@thi.ng/ecs/components/object-component.js

Entity Component System based around typed arrays & sparse sets

import { assert } from "@thi.ng/errors/assert";
import { AComponent } from "./acomponent.js";
class ObjectComponent extends AComponent {
  constructor(sparse, dense, opts) {
    super(opts.id, sparse, dense, new Array(dense.length));
    this.default = opts.default;
  }
  get size() {
    return 1;
  }
  get stride() {
    return 1;
  }
  packedValues() {
    return this.vals.slice(0, this.n);
  }
  resize(pool, cap) {
    assert(cap >= this.dense.length, "can't decrease capacity");
    if (cap === this.dense.length) return;
    const sparse = pool.reallocArray(this.sparse, cap);
    const dense = pool.reallocArray(this.dense, cap);
    assert(!!(sparse && dense), `couldn't resize component: ${this.id}`);
    this.sparse = sparse;
    this.dense = dense;
  }
  get(id) {
    let i = this.sparse[id];
    return i < this.n && this.dense[i] === id ? this.vals[i] : void 0;
  }
  getIndex(i) {
    return i < this.n ? this.vals[i] : void 0;
  }
  setIndexUnsafe(i, v, notify = true) {
    this.vals[i] = v;
    notify && this.notifyChange(this.dense[i]);
  }
  swapIndices(src, dest) {
    if (src === dest) return false;
    const { dense, sparse, vals } = this;
    const ss = dense[src];
    const sd = dense[dest];
    dense[src] = sd;
    dense[dest] = ss;
    sparse[ss] = dest;
    sparse[sd] = src;
    const tmp = vals[src];
    vals[src] = vals[dest];
    vals[dest] = tmp;
    return true;
  }
  moveIndex(src, dest) {
    const vals = this.vals;
    vals[dest] = vals[src];
    delete vals[src];
  }
}
export {
  ObjectComponent
};