/*=========================================================================

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkSelectPolyData.h,v $
  Language:  C++
  Date:      $Date: 2001/10/11 13:37:14 $
  Version:   $Revision: 1.18 $


Copyright (c) 1993-2001 Ken Martin, Will Schroeder, Bill Lorensen 
All rights reserved.

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modification, are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   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''
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

=========================================================================*/
// .NAME vtkSelectPolyData - select portion of polygonal mesh; generate selection scalars
// .SECTION Description
// vtkSelectPolyData is a filter that selects polygonal data based on
// defining a "loop" and indicating the region inside of the loop. The
// mesh within the loop consists of complete cells (the cells are not
// cut). Alternatively, this filter can be used to generate scalars.
// These scalar values, which are a distance measure to the loop, can
// be used to clip, contour. or extract data (i.e., anything that an
// implicit function can do). 
//
// The loop is defined by an array of x-y-z point coordinates.
// (Coordinates should be in the same coordinate space as the input
// polygonal data.) The loop can be concave and non-planar, but not
// self-intersecting. The input to the filter is a polygonal mesh
// (only surface primitives such as triangle strips and polygons); the
// output is either a) a portion of the original mesh laying within
// the selection loop (GenerateSelectionScalarsOff); or b) the same
// polygonal mesh with the addition of scalar values
// (GenerateSelectionScalarsOn).
//
// The algorithm works as follows. For each point coordinate in the
// loop, the closest point in the mesh is found. The result is a loop
// of closest point ids from the mesh. Then, the edges in the mesh
// connecting the closest points (and laying along the lines forming
// the loop) are found. A greedy edge tracking procedure is used as
// follows. At the current point, the mesh edge oriented in the
// direction of and whose end point is closest to the line is
// chosen. The edge is followed to the new end point, and the
// procedure is repeated. This process continues until the entire loop
// has been created. 
// 
// To determine what portion of the mesh is inside and outside of the
// loop, three options are possible. 1) the smallest connected region,
// 2) the largest connected region, and 3) the connected region
// closest to a user specified point. (Set the ivar SelectionMode.)
// 
// Once the loop is computed as above, the GenerateSelectionScalars
// controls the output of the filter. If on, then scalar values are
// generated based on distance to the loop lines. Otherwise, the cells
// laying inside the selection loop are output. By default, the mesh
// lying within the loop is output; however, if InsideOut is on, then
// the portion of the mesh lying outside of the loop is output.
//
// The filter can be configured to generate the unselected portions of
// the mesh as output by setting GenerateUnselectedOutput. Use the
// method GetUnselectedOutput to access this output. (Note: this flag
// is pertinent only when GenerateSelectionScalars is off.)

// .SECTION Caveats
// Make sure that the points you pick are on a connected surface. If
// not, then the filter will generate an empty or partial result. Also,
// self-intersecting loops will generate unpredictable results.
//
// During processing of the data, non-triangular cells are converted to
// triangles if GenerateSelectionScalars is off.

// .SECTION See Also
// vtkImplicitSelectionLoop

#ifndef __vtkSelectPolyData_h
#define __vtkSelectPolyData_h

#include "vtkPolyDataToPolyDataFilter.h"

#define VTK_INSIDE_SMALLEST_REGION 0
#define VTK_INSIDE_LARGEST_REGION 1
#define VTK_INSIDE_CLOSEST_POINT_REGION 2

class vtkCharArray;

class VTK_GRAPHICS_EXPORT vtkSelectPolyData : public vtkPolyDataToPolyDataFilter
{
public:
  // Description:
  // Instantiate object with InsideOut turned off, and 
  // GenerateSelectionScalars turned off. The unselected output
  // is not generated, and the inside mode is the smallest region.
  static vtkSelectPolyData *New();

  vtkTypeMacro(vtkSelectPolyData,vtkPolyDataToPolyDataFilter);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Set/Get the flag to control behavior of the filter. If
  // GenerateSelectionScalars is on, then the output of the filter
  // is the same as the input, except that scalars are generated.
  // If off, the filter outputs the cells laying inside the loop, and
  // does not generate scalars.
  vtkSetMacro(GenerateSelectionScalars,int);
  vtkGetMacro(GenerateSelectionScalars,int);
  vtkBooleanMacro(GenerateSelectionScalars,int);

  // Description:
  // Set/Get the InsideOut flag. When off, the mesh within the loop is
  // extracted. When on, the mesh outside the loop is extracted.
  vtkSetMacro(InsideOut,int);
  vtkGetMacro(InsideOut,int);
  vtkBooleanMacro(InsideOut,int);

  // Description:
  // Set/Get the array of point coordinates defining the loop. There must
  // be at least three points used to define a loop.
  vtkSetObjectMacro(Loop,vtkPoints);
  vtkGetObjectMacro(Loop,vtkPoints);

  // Description:
  // Control how inside/outside of loop is defined.
  vtkSetClampMacro(SelectionMode,int,
             VTK_INSIDE_SMALLEST_REGION,VTK_INSIDE_CLOSEST_POINT_REGION);
  vtkGetMacro(SelectionMode,int);
  void SetSelectionModeToSmallestRegion()
    {this->SetSelectionMode(VTK_INSIDE_SMALLEST_REGION);};
  void SetSelectionModeToLargestRegion()
    {this->SetSelectionMode(VTK_INSIDE_LARGEST_REGION);};
  void SetSelectionModeToClosestPointRegion()
    {this->SetSelectionMode(VTK_INSIDE_CLOSEST_POINT_REGION);};
  const char *GetSelectionModeAsString();

  // Description:
  // Control whether a second output is generated. The second output
  // contains the polygonal data that's not been selected.
  vtkSetMacro(GenerateUnselectedOutput,int);
  vtkGetMacro(GenerateUnselectedOutput,int);
  vtkBooleanMacro(GenerateUnselectedOutput,int);

  // Description:
  // Return output that hasn't been selected (if GenreateUnselectedOutput is
  // enabled).
  vtkPolyData *GetUnselectedOutput() {return this->UnselectedOutput;};

  // Description:
  // Return the (mesh) edges of the selection region.
  vtkPolyData *GetSelectionEdges() {return this->SelectionEdges;};

  // Overload GetMTime() because we depend on Loop
  unsigned long int GetMTime();

  // Description:
  // Handle the source/data loop.
  void UnRegister(vtkObject *o);

  // Description:
  // Test to see if this object is in a reference counting loop.
  virtual int InRegisterLoop(vtkObject *);

protected:
  vtkSelectPolyData();
  ~vtkSelectPolyData();

  void Execute();

  int GenerateSelectionScalars;
  int InsideOut;
  vtkPoints *Loop;
  int SelectionMode;
  float ClosestPoint[3];
  int GenerateUnselectedOutput;
  vtkPolyData *UnselectedOutput;
  vtkPolyData *SelectionEdges;

private:
  vtkPolyData *Mesh;
  void GetPointNeighbors (vtkIdType ptId, vtkIdList *nei);
private:
  vtkSelectPolyData(const vtkSelectPolyData&);  // Not implemented.
  void operator=(const vtkSelectPolyData&);  // Not implemented.
};

// Description:
// Return the method of determining in/out of loop as a string.
inline const char *vtkSelectPolyData::GetSelectionModeAsString(void)
{
  if ( this->SelectionMode == VTK_INSIDE_SMALLEST_REGION ) 
    {
    return "InsideSmallestRegion";
    }
  else if ( this->SelectionMode == VTK_INSIDE_LARGEST_REGION ) 
    {
    return "InsideLargestRegion";
    }
  else 
    {
    return "InsideClosestPointRegion";
    }
}

#endif


