GLSL HSB to RGB function

I'm sure it could be optimized, but here it is..



vec3 HSBToRGB(vec3 colorIn)
{

float h=colorIn.x;
float sl=colorIn.y;
float l=colorIn.z;

float v;
float r,g,b;

r = l; // default to gray
g = l;
b = l;

v = (l <= 0.5) ? (l * (1.0 + sl)) : (l + sl - l * sl);

if (v > 0.0)
{

float m;
float sv;
int sextant;
float frac, vsf, mid1, mid2;


m = l + l - v;
sv = (v - m ) / v;
h *= 6.0;
sextant = int(h);
frac = h - float(sextant);
vsf = v * sv * frac;
mid1 = m + vsf;
mid2 = v - vsf;

if(sextant==0)
{
r = v;
g = mid1;
b = m;
}
else if(sextant==1)
{
r = mid2;
g = v;
b = m;
}
else if(sextant==2)
{
r = m;
g = v;
b = mid1;
}
else if(sextant==3)
{
r = m;
g = mid2;
b = v;
}
else if(sextant==4)
{
r = mid1;
g = m;
b = v;
}
else if(sextant==5)
{
r = v;
g = m;
b = mid2;
}

}

vec3 rgb;

rgb.r = r;
rgb.g = g;
rgb.b = b;

return rgb;

}