if(!(dc->dpy = XOpenDisplay(NULL)))
eprintf("cannot open display\n");
dc->gc = XCreateGC(dc->dpy, DefaultRootWindow(dc->dpy), 0, NULL);
XSetLineAttributes(dc->dpy, dc->gc, 1, LineSolid, CapButt, JoinMiter);
if(!(dc->dpy = XOpenDisplay(NULL)))
eprintf("cannot open display\n");
dc->gc = XCreateGC(dc->dpy, DefaultRootWindow(dc->dpy), 0, NULL);
XSetLineAttributes(dc->dpy, dc->gc, 1, LineSolid, CapButt, JoinMiter);