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

  Program:   Visualization Toolkit
  Module:    vtkWarpScalar.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.

=========================================================================*/
// .NAME vtkWarpScalar - deform geometry with scalar data
// .SECTION Description
// vtkWarpScalar is a filter that modifies point coordinates by moving
// points along point normals by the scalar amount times the scale factor.
// Useful for creating carpet or x-y-z plots.
//
// If normals are not present in data, the Normal instance variable will
// be used as the direction along which to warp the geometry. If normals are
// present but you would like to use the Normal instance variable, set the 
// UseNormal boolean to true.
//
// If XYPlane boolean is set true, then the z-value is considered to be 
// a scalar value (still scaled by scale factor), and the displacement is
// along the z-axis. If scalars are also present, these are copied through
// and can be used to color the surface.
//
// Note that the filter passes both its point data and cell data to
// its output, except for normals, since these are distorted by the
// warping.


#ifndef __vtkWarpScalar_h
#define __vtkWarpScalar_h

#include "vtkPointSetToPointSetFilter.h"

class vtkDataArray;

class VTK_GRAPHICS_EXPORT vtkWarpScalar : public vtkPointSetToPointSetFilter
{
public:
  static vtkWarpScalar *New();
  vtkTypeRevisionMacro(vtkWarpScalar,vtkPointSetToPointSetFilter);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Specify value to scale displacement.
  vtkSetMacro(ScaleFactor,double);
  vtkGetMacro(ScaleFactor,double);

  // Description:
  // Turn on/off use of user specified normal. If on, data normals
  // will be ignored and instance variable Normal will be used instead.
  vtkSetMacro(UseNormal,int);
  vtkGetMacro(UseNormal,int);
  vtkBooleanMacro(UseNormal,int);

  // Description:
  // Normal (i.e., direction) along which to warp geometry. Only used
  // if UseNormal boolean set to true or no normals available in data.
  vtkSetVector3Macro(Normal,double);
  vtkGetVectorMacro(Normal,double,3);

  // Description:
  // Turn on/off flag specifying that input data is x-y plane. If x-y plane,
  // then the z value is used to warp the surface in the z-axis direction 
  // (times the scale factor) and scalars are used to color the surface.
  vtkSetMacro(XYPlane,int);
  vtkGetMacro(XYPlane,int);
  vtkBooleanMacro(XYPlane,int);

  // Description:
  // If you want to warp by an arbitrary scalar 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:
  vtkWarpScalar();
  ~vtkWarpScalar();

  void Execute();

  double ScaleFactor;
  int UseNormal;
  double Normal[3];
  int XYPlane;

  //BTX
  double *(vtkWarpScalar::*PointNormal)(vtkIdType id, vtkDataArray *normals);
  double *DataNormal(vtkIdType id, vtkDataArray *normals=NULL);
  double *InstanceNormal(vtkIdType id, vtkDataArray *normals=NULL);
  double *ZNormal(vtkIdType id, vtkDataArray *normals=NULL);
  //ETX

  char *InputScalarsSelection;
  vtkSetStringMacro(InputScalarsSelection);

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

#endif
