convex_hull.h

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// -*-c++-*-
 
/*
 *Copyright:
 
 Copyright (C) Hidehisa Akiyama
 
 This code is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 3 of the License, or (at your option) any later version.
 
 This library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Lesser General Public License for more details.
 
 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 *EndCopyright:
 */
 
#ifndef RCSC_GEOM_CONVEX_HULL_H
#define RCSC_GEOM_CONVEX_HULL_H
 
#include <rcsc/geom/vector_2d.h>
#include <rcsc/geom/segment_2d.h>
#include <rcsc/geom/polygon_2d.h>
 
#include <vector>
#include <set>
 
namespace rcsc {
 
class ConvexHull {
public:
    typedef std::vector< Vector2D > PointCont; 
    typedef std::vector< Vector2D > VertexCont; 
    typedef std::vector< Segment2D > EdgeCont; 
 
    enum MethodType {
        DirectMethod,
        WrappingMethod,
        GrahamScan,
        // IncrementalMethod,
        // DivideConquer,
        // QuickMethod,
        // InnerPointsElimination,
    };
 
private:
 
    PointCont M_input_points; 
 
    VertexCont M_vertices; 
    EdgeCont M_edges; 
 
 
    // not used
    ConvexHull( const ConvexHull & ) = delete;
    ConvexHull & operator=( const ConvexHull & ) = delete;
 
public:
 
    ConvexHull();
 
    ConvexHull( const PointCont & v );
 
    void clear();
 
    void clearResults();
 
    void addPoint( const Vector2D & p )
      {
          M_input_points.push_back( p );
      }
 
    void addPoints( const PointCont & v )
      {
          M_input_points.insert( M_input_points.end(), v.begin(), v.end() );
      }
 
    // void compute();
 
    void compute( const MethodType type = WrappingMethod );
 
    const PointCont & inputPoints() const
      {
          return M_input_points;
      }
 
    const VertexCont & vertices() const
      {
          return M_vertices;
      }
 
    const EdgeCont & edges() const
      {
          return M_edges;
      }
 
private:
 
    void computeDirectMethod();
 
    void computeWrappingMethod();
 
    void computeGrahamScan();
 
    // void computeIncrementalMethod();
 
    // void computeDivideAndConquer();
 
    // void computeQuickMethod();
 
    // void computeInnerPointsElimination();
 
private:
 
    size_t getMinPointIndex() const;
 
    void sortPointsByAngleFrom( const size_t index );
 
public:
 
    Polygon2D toPolygon() const;
 
    std::ostream & printInputPoints( std::ostream & os ) const;
 
    std::ostream & printVertices( std::ostream & os ) const;
 
    std::ostream & printEdges( std::ostream & os ) const;
 
};
 
}
 
#endif