molstar
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A comprehensive macromolecular library.
163 lines (162 loc) • 5.24 kB
JavaScript
;
/**
* Copyright (c) 2019-2023 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* @author Alexander Rose <alexander.rose@weirdbyte.de>
*
* Color conversion code adapted from chroma.js (https://github.com/gka/chroma.js)
* Copyright (c) 2011-2018, Gregor Aisch, BSD license
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.Lab = Lab;
const color_1 = require("../color");
const hcl_1 = require("./hcl");
const misc_1 = require("../../../mol-math/misc");
const interpolate_1 = require("../../../mol-math/interpolate");
/**
* CIE LAB color
*
* - L* [0..100] - lightness from black to white
* - a [-100..100] - green (-) to red (+)
* - b [-100..100] - blue (-) to yellow (+)
*
* see https://en.wikipedia.org/wiki/CIELAB_color_space
*/
function Lab() {
return Lab.zero();
}
(function (Lab) {
function zero() {
const out = [0.1, 0.0, 0.0];
out[0] = 0;
return out;
}
Lab.zero = zero;
function create(l, a, b) {
const out = zero();
out[0] = l;
out[1] = a;
out[2] = b;
return out;
}
Lab.create = create;
function set(out, l, a, b) {
out[0] = l;
out[1] = a;
out[2] = b;
return out;
}
Lab.set = set;
/** simple eucledian distance, not perceptually uniform */
function distance(a, b) {
const x = b[0] - a[0], y = b[1] - a[1], z = b[2] - a[2];
return Math.sqrt(x * x + y * y + z * z);
}
Lab.distance = distance;
function fromColor(out, color) {
const [r, g, b] = color_1.Color.toRgb(color);
const [x, y, z] = rgbToXyz(r, g, b);
const l = 116 * y - 16;
out[0] = l < 0 ? 0 : l;
out[1] = 500 * (x - y);
out[2] = 200 * (y - z);
return out;
}
Lab.fromColor = fromColor;
function fromHcl(out, hcl) {
return hcl_1.Hcl.toLab(out, hcl);
}
Lab.fromHcl = fromHcl;
function toColor(lab) {
let y = (lab[0] + 16) / 116;
let x = isNaN(lab[1]) ? y : y + lab[1] / 500;
let z = isNaN(lab[2]) ? y : y - lab[2] / 200;
y = Yn * lab_xyz(y);
x = Xn * lab_xyz(x);
z = Zn * lab_xyz(z);
const r = xyz_rgb(3.2404542 * x - 1.5371385 * y - 0.4985314 * z); // D65 -> sRGB
const g = xyz_rgb(-0.9692660 * x + 1.8760108 * y + 0.0415560 * z);
const b = xyz_rgb(0.0556434 * x - 0.2040259 * y + 1.0572252 * z);
return color_1.Color.fromRgb(Math.round((0, interpolate_1.clamp)(r, 0, 255)), Math.round((0, interpolate_1.clamp)(g, 0, 255)), Math.round((0, interpolate_1.clamp)(b, 0, 255)));
}
Lab.toColor = toColor;
function toHcl(out, lab) {
const [l, a, b] = lab;
const c = Math.sqrt(a * a + b * b);
let h = ((0, misc_1.radToDeg)(Math.atan2(b, a)) + 360) % 360;
if (Math.round(c * 10000) === 0)
h = Number.NaN;
out[0] = h;
out[1] = c;
out[2] = l;
return out;
}
Lab.toHcl = toHcl;
function copy(out, c) {
out[0] = c[0];
out[1] = c[1];
out[2] = c[2];
return out;
}
Lab.copy = copy;
function darken(out, c, amount) {
out[0] = c[0] - Kn * amount;
out[1] = c[1];
out[2] = c[2];
return out;
}
Lab.darken = darken;
function lighten(out, c, amount) {
return darken(out, c, -amount);
}
Lab.lighten = lighten;
const tmpSaturateHcl = [0, 0, 0];
function saturate(out, c, amount) {
toHcl(tmpSaturateHcl, c);
return hcl_1.Hcl.toLab(out, hcl_1.Hcl.saturate(tmpSaturateHcl, tmpSaturateHcl, amount));
}
Lab.saturate = saturate;
function desaturate(out, c, amount) {
return saturate(out, c, -amount);
}
Lab.desaturate = desaturate;
// Corresponds roughly to RGB brighter/darker
const Kn = 18;
/** D65 standard referent */
const Xn = 0.950470;
const Yn = 1;
const Zn = 1.088830;
const T0 = 0.137931034; // 4 / 29
const T1 = 0.206896552; // 6 / 29
const T2 = 0.12841855; // 3 * t1 * t1
const T3 = 0.008856452; // t1 * t1 * t1
/** convert component from xyz to rgb */
function xyz_rgb(c) {
return 255 * (c <= 0.00304 ? 12.92 * c : 1.055 * Math.pow(c, 1 / 2.4) - 0.055);
}
/** convert component from lab to xyz */
function lab_xyz(t) {
return t > T1 ? t * t * t : T2 * (t - T0);
}
/** convert component from rgb to xyz */
function rgb_xyz(c) {
if ((c /= 255) <= 0.04045)
return c / 12.92;
return Math.pow((c + 0.055) / 1.055, 2.4);
}
/** convert component from xyz to lab */
function xyz_lab(t) {
if (t > T3)
return Math.pow(t, 1 / 3);
return t / T2 + T0;
}
function rgbToXyz(r, g, b) {
r = rgb_xyz(r);
g = rgb_xyz(g);
b = rgb_xyz(b);
const x = xyz_lab((0.4124564 * r + 0.3575761 * g + 0.1804375 * b) / Xn);
const y = xyz_lab((0.2126729 * r + 0.7151522 * g + 0.0721750 * b) / Yn);
const z = xyz_lab((0.0193339 * r + 0.1191920 * g + 0.9503041 * b) / Zn);
return [x, y, z];
}
})(Lab || (exports.Lab = Lab = {}));