/**
* A class representing a Color.
*
* @property {Float32Array} components A typed array storing the components of this color (rgba).
*/
Lore.Color = class Color {
/**
* Creates an instance of Color.
* @param {Number} r The red component (0.0 - 1.0).
* @param {Number} g The green component (0.0 - 1.0).
* @param {Number} b The blue component (0.0 - 1.0).
* @param {Number} a The alpha component (0.0 - 1.0).
*/
constructor(r, g, b, a) {
if (arguments.length === 1) {
this.components = new Float32Array(r);
} else {
this.components = new Float32Array(4);
this.components[0] = r || 0.0;
this.components[1] = g || 0.0;
this.components[2] = b || 0.0;
this.components[3] = a || 1.0;
}
}
/**
* Set the red, green, blue and alpha components of the color.
*
* @param {Number} r The red component (0.0 - 1.0).
* @param {Number} g The green component (0.0 - 1.0).
* @param {Number} b The blue component (0.0 - 1.0).
* @param {Number} a The alpha component (0.0 - 1.0).
* @returns {Lore.Color} Returns itself.
*/
set(r, g, b, a) {
this.components[0] = r;
this.components[1] = g;
this.components[2] = b;
if (arguments.length == 4) {
this.components[3] = a;
}
return this;
}
/**
* Set the r,g,b,a components from a hex string.
*
* @static
* @param {String} hex A hex string in the form of #ABCDEF or #ABC.
* @returns {Lore.Color} A color representing the hex string.
*/
static fromHex(hex) {
// Thanks to Tim Down
// http://stackoverflow.com/questions/5623838/rgb-to-hex-and-hex-to-rgb
let shorthandRegex = /^#?([a-f\d])([a-f\d])([a-f\d])$/i;
hex = hex.replace(shorthandRegex, function (m, r, g, b) {
return r + r + g + g + b + b;
});
let result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
let r = parseInt(result[1], 16);
let g = parseInt(result[2], 16);
let b = parseInt(result[3], 16);
return result ? new Lore.Color(r / 255.0, g / 255.0, b / 255.0, 1.0) : null;
}
/**
* Get the r, g or b value from a hue component.
*
* @static
* @param {Number} p
* @param {Number} q
* @param {Number} t
* @returns {Number} The r, g or b component value.
*/
static hueToRgb(p, q, t) {
if (t < 0) {
t += 1;
} else if (t > 1) {
t -= 1;
} else if (t < 0.1667) {
return p + (q - p) * 6 * t;
} else if (t < 0.5) {
return q;
} else if (t < 0.6667) {
return p + (q - p) * (0.6667 - t) * 6;
}
return p;
}
/**
* Converts HSL to RGB.
*
* @static
* @param {Number} h The hue component.
* @param {Number} s The saturation component.
* @param {Number} l The lightness component.
* @returns {Number[]} An array containing the r, g and b values ([r, g, b]).
*/
static hslToRgb(h, s, l) {
let r, g, b;
if (s == 0) {
r = g = b = l;
} else {
let q = l < 0.5 ? l * (1 + s) : l + s - l * s;
let p = 2 * l - q;
r = Lore.Color.hueToRgb(p, q, h + 0.3333);
g = Lore.Color.hueToRgb(p, q, h);
b = Lore.Color.hueToRgb(p, q, h - 0.3333);
}
return [r, g, b];
}
/**
* Converts RGB to HSL.
*
* @static
* @param {Number} r The red component.
* @param {Number} g The green component.
* @param {Number} b The blue component.
* @returns {Number[]} An array containing the h, s and l values ([h, s, l]).
*/
static rgbToHsl(r, g, b) {
r /= 255, g /= 255, b /= 255;
let max = Math.max(r, g, b),
min = Math.min(r, g, b);
let h, s, l = (max + min) / 2;
if (max == min) {
h = s = 0; // achromatic
} else {
let d = max - min;
s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
switch (max) {
case r:
h = (g - b) / d + (g < b ? 6 : 0);
break;
case g:
h = (b - r) / d + 2;
break;
case b:
h = (r - g) / d + 4;
break;
}
h /= 6;
}
return [h, s, l];
}
/**
* Shifts the hue so that 0.0 represents blue and 1.0 represents magenta.
*
* @static
* @param {Number} hue A hue component.
* @returns {Number} The hue component shifted so that 0.0 is blue and 1.0 is magenta.
*/
static gdbHueShift(hue) {
hue = 0.85 * hue + 0.66;
if (hue > 1.0) {
hue = hue - 1.0;
}
hue = (1 - hue) + 0.33
if (hue > 1.0) {
hue = hue - 1.0
}
return hue;
}
}