GameProgrammerArt

Math

C/C++

pixeltype HSLtoRGB(pixeltype palette_color){
	//0.0f <= h <  360.0f
	//0.0f <= s <= 1.0f
	//0.0f <= l <= 1.0f
	double h = (double)(HUE_OF(palette_color));
    double s = (double)(SATURATION_OF(palette_color));
    double l = (double)(LIGHTNESS_OF(palette_color));
	double q, p, h_k;
	double rgb[3];

	if(l < 0.5f){
		q = l * (1 + s);
	}else{
		q = l + s - (l * s);
	}
	p = 2 * l - q;
	h_k = h / 360.0f;
	rgb[0] = h_k + (1 / 3);
	rgb[1] = h_k;
	rgb[2] = h_k - (1 / 3);
	for(size_t i = 0; i < 3; i++){
		if(rgb[i] < (1 / 6)){
			rgb[i] = p + ((q - p) * 6.0f * rgb[i]);
		}else if(rgb[i] >= (1 / 6) && rgb[i] < (1 / 2)){
			rgb[i] = q;
		}else if(rgb[i] >= (1 / 2) && rgb[i] < (2 / 3)){
			rgb[i] = p + ((q - p) * 6.0f * ((2 / 3) - rgb[i]));
		}else{
			rgb[i] = p;
		}
	}
	//0.0f <= rgb[0] <= 1.0f
	//0.0f <= rgb[1] <= 1.0f
	//0.0f <= rgb[2] <= 1.0f
	return RGB_OF(rgb[0], rgb[1], rgb[2]);
}