/**
* Color management.
*
* @author Alain Pitiot
* @version 2022.2.3
* @copyright (c) 2017-2020 Ilixa Ltd. (http://ilixa.com) (c) 2020-2022 Open Science Tools Ltd. (https://opensciencetools.org)
* @license Distributed under the terms of the MIT License
*/
/**
* <p>This class handles multiple color spaces, and offers various
* static methods for converting colors from one space to another.</p>
*
* <p>The constructor accepts the following color representations:
* <ul>
* <li>a named color, e.g. 'aliceblue' (the colorspace must be RGB)</li>
* <li>an hexadecimal string representation, e.g. '#FF0000' (the colorspace must be RGB)</li>
* <li>an hexadecimal number representation, e.g. 0xFF0000 (the colorspace must be RGB)</li>
* <li>a triplet of numbers, e.g. [-1, 0, 1], [0, 128, 255] (the numbers must be within the range determined by the colorspace)</li>
* </ul>
* </p>
*
* <p>Note: internally, colors are represented as a [r,g,b] triplet with r,g,b in [0,1].</p>
*
* @todo implement HSV, DKL, and LMS colorspaces
*/
export class Color
{
/**
* @memberof module:util
* @param {string|number|Array.<number>|undefined} [obj= 'black'] - an object representing a color
* @param {module:util.Color#COLOR_SPACE|undefined} [colorspace=Color.COLOR_SPACE.RGB] - the colorspace of that color
*/
constructor(obj = "black", colorspace = Color.COLOR_SPACE.RGB)
{
const response = {
origin: "Color",
context: "when defining a color",
};
// named color (e.g. 'seagreen') or string hexadecimal representation (e.g. '#FF0000'):
// note: we expect the color space to be RGB
if (typeof obj == "string")
{
if (colorspace !== Color.COLOR_SPACE.RGB)
{
throw Object.assign(response, {
error: "the colorspace must be RGB for a named color",
});
}
// hexademical representation:
if (obj[0] === "#")
{
this._hex = obj;
}
// named color:
else
{
if (!(obj.toLowerCase() in Color.NAMED_COLORS))
{
throw Object.assign(response, { error: "unknown named color: " + obj });
}
this._hex = Color.NAMED_COLORS[obj.toLowerCase()];
}
this._rgb = Color.hexToRgb(this._hex);
}
// hexadecimal number representation (e.g. 0xFF0000)
// note: we expect the color space to be RGB
else if (typeof obj == "number")
{
if (colorspace !== Color.COLOR_SPACE.RGB)
{
throw Object.assign(response, {
error: "the colorspace must be RGB for"
+ " a"
+ " named color",
});
}
this._rgb = Color._intToRgb(obj);
}
// array of numbers:
else if (Array.isArray(obj))
{
Color._checkTypeAndRange(obj);
let [a, b, c] = obj;
// check range and convert to [0,1]:
if (colorspace !== Color.COLOR_SPACE.RGB255)
{
Color._checkTypeAndRange(obj, [-1, 1]);
a = (a + 1.0) / 2.0;
b = (b + 1.0) / 2.0;
c = (c + 1.0) / 2.0;
}
// get RGB components:
switch (colorspace)
{
case Color.COLOR_SPACE.RGB255:
Color._checkTypeAndRange(obj, [0, 255]);
this._rgb = [a / 255.0, b / 255.0, c / 255.0];
break;
case Color.COLOR_SPACE.RGB:
this._rgb = [a, b, c];
break;
case Color.COLOR_SPACE.HSV:
break;
case Color.COLOR_SPACE.DKL:
break;
case Color.COLOR_SPACE.LMS:
break;
default:
throw Object.assign(response, { error: "unknown colorspace: " + colorspace });
}
}
else if (obj instanceof Color)
{
this._rgb = obj._rgb.slice();
}
this._rgbFull = this._rgb.map(c => c * 2 - 1);
}
/**
* Get the [0,1] RGB triplet equivalent of this Color.
*
* @return {Array.<number>} the [0,1] RGB triplet equivalent
*/
get rgb()
{
return this._rgb;
}
/**
* Get the [-1,1] RGB triplet equivalent of this Color.
*
* @return {Array.<number>} the [-1,1] RGB triplet equivalent
*/
get rgbFull()
{
return this._rgbFull;
}
/**
* Get the [0,255] RGB triplet equivalent of this Color.
*
* @return {Array.<number>} the [0,255] RGB triplet equivalent
*/
get rgb255()
{
return [Math.round(this._rgb[0] * 255.0), Math.round(this._rgb[1] * 255.0), Math.round(this._rgb[2] * 255.0)];
}
/**
* Get the hexadecimal color code equivalent of this Color.
*
* @return {string} the hexadecimal color code equivalent
*/
get hex()
{
if (typeof this._hex === "undefined")
{
this._hex = Color._rgbToHex(this._rgb);
}
return this._hex;
}
/**
* Get the integer code equivalent of this Color.
*
* @return {number} the integer code equivalent
*/
get int()
{
if (typeof this._int === "undefined")
{
this._int = Color._rgbToInt(this._rgb);
}
return this._int;
}
/*
get hsv() {
if (typeof this._hsv === 'undefined')
this._hsv = Color._rgbToHsv(this._rgb);
return this._hsv;
}
get dkl() {
if (typeof this._dkl === 'undefined')
this._dkl = Color._rgbToDkl(this._rgb);
return this._dkl;
}
get lms() {
if (typeof this._lms === 'undefined')
this._lms = Color._rgbToLms(this._rgb);
return this._lms;
}
*/
/**
* String representation of the color, i.e. the hexadecimal representation.
*
* @return {string} the representation.
*/
toString()
{
return this.hex;
}
/**
* Get the [0,255] RGB triplet equivalent of the hexadecimal color code.
*
* @param {string} hex - the hexadecimal color code
* @return {Array.<number>} the [0,255] RGB triplet equivalent
*/
static hexToRgb255(hex)
{
const result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
if (result == null)
{
throw {
origin: "Color.hexToRgb255",
context: "when converting an hexadecimal color code to its 255- or [0,1]-based RGB color representation",
error: "unable to parse the argument: wrong type or wrong code",
};
}
return [parseInt(result[1], 16), parseInt(result[2], 16), parseInt(result[3], 16)];
}
/**
* Get the [0,1] RGB triplet equivalent of the hexadecimal color code.
*
* @param {string} hex - the hexadecimal color code
* @return {Array.<number>} the [0,1] RGB triplet equivalent
*/
static hexToRgb(hex)
{
const [r255, g255, b255] = Color.hexToRgb255(hex);
return [r255 / 255.0, g255 / 255.0, b255 / 255.0];
}
/**
* Get the hexadecimal color code equivalent of the [0, 255] RGB triplet.
*
* @param {Array.<number>} rgb255 - the [0, 255] RGB triplet
* @return {string} the hexadecimal color code equivalent
*/
static rgb255ToHex(rgb255)
{
const response = {
origin: "Color.rgb255ToHex",
context: "when converting an rgb triplet to its hexadecimal color representation",
};
try
{
Color._checkTypeAndRange(rgb255, [0, 255]);
return Color._rgb255ToHex(rgb255);
}
catch (error)
{
throw Object.assign(response, { error });
}
}
/**
* Get the hexadecimal color code equivalent of the [0, 1] RGB triplet.
*
* @param {Array.<number>} rgb - the [0, 1] RGB triplet
* @return {string} the hexadecimal color code equivalent
*/
static rgbToHex(rgb)
{
const response = {
origin: "Color.rgbToHex",
context: "when converting an rgb triplet to its hexadecimal color representation",
};
try
{
Color._checkTypeAndRange(rgb, [0, 1]);
return Color._rgbToHex(rgb);
}
catch (error)
{
throw Object.assign(response, { error });
}
}
/**
* Get the integer equivalent of the [0, 1] RGB triplet.
*
* @param {Array.<number>} rgb - the [0, 1] RGB triplet
* @return {number} the integer equivalent
*/
static rgbToInt(rgb)
{
const response = {
origin: "Color.rgbToInt",
context: "when converting an rgb triplet to its integer representation",
};
try
{
Color._checkTypeAndRange(rgb, [0, 1]);
return Color._rgbToInt(rgb);
}
catch (error)
{
throw Object.assign(response, { error });
}
}
/**
* Get the integer equivalent of the [0, 255] RGB triplet.
*
* @param {Array.<number>} rgb255 - the [0, 255] RGB triplet
* @return {number} the integer equivalent
*/
static rgb255ToInt(rgb255)
{
const response = {
origin: "Color.rgb255ToInt",
context: "when converting an rgb triplet to its integer representation",
};
try
{
Color._checkTypeAndRange(rgb255, [0, 255]);
return Color._rgb255ToInt(rgb255);
}
catch (error)
{
throw Object.assign(response, { error });
}
}
/**
* Get the hexadecimal color code equivalent of the [0, 255] RGB triplet.
*
* <p>Note: this is the fast, unsafe version which does not check for argument sanity</p>
*
* @protected
* @param {Array.<number>} rgb255 - the [0, 255] RGB triplet
* @return {string} the hexadecimal color code equivalent
*/
static _rgb255ToHex(rgb255)
{
return "#" + ((1 << 24) + (rgb255[0] << 16) + (rgb255[1] << 8) + rgb255[2]).toString(16).slice(1);
}
/**
* Get the hexadecimal color code equivalent of the [0, 1] RGB triplet.
*
* <p>Note: this is the fast, unsafe version which does not check for argument sanity</p>
*
* @protected
* @param {Array.<number>} rgb - the [0, 1] RGB triplet
* @return {string} the hexadecimal color code equivalent
*/
static _rgbToHex(rgb)
{
const rgb255 = [Math.round(rgb[0] * 255), Math.round(rgb[1] * 255), Math.round(rgb[2] * 255)];
return Color._rgb255ToHex(rgb255);
}
/**
* Get the integer equivalent of the [0, 1] RGB triplet.
*
* <p>Note: this is the fast, unsafe version which does not check for argument sanity</p>
*
* @protected
* @param {Array.<number>} rgb - the [0, 1] RGB triplet
* @return {number} the integer equivalent
*/
static _rgbToInt(rgb)
{
const rgb255 = [Math.round(rgb[0] * 255), Math.round(rgb[1] * 255), Math.round(rgb[2] * 255)];
return Color._rgb255ToInt(rgb255);
}
/**
* Get the integer equivalent of the [0, 255] RGB triplet.
*
* <p>Note: this is the fast, unsafe version which does not check for argument sanity</p>
*
* @protected
* @param {Array.<number>} rgb255 - the [0, 255] RGB triplet
* @return {number} the integer equivalent
*/
static _rgb255ToInt(rgb255)
{
return rgb255[0] * 0x10000 + rgb255[1] * 0x100 + rgb255[2];
}
/**
* Get the [0, 255] based RGB triplet equivalent of the integer color code.
*
* <p>Note: this is the fast, unsafe version which does not check for argument sanity</p>
*
* @protected
* @param {number} hex - the integer color code
* @return {Array.<number>} the [0, 255] RGB equivalent
*/
static _intToRgb255(hex)
{
const r255 = hex >>> 0x10;
const g255 = (hex & 0xFF00) / 0x100;
const b255 = hex & 0xFF;
return [r255, g255, b255];
}
/**
* Get the [0, 1] based RGB triplet equivalent of the integer color code.
*
* <p>Note: this is the fast, unsafe version which does not check for argument sanity</p>
*
* @protected
* @param {number} hex - the integer color code
* @return {Array.<number>} the [0, 1] RGB equivalent
*/
static _intToRgb(hex)
{
const [r255, g255, b255] = Color._intToRgb255(hex);
return [r255 / 255.0, g255 / 255.0, b255 / 255.0];
}
/**
* Check that the argument is an array of numbers of size 3, and, potentially, that its elements fall within the range.
*
* @protected
* @param {any} arg - the argument
* @param {Array.<number>} [range] - the lower and higher bounds of the range
* @return {boolean} whether the argument is an array of numbers of size 3, and, potentially, whether its elements fall within the range (if range is not undefined)
*/
static _checkTypeAndRange(arg, range = undefined)
{
if (
!Array.isArray(arg) || arg.length !== 3
|| typeof arg[0] !== "number" || typeof arg[1] !== "number" || typeof arg[2] !== "number"
)
{
throw "the argument should be an array of numbers of length 3";
}
if (typeof range !== "undefined" && (arg[0] < range[0] || arg[0] > range[1] || arg[1] < range[0] || arg[1] > range[1] || arg[2] < range[0] || arg[2] > range[1]))
{
throw "the color components should all belong to [" + range[0] + ", " + range[1] + "]";
}
}
}
/**
* Color spaces.
*
* @enum {Symbol}
* @readonly
*/
Color.COLOR_SPACE = {
/**
* RGB colorspace: [r,g,b] with r,g,b in [-1, 1]
*/
RGB: Symbol.for("RGB"),
/**
* RGB255 colorspace: [r,g,b] with r,g,b in [0, 255]
*/
RGB255: Symbol.for("RGB255"),
/*
HSV: Symbol.for('HSV'),
DKL: Symbol.for('DKL'),
LMS: Symbol.for('LMS')
*/
};
/**
* Named colors.
*
* @enum {string}
* @readonly
*/
Color.NAMED_COLORS = {
"aliceblue": "#F0F8FF",
"antiquewhite": "#FAEBD7",
"aqua": "#00FFFF",
"aquamarine": "#7FFFD4",
"azure": "#F0FFFF",
"beige": "#F5F5DC",
"bisque": "#FFE4C4",
"black": "#000000",
"blanchedalmond": "#FFEBCD",
"blue": "#0000FF",
"blueviolet": "#8A2BE2",
"brown": "#A52A2A",
"burlywood": "#DEB887",
"cadetblue": "#5F9EA0",
"chartreuse": "#7FFF00",
"chocolate": "#D2691E",
"coral": "#FF7F50",
"cornflowerblue": "#6495ED",
"cornsilk": "#FFF8DC",
"crimson": "#DC143C",
"cyan": "#00FFFF",
"darkblue": "#00008B",
"darkcyan": "#008B8B",
"darkgoldenrod": "#B8860B",
"darkgray": "#A9A9A9",
"darkgrey": "#A9A9A9",
"darkgreen": "#006400",
"darkkhaki": "#BDB76B",
"darkmagenta": "#8B008B",
"darkolivegreen": "#556B2F",
"darkorange": "#FF8C00",
"darkorchid": "#9932CC",
"darkred": "#8B0000",
"darksalmon": "#E9967A",
"darkseagreen": "#8FBC8B",
"darkslateblue": "#483D8B",
"darkslategray": "#2F4F4F",
"darkslategrey": "#2F4F4F",
"darkturquoise": "#00CED1",
"darkviolet": "#9400D3",
"deeppink": "#FF1493",
"deepskyblue": "#00BFFF",
"dimgray": "#696969",
"dimgrey": "#696969",
"dodgerblue": "#1E90FF",
"firebrick": "#B22222",
"floralwhite": "#FFFAF0",
"forestgreen": "#228B22",
"fuchsia": "#FF00FF",
"gainsboro": "#DCDCDC",
"ghostwhite": "#F8F8FF",
"gold": "#FFD700",
"goldenrod": "#DAA520",
"gray": "#808080",
"grey": "#808080",
"green": "#008000",
"greenyellow": "#ADFF2F",
"honeydew": "#F0FFF0",
"hotpink": "#FF69B4",
"indianred": "#CD5C5C",
"indigo": "#4B0082",
"ivory": "#FFFFF0",
"khaki": "#F0E68C",
"lavender": "#E6E6FA",
"lavenderblush": "#FFF0F5",
"lawngreen": "#7CFC00",
"lemonchiffon": "#FFFACD",
"lightblue": "#ADD8E6",
"lightcoral": "#F08080",
"lightcyan": "#E0FFFF",
"lightgoldenrodyellow": "#FAFAD2",
"lightgray": "#D3D3D3",
"lightgrey": "#D3D3D3",
"lightgreen": "#90EE90",
"lightpink": "#FFB6C1",
"lightsalmon": "#FFA07A",
"lightseagreen": "#20B2AA",
"lightskyblue": "#87CEFA",
"lightslategray": "#778899",
"lightslategrey": "#778899",
"lightsteelblue": "#B0C4DE",
"lightyellow": "#FFFFE0",
"lime": "#00FF00",
"limegreen": "#32CD32",
"linen": "#FAF0E6",
"magenta": "#FF00FF",
"maroon": "#800000",
"mediumaquamarine": "#66CDAA",
"mediumblue": "#0000CD",
"mediumorchid": "#BA55D3",
"mediumpurple": "#9370DB",
"mediumseagreen": "#3CB371",
"mediumslateblue": "#7B68EE",
"mediumspringgreen": "#00FA9A",
"mediumturquoise": "#48D1CC",
"mediumvioletred": "#C71585",
"midnightblue": "#191970",
"mintcream": "#F5FFFA",
"mistyrose": "#FFE4E1",
"moccasin": "#FFE4B5",
"navajowhite": "#FFDEAD",
"navy": "#000080",
"oldlace": "#FDF5E6",
"olive": "#808000",
"olivedrab": "#6B8E23",
"orange": "#FFA500",
"orangered": "#FF4500",
"orchid": "#DA70D6",
"palegoldenrod": "#EEE8AA",
"palegreen": "#98FB98",
"paleturquoise": "#AFEEEE",
"palevioletred": "#DB7093",
"papayawhip": "#FFEFD5",
"peachpuff": "#FFDAB9",
"peru": "#CD853F",
"pink": "#FFC0CB",
"plum": "#DDA0DD",
"powderblue": "#B0E0E6",
"purple": "#800080",
"red": "#FF0000",
"rosybrown": "#BC8F8F",
"royalblue": "#4169E1",
"saddlebrown": "#8B4513",
"salmon": "#FA8072",
"sandybrown": "#F4A460",
"seagreen": "#2E8B57",
"seashell": "#FFF5EE",
"sienna": "#A0522D",
"silver": "#C0C0C0",
"skyblue": "#87CEEB",
"slateblue": "#6A5ACD",
"slategray": "#708090",
"slategrey": "#708090",
"snow": "#FFFAFA",
"springgreen": "#00FF7F",
"steelblue": "#4682B4",
"tan": "#D2B48C",
"teal": "#008080",
"thistle": "#D8BFD8",
"tomato": "#FF6347",
"turquoise": "#40E0D0",
"violet": "#EE82EE",
"wheat": "#F5DEB3",
"white": "#FFFFFF",
"whitesmoke": "#F5F5F5",
"yellow": "#FFFF00",
"yellowgreen": "#9ACD32",
};