#ifndef RIGEOMETRY_H
#define RIGEOMETRY_H

#ifndef   RIVECTOR3_H
#include <RiVector3.H>
#endif



/************************************************************
 * geometry class declaration
 ************************************************************/


/***************************************************************
CLASS
    RiGeometry
     Handles general geometric queries on RiVector3 and RiVector2

DESCRIPTION
     Class to hold all support functions for geometry (ie RiVector3
     and RiVector2).  All checks for coplanarity, colinearity, non-exact
     RiVector3 equality, and other general queries that shouldn't clutter
     up RiVector3 and RiVector2 belong here.

****************************************************************/

class RiGeometry {
public:
		//// Return the index [0-2] for the minimum element of the absolute value of the vector
    static int IndexOfMinAbsComponent( const RiVector3& v );
		//// Return the index [0-2] for the maximum element of the absolute value of the vector
    static int IndexOfMaxAbsComponent( const RiVector3& v );
		//// Return a vector perpendicular to the given vector.
    static RiVector3 PerpendicularVector(const RiVector3 &v);
                //// Return the angle between two RiVectors in radians
    static RiReal AngleBetweenVectors(const RiVector3& v1, const RiVector3& v2);

                //// returns reflection of a with respect to n
    static RiVector3 Reflect( const RiVector3& a, const RiVector3& n );
                //// returns unit reflection of unit  a with respect to unit n
    static RiUnitVector3 UnitReflect( const RiUnitVector3& a, const RiUnitVector3& n );
                //// returns unit vector v in direction (theta, phi), 
                // where theta is angle in radians between v and z-axis,
                // and phi is the azimuthal angle relative to x-axis 
     static RiUnitVector3 DirectionFromSphericalCoordinates( RiReal theta, RiReal phi );
private:
    RiGeometry();
};

inline int RiGeometry::IndexOfMinAbsComponent( const RiVector3& v ) {
    RiReal x = fabs(v[0]);	
    RiReal y = fabs(v[1]);	
    RiReal z = fabs(v[2]);	
	     
    if (x < y && x < z)
      return 0;
    else if (y < z)
      return 1;
    else
      return 2;
}

inline int RiGeometry::IndexOfMaxAbsComponent( const RiVector3& v ) {
  if (fabs(v[0]) > fabs(v[1]) && fabs(v[0]) > fabs(v[2]))
      return 0;
  else if (fabs(v[1]) > fabs(v[2]))
      return 1;
  else
      return 2;
}


#endif // RIGEOMETRY_H