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glgraph.h

/*
Copyright (c) 2000-2003 Lee Thomason (www.grinninglizard.com)

Grinning Lizard Utilities. Note that software that uses the 
utility package (including Lilith3D and Kyra) have more restrictive
licences which applies to code outside of the utility package.


This software is provided 'as-is', without any express or implied 
warranty. In no event will the authors be held liable for any 
damages arising from the use of this software.

Permission is granted to anyone to use this software for any 
purpose, including commercial applications, and to alter it and 
redistribute it freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must 
not claim that you wrote the original software. If you use this 
software in a product, an acknowledgment in the product documentation 
would be appreciated but is not required.

2. Altered source versions must be plainly marked as such, and 
must not be misrepresented as being the original software.

3. This notice may not be removed or altered from any source 
distribution.
*/

#ifndef GLGRAPH_INCLUDED
#define GLGRAPH_INCLUDED

#include "gllist.h"
#include "gldynarray.h"
#include "glinsidelist.h"
#include "glcirclelist.h"


/*      A class to solve a graph algorith. Vertices and edges, which have a travel cost, in
        a connected system.
*/
class GlGraph
{
  public:

        GlGraph( int numVertex );
        ~GlGraph();

        void AddBiEdge( int source, int dest, int length );

        void AddBiEdge( int source, int dest, int lengthSourceToDest, int lengthDestToSource );

        void AddEdge( int source, int dest, int length );

        void GetPath( int source, int dest, int *nextVertex, int* length, int *distance );

        #ifdef DEBUG
                void DumpVertex();
        #endif

  private:
        struct DataPoint
        {
                int             distance;       // from the DataPoint to the destination
                int             vertex;         // the vertex to take
        };

        struct Edge
        {
                int lengthTo;   // how long the edge is, from the source vertex to 'toVertex'
                int lengthFrom; // how long the edge is, from the 'toVertex' back to the source
                int toVertex;   // which vertex this edge goes to

                bool operator==( const Edge& rhs )      { return lengthTo == rhs.lengthTo && lengthFrom == rhs.lengthFrom && toVertex == rhs.toVertex; }
        };

        struct Vertex
        {
                Vertex() : destinationCalculated( false ) {}

                bool                    destinationCalculated;
                GlSList< Edge > edgeList;
        };
        
        void LowerAddEdge( int v0, int v1, int length0to1, int length1to0 );
        void ShortestPathCalc( int destVertex );
        DataPoint* GetDataPoint( int source, int dest ) { return ( dataPoint + dest * numVertex + source ); }
        int FindCheapest( GlCircleList<int>* set, int dest );

        enum {
                GL_INFINITE = 0x1000000
        };

        int                                     numVertex;
        Vertex                          *vertex;
        DataPoint                       *dataPoint;
};


#endif

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