CONVERTISSEUR DE RGB <-> TSL

// JScript source code
//Red : 0..255
//Green : 0..255
//Blue : 0..255
//Hue : 0,0..360,0<=>0..255
//Lum : 0,0..1,0<=>0..255
//Sat : 0,0..1,0<=>0..255

//Retourne un tableau de 3 valeurs : H,S,L
function RGB2HSL (r, g, b)
{
	red = Math.round (r);
	green = Math.round (g);
	blue = Math.round (b);
	var minval = Math.min (red, Math.min (green, blue));
	var maxval = Math.max (red, Math.max (green, blue));
	var mdiff = maxval - minval + 0.0;
	var msum = maxval + minval + 0.0;
	var luminance = msum / 510.0;
	var saturation;
	var hue;
	if (maxval == minval)
	{
		saturation = 0.0;
		hue = 0.0;
	}
	else
	{
		var rnorm = (maxval - red) / mdiff;
		var gnorm = (maxval - green) / mdiff;
		var bnorm = (maxval - blue) / mdiff;
		saturation = (luminance <= 0.5) ? (mdiff / msum) : (mdiff / (510.0 - msum));
		if (red == maxval)
			hue = 60.0 * (6.0 + bnorm - gnorm);
		if (green == maxval)
			hue = 60.0 * (2.0 + rnorm - bnorm);
		if (blue == maxval)
			hue = 60.0 * (4.0 + gnorm - rnorm);
		if (hue > 360.0)
			hue -= 360.0;
	}
	return new Array (Math.round (hue * 255.0 / 360.0), Math.round (saturation * 255.0), Math.round (luminance * 255.0));
}

function Magic (rm1, rm2, rh)
{
	var retval = rm1;
	if (rh > 360.0)
		rh -= 360.0;
	if (rh < 0.0)
		rh += 360.0;
	if (rh < 60.0)
		retval = rm1 + (rm2 - rm1) * rh / 60.0;
	else if (rh < 180.0)
		retval = rm2;
	else if (rh < 240.0)
		retval = rm1 + (rm2 - rm1) * (240.0 - rh) / 60.0;
	return Math.round (retval * 255);
}

//Retourne un tableau de 3 valeurs : R,G,B
function HSL2RGB (h, s, l)
{
	var hue = h * 360.0 / 255.0;
	var saturation = s / 255.0;
	var luminance = l / 255.0;
	var red;
	var green;
	var blue;
	if (saturation == 0.0)
	{
		red = green = blue = Math.round (luminance * 255.0);
	}
	else
	{
		var rm1;
		var rm2;
		if (luminance <= 0.5)
			rm2 = luminance + luminance * saturation;
		else
			rm2 = luminance + saturation - luminance * saturation;
		rm1 = 2.0 * luminance - rm2;
		red = Magic (rm1, rm2, hue + 120.0);
		green = Magic (rm1, rm2, hue);
		blue = Magic (rm1, rm2, hue - 120.0);
	}
	return new Array (red, green, blue);
}