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

  Program:   Visualization Toolkit
  Module:    vtkContourGrid.h
  Language:  C++
  Date:      $Date$
  Version:   $Revision$

  Copyright (c) 1993-2002 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.

=========================================================================*/
// .NAME vtkContourGrid - generate isosurfaces/isolines from scalar values (specialized for unstructured grids)
// .SECTION Description
// vtkContourGrid is a filter that takes as input datasets of type
// vtkUnstructuredGrid and generates on output isosurfaces and/or
// isolines. The exact form of the output depends upon the dimensionality of
// the input data.  Data consisting of 3D cells will generate isosurfaces,
// data consisting of 2D cells will generate isolines, and data with 1D or 0D
// cells will generate isopoints. Combinations of output type are possible if
// the input dimension is mixed.
//
// To use this filter you must specify one or more contour values.
// You can either use the method SetValue() to specify each contour
// value, or use GenerateValues() to generate a series of evenly
// spaced contours. It is also possible to accelerate the operation of
// this filter (at the cost of extra memory) by using a
// vtkScalarTree. A scalar tree is used to quickly locate cells that
// contain a contour surface. This is especially effective if multiple
// contours are being extracted. If you want to use a scalar tree,
// invoke the method UseScalarTreeOn().
//
// If the input data is structured, consider using a filter that is
// optimized for structured data. These can be found in the patented
// classes of vtk.

// .SECTION Caveats
// For unstructured data or structured grids, normals and gradients
// are not computed. Use vtkPolyDataNormals to compute the surface
// normals of the resulting isosurface.

// .SECTION See Also
// vtkMarchingContourFilter vtkKitwareContourFilter
// vtkMarchingCubes vtkSliceCubes vtkDividingCubes vtkMarchingSquares
// vtkImageMarchingCubes

#ifndef __vtkContourGrid_h
#define __vtkContourGrid_h

#include "vtkUnstructuredGridToPolyDataFilter.h"
#include "vtkContourValues.h"

class vtkScalarTree;
class vtkEdgeTable;
class vtkPointLocator;

class VTK_GRAPHICS_EXPORT vtkContourGrid : public vtkUnstructuredGridToPolyDataFilter
{
public:
  vtkTypeRevisionMacro(vtkContourGrid,vtkUnstructuredGridToPolyDataFilter);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Construct object with initial range (0,1) and single contour value
  // of 0.0.
  static vtkContourGrid *New();

  // Description:
  // Methods to set / get contour values.
  void SetValue(int i, float value);
  float GetValue(int i);
  float *GetValues();
  void GetValues(float *contourValues);
  void SetNumberOfContours(int number);
  int GetNumberOfContours();
  void GenerateValues(int numContours, float range[2]);
  void GenerateValues(int numContours, float rangeStart, float rangeEnd);

  // Description:
  // Modified GetMTime Because we delegate to vtkContourValues
  unsigned long GetMTime();

  // Description:
  // Set/Get the computation of normals. Normal computation is fairly
  // expensive in both time and storage. If the output data will be
  // processed by filters that modify topology or geometry, it may be
  // wise to turn Normals and Gradients off.
  vtkSetMacro(ComputeNormals,int);
  vtkGetMacro(ComputeNormals,int);
  vtkBooleanMacro(ComputeNormals,int);

  // Description:
  // Set/Get the computation of gradients. Gradient computation is
  // fairly expensive in both time and storage. Note that if
  // ComputeNormals is on, gradients will have to be calculated, but
  // will not be stored in the output dataset.  If the output data
  // will be processed by filters that modify topology or geometry, it
  // may be wise to turn Normals and Gradients off.
  vtkSetMacro(ComputeGradients,int);
  vtkGetMacro(ComputeGradients,int);
  vtkBooleanMacro(ComputeGradients,int);

  // Description:
  // Set/Get the computation of scalars.
  vtkSetMacro(ComputeScalars,int);
  vtkGetMacro(ComputeScalars,int);
  vtkBooleanMacro(ComputeScalars,int);

  // Description:
  // Enable the use of a scalar tree to accelerate contour extraction.
  vtkSetMacro(UseScalarTree,int);
  vtkGetMacro(UseScalarTree,int);
  vtkBooleanMacro(UseScalarTree,int);

  // Description:
  // Set / get a spatial locator for merging points. By default, 
  // an instance of vtkMergePoints is used.
  void SetLocator(vtkPointLocator *locator);
  vtkGetObjectMacro(Locator,vtkPointLocator);

  // Description:
  // Create default locator. Used to create one when none is
  // specified. The locator is used to merge coincident points.
  void CreateDefaultLocator();

  // Description:
  // If you want to contour by an arbitrary array, then set its name here.
  // By default this in NULL and the filter will use the active scalar array.
  vtkGetStringMacro(InputScalarsSelection);
  void SelectInputScalars(const char *fieldName) 
    {this->SetInputScalarsSelection(fieldName);}
  
protected:
  vtkContourGrid();
  ~vtkContourGrid();

  void Execute();

  vtkContourValues *ContourValues;
  int ComputeNormals;
  int ComputeGradients;
  int ComputeScalars;
  vtkPointLocator *Locator;
  int UseScalarTree;
  vtkScalarTree *ScalarTree;
  vtkEdgeTable *EdgeTable;
  
  char *InputScalarsSelection;
  vtkSetStringMacro(InputScalarsSelection);

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

// Description:
// Set a particular contour value at contour number i. The index i ranges 
// between 0<=i<NumberOfContours.
inline void vtkContourGrid::SetValue(int i, float value)
{this->ContourValues->SetValue(i,value);}

// Description:
// Get the ith contour value.
inline float vtkContourGrid::GetValue(int i)
{return this->ContourValues->GetValue(i);}

// Description:
// Get a pointer to an array of contour values. There will be
// GetNumberOfContours() values in the list.
inline float *vtkContourGrid::GetValues()
{return this->ContourValues->GetValues();}

// Description:
// Fill a supplied list with contour values. There will be
// GetNumberOfContours() values in the list. Make sure you allocate
// enough memory to hold the list.
inline void vtkContourGrid::GetValues(float *contourValues)
{this->ContourValues->GetValues(contourValues);}

// Description:
// Set the number of contours to place into the list. You only really
// need to use this method to reduce list size. The method SetValue()
// will automatically increase list size as needed.
inline void vtkContourGrid::SetNumberOfContours(int number)
{this->ContourValues->SetNumberOfContours(number);}

// Description:
// Get the number of contours in the list of contour values.
inline int vtkContourGrid::GetNumberOfContours()
{return this->ContourValues->GetNumberOfContours();}

// Description:
// Generate numContours equally spaced contour values between specified
// range. Contour values will include min/max range values.
inline void vtkContourGrid::GenerateValues(int numContours, float range[2])
{this->ContourValues->GenerateValues(numContours, range);}

// Description:
// Generate numContours equally spaced contour values between specified
// range. Contour values will include min/max range values.
inline void vtkContourGrid::GenerateValues(int numContours, float
                                             rangeStart, float rangeEnd)
{this->ContourValues->GenerateValues(numContours, rangeStart, rangeEnd);}


#endif


