public static XMVector RotationAxis(XMVector axis, float angle)
{
Debug.Assert(!XMVector3.Equal(axis, XMGlobalConstants.Zero), "Reviewed");
Debug.Assert(!XMVector3.IsInfinite(axis), "Reviewed");
XMVector normal = XMVector3.Normalize(axis);
return(XMQuaternion.RotationNormal(normal, angle));
}
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 RgbToHsl(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 max = XMVector.Max(r, XMVector.Max(g, b));
XMVector l = XMVector.Multiply(XMVector.Add(min, max), XMGlobalConstants.OneHalf);
XMVector d = XMVector.Subtract(max, min);
XMVector la = XMVector.Select(rgb, l, XMGlobalConstants.Select1110);
if (XMVector3.Less(d, XMGlobalConstants.Epsilon))
{
// Achromatic, assume H and S of 0
return(XMVector.Select(la, XMGlobalConstants.Zero, XMGlobalConstants.Select1100));
}
else
{
XMVector s;
XMVector h;
XMVector d2 = XMVector.Add(min, max);
if (XMVector3.Greater(l, XMGlobalConstants.OneHalf))
{
// d / (2-max-min)
s = XMVector.Divide(d, XMVector.Subtract(XMGlobalConstants.Two, d2));
}
else
{
// d / (max+min)
s = XMVector.Divide(d, d2);
}
if (XMVector3.Equal(r, max))
{
// Red is max
h = XMVector.Divide(XMVector.Subtract(g, b), d);
}
else if (XMVector3.Equal(g, max))
{
// 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);
if (XMVector3.Less(h, XMGlobalConstants.Zero))
{
h = XMVector.Add(h, XMGlobalConstants.One);
}
XMVector lha = XMVector.Select(la, h, XMGlobalConstants.Select1100);
return(XMVector.Select(s, lha, XMGlobalConstants.Select1011));
}
}
