@studiometa/js-toolkit/utils/math/smoothTo.js

A set of useful little bits of JavaScript to boost your project! 🚀

import { damp } from "./damp.js";
import { spring } from "./spring.js";
import { isFunction, isDefined } from "../is.js";
function smoothTo(start = 0, options = {}) {
  const fns = /* @__PURE__ */ new Set();
  let damping = options.damping ?? 0.6;
  let precision = options.precision ?? 1 / 1e8;
  let stiffness = options.stiffness ?? 0.1;
  let mass = options.mass ?? 1;
  let isSpring = options.spring === true || isDefined(options.stiffness) || isDefined(options.mass);
  let value = start;
  let smoothed = start;
  let velocity = 0;
  function tick() {
    if (isSpring) {
      [smoothed, velocity] = spring(value, smoothed, velocity, stiffness, damping, mass, precision);
    } else {
      smoothed = damp(value, smoothed, damping, precision);
    }
    for (const fn of fns) {
      fn(smoothed);
    }
    if (smoothed !== value) requestAnimationFrame(tick);
  }
  function subscribe(fn) {
    if (isFunction(fn)) {
      fns.add(fn);
    }
    return () => unsubscribe(fn);
  }
  function unsubscribe(fn) {
    return fns.delete(fn);
  }
  function update(newValue) {
    if (!isDefined(newValue)) {
      return smoothed;
    }
    value = newValue;
    tick();
    return smoothed;
  }
  update.subscribe = subscribe;
  update.unsubscribe = unsubscribe;
  update.raw = () => value;
  update.add = (val) => update(value + val);
  update.damping = (val) => damping = val ?? damping;
  update.precision = (val) => precision = val ?? precision;
  update.stiffness = (val) => stiffness = val ?? stiffness;
  update.spring = (val) => isSpring = val ?? isSpring;
  update(start);
  return update;
}
export {
  smoothTo
};
//# sourceMappingURL=smoothTo.js.map