@mapwhit/style-expressions/lib/util/interpolate.js

Process expressions in map style.

import Color from './color.js';

export function number(a, b, t) {
  return a * (1 - t) + b * t;
}

export function color(from, to, t) {
  return new Color(number(from.r, to.r, t), number(from.g, to.g, t), number(from.b, to.b, t), number(from.a, to.a, t));
}

export function array(from, to, t) {
  return from.map((d, i) => {
    return number(d, to[i], t);
  });
}