HSL To RGB

This algorithm converts HSL color model to RGB color model.

• C#
• VB.Net
• C
• C++
• PHP

									struct RGB
{
	unsigned char R;
	unsigned char G;
	unsigned char B;
};

struct HSL
{
	int H;
	float S;
	float L;
};

float HueToRGB(float v1, float v2, float vH)
{
	if (vH < 0)
		vH += 1;

	if (vH > 1)
		vH -= 1;

	if ((6 * vH) < 1)
		return (v1 + (v2 - v1) * 6 * vH);

	if ((2 * vH) < 1)
		return v2;

	if ((3 * vH) < 2)
		return (v1 + (v2 - v1) * ((2.0f / 3) - vH) * 6);

	return v1;
}

struct RGB HSLToRGB(struct HSL hsl) {
	struct RGB rgb;

	if (hsl.S == 0)
	{
		rgb.R = rgb.G = rgb.B = (unsigned char)(hsl.L * 255);
	}
	else
	{
		float v1, v2;
		float hue = (float)hsl.H / 360;

		v2 = (hsl.L < 0.5) ? (hsl.L * (1 + hsl.S)) : ((hsl.L + hsl.S) - (hsl.L * hsl.S));
		v1 = 2 * hsl.L - v2;

		rgb.R = (unsigned char)(255 * HueToRGB(v1, v2, hue + (1.0f / 3)));
		rgb.G = (unsigned char)(255 * HueToRGB(v1, v2, hue));
		rgb.B = (unsigned char)(255 * HueToRGB(v1, v2, hue - (1.0f / 3)));
	}

	return rgb;
}
								

Example

									struct HSL data = { 138, 0.50f, 0.76f };
struct RGB value = HSLToRGB(data);
								

Output

									R: 163
G: 224
B: 181