/*=========================================================================

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkClipDataSet.h,v $
  Language:  C++
  Date:      $Date: 2001/10/11 13:36:49 $
  Version:   $Revision: 1.4 $


Copyright (c) 1993-2001 Ken Martin, Will Schroeder, Bill Lorensen 
All rights reserved.

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 * Redistributions of source code must retain the above copyright notice,
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   and/or other materials provided with the distribution.

 * Neither name of Ken Martin, Will Schroeder, or Bill Lorensen nor the names
   of any contributors may be used to endorse or promote products derived
   from this software without specific prior written permission.

 * Modified source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

=========================================================================*/
// .NAME vtkClipDataSet - clip any dataset with user-specified implicit function or input scalar data
// .SECTION Description
// vtkClipDataSet is a filter that any type of dataset using either
// any subclass of vtkImplicitFunction, or the input scalar
// data. Clipping means that it actually "cuts" through the cells of
// the dataset, returning everything inside of the specified implicit
// function (or greater than the scalar value) including "pieces" of
// a cell. (Compare this with vtkExtractGeometry, which pulls out
// entire, uncut cells.) The output of this filter is an unstructured
// grid.
//
// To use this filter, you must decide if you will be clipping with an
// implicit function, or whether you will be using the input scalar
// data.  If you want to clip with an implicit function, you must:
// 1) define an implicit function
// 2) set it with the SetClipFunction method
// 3) apply the GenerateClipScalarsOn method
// If a ClipFunction is not specified, or GenerateClipScalars is off
// (the default), then the input's scalar data will be used to clip
// the polydata.
//
// You can also specify a scalar value, which is used to decide what is
// inside and outside of the implicit function. You can also reverse the
// sense of what inside/outside is by setting the InsideOut instance
// variable. (The clipping algorithm proceeds by computing an implicit
// function value or using the input scalar data for each point in the
// dataset. This is compared to the scalar value to determine
// inside/outside.)
//
// This filter can be configured to compute a second output. The
// second output is the part of the cell that is clipped away. Set the
// GenerateClippedData boolean on if you wish to access this output data.

// .SECTION Caveats
// vtkClipDataSet will triangulate all types of 3D cells (i.e., create
// tetrahedra). This is true even if the cell is not actually cut. This
// is necessary to preserve compatibility across face neighbors. 2D cells
// will only be triangulated if the cutting function passes through them.

// .SECTION See Also
// vtkImplicitFunction vtkCutter vtkClipVolume vtkClipPolyData

#ifndef __vtkClipDataSet_h
#define __vtkClipDataSet_h

#include "vtkDataSetToUnstructuredGridFilter.h"
#include "vtkImplicitFunction.h"

class VTK_GRAPHICS_EXPORT vtkClipDataSet : public vtkDataSetToUnstructuredGridFilter
{
public:
  vtkTypeMacro(vtkClipDataSet,vtkDataSetToUnstructuredGridFilter);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Construct with user-specified implicit function; InsideOut turned off;
  // value set to 0.0; and generate clip scalars turned off.
  static vtkClipDataSet *New();

  // Description:
  // Set the clipping value of the implicit function (if clipping with
  // implicit function) or scalar value (if clipping with
  // scalars). The default value is 0.0. 
  vtkSetMacro(Value,float);
  vtkGetMacro(Value,float);
  
  // Description:
  // Set/Get the InsideOut flag. When off, a vertex is considered
  // inside the implicit function if its value is greater than the
  // Value ivar. When InsideOutside is turned on, a vertex is
  // considered inside the implicit function if its implicit function
  // value is less than or equal to the Value ivar.  InsideOut is off
  // by default.
  vtkSetMacro(InsideOut,int);
  vtkGetMacro(InsideOut,int);
  vtkBooleanMacro(InsideOut,int);

  // Description
  // Specify the implicit function with which to perform the
  // clipping. If you do not define an implicit function, then the input
  // scalar data will be used for clipping.
  vtkSetObjectMacro(ClipFunction,vtkImplicitFunction);
  vtkGetObjectMacro(ClipFunction,vtkImplicitFunction);

  // Description:
  // If this flag is enabled, then the output scalar values will be 
  // interpolated from the implicit function values, and not the 
  // input scalar data. If you enable this flag but do not provide an
  // implicit function an error will be reported.
  vtkSetMacro(GenerateClipScalars,int);
  vtkGetMacro(GenerateClipScalars,int);
  vtkBooleanMacro(GenerateClipScalars,int);

  // Description:
  // Control whether a second output is generated. The second output
  // contains the polygonal data that's been clipped away.
  vtkSetMacro(GenerateClippedOutput,int);
  vtkGetMacro(GenerateClippedOutput,int);
  vtkBooleanMacro(GenerateClippedOutput,int);

  // Description:
  // Return the Clipped output.
  vtkUnstructuredGrid *GetClippedOutput();

  // Description:
  // Specify 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:
  // Return the mtime also considering the locator and clip function.
  unsigned long GetMTime();

protected:
  vtkClipDataSet(vtkImplicitFunction *cf=NULL);
  ~vtkClipDataSet();

  void Execute();
  vtkImplicitFunction *ClipFunction;
  
  vtkPointLocator *Locator;
  int InsideOut;
  float Value;
  int GenerateClipScalars;

  int GenerateClippedOutput;
private:
  vtkClipDataSet(const vtkClipDataSet&);  // Not implemented.
  void operator=(const vtkClipDataSet&);  // Not implemented.
};

#endif
