/ray/src/lib/numerics/3d/plane3.cc

Go to the documentation of this file.

/*
 * lib/numerics/3d/plane3.cc
 * 
 * Plane template which represents plane in 3 dimensions. 
 * 
 * Copyright (c) 2004 by Wolfgang Wieser ] wwieser (a) gmx <*> de [ 
 * 
 * This file may be distributed and/or modified under the terms of the 
 * GNU General Public License version 2 as published by the Free Software 
 * Foundation. (See COPYING.GPL for details.)
 * 
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 * 
 */

#include "plane3.h"

namespace NUM   // numerics
{

// This is a hack which makes sure that the required instances for dbl 
// and flt are emitted. 
void _OMatrixInstantiationDummy()
{
    {
        Plane3<dbl> *p=NULL;
        Vector3<dbl> *v=NULL;
        p->compute(*v,*v,*v);
    }
    {
        Plane3<flt> *p=NULL;
        Vector3<flt> *v=NULL;
        p->compute(*v,*v,*v);
    }
}


template<typename T>int Plane3<T>::compute(const Vector3<T> &p0,
    const Vector3<T> &p1,const Vector3<T> &p2)
{
    // Compute the normal vector: 
    T da[3] = { p0[0]-p1[0], p0[1]-p1[1], p0[2]-p1[2] };
    T db[3] = { p2[0]-p1[0], p2[1]-p1[1], p2[2]-p1[2] };
    
    // normal = da x db. 
    _normal.cross(da,db);
    
    // Normalize the normal vector: 
    T len=_normal.len();
    if(len==0.0)
    {  _dist=0;  return(-2);  }  // normal are already 0 since len=0. 
    
    _normal*=1/len;
    
    // Compute distance from origin: 
    _dist = -dot(_normal,p0);
    
    return(0);
}

}  // end of namespace NUM

---