/*=========================================================================

  Program:   Visualization Toolkit
  Module:    $RCSfile$

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
/*-------------------------------------------------------------------------
  Copyright 2008 Sandia Corporation.
  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
  the U.S. Government retains certain rights in this software.
-------------------------------------------------------------------------*/
// .NAME vtkPBGLRandomGraphSource - Generates a distributed graph with
// random edges.
//
// .SECTION Description
// Generates a distributed graph with a specified number of vertices,
// with the density of edges specified by either an exact number of
// edges or the probability of an edge.  You may additionally specify
// whether to begin with a random tree (which enforces graph
// connectivity). This is the distributed-graph version of
// vtkRandomGraphSource.
//

#ifndef __vtkPBGLRandomGraphSource_h
#define __vtkPBGLRandomGraphSource_h

#include "vtkGraphAlgorithm.h"

class vtkGraph;
class vtkPVXMLElement;

class VTK_PARALLEL_EXPORT vtkPBGLRandomGraphSource : public vtkGraphAlgorithm
{
public:
  static vtkPBGLRandomGraphSource* New();
  vtkTypeRevisionMacro(vtkPBGLRandomGraphSource,vtkGraphAlgorithm);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // The number of vertices in the graph.
  vtkGetMacro(NumberOfVertices, vtkIdType);
  vtkSetClampMacro(NumberOfVertices, vtkIdType, 0, VTK_LARGE_ID);

  // Description:
  // If UseEdgeProbability is off, creates a graph with the specified number
  // of edges.  Duplicate (parallel) edges are allowed.
  vtkGetMacro(NumberOfEdges, vtkIdType);
  vtkSetClampMacro(NumberOfEdges, vtkIdType, 0, VTK_LARGE_ID);

  // Description:
  // If UseEdgeProbability is on, adds an edge with this probability between 0 and 1
  // for each pair of vertices in the graph.
  vtkGetMacro(EdgeProbability, double);
  vtkSetClampMacro(EdgeProbability, double, 0.0, 1.0);

  // Description:
  // When set, includes edge weights in an array named "edge_weights".
  // Defaults to off.  Weights are random between 0 and 1.
  vtkSetMacro(IncludeEdgeWeights, bool);
  vtkGetMacro(IncludeEdgeWeights, bool);
  vtkBooleanMacro(IncludeEdgeWeights, bool);

  // Description:
  // The name of the edge weight array. Default "edge weight".
  vtkSetStringMacro(EdgeWeightArrayName);
  vtkGetStringMacro(EdgeWeightArrayName);

  // Description:
  // When set, creates a directed graph, as opposed to an undirected graph.
  vtkSetMacro(Directed, bool);
  vtkGetMacro(Directed, bool);
  vtkBooleanMacro(Directed, bool);

  // Description:
  // When set, uses the EdgeProbability parameter to determine the
  // density of edges.  Otherwise, NumberOfEdges is used. Note that
  // using the EdgeProbability on a large, sparse graph is extremely
  // inefficient. For these cases, set NumberOfEdges to the expected
  // number of edges one would receive with the given EdgeProbability
  // and NumberOfVertices.
  vtkSetMacro(UseEdgeProbability, bool);
  vtkGetMacro(UseEdgeProbability, bool);
  vtkBooleanMacro(UseEdgeProbability, bool);

  // Description:
  // When set, builds a random tree structure first, then adds additional
  // random edges.
  vtkSetMacro(StartWithTree, bool);
  vtkGetMacro(StartWithTree, bool);
  vtkBooleanMacro(StartWithTree, bool);

  // Description:
  // If this flag is set to true, edges where the source and target
  // vertex are the same can be generated.  The default is to forbid
  // such loops.
  vtkSetMacro(AllowSelfLoops, bool);
  vtkGetMacro(AllowSelfLoops, bool);
  vtkBooleanMacro(AllowSelfLoops, bool);

  // Description:
  // When set, allows the generator to create a graph where the number
  // of outgoing edges is balanced across all of the processes. Such
  // graphs are faster to generate in parallel, but do not conform
  // exactly to the random graph model because the generator restricts
  // the domain of the randomly-generated source vertex of each edge.
  vtkSetMacro(AllowBalancedEdgeDistribution, bool);
  vtkGetMacro(AllowBalancedEdgeDistribution, bool);
  vtkBooleanMacro(AllowBalancedEdgeDistribution, bool);

  // Description:
  // Add pedigree ids to vertex and edge data.
  vtkSetMacro(GeneratePedigreeIds, bool);
  vtkGetMacro(GeneratePedigreeIds, bool);
  vtkBooleanMacro(GeneratePedigreeIds, bool);

  // Description:
  // The name of the vertex pedigree id array. Default "vertex id".
  // Vertex pedigree ids will be labeled from 0 to n-1 globally.
  vtkSetStringMacro(VertexPedigreeIdArrayName);
  vtkGetStringMacro(VertexPedigreeIdArrayName);

  // Description:
  // The name of the edge pedigree id array. Default "edge id".
  vtkSetStringMacro(EdgePedigreeIdArrayName);
  vtkGetStringMacro(EdgePedigreeIdArrayName);

  // Description:
  // Control the seed used for pseudo-random-number generation.
  // This ensures that vtkPBGLRandomGraphSource can produce repeatable
  // results. The seed values provided for each process should be different,
  vtkSetMacro(Seed, int);
  vtkGetMacro(Seed, int);

protected:
  vtkPBGLRandomGraphSource();
  ~vtkPBGLRandomGraphSource();
  vtkIdType NumberOfVertices;
  vtkIdType NumberOfEdges;
  double EdgeProbability;
  bool Directed;
  bool UseEdgeProbability;
  bool StartWithTree;
  bool IncludeEdgeWeights;
  bool AllowSelfLoops;
  bool AllowBalancedEdgeDistribution;
  bool GeneratePedigreeIds;
  int Seed;
  char* EdgeWeightArrayName;
  char* VertexPedigreeIdArrayName;
  char* EdgePedigreeIdArrayName;

  virtual int RequestData(
    vtkInformation*,
    vtkInformationVector**,
    vtkInformationVector*);

  // Description:
  // Creates directed or undirected output based on Directed flag.
  virtual int RequestDataObject(vtkInformation*,
                                vtkInformationVector** inputVector,
                                vtkInformationVector* outputVector);

private:
  vtkPBGLRandomGraphSource(const vtkPBGLRandomGraphSource&); // Not implemented
  void operator=(const vtkPBGLRandomGraphSource&);   // Not implemented
};

#endif

