@yagejs-addons/steering

Steering (movement AI) for YAGE (@yagejs-addons scope, independently versioned, NOT in the engine fixed group). A headless weighted-sum blend model plus a @yagejs/core Component host. The root entry is pure @yagejs/core; @yagejs-addons/steering/physics adds a RigidBodyComponent-detecting agent.

Install

npm install @yagejs-addons/steering
npm install @yagejs/core # engine peer (single install, reused — not bundled)
npm install @yagejs/physics # only if you import @yagejs-addons/steering/physics

Peers: @yagejs/core (required), @yagejs/physics (optional — the /physics entry only). No runtime deps.

Entry points

No /presenters subpath — steering has no view to swap, only a velocity to compute. The /physics entry exists so the root stays physics-free:

import { SteeringAgent, seek, flee, arrive, wander, pursue, evade, avoidObstacles, separation, alignment, cohesion, followPath, contain, Steering } from "@yagejs-addons/steering";
import { avoidColliders, physicsNeighbors, PhysicsSteeringAgent } from "@yagejs-addons/steering/physics";

5-minute setup

import { SteeringAgent, seek } from "@yagejs-addons/steering";
import { Transform } from "@yagejs/core";

// enemy is an Entity with a Transform. The default output integrates it:
// position += velocity * dt. Nothing else to wire.
enemy.add(
  new SteeringAgent({
    maxSpeed: 120,
    behaviors: [seek(() => player.get(Transform).position)],
  }),
);

Physics body — mount PhysicsSteeringAgent next to a RigidBodyComponent and it drives it. Impulse drive (the default) means real two-way physics: the agent pushes crates, takes knockback, and steering pulls it back on course at maxAcceleration:

import { PhysicsSteeringAgent } from "@yagejs-addons/steering/physics";

enemy.add(
  new PhysicsSteeringAgent({
    maxSpeed: 130,
    maxAcceleration: 500, // default 4x maxSpeed; the per-frame impulse is the capped correction
    behaviors: [arrive(() => waypoint, { slowRadius: 140 })],
  }),
);

Or use the structural body option on the root class — the addon's root entry never imports physics; { setVelocity, getVelocity } is satisfied by RigidBodyComponent as-is, and by any custom mover object:

import { SteeringAgent, arrive } from "@yagejs-addons/steering";
import { RigidBodyComponent } from "@yagejs/physics";

enemy.add(
  new SteeringAgent({
    maxSpeed: 130,
    maxAcceleration: 500,
    behaviors: [arrive(() => waypoint)],
    body: enemy.get(RigidBodyComponent),
  }),
);

See the full docs for blending, obstacle avoidance, flocking, path-following, containment, drive modes, and the headless/manual-drive API.

Live escape hatches

agent.steering.add(flee(() => boss.position, { weight: 4 })); // add behavior live
agent.maxSpeed = 200; // retune
agent.velocity; // Vec2 the agent is steering toward — for a debug arrow
agent.stop(); // halt now: zeroes the model AND the body/output
agent.enabled = false; // pause ticking without removing the component

Not in v1

A bundled debug presenter is deferred — read agent.velocity and draw the arrow yourself. See the steering doc for details.