========== Constructors and Assignment ===================== Default constructor (identity rotation)
{ }
Construct from an angle
======== Components ============== Set given the angle.
{ SetAngle(angle); }
Get the angle
{ angle = atan2 (fSin,fCos); }
{ GetAngle(angle); }
Angle of rotation
{ return atan2 (fSin,fCos); }
Sine or Cosine of the rotation angle
{ return fSin; }
{ return fCos; }
Overload operator * for rotation on a vector
Invert a rotation in place
{ fAngle = -fAngle; fSin = -fSin; }
Return inverse of a rotation
{ RotationY t(*this); t.Invert(); return t; }
