#include <stdlib.h>
#include <stdio.h>
#include <X11/Xlib.h>
#include <X11/extensions/Xcomposite.h>
#include <X11/extensions/Xdamage.h>

static int comp_event, comp_error;
static int damage_event, damage_error;

static void
disaster (const char *what)
{
    exit (-1);
}

static void
dump_events (Display *dpy, const char *header)
{
    int did_header = 0;

    XSync (dpy, False);

    while (XPending (dpy))
    {
        XEvent event;

        XNextEvent (dpy, &event);

        if (header)
        {
            if (!did_header)
            {
                printf ("%s", header);
                did_header = 1;
            }

            if (event.type == damage_event)
            {
                printf ("  event: damage  (%lx)\n",
                        event.xany.window);
            }
	    else
	    {
		printf ("  event on window: (%lx)\n",
			event.xany.window);
	    }
        }
    }
}

static void
paint_window (Display *dpy, Window window, unsigned long pixel)
{
    XGCValues gc_values;
    GC gc;

    gc_values.foreground = pixel;
    gc = XCreateGC (dpy, window, GCForeground, &gc_values);

    XFillRectangle (dpy, window, gc, 0, 0, 32000, 32000);

    XFreeGC (dpy, gc);
}

int
main ()
{
    Display *dpy = XOpenDisplay (NULL);
    Window toplevel;
    Window child;
    Pixmap pixmap;
    Damage d;
    GC gc;
    int i;

    toplevel = XCreateSimpleWindow (dpy, XDefaultRootWindow (dpy),
				    100, 100, 600, 400, 0, 0, 0xffffffff);
    XMapWindow (dpy, toplevel);

    XFlush (dpy);
    usleep (1000);      /* wait for wm to map window */

    if (!XCompositeQueryExtension (dpy, &comp_event, &comp_error))
        disaster ("No composite extension found\n");
    if (!XDamageQueryExtension (dpy, &damage_event, &damage_error))
	disaster ("No damage extension found\n");

    XCompositeRedirectSubwindows (dpy, toplevel,
                                  CompositeRedirectManual);

    child = XCreateSimpleWindow (dpy, toplevel,
				 50, 50, 500, 300,
				 0, 0, 0x000000ff);

    printf ("Created window: %lx\n", child);
    
    XMapWindow (dpy, child);
    
    pixmap = XCompositeNameWindowPixmap (dpy, child);

    printf ("Named pixmap  %lx\n", pixmap);
    
    XDamageCreate (dpy, child, XDamageReportRawRectangles);
    XDamageCreate (dpy, pixmap, XDamageReportRawRectangles);

    XSync (dpy, False);

    for (i = 0; i < 10; ++i)
    {
	paint_window (dpy, child, 0xff00ffff);
	
        dump_events (dpy, "events\n");

        usleep (5000);
    }
    
    sleep (10);
    
    return 0;
}