sys_follow

Update the entity's position to follow another entity.

import {mat4_get_translation} from "../../lib/mat4.js"; import {Vec3} from "../../lib/math.js"; import {vec3_lerp} from "../../lib/vec3.js"; import {Entity} from "../../lib/world.js"; import {Game} from "../game.js"; import {Has} from "../world.js";

export function sys_follow(game: Game, delta: number) { for (let ent = 0; ent < game.World.Signature.length; ent++) { if ((game.World.Signature[ent] & QUERY) === QUERY) { update(game, ent); } } }

function update(game: Game, entity: Entity) { // Follower must be a top-level transform for this to work. let transform = game.World.Transform[entity]; let follow = game.World.Follow[entity]; let target_transform = game.World.Transform[follow.Target]; mat4_get_translation(target_position, target_transform.World); vec3_lerp(transform.Translation, transform.Translation, target_position, follow.Stiffness); game.World.Signature[entity] |= Has.Dirty; }