@rpgjs/physic/dist/index41.js

A deterministic 2D top-down physics library for RPG, sandbox and MMO games

import { AABB } from "./index4.js";
import { Vector2 } from "./index2.js";
const EPSILON = 1e-3;
class SeekAvoid {
  /**
   * @param engine - Physics engine used for spatial queries
   * @param targetProvider - Function returning the target entity (or null)
   * @param maxSpeed - Maximum speed in units per second
   * @param repulseRadius - Radius in which obstacles apply repulsion
   * @param repulseWeight - Strength of the repulsion force
   * @param arriveRadius - Distance considered as arrival
   */
  constructor(engine, targetProvider, maxSpeed = 2.5, repulseRadius = 2, repulseWeight = 4, arriveRadius = 0.5) {
    this.engine = engine;
    this.targetProvider = targetProvider;
    this.maxSpeed = maxSpeed;
    this.repulseRadius = repulseRadius;
    this.repulseWeight = repulseWeight;
    this.repulseRadiusSq = repulseRadius * repulseRadius;
    this.arriveRadiusSq = arriveRadius * arriveRadius;
  }
  update(body, _dt) {
    const entity = body.getEntity?.();
    if (!entity) {
      throw new Error("SeekAvoid requires a movement body backed by a physics entity.");
    }
    const target = this.targetProvider();
    if (!target) {
      body.setVelocity({ x: 0, y: 0 });
      return;
    }
    const toTarget = new Vector2(target.position.x - entity.position.x, target.position.y - entity.position.y);
    const distSq = toTarget.lengthSquared();
    let arrived = false;
    if (distSq <= this.arriveRadiusSq) {
      toTarget.set(0, 0);
      arrived = true;
    } else if (distSq > 0) {
      toTarget.divInPlace(Math.sqrt(distSq));
    }
    const bounds = AABB.fromCenterSize(entity.position.x, entity.position.y, this.repulseRadius * 2, this.repulseRadius * 2);
    const neighbors = this.engine.queryAABB(bounds);
    const push = new Vector2(0, 0);
    if (!arrived) {
      for (const other of neighbors) {
        if (other === entity || other === target || other.isStatic()) {
          continue;
        }
        const diff = new Vector2(entity.position.x - other.position.x, entity.position.y - other.position.y);
        let d2 = diff.lengthSquared();
        if (d2 > this.repulseRadiusSq) {
          continue;
        }
        if (d2 < EPSILON) {
          d2 = EPSILON;
        }
        const weight = this.repulseWeight / d2;
        push.addInPlace(diff.mul(weight));
      }
    }
    const pushLength = push.length();
    const maxPush = this.maxSpeed * 0.5;
    if (pushLength > maxPush && pushLength > 0) {
      push.mulInPlace(maxPush / pushLength);
    }
    const desired = toTarget.mul(this.maxSpeed).add(push);
    const desiredLength = desired.length();
    const maxCombinedSpeed = this.maxSpeed * 1.5;
    if (desiredLength > maxCombinedSpeed && desiredLength > 0) {
      desired.mulInPlace(maxCombinedSpeed / desiredLength);
    }
    if (!Number.isFinite(desired.x) || !Number.isFinite(desired.y)) {
      body.setVelocity({ x: 0, y: 0 });
      return;
    }
    body.setVelocity(desired);
  }
  setParameters(maxSpeed, repulseRadius, repulseWeight, arriveRadius) {
    if (maxSpeed !== void 0) {
      this.maxSpeed = maxSpeed;
    }
    if (repulseRadius !== void 0) {
      this.repulseRadius = repulseRadius;
      this.repulseRadiusSq = repulseRadius * repulseRadius;
    }
    if (repulseWeight !== void 0) {
      this.repulseWeight = repulseWeight;
    }
    if (arriveRadius !== void 0) {
      this.arriveRadiusSq = arriveRadius * arriveRadius;
    }
  }
}
export {
  SeekAvoid
};
//# sourceMappingURL=index41.js.map