@polygonjs/polygonjs/dist/src/core/softBody/SoftBodyConstraint.js

node-based WebGL 3D engine https://polygonjs.com

"use strict";
import { Vector3 } from "three";
import { vecCopy } from "./SoftBodyMath";
let nextId = 0;
const _p = [0, 0, 0];
export class SoftBodyConstraint {
  constructor(_softBody, pointIndex) {
    this._softBody = _softBody;
    this.pointIndex = pointIndex;
    this.id = nextId++;
    this.invMass = 0;
    this._previousPosition = new Vector3();
    this._position = new Vector3();
    this._velocity = new Vector3();
    if (!this._softBody) {
      return;
    }
    vecCopy(_p, 0, this._softBody.pos, this.pointIndex);
    this._position.fromArray(_p);
    this._previousPosition.copy(this._position);
  }
  dispose() {
    this._softBody = null;
  }
  setPosition(position, lerp, dt) {
    if (!this._softBody) {
      return;
    }
    this._position.lerp(position, lerp);
    this._position.toArray(_p);
    vecCopy(this._softBody.pos, this.pointIndex, _p, 0);
    this._velocity.copy(position).sub(this._previousPosition).divideScalar(dt);
    this._previousPosition.copy(this._position);
  }
  velocity(target) {
    this._velocity.toArray(target);
  }
}