@thi.ng/boids/behaviors/cohesion.js

n-dimensional boids simulation with modular behavior system

import { __ensureFn } from "../internal/ensure.js";
const cohesion = (maxDist, weight = 1, pred = () => true) => {
  const $maxDist = __ensureFn(maxDist);
  const centroid = [];
  return {
    weight: __ensureFn(weight),
    update: (boid) => {
      const { add, mulN, setN } = boid.api;
      const neighbors = boid.neighbors($maxDist(boid), boid.pos.curr);
      setN(centroid, 0);
      const num = neighbors.length;
      let used = 0, i, n;
      for (i = 0; i < num; i++) {
        n = neighbors[i];
        if (n !== boid && pred(boid, n)) {
          add(centroid, centroid, n.pos.curr);
          used++;
        }
      }
      return used > 0 ? boid.steerTowards(mulN(centroid, centroid, 1 / used)) : centroid;
    }
  };
};
export {
  cohesion
};