RGB <-> HSV conversion

rgb-hsv.js

	// input: h in [0,360] and s,v in [0,1]
	// output: r,g,b in [0,1]
	hsv2rgb(h,s,v) {
		const f= (n,k=(n+h/60)%6) => v - v*s*Math.max( Math.min(k,4-k,1), 0);
		return [f(5),f(3),f(1)];
	}

	// input: r,g,b in [0,1]
	// output: h in [0,360) and s,v in [0,1]
	rgb2hsv(r,g,b) {
		let v=Math.max(r,g,b), c=v-Math.min(r,g,b);
		let h= c && ((v==r) ? (g-b)/c : ((v==g) ? 2+(b-r)/c : 4+(r-g)/c)); 
		return [60*(h<0?h+6:h), v&&c/v, v];
	}