three.js/examples/js/math/ColorConverter.js

( function () {

	const _hsl = {};

	class ColorConverter {

		static setHSV( color, h, s, v ) {

			// https://gist.github.com/xpansive/1337890#file-index-js
			h = THREE.MathUtils.euclideanModulo( h, 1 );
			s = THREE.MathUtils.clamp( s, 0, 1 );
			v = THREE.MathUtils.clamp( v, 0, 1 );
			return color.setHSL( h, s * v / ( ( h = ( 2 - s ) * v ) < 1 ? h : 2 - h ), h * 0.5 );

		}

		static getHSV( color, target ) {

			if ( target === undefined ) {

				console.warn( 'THREE.ColorConverter: .getHSV() target is now required' );
				target = {
					h: 0,
					s: 0,
					l: 0
				};

			}

			color.getHSL( _hsl ); // based on https://gist.github.com/xpansive/1337890#file-index-js

			_hsl.s *= _hsl.l < 0.5 ? _hsl.l : 1 - _hsl.l;
			target.h = _hsl.h;
			target.s = 2 * _hsl.s / ( _hsl.l + _hsl.s );
			target.v = _hsl.l + _hsl.s;
			return target;

		} // where c, m, y, k is between 0 and 1


		static setCMYK( color, c, m, y, k ) {

			const r = ( 1 - c ) * ( 1 - k );
			const g = ( 1 - m ) * ( 1 - k );
			const b = ( 1 - y ) * ( 1 - k );
			return color.setRGB( r, g, b );

		}

		static getCMYK( color, target ) {

			if ( target === undefined ) {

				console.warn( 'THREE.ColorConverter: .getCMYK() target is now required' );
				target = {
					c: 0,
					m: 0,
					y: 0,
					k: 0
				};

			}

			const r = color.r;
			const g = color.g;
			const b = color.b;
			const k = 1 - Math.max( r, g, b );
			const c = ( 1 - r - k ) / ( 1 - k );
			const m = ( 1 - g - k ) / ( 1 - k );
			const y = ( 1 - b - k ) / ( 1 - k );
			target.c = c;
			target.m = m;
			target.y = y;
			target.k = k;
			return target;

		}

	}

	THREE.ColorConverter = ColorConverter;

} )();