vtkGreedyTerrainDecimation.h

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

  Program:   Visualization Toolkit
  Module:    vtkGreedyTerrainDecimation.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.

=========================================================================*/
#ifndef vtkGreedyTerrainDecimation_h
#define vtkGreedyTerrainDecimation_h

#include "vtkFiltersHybridModule.h" // For export macro
#include "vtkPolyDataAlgorithm.h"

class vtkPriorityQueue;
class vtkDataArray;
class vtkPointData;
class vtkIdList;
class vtkDoubleArray;
class vtkFloatArray;

// PIMPL Encapsulation for STL containers
class vtkGreedyTerrainDecimationTerrainInfoType;
class vtkGreedyTerrainDecimationPointInfoType;

#define VTK_ERROR_NUMBER_OF_TRIANGLES 0
#define VTK_ERROR_SPECIFIED_REDUCTION 1
#define VTK_ERROR_ABSOLUTE 2
#define VTK_ERROR_RELATIVE 3

class VTKFILTERSHYBRID_EXPORT vtkGreedyTerrainDecimation : public vtkPolyDataAlgorithm
{
public:
  vtkTypeMacro(vtkGreedyTerrainDecimation, vtkPolyDataAlgorithm);
  void PrintSelf(ostream& os, vtkIndent indent) override;

  static vtkGreedyTerrainDecimation* New();


  vtkSetClampMacro(ErrorMeasure, int, VTK_ERROR_NUMBER_OF_TRIANGLES, VTK_ERROR_RELATIVE);
  vtkGetMacro(ErrorMeasure, int);
  void SetErrorMeasureToNumberOfTriangles()
  {
    this->SetErrorMeasure(VTK_ERROR_NUMBER_OF_TRIANGLES);
  }
  void SetErrorMeasureToSpecifiedReduction()
  {
    this->SetErrorMeasure(VTK_ERROR_SPECIFIED_REDUCTION);
  }
  void SetErrorMeasureToAbsoluteError() { this->SetErrorMeasure(VTK_ERROR_ABSOLUTE); }
  void SetErrorMeasureToRelativeError() { this->SetErrorMeasure(VTK_ERROR_RELATIVE); }


  vtkSetClampMacro(NumberOfTriangles, vtkIdType, 2, VTK_ID_MAX);
  vtkGetMacro(NumberOfTriangles, vtkIdType);


  vtkSetClampMacro(Reduction, double, 0.0, 1.0);
  vtkGetMacro(Reduction, double);


  vtkSetClampMacro(AbsoluteError, double, 0.0, VTK_DOUBLE_MAX);
  vtkGetMacro(AbsoluteError, double);


  vtkSetClampMacro(RelativeError, double, 0.0, VTK_DOUBLE_MAX);
  vtkGetMacro(RelativeError, double);


  vtkSetMacro(BoundaryVertexDeletion, vtkTypeBool);
  vtkGetMacro(BoundaryVertexDeletion, vtkTypeBool);
  vtkBooleanMacro(BoundaryVertexDeletion, vtkTypeBool);


  vtkSetMacro(ComputeNormals, vtkTypeBool);
  vtkGetMacro(ComputeNormals, vtkTypeBool);
  vtkBooleanMacro(ComputeNormals, vtkTypeBool);

protected:
  vtkGreedyTerrainDecimation();
  ~vtkGreedyTerrainDecimation() override;

  int RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;
  int FillInputPortInformation(int port, vtkInformation* info) override;

  vtkTypeBool ComputeNormals;
  vtkFloatArray* Normals;
  void ComputePointNormal(int i, int j, float n[3]);

  // ivars that the API addresses
  int ErrorMeasure;
  vtkIdType NumberOfTriangles;
  double Reduction;
  double AbsoluteError;
  double RelativeError;
  vtkTypeBool BoundaryVertexDeletion; // Can we delete boundary vertices?

  // Used for convenience
  vtkPolyData* Mesh;
  vtkPointData* InputPD;
  vtkPointData* OutputPD;
  vtkDoubleArray* Points;
  vtkDataArray* Heights;
  vtkIdType CurrentPointId;
  double Tolerance;
  vtkIdList* Neighbors;
  int Dimensions[3];
  double Origin[3];
  double Spacing[3];
  vtkIdType MaximumNumberOfTriangles;
  double Length;

  // Bookkeeping arrays
  vtkPriorityQueue* TerrainError;                         // errors for each pt in height field
  vtkGreedyTerrainDecimationTerrainInfoType* TerrainInfo; // owning triangle for each pt
  vtkGreedyTerrainDecimationPointInfoType* PointInfo;     // map mesh pt id to input pt id

  // Make a guess at initial allocation
  void EstimateOutputSize(const vtkIdType numInputPts, vtkIdType& numPts, vtkIdType& numTris);

  // Returns non-zero if the error measure is satisfied.
  virtual int SatisfiesErrorMeasure(double error);

  // Insert all the boundary vertices into the TIN
  void InsertBoundaryVertices();

  // Insert a point into the triangulation; get a point from the triangulation
  vtkIdType AddPointToTriangulation(vtkIdType inputPtId);
  vtkIdType InsertNextPoint(vtkIdType inputPtId, double x[3]);
  double* GetPoint(vtkIdType id);
  void GetPoint(vtkIdType id, double x[3]);

  // Helper functions
  void GetTerrainPoint(int i, int j, double x[3]);
  void ComputeImageCoordinates(vtkIdType inputPtId, int ij[2]);
  int InCircle(double x[3], double x1[3], double x2[3], double x3[3]);
  vtkIdType FindTriangle(double x[3], vtkIdType ptIds[3], vtkIdType tri, double tol,
    vtkIdType nei[3], vtkIdList* neighbors, int& status);
  void CheckEdge(vtkIdType ptId, double x[3], vtkIdType p1, vtkIdType p2, vtkIdType tri, int depth);

  void UpdateTriangles(vtkIdType meshPtId); // update all points connected to this point
  void UpdateTriangle(vtkIdType triId, vtkIdType p1, vtkIdType p2, vtkIdType p3);
  void UpdateTriangle(vtkIdType triId, int ij1[2], int ij2[2], int ij3[2], double h[4]);

  int CharacterizeTriangle(int ij1[2], int ij2[2], int ij[3], int*& min, int*& max, int*& midL,
    int*& midR, int*& mid, int mid2[2], double h[3], double& hMin, double& hMax, double& hL,
    double& hR);

private:
  vtkGreedyTerrainDecimation(const vtkGreedyTerrainDecimation&) = delete;
  void operator=(const vtkGreedyTerrainDecimation&) = delete;
};

#endif