#include <stdio.h>
#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <GL/glx.h>
#include <GL/gl.h>

#include "units.h"

static void createGLWin(Display *dpy, int width, int height, Window *rWin, GLXContext *rCtx);
static void useGL(Display *dpy, Window win, GLXContext ctx, int width, int height);

static void
doIt()
{
  Display *disp1;
  Window win1;
  GLXContext ctx1;

  disp1 = XOpenDisplay(NULL);
  createGLWin(disp1, 200, 200, &win1, &ctx1);
  if(0 != win1 && 0 != ctx1) {
    useGL(disp1, win1, ctx1, 200, 200);

    glXMakeCurrent(disp1, 0, 0);
    glXDestroyContext(disp1, ctx1);
  }
  XCloseDisplay(disp1);
}

int
main(int argc, char **argv)
{
  doIt();
  return 0;
}

/* attributes for a double buffered visual in RGBA format with at least
 * 4 bits per color and a 16 bit depth buffer */
static int attrListDbl[] = { GLX_RGBA, GLX_DOUBLEBUFFER, 
  GLX_RED_SIZE, 4, 
  GLX_GREEN_SIZE, 4, 
  GLX_BLUE_SIZE, 4, 
  GLX_DEPTH_SIZE, 16,
  None };

void createGLWin(Display *dpy, int width, int height, Window *rWin, GLXContext *rCtx)
{
  int screen = DefaultScreen(dpy);
  XVisualInfo *vi = glXChooseVisual(dpy, screen, attrListDbl);
  Colormap cmap;
  XSetWindowAttributes attr;

  /* create a GLX context */
  *rCtx = glXCreateContext(dpy, vi, 0, GL_TRUE);
  /* create a color map */
  cmap = XCreateColormap(dpy, RootWindow(dpy, vi->screen), vi->visual, AllocNone);
  attr.colormap = cmap;
  attr.border_pixel = 0;

  /* create a window in window mode*/
  attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask |
    StructureNotifyMask;
  *rWin = XCreateWindow(dpy, RootWindow(dpy, vi->screen),
    0, 0, width, height, 0, vi->depth, InputOutput, vi->visual,
    CWBorderPixel | CWColormap | CWEventMask, &attr);

  XMapRaised(dpy, *rWin);
}

void useGL(Display *dpy, Window win, GLXContext ctx, int width, int height)
{
  glXMakeCurrent(dpy, win, ctx);

  testTextureUnits();
}