mcopy/app/src/colors.js

710 lines
21 KiB
JavaScript
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

;(function(window, undefined){
"use strict"
var _valueRanges = {
rgb: {r: [0, 255], g: [0, 255], b: [0, 255]},
hsv: {h: [0, 360], s: [0, 100], v: [0, 100]},
hsl: {h: [0, 360], s: [0, 100], l: [0, 100]},
cmy: {c: [0, 100], m: [0, 100], y: [0, 100]},
cmyk: {c: [0, 100], m: [0, 100], y: [0, 100], k: [0, 100]},
Lab: {L: [0, 100], a: [-128, 127], b: [-128, 127]},
XYZ: {X: [0, 100], Y: [0, 100], Z: [0, 100]},
alpha: {alpha: [0, 1]},
HEX: {HEX: [0, 16777215]} // maybe we don't need this
},
_instance = {},
_colors = {},
// http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html for more
XYZMatrix = { // Observer = 2° (CIE 1931), Illuminant = D65
X: [ 0.4124564, 0.3575761, 0.1804375],
Y: [ 0.2126729, 0.7151522, 0.0721750],
Z: [ 0.0193339, 0.1191920, 0.9503041],
R: [ 3.2404542, -1.5371385, -0.4985314],
G: [-0.9692660, 1.8760108, 0.0415560],
B: [ 0.0556434, -0.2040259, 1.0572252]
},
grey = {r: 0.298954, g: 0.586434, b: 0.114612}, // CIE-XYZ 1931
luminance = {r: 0.2126, g: 0.7152, b: 0.0722}, // W3C 2.0
_math = Math,
_parseint = parseInt,
Colors = window.Colors = function(options) {
this.colors = {RND: {}};
this.options = {
color: 'rgba(204, 82, 37, 0.8)', // init value(s)...
XYZMatrix: XYZMatrix,
// XYZReference: {},
grey: grey,
luminance: luminance,
valueRanges: _valueRanges
// customBG: '#808080'
// convertCallback: undefined,
// allMixDetails: false
};
initInstance(this, options || {});
},
initInstance = function(THIS, options) {
var matrix,
importColor,
_options = THIS.options,
customBG;
focusInstance(THIS);
for (var option in options) {
if (options[option] !== undefined) _options[option] = options[option];
}
matrix = _options.XYZMatrix;
if (!options.XYZReference) _options.XYZReference = {
X: matrix.X[0] + matrix.X[1] + matrix.X[2],
Y: matrix.Y[0] + matrix.Y[1] + matrix.Y[2],
Z: matrix.Z[0] + matrix.Z[1] + matrix.Z[2]
};
customBG = _options.customBG;
_options.customBG = (typeof customBG === 'string') ? ColorConverter.txt2color(customBG).rgb : customBG;
_colors = setColor(THIS.colors, _options.color, undefined, true); // THIS.colors = _colors =
},
focusInstance = function(THIS) {
if (_instance !== THIS) {
_instance = THIS;
_colors = THIS.colors;
}
};
Colors.prototype.setColor = function(newCol, type, alpha) {
focusInstance(this);
if (newCol) {
return setColor(this.colors, newCol, type, undefined, alpha);
} else {
if (alpha !== undefined) {
this.colors.alpha = limitValue(alpha, 0, 1);
}
return convertColors(type);
}
};
Colors.prototype.getColor = function(type) {
var result = this.colors, n = 0;
if (type) {
type = type.split('.');
while (result[type[n]]) {
result = result[type[n++]];
}
if (type.length !== n) {
result = undefined;
}
}
return result;
};
Colors.prototype.setCustomBackground = function(col) { // wild gues,... check again...
focusInstance(this); // needed???
this.options.customBG = (typeof col === 'string') ? ColorConverter.txt2color(col).rgb : col;
// return setColor(this.colors, this.options.customBG, 'rgb', true); // !!!!RGB
return setColor(this.colors, undefined, 'rgb'); // just recalculate existing
};
Colors.prototype.saveAsBackground = function() { // alpha
focusInstance(this); // needed???
// return setColor(this.colors, this.colors.RND.rgb, 'rgb', true);
return setColor(this.colors, undefined, 'rgb', true);
};
Colors.prototype.convertColor = function(color, type) {
var convert = ColorConverter,
ranges = _valueRanges,
types = type.split('2'),
fromType = types[0],
toType = types[1],
test = /(?:RG|HS|CM|LA)/,
normalizeFrom = test.test(fromType),
normalizeTo = test.test(toType),
exceptions = {LAB: 'Lab'},
normalize = function(color, type, reverse) {
var result = {},
Lab = type === 'Lab' ? 1 : 0;
for (var n in color) { // faster (but bigger) way: if/else outside 2 for loops
result[n] = reverse ?
_math.round(color[n] * (Lab || ranges[type][n][1])) :
color[n] / (Lab || ranges[type][n][1]);
}
return result;
};
fromType = ranges[fromType] ? fromType : exceptions[fromType] || fromType.toLowerCase();
toType = ranges[toType] ? toType : exceptions[toType] || toType.toLowerCase();
if (normalizeFrom && type !== 'RGB2HEX') { // from ABC to abc
color = normalize(color, fromType);
}
color = fromType === toType ? color : ( // same type; returns same/normalized version
convert[fromType + '2' + toType] ? convert[fromType + '2' + toType](color, true) : // existing converter
toType === 'HEX' ? convert.RGB2HEX(type === 'RGB2HEX' ? color : normalize(fromType === 'rgb' ? color :
convert[fromType + '2rgb'](color, true), 'rgb', true)) :
convert['rgb2' + toType](convert[fromType + '2rgb'](color, true), true) // not in ColorConverter
);
if (normalizeTo) { // from abc to ABC
color = normalize(color, toType, true);
}
return color;
};
// ------------------------------------------------------ //
// ---------- Color calculation related stuff ---------- //
// -------------------------------------------------------//
function setColor(colors, color, type, save, alpha) { // color only full range
if (typeof color === 'string') {
var color = ColorConverter.txt2color(color); // new object
type = color.type;
_colors[type] = color[type];
alpha = alpha !== undefined ? alpha : color.alpha;
} else if (color) {
for (var n in color) {
colors[type][n] = limitValue(color[n] / _valueRanges[type][n][1], 0 , 1);
}
}
if (alpha !== undefined) {
colors.alpha = limitValue(+alpha, 0, 1);
}
return convertColors(type, save ? colors : undefined);
}
function saveAsBackground(RGB, rgb, alpha) {
var grey = _instance.options.grey,
color = {};
color.RGB = {r: RGB.r, g: RGB.g, b: RGB.b};
color.rgb = {r: rgb.r, g: rgb.g, b: rgb.b};
color.alpha = alpha;
// color.RGBLuminance = getLuminance(RGB);
color.equivalentGrey = _math.round(grey.r * RGB.r + grey.g * RGB.g + grey.b * RGB.b);
color.rgbaMixBlack = mixColors(rgb, {r: 0, g: 0, b: 0}, alpha, 1);
color.rgbaMixWhite = mixColors(rgb, {r: 1, g: 1, b: 1}, alpha, 1);
color.rgbaMixBlack.luminance = getLuminance(color.rgbaMixBlack, true);
color.rgbaMixWhite.luminance = getLuminance(color.rgbaMixWhite, true);
if (_instance.options.customBG) {
color.rgbaMixCustom = mixColors(rgb, _instance.options.customBG, alpha, 1);
color.rgbaMixCustom.luminance = getLuminance(color.rgbaMixCustom, true);
_instance.options.customBG.luminance = getLuminance(_instance.options.customBG, true);
}
return color;
}
function convertColors(type, colorObj) {
// console.time('convertColors');
var _Math = _math,
colors = colorObj || _colors,
convert = ColorConverter,
options = _instance.options,
ranges = _valueRanges,
RND = colors.RND,
// type = colorType, // || _mode.type,
modes, mode = '', from = '', // value = '',
exceptions = {hsl: 'hsv', cmyk: 'cmy', rgb: type},
RGB = RND.rgb, SAVE, SMART;
if (type !== 'alpha') {
for (var typ in ranges) {
if (!ranges[typ][typ]) { // no alpha|HEX
if (type !== typ && typ !== 'XYZ') {
from = exceptions[typ] || 'rgb';
colors[typ] = convert[from + '2' + typ](colors[from]);
}
if (!RND[typ]) RND[typ] = {};
modes = colors[typ];
for(mode in modes) {
RND[typ][mode] = _Math.round(modes[mode] * (typ === 'Lab' ? 1 : ranges[typ][mode][1]));
}
}
}
if (type !== 'Lab') {
delete colors._rgb;
}
RGB = RND.rgb;
colors.HEX = convert.RGB2HEX(RGB);
colors.equivalentGrey =
options.grey.r * colors.rgb.r +
options.grey.g * colors.rgb.g +
options.grey.b * colors.rgb.b;
colors.webSave = SAVE = getClosestWebColor(RGB, 51);
// colors.webSave.HEX = convert.RGB2HEX(colors.webSave);
colors.webSmart = SMART = getClosestWebColor(RGB, 17);
// colors.webSmart.HEX = convert.RGB2HEX(colors.webSmart);
colors.saveColor =
RGB.r === SAVE.r && RGB.g === SAVE.g && RGB.b === SAVE.b ? 'web save' :
RGB.r === SMART.r && RGB.g === SMART.g && RGB.b === SMART.b ? 'web smart' : '';
colors.hueRGB = convert.hue2RGB(colors.hsv.h);
if (colorObj) {
colors.background = saveAsBackground(RGB, colors.rgb, colors.alpha);
}
} // else RGB = RND.rgb;
var rgb = colors.rgb, // for better minification...
alpha = colors.alpha,
luminance = 'luminance',
background = colors.background,
rgbaMixBlack, rgbaMixWhite, rgbaMixCustom,
rgbaMixBG, rgbaMixBGMixBlack, rgbaMixBGMixWhite, rgbaMixBGMixCustom,
_mixColors = mixColors,
_getLuminance = getLuminance,
_getWCAG2Ratio = getWCAG2Ratio,
_getHueDelta = getHueDelta;
rgbaMixBlack = _mixColors(rgb, {r: 0, g: 0, b: 0}, alpha, 1);
rgbaMixBlack[luminance] = _getLuminance(rgbaMixBlack, true);
colors.rgbaMixBlack = rgbaMixBlack;
rgbaMixWhite = _mixColors(rgb, {r: 1, g: 1, b: 1}, alpha, 1);
rgbaMixWhite[luminance] = _getLuminance(rgbaMixWhite, true);
colors.rgbaMixWhite = rgbaMixWhite;
if (options.allMixDetails) {
rgbaMixBlack.WCAG2Ratio = _getWCAG2Ratio(rgbaMixBlack[luminance], 0);
rgbaMixWhite.WCAG2Ratio = _getWCAG2Ratio(rgbaMixWhite[luminance], 1);
if (options.customBG) {
rgbaMixCustom = _mixColors(rgb, options.customBG, alpha, 1);
rgbaMixCustom[luminance] = _getLuminance(rgbaMixCustom, true);
rgbaMixCustom.WCAG2Ratio = _getWCAG2Ratio(rgbaMixCustom[luminance], options.customBG[luminance]);
colors.rgbaMixCustom = rgbaMixCustom;
}
rgbaMixBG = _mixColors(rgb, background.rgb, alpha, background.alpha);
rgbaMixBG[luminance] = _getLuminance(rgbaMixBG, true); // ?? do we need this?
colors.rgbaMixBG = rgbaMixBG;
rgbaMixBGMixBlack = _mixColors(rgb, background.rgbaMixBlack, alpha, 1);
rgbaMixBGMixBlack[luminance] = _getLuminance(rgbaMixBGMixBlack, true);
rgbaMixBGMixBlack.WCAG2Ratio = _getWCAG2Ratio(rgbaMixBGMixBlack[luminance],
background.rgbaMixBlack[luminance]);
/* ------ */
rgbaMixBGMixBlack.luminanceDelta = _Math.abs(
rgbaMixBGMixBlack[luminance] - background.rgbaMixBlack[luminance]);
rgbaMixBGMixBlack.hueDelta = _getHueDelta(background.rgbaMixBlack, rgbaMixBGMixBlack, true);
/* ------ */
colors.rgbaMixBGMixBlack = rgbaMixBGMixBlack;
rgbaMixBGMixWhite = _mixColors(rgb, background.rgbaMixWhite, alpha, 1);
rgbaMixBGMixWhite[luminance] = _getLuminance(rgbaMixBGMixWhite, true);
rgbaMixBGMixWhite.WCAG2Ratio = _getWCAG2Ratio(rgbaMixBGMixWhite[luminance],
background.rgbaMixWhite[luminance]);
/* ------ */
rgbaMixBGMixWhite.luminanceDelta = _Math.abs(
rgbaMixBGMixWhite[luminance] - background.rgbaMixWhite[luminance]);
rgbaMixBGMixWhite.hueDelta = _getHueDelta(background.rgbaMixWhite, rgbaMixBGMixWhite, true);
/* ------ */
colors.rgbaMixBGMixWhite = rgbaMixBGMixWhite;
}
if (options.customBG) {
rgbaMixBGMixCustom = _mixColors(rgb, background.rgbaMixCustom, alpha, 1);
rgbaMixBGMixCustom[luminance] = _getLuminance(rgbaMixBGMixCustom, true);
rgbaMixBGMixCustom.WCAG2Ratio = _getWCAG2Ratio(rgbaMixBGMixCustom[luminance],
background.rgbaMixCustom[luminance]);
colors.rgbaMixBGMixCustom = rgbaMixBGMixCustom;
/* ------ */
rgbaMixBGMixCustom.luminanceDelta = _Math.abs(
rgbaMixBGMixCustom[luminance] - background.rgbaMixCustom[luminance]);
rgbaMixBGMixCustom.hueDelta = _getHueDelta(background.rgbaMixCustom, rgbaMixBGMixCustom, true);
/* ------ */
}
colors.RGBLuminance = _getLuminance(RGB);
colors.HUELuminance = _getLuminance(colors.hueRGB);
// renderVars.readyToRender = true;
if (options.convertCallback) {
options.convertCallback(colors, type); //, convert); //, _mode);
}
// console.timeEnd('convertColors')
// if (colorObj)
return colors;
}
// ------------------------------------------------------ //
// ------------------ color conversion ------------------ //
// -------------------------------------------------------//
var ColorConverter = {
txt2color: function(txt) {
var color = {},
parts = txt.replace(/(?:#|\)|%)/g, '').split('('),
values = (parts[1] || '').split(/,\s*/),
type = parts[1] ? parts[0].substr(0, 3) : 'rgb',
m = '';
color.type = type;
color[type] = {};
if (parts[1]) {
for (var n = 3; n--; ) {
m = type[n] || type.charAt(n); // IE7
color[type][m] = +values[n] / _valueRanges[type][m][1];
}
} else {
color.rgb = ColorConverter.HEX2rgb(parts[0]);
}
// color.color = color[type];
color.alpha = values[3] ? +values[3] : 1;
return color;
},
RGB2HEX: function(RGB) {
return (
(RGB.r < 16 ? '0' : '') + RGB.r.toString(16) +
(RGB.g < 16 ? '0' : '') + RGB.g.toString(16) +
(RGB.b < 16 ? '0' : '') + RGB.b.toString(16)
).toUpperCase();
},
HEX2rgb: function(HEX) {
var _parseInt = _parseint;
HEX = HEX.split(''); // IE7
return {
r: _parseInt(HEX[0] + HEX[HEX[3] ? 1 : 0], 16) / 255,
g: _parseInt(HEX[HEX[3] ? 2 : 1] + (HEX[3] || HEX[1]), 16) / 255,
b: _parseInt((HEX[4] || HEX[2]) + (HEX[5] || HEX[2]), 16) / 255
};
},
hue2RGB: function(hue) {
var _Math = _math,
h = hue * 6,
mod = ~~h % 6, // Math.floor(h) -> faster in most browsers
i = h === 6 ? 0 : (h - mod);
return {
r: _Math.round([1, 1 - i, 0, 0, i, 1][mod] * 255),
g: _Math.round([i, 1, 1, 1 - i, 0, 0][mod] * 255),
b: _Math.round([0, 0, i, 1, 1, 1 - i][mod] * 255)
};
},
// ------------------------ HSV ------------------------ //
rgb2hsv: function(rgb) { // faster
var _Math = _math,
r = rgb.r,
g = rgb.g,
b = rgb.b,
k = 0, chroma, min, s;
if (g < b) {
g = b + (b = g, 0);
k = -1;
}
min = b;
if (r < g) {
r = g + (g = r, 0);
k = -2 / 6 - k;
min = _Math.min(g, b); // g < b ? g : b; ???
}
chroma = r - min;
s = r ? (chroma / r) : 0;
return {
h: s < 1e-15 ? ((_colors && _colors.hsl && _colors.hsl.h) || 0) :
chroma ? _Math.abs(k + (g - b) / (6 * chroma)) : 0,
s: r ? (chroma / r) : ((_colors && _colors.hsv && _colors.hsv.s) || 0), // ??_colors.hsv.s || 0
v: r
};
},
hsv2rgb: function(hsv) {
var h = hsv.h * 6,
s = hsv.s,
v = hsv.v,
i = ~~h, // Math.floor(h) -> faster in most browsers
f = h - i,
p = v * (1 - s),
q = v * (1 - f * s),
t = v * (1 - (1 - f) * s),
mod = i % 6;
return {
r: [v, q, p, p, t, v][mod],
g: [t, v, v, q, p, p][mod],
b: [p, p, t, v, v, q][mod]
};
},
// ------------------------ HSL ------------------------ //
hsv2hsl: function(hsv) {
var l = (2 - hsv.s) * hsv.v,
s = hsv.s * hsv.v;
s = !hsv.s ? 0 : l < 1 ? (l ? s / l : 0) : s / (2 - l);
return {
h: hsv.h,
s: !hsv.v && !s ? ((_colors && _colors.hsl && _colors.hsl.s) || 0) : s, // ???
l: l / 2
};
},
rgb2hsl: function(rgb, dependent) { // not used in Color
var hsv = ColorConverter.rgb2hsv(rgb);
return ColorConverter.hsv2hsl(dependent ? hsv : (_colors.hsv = hsv));
},
hsl2rgb: function(hsl) {
var h = hsl.h * 6,
s = hsl.s,
l = hsl.l,
v = l < 0.5 ? l * (1 + s) : (l + s) - (s * l),
m = l + l - v,
sv = v ? ((v - m) / v) : 0,
sextant = ~~h, // Math.floor(h) -> faster in most browsers
fract = h - sextant,
vsf = v * sv * fract,
t = m + vsf,
q = v - vsf,
mod = sextant % 6;
return {
r: [v, q, m, m, t, v][mod],
g: [t, v, v, q, m, m][mod],
b: [m, m, t, v, v, q][mod]
};
},
// ------------------------ CMYK ------------------------ //
// Quote from Wikipedia:
// "Since RGB and CMYK spaces are both device-dependent spaces, there is no
// simple or general conversion formula that converts between them.
// Conversions are generally done through color management systems, using
// color profiles that describe the spaces being converted. Nevertheless, the
// conversions cannot be exact, since these spaces have very different gamuts."
// Translation: the following are just simple RGB to CMY(K) and visa versa conversion functions.
rgb2cmy: function(rgb) {
return {
c: 1 - rgb.r,
m: 1 - rgb.g,
y: 1 - rgb.b
};
},
cmy2cmyk: function(cmy) {
var _Math = _math,
k = _Math.min(_Math.min(cmy.c, cmy.m), cmy.y),
t = 1 - k || 1e-20;
return { // regular
c: (cmy.c - k) / t,
m: (cmy.m - k) / t,
y: (cmy.y - k) / t,
k: k
};
},
cmyk2cmy: function(cmyk) {
var k = cmyk.k;
return { // regular
c: cmyk.c * (1 - k) + k,
m: cmyk.m * (1 - k) + k,
y: cmyk.y * (1 - k) + k
};
},
cmy2rgb: function(cmy) {
return {
r: 1 - cmy.c,
g: 1 - cmy.m,
b: 1 - cmy.y
};
},
rgb2cmyk: function(rgb, dependent) {
var cmy = ColorConverter.rgb2cmy(rgb); // doppelt??
return ColorConverter.cmy2cmyk(dependent ? cmy : (_colors.cmy = cmy));
},
cmyk2rgb: function(cmyk, dependent) {
var cmy = ColorConverter.cmyk2cmy(cmyk); // doppelt??
return ColorConverter.cmy2rgb(dependent ? cmy : (_colors.cmy = cmy));
},
// ------------------------ LAB ------------------------ //
XYZ2rgb: function(XYZ, skip) {
var _Math = _math,
M = _instance.options.XYZMatrix,
X = XYZ.X,
Y = XYZ.Y,
Z = XYZ.Z,
r = X * M.R[0] + Y * M.R[1] + Z * M.R[2],
g = X * M.G[0] + Y * M.G[1] + Z * M.G[2],
b = X * M.B[0] + Y * M.B[1] + Z * M.B[2],
N = 1 / 2.4;
M = 0.0031308;
r = (r > M ? 1.055 * _Math.pow(r, N) - 0.055 : 12.92 * r);
g = (g > M ? 1.055 * _Math.pow(g, N) - 0.055 : 12.92 * g);
b = (b > M ? 1.055 * _Math.pow(b, N) - 0.055 : 12.92 * b);
if (!skip) { // out of gammut
_colors._rgb = {r: r, g: g, b: b};
}
return {
r: limitValue(r, 0, 1),
g: limitValue(g, 0, 1),
b: limitValue(b, 0, 1)
};
},
rgb2XYZ: function(rgb) {
var _Math = _math,
M = _instance.options.XYZMatrix,
r = rgb.r,
g = rgb.g,
b = rgb.b,
N = 0.04045;
r = (r > N ? _Math.pow((r + 0.055) / 1.055, 2.4) : r / 12.92);
g = (g > N ? _Math.pow((g + 0.055) / 1.055, 2.4) : g / 12.92);
b = (b > N ? _Math.pow((b + 0.055) / 1.055, 2.4) : b / 12.92);
return {
X: r * M.X[0] + g * M.X[1] + b * M.X[2],
Y: r * M.Y[0] + g * M.Y[1] + b * M.Y[2],
Z: r * M.Z[0] + g * M.Z[1] + b * M.Z[2]
};
},
XYZ2Lab: function(XYZ) {
var _Math = _math,
R = _instance.options.XYZReference,
X = XYZ.X / R.X,
Y = XYZ.Y / R.Y,
Z = XYZ.Z / R.Z,
N = 16 / 116, M = 1 / 3, K = 0.008856, L = 7.787037;
X = X > K ? _Math.pow(X, M) : (L * X) + N;
Y = Y > K ? _Math.pow(Y, M) : (L * Y) + N;
Z = Z > K ? _Math.pow(Z, M) : (L * Z) + N;
return {
L: (116 * Y) - 16,
a: 500 * (X - Y),
b: 200 * (Y - Z)
};
},
Lab2XYZ: function(Lab) {
var _Math = _math,
R = _instance.options.XYZReference,
Y = (Lab.L + 16) / 116,
X = Lab.a / 500 + Y,
Z = Y - Lab.b / 200,
X3 = _Math.pow(X, 3),
Y3 = _Math.pow(Y, 3),
Z3 = _Math.pow(Z, 3),
N = 16 / 116, K = 0.008856, L = 7.787037;
return {
X: (X3 > K ? X3 : (X - N) / L) * R.X,
Y: (Y3 > K ? Y3 : (Y - N) / L) * R.Y,
Z: (Z3 > K ? Z3 : (Z - N) / L) * R.Z
};
},
rgb2Lab: function(rgb, dependent) {
var XYZ = ColorConverter.rgb2XYZ(rgb);
return ColorConverter.XYZ2Lab(dependent ? XYZ : (_colors.XYZ = XYZ));
},
Lab2rgb: function(Lab, dependent) {
var XYZ = ColorConverter.Lab2XYZ(Lab);
return ColorConverter.XYZ2rgb(dependent ? XYZ : (_colors.XYZ = XYZ), dependent);
}
};
// ------------------------------------------------------ //
// ------------------ helper functions ------------------ //
// -------------------------------------------------------//
function getClosestWebColor(RGB, val) {
var out = {},
tmp = 0,
half = val / 2;
for (var n in RGB) {
tmp = RGB[n] % val; // 51 = 'web save', 17 = 'web smart'
out[n] = RGB[n] + (tmp > half ? val - tmp : -tmp);
}
return out;
}
function getHueDelta(rgb1, rgb2, nominal) {
var _Math = _math;
return (_Math.max(rgb1.r - rgb2.r, rgb2.r - rgb1.r) +
_Math.max(rgb1.g - rgb2.g, rgb2.g - rgb1.g) +
_Math.max(rgb1.b - rgb2.b, rgb2.b - rgb1.b)) * (nominal ? 255 : 1) / 765;
}
function getLuminance(rgb, normalized) {
var div = normalized ? 1 : 255,
RGB = [rgb.r / div, rgb.g / div, rgb.b / div],
luminance = _instance.options.luminance;
for (var i = RGB.length; i--; ) {
RGB[i] = RGB[i] <= 0.03928 ? RGB[i] / 12.92 : _math.pow(((RGB[i] + 0.055) / 1.055), 2.4);
}
return ((luminance.r * RGB[0]) + (luminance.g * RGB[1]) + (luminance.b * RGB[2]));
}
function mixColors(topColor, bottomColor, topAlpha, bottomAlpha) {
var newColor = {},
alphaTop = (topAlpha !== undefined ? topAlpha : 1),
alphaBottom = (bottomAlpha !== undefined ? bottomAlpha : 1),
alpha = alphaTop + alphaBottom * (1 - alphaTop); // 1 - (1 - alphaTop) * (1 - alphaBottom);
for(var n in topColor) {
newColor[n] = (topColor[n] * alphaTop + bottomColor[n] * alphaBottom * (1 - alphaTop)) / alpha;
}
newColor.a = alpha;
return newColor;
}
function getWCAG2Ratio(lum1, lum2) {
var ratio = 1;
if (lum1 >= lum2) {
ratio = (lum1 + 0.05) / (lum2 + 0.05);
} else {
ratio = (lum2 + 0.05) / (lum1 + 0.05);
}
return _math.round(ratio * 100) / 100;
}
function limitValue(value, min, max) {
// return Math.max(min, Math.min(max, value)); // faster??
return (value > max ? max : value < min ? min : value);
}
})(window);