderr,"%s: can't open display\n",__progname);
    exit(1);
  }
 vi = XGetVisualInfo(disp,0,0,&nvi);
 printf("visual count: %d\n",nvi);
 for (i=0;i<nvi;i++)
  { printf("[%d]: v=%p id=%lu scr=%d dp=%u cl=%s masks=%lx/%lx/%lx cms=%d b/rgb=%d\n",
	i, (void *)vi[i].visual, (unsigned long int)vi[i].visualid,
	vi[i].screen, vi[i].depth, classname(vi[i].class),
	vi[i].red_mask, vi[i].green_mask, vi[i].blue_mask,
	vi[i].colormap_size, vi[i].bits_per_rgb );
    for (j=0;j<nattribs;j++)
     { printf("  %s = ",attribs[j].name);
       e = glXGetConfig(disp,&vi[i],attribs[j].attrib,&value);
       switch (e)
	{ case GLX_NO_EXTENSION:
	     printf("*** No GLX extension support!\n");
	     exit(1);
	     break;
	  case GLX_BAD_SCREEN:
	     printf("*** Nonexistent screen!\n");
	     exit(1);
	     break;
	  case GLX_BAD_ATTRIBUTE:
	     printf("*** Bad attribute %d!\n",attribs[j].attrib);
	     exit(1);
	     break;
	  case GLX_BAD_VISUAL:
	     printf("*** Non-GL visual!\n");
	     break;
	  case 0:
	     printf("%d\n",value);
	     break;
	  default:
	     printf("*** Strange error %d\n",e);
	     exit(1);
	     break;
	}
     }
  }
 return(0);
}