@thi.ng/rstream/tween.js

Reactive streams & subscription primitives for constructing dataflow graphs / pipelines

import { isNumber } from "@thi.ng/checks/is-number";
import { dedupe } from "@thi.ng/transducers/dedupe";
import { reducer } from "@thi.ng/transducers/reduce";
import { scan } from "@thi.ng/transducers/scan";
import { fromInterval } from "./interval.js";
import { fromRAF } from "./raf.js";
import { sync } from "./sync.js";
const tween = (src, initial, mix, stop, clock) => sync({
  src: {
    src,
    _: clock == null ? fromRAF() : isNumber(clock) ? fromInterval(clock) : clock
  },
  closeIn: "first"
}).transform(
  scan(
    reducer(
      () => initial,
      (acc, { src: src2 }) => mix(acc, src2)
    )
  ),
  dedupe(stop || (() => false))
);
const tweenNumber = (src, init = 0, speed = 0.05, eps = 1e-3, clock) => tween(
  src,
  init,
  (a, b) => a + (b - a) * speed,
  (a, b) => Math.abs(a - b) < eps,
  clock
);
export {
  tween,
  tweenNumber
};