/* find solutions */
a = (di->r * di->r - f->discs[n].r * f->discs[n].r + d * d) / (2 * d);
p2x = di->x + a * (f->discs[n].x - di->x) / d;
/* find solutions */
a = (di->r * di->r - f->discs[n].r * f->discs[n].r + d * d) / (2 * d);
p2x = di->x + a * (f->discs[n].x - di->x) / d;
f->off_map = window;
# else
f->off_map = XCreatePixmap(dpy, window, f->width, f->height, f->visdepth);
f->off_map = window;
# else
f->off_map = XCreatePixmap(dpy, window, f->width, f->height, f->visdepth);