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

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


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

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 * 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.

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   misrepresented as being the original software.

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ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
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=========================================================================*/
// .NAME vtkTriangularTexture - generate 2D triangular texture map
// .SECTION Description
// vtkTriangularTexture is a filter that generates a 2D texture map based on 
// the paper "Opacity-modulating Triangular Textures for Irregular Surfaces,"
// by Penny Rheingans, IEEE Visualization '96, pp. 219-225.
// The textures assume texture coordinates of (0,0), (1.0) and
// (.5, sqrt(3)/2). The sequence of texture values is the same along each
// edge of the triangular texture map. So, the assignment order of texture
// coordinates is arbitrary.

// .SECTION See Also
// vtkTriangularTCoords

#ifndef __vtkTriangularTexture_h
#define __vtkTriangularTexture_h

#include "vtkStructuredPointsSource.h"

class VTK_EXPORT vtkTriangularTexture : public vtkStructuredPointsSource
{
public:
  vtkTypeMacro(vtkTriangularTexture,vtkStructuredPointsSource);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Instantiate object with XSize and YSize = 64; the texture pattern =1
  // (opaque at centroid); and the scale factor set to 1.0.
  static vtkTriangularTexture *New();

  // Description:
  // Set a Scale Factor.
  vtkSetMacro(ScaleFactor,float);
  vtkGetMacro(ScaleFactor,float);

  // Description:
  // Set the X texture map dimension. Default is 64.
  vtkSetMacro(XSize,int);
  vtkGetMacro(XSize,int);

  // Description:
  // Set the Y texture map dimension. Default is 64.
  vtkSetMacro(YSize,int);
  vtkGetMacro(YSize,int);

  // Description:
  // Set the texture pattern.
  //    1 = opaque at centroid (default)
  //    2 = opaque at vertices
  //    3 = opaque in rings around vertices
  vtkSetClampMacro(TexturePattern,int,1,3);
  vtkGetMacro(TexturePattern,int);

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

  void Execute();

  int XSize;
  int YSize;
  float ScaleFactor;

  int TexturePattern;
};

#endif


