oxjs/source/Ox/js/Color.js

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JavaScript

/*@
Ox.hsl <f> Takes RGB values and returns HSL values
(rgb) <[n]> HSL values
(r, g, b) <[n]> HSL values
rgb <[n]> RGB values
r <n> red
g <n> green
b <n> blue
> Ox.hsl([0, 0, 0])
[0, 0, 0]
> Ox.hsl([255, 255, 255])
[0, 0, 1]
> Ox.hsl(0, 255, 0)
[120, 1, 0.5]
@*/
Ox.hsl = function(rgb) {
if (arguments.length == 3) {
rgb = Ox.makeArray(arguments);
}
rgb = rgb.map(function(val) {
return val / 255;
});
var max = Ox.max(rgb),
min = Ox.min(rgb),
hsl = [0, 0, 0];
hsl[2] = 0.5 * (max + min);
if (max == min) {
hsl[0] = 0;
hsl[1] = 0;
} else {
if (max == rgb[0]) {
hsl[0] = (60 * (rgb[1] - rgb[2]) / (max - min) + 360) % 360;
} else if (max == rgb[1]) {
hsl[0] = 60 * (rgb[2] - rgb[0]) / (max - min) + 120;
} else if (max == rgb[2]) {
hsl[0] = 60 * (rgb[0] - rgb[1]) / (max - min) + 240;
}
if (hsl[2] <= 0.5) {
hsl[1] = (max - min) / (2 * hsl[2]);
} else {
hsl[1] = (max - min) / (2 - 2 * hsl[2]);
}
}
return hsl;
};
/*@
Ox.rgb <f> Takes HSL values and returns RGB values
(hsl) <[n]> RGB values
(h, s, l) <[n]> RGB values
hsl <[n]> HSL values
h <n> hue
s <n> saturation
l <n> lightness
> Ox.rgb([0, 0, 0])
[0, 0, 0]
> Ox.rgb([0, 0, 1])
[255, 255, 255]
> Ox.rgb(120, 1, 0.5)
[0, 255, 0]
@*/
Ox.rgb = function(hsl) {
if (arguments.length == 3) {
hsl = Ox.makeArray(arguments);
}
hsl[0] /= 360;
var rgb = [0, 0, 0],
v1, v2, v3;
if (hsl[1] == 0) {
rgb = [hsl[2], hsl[2], hsl[2]];
} else {
if (hsl[2] < 0.5) {
v2 = hsl[2] * (1 + hsl[1]);
} else {
v2 = hsl[1] + hsl[2] - (hsl[1] * hsl[2]);
}
v1 = 2 * hsl[2] - v2;
rgb.forEach(function(v, i) {
v3 = hsl[0] + (1 - i) * 1/3;
if (v3 < 0) {
v3++;
} else if (v3 > 1) {
v3--;
}
if (v3 < 1/6) {
rgb[i] = v1 + ((v2 - v1) * 6 * v3);
} else if (v3 < 0.5) {
rgb[i] = v2;
} else if (v3 < 2/3) {
rgb[i] = v1 + ((v2 - v1) * 6 * (2/3 - v3));
} else {
rgb[i] = v1;
}
});
}
return rgb.map(function(v) {
return v * 255;
});
};