NodePairEnergy.h

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/*
 * $Revision: 2523 $
 *
 * last checkin:
 *   $Author: gutwenger $
 *   $Date: 2012-07-02 20:59:27 +0200 (Mon, 02 Jul 2012) $
 ***************************************************************/

#ifdef _MSC_VER
#pragma once
#endif

#ifndef OGDF_NODE_PAIR_ENERGY_H
#define OGDF_NODE_PAIR_ENERGY_H


#include <ogdf/internal/energybased/AdjacencyOracle.h>
#include <ogdf/internal/energybased/EnergyFunction.h>
#include <ogdf/internal/energybased/IntersectionRectangle.h>


namespace ogdf {

class NodePairEnergy: public EnergyFunction {
public:
    //Initializes data dtructures to speed up later computations
    NodePairEnergy(const String energyname, GraphAttributes &AG);
    virtual ~NodePairEnergy() {delete m_nodeNums; delete m_pairEnergy;}
    //computes the energy of the initial layout
    void computeEnergy();
protected:
    //computes the energy stored by a pair of vertices at the given positions
    virtual double computeCoordEnergy(node, node, const DPoint&, const DPoint&) const = 0;
    //returns the internal number given to each vertex
    int nodeNum(node v) const { return (*m_nodeNums)[v]; }
    //returns true in constant time if two vertices are adjacent
    bool adjacent(const node v, const node w) const {return m_adjacentOracle.adjacent(v,w);}
    //returns the shape of a vertex as an IntersectionRectangle
    const IntersectionRectangle& shape(const node v) const {return m_shape[v];}

#ifdef OGDF_DEBUG
    virtual void printInternalData() const;
#endif

private:
    NodeArray<int> *m_nodeNums;//stores internal number of each vertex
    Array2D<double> *m_pairEnergy;//stores for each pair of vertices its energy
    NodeArray<double> m_candPairEnergy;//stores for each vertex its pair energy with
    //respect to the vertex to be moved if its new position is chosen
    NodeArray<IntersectionRectangle> m_shape;//stores the shape of each vertex as
    //an IntersectionRectangle
    List<node> m_nonIsolated;//list of vertices with degree greater zero
    const AdjacencyOracle m_adjacentOracle;//structure for constant time adjacency queries
    //function computes energy stored in a certain pair of vertices
    double computePairEnergy(const node v, const node w) const;
    //computes energy of whole layout if new position of the candidate vertex is chosen
    void compCandEnergy();
    //If a candidate change is chosen as the new position, this function sets the
    //internal data accordingly
    void internalCandidateTaken();
    };


}// namespace ogdf

#endif