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

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkEllipticalButtonSource.h,v $

  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 vtkEllipticalButtonSource - create a ellipsoidal-shaped button
// .SECTION Description
// vtkEllipticalButtonSource creates a ellipsoidal shaped button with
// texture coordinates suitable for application of a texture map. This
// provides a way to make nice looking 3D buttons. The buttons are 
// represented as vtkPolyData that includes texture coordinates and
// normals. The button lies in the x-y plane.
//
// To use this class you must define the major and minor axes lengths of an
// ellipsoid (expressed as width (x), height (y) and depth (z)). The button
// has a rectangular mesh region in the center with texture coordinates that
// range smoothly from (0,1). (This flat region is called the texture
// region.) The outer, curved portion of the button (called the shoulder) has
// texture coordinates set to a user specified value (by default (0,0).
// (This results in coloring the button curve the same color as the (s,t)
// location of the texture map.) The resolution in the radial direction, the
// texture region, and the shoulder region must also be set. The button can
// be moved by specifying an origin.

#ifndef __vtkEllipticalButtonSource_h
#define __vtkEllipticalButtonSource_h

#include "vtkButtonSource.h"

class vtkCellArray;
class vtkFloatArray;
class vtkPoints;

class VTK_GRAPHICS_EXPORT vtkEllipticalButtonSource : public vtkButtonSource 
{
public:
  void PrintSelf(ostream& os, vtkIndent indent);
  vtkTypeRevisionMacro(vtkEllipticalButtonSource,vtkButtonSource);

  // Description:
  // Construct a circular button with depth 10% of its height.
  static vtkEllipticalButtonSource *New();

  // Description:
  // Set/Get the width of the button (the x-ellipsoid axis length * 2).
  vtkSetClampMacro(Width,double,0.0,VTK_DOUBLE_MAX);
  vtkGetMacro(Width,double);

  // Description:
  // Set/Get the height of the button (the y-ellipsoid axis length * 2).
  vtkSetClampMacro(Height,double,0.0,VTK_DOUBLE_MAX);
  vtkGetMacro(Height,double);

  // Description:
  // Set/Get the depth of the button (the z-eliipsoid axis length).
  vtkSetClampMacro(Depth,double,0.0,VTK_DOUBLE_MAX);
  vtkGetMacro(Depth,double);

  // Description:
  // Specify the resolution of the button in the circumferential direction.
  vtkSetClampMacro(CircumferentialResolution,int,4,VTK_LARGE_INTEGER);
  vtkGetMacro(CircumferentialResolution,int);

  // Description:
  // Specify the resolution of the texture in the radial direction in the
  // texture region.
  vtkSetClampMacro(TextureResolution,int,1,VTK_LARGE_INTEGER);
  vtkGetMacro(TextureResolution,int);

  // Description:
  // Specify the resolution of the texture in the radial direction in the
  // shoulder region.
  vtkSetClampMacro(ShoulderResolution,int,1,VTK_LARGE_INTEGER);
  vtkGetMacro(ShoulderResolution,int);

  // Description:
  // Set/Get the radial ratio. This is the measure of the radius of the
  // outer ellipsoid to the inner ellipsoid of the button. The outer
  // ellipsoid is the boundary of the button defined by the height and
  // width. The inner ellipsoid circumscribes the texture region. Larger
  // RadialRatio's cause the button to be more rounded (and the texture
  // region to be smaller); smaller ratios produce sharply curved shoulders
  // with a larger texture region.
  vtkSetClampMacro(RadialRatio,double,1.0,VTK_DOUBLE_MAX);
  vtkGetMacro(RadialRatio,double);

protected:
  vtkEllipticalButtonSource();
  ~vtkEllipticalButtonSource() {}

  int RequestData(vtkInformation *, vtkInformationVector **, vtkInformationVector *);

  double Width;
  double Height;
  double Depth;
  int   CircumferentialResolution;
  int   TextureResolution;
  int   ShoulderResolution;
  double RadialRatio;

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

  //internal variable related to axes of ellipsoid
  double A;
  double A2;
  double B;
  double B2;
  double C;
  double C2;
  
  double ComputeDepth(int inTextureRegion, double x, double y, double n[3]);
  void InterpolateCurve(int inTextureRegion, vtkPoints *newPts, int numPts,
                        vtkFloatArray *normals, vtkFloatArray *tcoords, 
                        int res, int c1StartPoint,int c1Incr,
                        int c2StartPoint,int s2Incr, int startPoint,int incr);
  void CreatePolygons(vtkCellArray *newPolys, int num, int res, int startIdx);
  void IntersectEllipseWithLine(double a2, double b2, double dX, double dY, 
                                double& xe, double& ye);
  
    
};

#endif