vcglib: smallest_enclosing.h Source File

00001 #pragma once
00002 /****************************************************************************
00003 * VCGLib                                                            o o     *
00004 * Visual and Computer Graphics Library                            o     o   *
00005 *                                                                _   O  _   *
00006 * Copyright(C) 2004                                                \/)\/    *
00007 * Visual Computing Lab                                            /\/|      *
00008 * ISTI - Italian National Research Council                           |      *
00009 *                                                                    \      *
00010 * All rights reserved.                                                      *
00011 *                                                                           *
00012 * This program is free software; you can redistribute it and/or modify      *   
00013 * it under the terms of the GNU General Public License as published by      *
00014 * the Free Software Foundation; either version 2 of the License, or         *
00015 * (at your option) any later version.                                       *
00016 *                                                                           *
00017 * This program is distributed in the hope that it will be useful,           *
00018 * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
00019 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             *
00020 * GNU General Public License (http://www.gnu.org/licenses/gpl.txt)          *
00021 * for more details.                                                         *
00022 *                                                                           *
00023 ****************************************************************************/
00024 /****************************************************************************
00025   History
00026 
00027 $Log: not supported by cvs2svn $
00028 Revision 1.5  2007/11/07 09:37:20  ganovelli
00029 added draft for sphereofsphres enclosing
00030 
00031 Revision 1.4  2006/09/14 08:46:00  ganovelli
00032 added inclusion of sphere3
00033 
00034 Revision 1.3  2006/07/12 12:13:23  zifnab1974
00035 static keyword only in declaration not in implementation
00036 
00037 Revision 1.2  2006/07/10 10:38:16  turini
00038 minor changes in SphereOfTetra()
00039 
00040 Revision 1.1  2006/07/06 12:37:18  ganovelli
00041 draft version. For the triangle is not tehe smallest enclosing sphere and for the set of spheres works only for two spheres
00042 
00043 
00044 
00045 ****************************************************************************/
00046 
00047 #include <vcg/space/triangle3.h>
00048 #include <vcg/space/tetra3.h>
00049 #include <vcg/space/sphere3.h>
00050 #include <assert.h>
00051 namespace vcg{
00058 struct SmallestEnclosing {
00059 
00061         template <class TriangleType>
00062                 static Sphere3<typename TriangleType::ScalarType>  SphereOfTriangle(const TriangleType & t); 
00063 
00065         template <class TetraType>
00066                 static Sphere3<typename TetraType::ScalarType>  SphereOfTetra(const TetraType & t); 
00067 
00069         template <class SphereType>
00070                 static SphereType  SphereOfSpheres( const SphereType & s0,const SphereType & s1); 
00071 
00073         template <class SphereContType>
00074                 static typename SphereContType::value_type  SphereOfSpheres( const SphereContType & t); 
00075 };
00078 template <class TriangleType>
00079 Sphere3<typename TriangleType::ScalarType> 
00080 SmallestEnclosing::SphereOfTriangle(const TriangleType & t){
00081         return Sphere3<typename TriangleType::ScalarType>(t.Barycenter(),(t.Barycenter()-t.cP(0)).Norm() );
00082 }
00083 
00084 template <class TetraType>
00085 Sphere3<typename TetraType::ScalarType> 
00086 SmallestEnclosing::SphereOfTetra(const TetraType & t){
00087         return Sphere3<typename TetraType::ScalarType>( t.Barycenter(),( t.Barycenter() - t.cP(0) ).Norm() );
00088 }
00089 
00090 template <class SphereType>
00091   SphereType 
00092  SmallestEnclosing::
00093 SphereOfSpheres(  const   SphereType  & s0, const  SphereType  & s1)
00094 {
00095         typename SphereType::ScalarType radius;
00096         vcg::Point3f center;
00097 
00098         if(s0.Radius()==-1.0) return s1; else if(s1.Radius()==-1.0) return s0;
00099 
00100         float dst = (s1.Center()-s0.Center()).Norm() ;
00101         radius = (dst+s1.Radius()+s0.Radius())/2;
00102         Point3f a=s0.Center();
00103         Point3f b=s1.Center();
00104         Point3f dir = (b-a).Normalize();
00105         a = a - dir*s0.Radius();
00106         b = b + dir*s1.Radius();
00107         center = (a+b)/2.0;
00108 
00109         return  SphereType(center,radius);
00110 }
00111 
00112 template <typename SphereContType>
00113 typename SphereContType::value_type
00114  SmallestEnclosing::
00115 SphereOfSpheres(  const SphereContType & spheres)
00116 {
00117         typename SphereContType::value_type::ScalarType radius;
00118         typename SphereContType::value_type res;
00119         typename SphereContType::const_iterator si;
00120 
00121         for(si = spheres.begin(); si != spheres.end(); ++si){
00122                 res  = SphereOfSpheres(res,*si);
00123         }
00124 
00125         return res;
00126 }
00127 }
00128 
00129