mirror of https://github.com/thangisme/notes.git
94 lines
2.9 KiB
JavaScript
94 lines
2.9 KiB
JavaScript
module.exports = function HSV(color) {
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color.installColorSpace('HSV', ['hue', 'saturation', 'value', 'alpha'], {
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rgb: function () {
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var hue = this._hue,
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saturation = this._saturation,
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value = this._value,
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i = Math.min(5, Math.floor(hue * 6)),
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f = hue * 6 - i,
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p = value * (1 - saturation),
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q = value * (1 - f * saturation),
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t = value * (1 - (1 - f) * saturation),
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red,
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green,
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blue;
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switch (i) {
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case 0:
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red = value;
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green = t;
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blue = p;
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break;
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case 1:
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red = q;
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green = value;
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blue = p;
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break;
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case 2:
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red = p;
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green = value;
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blue = t;
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break;
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case 3:
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red = p;
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green = q;
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blue = value;
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break;
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case 4:
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red = t;
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green = p;
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blue = value;
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break;
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case 5:
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red = value;
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green = p;
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blue = q;
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break;
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}
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return new color.RGB(red, green, blue, this._alpha);
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},
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hsl: function () {
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var l = (2 - this._saturation) * this._value,
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sv = this._saturation * this._value,
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svDivisor = l <= 1 ? l : (2 - l),
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saturation;
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// Avoid division by zero when lightness approaches zero:
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if (svDivisor < 1e-9) {
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saturation = 0;
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} else {
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saturation = sv / svDivisor;
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}
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return new color.HSL(this._hue, saturation, l / 2, this._alpha);
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},
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fromRgb: function () { // Becomes one.color.RGB.prototype.hsv
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var red = this._red,
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green = this._green,
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blue = this._blue,
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max = Math.max(red, green, blue),
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min = Math.min(red, green, blue),
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delta = max - min,
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hue,
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saturation = (max === 0) ? 0 : (delta / max),
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value = max;
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if (delta === 0) {
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hue = 0;
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} else {
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switch (max) {
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case red:
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hue = (green - blue) / delta / 6 + (green < blue ? 1 : 0);
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break;
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case green:
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hue = (blue - red) / delta / 6 + 1 / 3;
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break;
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case blue:
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hue = (red - green) / delta / 6 + 2 / 3;
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break;
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}
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}
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return new color.HSV(hue, saturation, value, this._alpha);
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}
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});
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};
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