Some useful color management and conversion utilities, specifically intended for use with THREE.js

rainbow-v0.0.1.js

/* Collection of useful utilities for processing and transforming color values.
*/

define(function(require, exports, module) {
    let THREE = require("lib/three-v0.115.0");

    exports.hsv2rgb = function(hsv) {
        /* Useful HSV-to-RGB conversion
        */
        let hue = hsv[0] * 360;
        let sat = hsv[1];
        let val = hsv[2];
        let chr = val * sat;
        let hue_ = hue / 60;
        let rem = chr * (1 - Math.abs(hue_ % 2 - 1));
        let rgb = [0, 0, 0];
        if (0 <= hue_ && hue_ <= 1) {
            rgb[0] = chr;
            rgb[1] = rem;
        } else if (1 <= hue_ && hue_ <= 2) {
            rgb[0] = rem;
            rgb[1] = chr;
        } else if (2 <= hue_ && hue_ <= 3) {
            rgb[1] = chr;
            rgb[2] = rem;
        } else if (3 <= hue_ && hue_ <= 4) {
            rgb[1] = rem;
            rgb[2] = chr;
        } else if (4 <= hue_ && hue_ <= 5) {
            rgb[2] = chr;
            rgb[0] = rem;
        } else if (5 <= hue_ && hue_ <= 6) {
            rgb[2] = rem;
            rgb[0] = chr;
        }
        let off = val - chr;
        return [rgb[0] + off, rgb[1] + off, rgb[2] + off];
    };

	exports.parseColor = function(integer) {
		/* Converts a 24-bit integer to a THREE.js color value
		*/
		let b = integer % 256;
		integer = (integer - b) / 256;
		let g = integer % 256;
		integer = (integer - g) / 256;
		let r = integer;
		return new THREE.Color(r / 255, g / 255, b / 255);
    };
    
    exports.three2hex = function(rgb) {
        /* Returns a hex string (with leading "#") conversion of the given
           THREE.Color object
        */
        let r = Math.round(rgb.r * 255).toString(16);
        let g = Math.round(rgb.g * 255).toString(16);
        let b = Math.round(rgb.b * 255).toString(16);
        return `#${r}${g}${b}`;
    };
	
    Object.assign(exports, {
	    "__uni__": "com.github.tythos.rainbow",
	    "__semver__": "0.0.1",
	    "__author__": "code@tythos.net",
	    "__license__": "MIT" // SPDX Identifier
    });
});