#include <X11/Xlib.h>
#include <X11/extensions/Xdamage.h>
#include <X11/extensions/Xrender.h>
#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

static char glyphdata[4096] =
{
};

static GlyphSet
make_glyphs (Display *dpy)
{
    GlyphSet glyphset;
    Glyph gid = 1;
    XGlyphInfo glyphinfo;
    int i;

    for (i = 0; i < sizeof (glyphdata); ++i)
    {
	glyphdata[i] = i & 0x07;
    }

    glyphinfo.width = 64;
    glyphinfo.height = 64;
    glyphinfo.x = 0;
    glyphinfo.y = 0;
    glyphinfo.xOff = 0;
    glyphinfo.yOff = 0;

    glyphset = XRenderCreateGlyphSet (
	dpy, XRenderFindStandardFormat (dpy, PictStandardA8));

    XRenderAddGlyphs (
	dpy, glyphset, &gid, &glyphinfo, 1, glyphdata, 64 * 64);

    return glyphset;
}


int
main ()
{
    Display *dpy = XOpenDisplay (NULL);
    Window window;
    Damage damage;
    int devent, derror;
    int revent, rerror;
    Picture dst;
    Picture src;
    XRenderPictureAttributes attr;
    GlyphSet glyphset;
    XRenderColor color =
    {
	0x8080, 0xffff, 0x3232, 0xefef
    };

    window = XCreateSimpleWindow (
	dpy, DefaultRootWindow (dpy), 100, 100,
	300, 300, 0, 0, 0);

    XDamageQueryExtension (dpy, &devent, &derror);
    XRenderQueryExtension (dpy, &revent, &rerror);

    damage = XDamageCreate (dpy, window, XDamageReportRawRectangles);

    XMapWindow (dpy, window);

    src = XRenderCreateSolidFill (dpy, &color);
    dst = XRenderCreatePicture (
	dpy, window, XRenderFindStandardFormat (dpy, PictStandardRGB24),
	0, &attr);

    glyphset = make_glyphs(dpy);

    for (;;)
    {
	XEvent event;
	char c = 1;
	int dstx = rand() % 300;
	int dsty = rand() % 300;

	XSync (dpy, False);

	while (XPending (dpy))
	{
	    XNextEvent (dpy, &event);

	    if (event.type == devent + XDamageNotify)
		printf ("Got damage\n");
	}

	XRenderCompositeString8 (dpy, PictOpOver, src, dst, NULL,
				 glyphset, 0, 0, dstx, dsty, &c, 1);

	usleep (70000);
    }
    return 0;
}