math3d/basis.h

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#ifndef MATH3D_BASIS_H
#define MATH3D_BASIS_H

#include "primitives.h"

namespace Math3D {


  inline void GetCanonicalBasis(const Vector2& x,Vector2&y) {
    y.setPerpendicular(x);
  } 
  inline void GetCanonicalBasis(const Vector3& x,Vector3&y,Vector3& z) {
    Real scale;
    if(FuzzyEquals(x.x,1.0)) scale = 0;
    else if(FuzzyEquals(x.x,-1.0)) {  //A complete flip of the basis
      y.set(0.0,-1.0,0.0);
      z.set(0.0,0.0,1.0);
      return;
    }
    else scale = (1.0-x.x)/(1.0-Sqr(x.x));
    y.x = -x.y;
    y.y = x.x + scale*Sqr(x.z);
    y.z = -scale*x.y*x.z;
    z.x = -x.z;
    z.y = -scale*x.y*x.z;
    z.z = x.x + scale*Sqr(x.y);
  }

} //namespace Math3D

#endif