private void updateCachedVars()
{
CosPhi = (float)Math.Cos(m_phi);
SinPhi = (float)Math.Sin(m_phi);
SinPhiShift = (float)Math.Sin(m_phi + Offset);
CosPhiShift = (float)Math.Cos(m_phi + Offset);
CosRho = (float)Math.Cos(m_rho);
SinRho = (float)Math.Sin(m_rho);
// update top
ILPoint3Df top = ILPoint3Df.normalize(-SinPhi * CosRho, CosPhi * CosRho, SinRho);
m_topX = top.X;
m_topY = top.Y;
m_topZ = top.Z;
computeQuadrant();
}
/// <summary>
/// rotate the vector, keep length
/// </summary>
/// <param name="normal">axis as rotation normal</param>
/// <param name="angleDeg">angle to move (radian)</param>
/// <returns>rotated version of this vector, does not change original vector</returns>
public ILPoint3Df Spin(ILPoint3Df normal, float angleDeg)
{
float a = angleDeg * (float)Math.PI / 180f;
float cosa = (float)Math.Cos(a);
float sina = (float)Math.Sin(a);
normal = ILPoint3Df.normalize(normal);
float omincosa = 1 - cosa;
ILPoint3Df ret = new ILPoint3Df(
(cosa + X * X * omincosa) * normal.X
+ (X * Y * omincosa - Z * sina) * normal.Y
+ (X * Z * omincosa + Y * sina) * normal.Z,
(Y * X * omincosa + Z * sina) * normal.X
+ (cosa + Y * Y * omincosa) * normal.Y
+ (Y * Z * omincosa - X * sina) * normal.Z,
(Z * X * omincosa - Y * sina) * normal.X
+ (Z * Y * omincosa + X * sina) * normal.Y
+ (cosa + Z * Z * omincosa) * normal.Z);
return(ret);
}
