import { add, type Hit, scale, type Vec } from "./given.ts";

/**
 * The new position after this frame's move, stopping at a collision if there is
 * one.
 *   hit === null -> pos + v         (take the whole move)
 *   hit          -> pos + v * time  (stop at the contact point)
 */
export function resolve(pos: Vec, v: Vec, hit: Hit | null): Vec {
	return hit ? add(pos, scale(v, hit.time)) : add(pos, v);
}