static Client *xytoclient(double x, double y,
		struct wlr_surface **surface, double *sx, double *sy);

static Client *xytoclient(double x, double y);

static Client *xytosurface(double x, double y,
		struct wlr_surface **surface, double *sx, double *sy);

		c = xytoclient(cursor->x, cursor->y, &surface, NULL, NULL);

		c = xytosurface(cursor->x, cursor->y, &surface, NULL, NULL);

	c = xytoclient(cursor->x, cursor->y, &surface, &sx, &sy);

	c = xytosurface(cursor->x, cursor->y, &surface, &sx, &sy);

	grabc = xytoclient(cursor->x, cursor->y, NULL, NULL, NULL);

	grabc = xytoclient(cursor->x, cursor->y);

xytoclient(double x, double y,
		struct wlr_surface **surface, double *sx, double *sy)

xytoclient(double x, double y)

	/* Find the topmost visible client (if any) under the cursor, including

	/* Find the topmost visible client (if any) at point (x, y), including

	wl_list_for_each(c, &stack, slink) {
		if (VISIBLEON(c, c->mon) && wlr_box_contains_point(&c->geom, x, y)) {
			/*
			 * XDG toplevels may have nested surfaces, such as popup windows
			 * for context menus or tooltips. This function tests if any of
			 * those are underneath the coordinates x and y (in layout
			 * coordinates). If so, it sets the surface pointer to that
			 * wlr_surface and the sx and sy coordinates to the coordinates
			 * relative to that surface's top-left corner.
			 */
			/* XXX set *surface to xdg_surface->surface instead of
			 * NULL?  what should sx/sy be in that case? */
			if (surface)
				*surface = wlr_xdg_surface_surface_at(c->xdg_surface,
						x - c->geom.x - c->bw,
						y - c->geom.y - c->bw, sx, sy);

	wl_list_for_each(c, &stack, slink)
		if (VISIBLEON(c, c->mon) && wlr_box_contains_point(&c->geom, x, y))

		}
	}

Client *
xytosurface(double x, double y,
		struct wlr_surface **surface, double *sx, double *sy)
{
	Client *c = xytoclient(x, y);
	/*
	 * XDG toplevels may have nested surfaces, such as popup windows
	 * for context menus or tooltips. This function tests if any of
	 * those are underneath the coordinates x and y (in layout
	 * coordinates). If so, it sets the surface pointer to that
	 * wlr_surface and the sx and sy coordinates to the coordinates
	 * relative to that surface's top-left corner.
	 */
	/* XXX set *surface to xdg_surface->surface otherwise?  what should
	 * sx/sy be in that case? */
	if (c)
		*surface = wlr_xdg_surface_surface_at(c->xdg_surface,
				x - c->geom.x - c->bw,
				y - c->geom.y - c->bw, sx, sy);
	return c;
}