@thi.ng/color/rgb/kelvin-rgba.js

Array-based color types, CSS parsing, conversions, transformations, declarative theme generation, gradients, presets

import { clamp01 } from "@thi.ng/math/interval";
import { setC4 } from "@thi.ng/vectors/setc";
import { srgb } from "../srgb/srgb.js";
const G1 = -0.6088425710866344;
const G2 = -0.001748900018414868;
const G3 = 0.4097731842899564;
const G4 = 1.2762722061615583;
const G5 = 3115080994769546e-19;
const G6 = 0.11013841706194392;
const R1 = 1.3803015908551253;
const R2 = 4478684462124118e-19;
const R3 = -0.15785750232675008;
const B1 = -0.9990954974165059;
const B2 = 0.0032447435545127036;
const B3 = 0.453646839257496;
const kelvinRgb = (out, kelvin, alpha = 1) => {
  kelvin *= 0.01;
  let t;
  return kelvin < 66 ? setC4(
    out || srgb(),
    1,
    clamp01(G1 + G2 * (t = kelvin - 2) + G3 * Math.log(t)),
    kelvin < 20 ? 0 : clamp01(
      B1 + B2 * (t = kelvin - 10) + B3 * Math.log(t)
    ),
    alpha
  ) : setC4(
    out || srgb(),
    clamp01(R1 + R2 * (t = kelvin - 55) + R3 * Math.log(t)),
    clamp01(G4 + G5 * (t = kelvin - 50) - G6 * Math.log(t)),
    1,
    alpha
  );
};
export {
  kelvinRgb
};