public static XMVector RgbToHsv(XMVector rgb)
{
XMVector r = XMVector.SplatX(rgb);
XMVector g = XMVector.SplatY(rgb);
XMVector b = XMVector.SplatZ(rgb);
XMVector min = XMVector.Min(r, XMVector.Min(g, b));
XMVector v = XMVector.Max(r, XMVector.Max(g, b));
XMVector d = XMVector.Subtract(v, min);
XMVector s = XMVector3.NearEqual(v, XMGlobalConstants.Zero, XMGlobalConstants.Epsilon) ?
XMGlobalConstants.Zero :
XMVector.Divide(d, v);
if (XMVector3.Less(d, XMGlobalConstants.Epsilon))
{
// Achromatic, assume H of 0
XMVector hv = XMVector.Select(v, XMGlobalConstants.Zero, XMGlobalConstants.Select1000);
XMVector hva = XMVector.Select(rgb, hv, XMGlobalConstants.Select1110);
return(XMVector.Select(s, hva, XMGlobalConstants.Select1011));
}
else
{
XMVector h;
if (XMVector3.Equal(r, v))
{
// Red is max
h = XMVector.Divide(XMVector.Subtract(g, b), d);
if (XMVector3.Less(g, b))
{
h = XMVector.Add(h, XMGlobalConstants.Six);
}
}
else if (XMVector3.Equal(g, v))
{
// Green is max
h = XMVector.Divide(XMVector.Subtract(b, r), d);
h = XMVector.Add(h, XMGlobalConstants.Two);
}
else
{
// Blue is max
h = XMVector.Divide(XMVector.Subtract(r, g), d);
h = XMVector.Add(h, XMGlobalConstants.Four);
}
h = XMVector.Divide(h, XMGlobalConstants.Six);
XMVector hv = XMVector.Select(v, h, XMGlobalConstants.Select1000);
XMVector hva = XMVector.Select(rgb, hv, XMGlobalConstants.Select1110);
return(XMVector.Select(s, hva, XMGlobalConstants.Select1011));
}
}
public static XMVector HslToRgb(XMVector hsl)
{
XMVector oneThird = XMVector.FromFloat(1.0f / 3.0f, 1.0f / 3.0f, 1.0f / 3.0f, 1.0f / 3.0f);
XMVector s = XMVector.SplatY(hsl);
XMVector l = XMVector.SplatZ(hsl);
if (XMVector3.NearEqual(s, XMGlobalConstants.Zero, XMGlobalConstants.Epsilon))
{
// Achromatic
return(XMVector.Select(hsl, l, XMGlobalConstants.Select1110));
}
else
{
XMVector h = XMVector.SplatX(hsl);
XMVector q;
if (XMVector3.Less(l, XMGlobalConstants.OneHalf))
{
q = XMVector.Multiply(l, XMVector.Add(XMGlobalConstants.One, s));
}
else
{
q = XMVector.Subtract(XMVector.Add(l, s), XMVector.Multiply(l, s));
}
XMVector p = XMVector.Subtract(XMVector.Multiply(XMGlobalConstants.Two, l), q);
XMVector r = XMColor.HueToClr(p, q, XMVector.Add(h, oneThird));
XMVector g = XMColor.HueToClr(p, q, h);
XMVector b = XMColor.HueToClr(p, q, XMVector.Subtract(h, oneThird));
XMVector rg = XMVector.Select(g, r, XMGlobalConstants.Select1000);
XMVector ba = XMVector.Select(hsl, b, XMGlobalConstants.Select1110);
return(XMVector.Select(ba, rg, XMGlobalConstants.Select1100));
}
}
