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graphics/vtkPiecewiseFunction.h

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

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkPiecewiseFunction.h,v $
  Language:  C++


Copyright (c) 1993-2001 Ken Martin, Will Schroeder, Bill Lorensen 
All rights reserved.

Redistribution and use in source and binary forms, with or without
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
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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

#ifndef __vtkPiecewiseFunction_h
#define __vtkPiecewiseFunction_h

#include "vtkDataObject.h"

class VTK_EXPORT vtkPiecewiseFunction : public vtkDataObject
{
public:
  static vtkPiecewiseFunction *New();
  vtkTypeMacro(vtkPiecewiseFunction,vtkDataObject);
  void PrintSelf(ostream& os, vtkIndent indent);

  vtkDataObject *MakeObject();
  void Initialize();
  void DeepCopy( vtkDataObject *f );
  void ShallowCopy( vtkDataObject *f );

  int GetDataObjectType() {return VTK_PIECEWISE_FUNCTION;};
  
  int  GetSize();

  void AddPoint( float x, float val );
  void RemovePoint( float x );

  void RemoveAllPoints();

  void AddSegment( float x1, float val1, float x2, float val2 );

  float GetValue( float x );

  float *GetDataPointer() {return this->Function;};

  float *GetRange();

  void GetTable( float x1, float x2, int size, float *table, int stride=1 );

  void BuildFunctionFromTable( float x1, float x2, int size,
                float *table, int stride=1 );
  
  vtkSetMacro( Clamping, int );
  vtkGetMacro( Clamping, int );
  vtkBooleanMacro( Clamping, int );

  const char  *GetType();

  unsigned long GetMTime();

  float GetFirstNonZeroValue();

protected:
  vtkPiecewiseFunction();
  ~vtkPiecewiseFunction();
  vtkPiecewiseFunction(const vtkPiecewiseFunction&) {};
  void operator=(const vtkPiecewiseFunction&) {};

  // Size of the array used to store function points
  int ArraySize;

  // Determines the function value outside of defined points
  // Zero = always return 0.0 outside of defined points
  // One  = clamp to the lowest value below defined points and
  //        highest value above defined points
  int Clamping;

  // Array of points ((X,Y) pairs)
  float  *Function;

  // Number of points used to specify function
  int   FunctionSize;

  // Min and max range of function point locations
  float FunctionRange[2];

  // Increases size of the function array. The array grows by a factor of 2
  // when the array limit has been reached.
  void IncreaseArraySize();

  // Private function to add a point to the function. Returns the array
  // index of the inserted point.
  int InsertPoint( float x, float val );

  // Move points one index down or up in the array. This is useful for 
  // inserting and deleting points into the array.
  void MovePoints( int index, int down );
};

#endif

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