#include "x11util.h"
extern "C" {
	#include <X11/Xlib.h>
	#include <X11/Xutil.h>
}
#include <cstring>
#include <cstdlib>
#include <cstdio>

static int eHandler(Display* dpy, XErrorEvent* e)
{
	char buf[1000];
	XGetErrorText(dpy, e->error_code, buf, 1000);
	fprintf(stderr, "X ERROR %d: %s\n", (int)e->error_code, buf);
	return 0;
}

extern "C"
void AddPixmapToBackground(unsigned const char* imgData, int width, int height, int depth, int bytesPerLine, int byteCount)
{
    Pixmap pix = 0;
    GC gc = NULL;
    XImage *xi = NULL;
    XGCValues gc_init;
    memset(&gc_init, 0, sizeof(gc_init));
    Display* dpy = XOpenDisplay(NULL);
    if (dpy == NULL)
    	return;
    XSetErrorHandler(&eHandler);
    int screen = DefaultScreen(dpy);
    Window root = RootWindow(dpy, screen);
    char *data = (char*)malloc(byteCount);
    memcpy(data, imgData, byteCount);
    xi = XCreateImage(dpy, CopyFromParent, depth, ZPixmap, 0, data, width, height, 32, bytesPerLine);
    if (xi == NULL)
    	goto cleanup;
    pix = XCreatePixmap(dpy, root, width, height, (unsigned int)DefaultDepth(dpy, screen));
    if (pix == 0)
    	goto cleanup;
    gc_init.foreground = BlackPixel(dpy, screen);
	gc_init.background = WhitePixel(dpy, screen);
	gc = XCreateGC(dpy, pix, GCForeground|GCBackground, &gc_init);
	if (gc == NULL)
	    goto cleanup;
	int res1, res2, res3;
	res1 = XPutImage(dpy, pix, gc, xi, 0, 0, 0, 0, width, height);
   	res2 = XSetWindowBackgroundPixmap(dpy, root, pix);
    res3 = XClearWindow(dpy, root);
cleanup:
	if (gc != NULL) {
		XFreeGC(dpy, gc);
	}
	if (pix != 0) {
		XFreePixmap(dpy, pix);
	}
	if (xi != NULL) {
		XDestroyImage(xi);
	}
    if (dpy != NULL) {
    	XCloseDisplay(dpy);
    }
}