vtkFast2DLayoutStrategy.h

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

  Program:   Visualization Toolkit
  Module:    vtkFast2DLayoutStrategy.h

  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.
-------------------------------------------------------------------------*/
#ifndef vtkFast2DLayoutStrategy_h
#define vtkFast2DLayoutStrategy_h

#include "vtkGraphLayoutStrategy.h"
#include "vtkInfovisLayoutModule.h" // For export macro

#include "vtkSmartPointer.h" // Required for smart pointer internal ivars.

class vtkFastSplatter;
class vtkFloatArray;
class vtkGraphToPolyData;
class vtkImageData;

class VTKINFOVISLAYOUT_EXPORT vtkFast2DLayoutStrategy : public vtkGraphLayoutStrategy
{
public:
  static vtkFast2DLayoutStrategy* New();

  vtkTypeMacro(vtkFast2DLayoutStrategy, vtkGraphLayoutStrategy);
  void PrintSelf(ostream& os, vtkIndent indent) override;


  vtkSetClampMacro(RandomSeed, int, 0, VTK_INT_MAX);
  vtkGetMacro(RandomSeed, int);


  vtkSetClampMacro(MaxNumberOfIterations, int, 0, VTK_INT_MAX);
  vtkGetMacro(MaxNumberOfIterations, int);


  vtkSetClampMacro(IterationsPerLayout, int, 0, VTK_INT_MAX);
  vtkGetMacro(IterationsPerLayout, int);


  vtkSetClampMacro(InitialTemperature, float, 0.0, VTK_FLOAT_MAX);
  vtkGetMacro(InitialTemperature, float);


  vtkSetClampMacro(CoolDownRate, double, 0.01, VTK_DOUBLE_MAX);
  vtkGetMacro(CoolDownRate, double);


  vtkSetMacro(RestDistance, float);
  vtkGetMacro(RestDistance, float);

  void Initialize() override;

  void Layout() override;

  int IsLayoutComplete() override { return this->LayoutComplete; }

protected:
  vtkFast2DLayoutStrategy();
  ~vtkFast2DLayoutStrategy() override;

  int MaxNumberOfIterations; // Maximum number of iterations.
  float InitialTemperature;
  float CoolDownRate; // Cool-down rate.  Note:  Higher # = Slower rate.

private:
  // An edge consists of two vertices joined together.
  // This struct acts as a "pointer" to those two vertices.
  typedef struct
  {
    vtkIdType from;
    vtkIdType to;
    float weight;
  } vtkLayoutEdge;

  // This class 'has a' vtkFastSplatter for the density grid
  vtkSmartPointer<vtkGraphToPolyData> GraphToPoly;
  vtkSmartPointer<vtkFastSplatter> DensityGrid;
  vtkSmartPointer<vtkImageData> SplatImage;
  vtkSmartPointer<vtkFloatArray> RepulsionArray;
  vtkSmartPointer<vtkFloatArray> AttractionArray;

  vtkLayoutEdge* EdgeArray;

  int RandomSeed;
  int IterationsPerLayout;
  int TotalIterations;
  int LayoutComplete;
  float Temp;
  float RestDistance;

  // Private helper methods
  void GenerateCircularSplat(vtkImageData* splat, int x, int y);
  void GenerateGaussianSplat(vtkImageData* splat, int x, int y);
  void ResolveCoincidentVertices();

  vtkFast2DLayoutStrategy(const vtkFast2DLayoutStrategy&) = delete;
  void operator=(const vtkFast2DLayoutStrategy&) = delete;
};

#endif