OpenWalnut  1.4.0
WGeometryFunctions.h
00001 //---------------------------------------------------------------------------
00002 //
00003 // Project: OpenWalnut ( http://www.openwalnut.org )
00004 //
00005 // Copyright 2009 OpenWalnut Community, BSV@Uni-Leipzig and CNCF@MPI-CBS
00006 // For more information see http://www.openwalnut.org/copying
00007 //
00008 // This file is part of OpenWalnut.
00009 //
00010 // OpenWalnut is free software: you can redistribute it and/or modify
00011 // it under the terms of the GNU Lesser General Public License as published by
00012 // the Free Software Foundation, either version 3 of the License, or
00013 // (at your option) any later version.
00014 //
00015 // OpenWalnut is distributed in the hope that it will be useful,
00016 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00017 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00018 // GNU Lesser General Public License for more details.
00019 //
00020 // You should have received a copy of the GNU Lesser General Public License
00021 // along with OpenWalnut. If not, see <http://www.gnu.org/licenses/>.
00022 //
00023 //---------------------------------------------------------------------------
00024 
00025 #ifndef WGEOMETRYFUNCTIONS_H
00026 #define WGEOMETRYFUNCTIONS_H
00027 
00028 #include <map>
00029 #include <utility>
00030 #include <vector>
00031 
00032 #include "../WAssert.h"
00033 #include "linearAlgebra/WVectorFixed.h"
00034 
00035 namespace utility
00036 {
00037     /**
00038      * \class Edge
00039      *
00040      * A helper class that is used to store edges as pairs of vertex indices. The indices are sorted.
00041      */
00042     class Edge : public std::pair< unsigned int, unsigned int >
00043     {
00044     public:
00045         /**
00046          * Constructor that sorts the input indices.
00047          *
00048          * \param i the first index.
00049          * \param j The second index.
00050          */
00051         Edge( unsigned int i, unsigned int j )
00052             : std::pair< unsigned int, unsigned int >( i < j ? i : j, i < j ? j : i )
00053         {
00054         }
00055 
00056         /**
00057          * Compare two edges. This operator defines a weak ordering on the edges.
00058          *
00059          * \param e The edge to compare to.
00060          * \return True, iff this edge is 'smaller' than the given edge.
00061          */
00062         bool operator < ( Edge const& e ) const
00063         {
00064             return first < e.first || ( first == e.first && second < e.second );
00065         }
00066 
00067         /**
00068          * Compare two edges for equality.
00069          *
00070          * \param e The edge to compare to.
00071          * \return True, iff this edge has the same vertex indices as the given edge.
00072          */
00073         bool operator == ( Edge const& e ) const
00074         {
00075             return first == e.first && second == e.second;
00076         }
00077     };
00078 
00079 } // namespace utility
00080 
00081 /**
00082  * Tesselates an icosahedron in order to generate a triangle-based approximation of a sphere.
00083  * The content of the provided vectors will be cleared and replaced. Triangle vertices are stored as
00084  * successive values in the triangle vector.
00085  *
00086  * \param[out] vertices The vertices of the mesh.
00087  * \param[out] triangles The resulting triangles as a list of indices into the vertex vector.
00088  * \param level The tesselation level.
00089  */
00090 void tesselateIcosahedron( std::vector< WVector3d >* vertices, std::vector< unsigned int >* triangles, unsigned int level );
00091 
00092 #endif  // WGEOMETRYFUNCTIONS_H