JAVASCRIPT

hsv to rgb js

const err = Object.freeze(["Invalid param"]);
class CLR {
    HSV_RGB(hue, sat, val){
		//gaurd
		if(!this.equal([typeof(hue), typeof(sat), typeof(val), "number"]) || !this.range(sat, 0, 1, true) || !this.range(val, 0, 1, true) || !this.range(hue, 0, 360, true))
			throw err[0];

		//imp vars
		let chr = val * sat;
		let hue_p = hue / 60;
		let m = val - chr;
		let x = chr * (1 - this.abs(hue_p % 2 - 1))
		//return value
		var temp;
		//processing
		switch(true) {
			case this.range(hue_p, 0, 1, false) || (hue_p == 0):
				temp = {red: chr, green: x, blue: 0};
				break;
			case this.range(hue_p, 1, 2, false) || (hue_p == 1):
				temp = {red: x, green: chr, blue: 0};
				break;
			case this.range(hue_p, 2, 3, false) || (hue_p == 2):
				temp = {red: 0, green: chr, blue: chr};
				break;
			case this.range(hue_p, 3, 4, false) || (hue_p == 3):
				temp = {red: 0, green: x, blue: chr};
				break;
			case this.range(hue_p, 4, 5, false) || (hue_p == 4):
				temp = {red: x, green: 0, blue: chr};
				break;
			case this.range(hue_p, 5, 6, false) || (hue_p == 5):
				temp = {red: chr, green: 0, blue: x};
				break;
		}

		return {red: (temp.red + m) * 255, green: (temp.green + m) * 255, blue: (temp.blue + m) * 255};
		//parseInt(number, 10).toString(base) change base
	}

	//return absolute value
	abs(val){
		//gaurd
		if(typeof(val) != "number")
			throw err[0];

		if(val < 0)
			return -val;
		else
			return val;
	}

	//check whether all values are in range
	range(val, l_bnd, u_bnd, inclusive){
		if(inclusive) {
			if(val <= u_bnd && val >= l_bnd)
				return true;
		}else {
			if(val < u_bnd && val > l_bnd)
				return true;
		}
		return false;
	}

	//check whether elements of array are all equal
	equal(arr){
		for(let i = 1; i < arr.length; i++)
			if(arr[i] != arr[0])
				return false;
		return true;
	}
}
let colour = new CLR();
//console.log(colour.equal([typeof(250), typeof(0.5), typeof(0.3), "number"]))
console.log(colour.HSV_RGB(250, 0.5, 0.3));