vtkFixedSizeHandleRepresentation3D.h

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

  Program:   Visualization Toolkit
  Module:    vtkFixedSizeHandleRepresentation.h

  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.

=========================================================================*/
/**
 * @class   vtkFixedSizeHandleRepresentation
 * @brief   A marker that has the same size in pixels.
 *
 *
 * This class is a concrete implementation of vtkHandleRepresentation. It is
 * meant to be used as a representation for vtkHandleWidget. Unlike the other
 * representations, this can maintain a constant size in pixels, regardless of
 * the camera zoom parameters. The size in pixels may be set via
 * SetHandleSizeInPixels. This representation renders the markers as spherical
 * blobs in 3D space with the width as specified above, defaults to 10 pixels.
 * The handles will have the same size in pixels, give or take a certain
 * tolerance, as specified by SetHandleSizeToleranceInPixels. The tolerance
 * defaults to half a pixel. PointPlacers may be used to specify constraints on
 * the placement of markers. For instance a vtkPolygonalSurfacePointPlacer
 * will constrain placement of these spherical handles to a surface mesh.
 *
 * @sa
 * vtkHandleRepresentation vtkHandleWidget
*/

#ifndef vtkFixedSizeHandleRepresentation3D_h
#define vtkFixedSizeHandleRepresentation3D_h

#include "vtkInteractionWidgetsModule.h" // For export macro
#include "vtkPolygonalHandleRepresentation3D.h"

class vtkSphereSource;

class VTKINTERACTIONWIDGETS_EXPORT vtkFixedSizeHandleRepresentation3D : public vtkPolygonalHandleRepresentation3D
{
public:

  /**
   * Instantiate this class.
   */
  static vtkFixedSizeHandleRepresentation3D *New();

  //@{
  /**
   * Standard vtk methods
   */
  vtkTypeMacro(vtkFixedSizeHandleRepresentation3D,
               vtkPolygonalHandleRepresentation3D);
  void PrintSelf(ostream& os, vtkIndent indent) override;
  //@}

  //@{
  /**
   * Get the object used to render the spherical handle marker
   */
  vtkGetObjectMacro( SphereSource, vtkSphereSource );
  //@}

  //@{
  /**
   * Set/Get the required handle size in pixels. Defaults to a width of
   * 10 pixels.
   */
  vtkSetMacro( HandleSizeInPixels, double );
  vtkGetMacro( HandleSizeInPixels, double );
  //@}

  //@{
  /**
   * Specify the acceptable handle size tolerance. During each render, the
   * handle 3D source will be updated to automatically match a display size
   * as specified by HandleSizeInPixels. This update will be done if the
   * handle size is larger than a tolerance. Default value of this
   * tolerance is half a pixel.
   */
  vtkSetMacro( HandleSizeToleranceInPixels, double );
  vtkGetMacro( HandleSizeToleranceInPixels, double );
  //@}

protected:
  vtkFixedSizeHandleRepresentation3D();
  ~vtkFixedSizeHandleRepresentation3D() override;

  /**
   * Recomputes the handle world size based on the set display size.
   */
  void BuildRepresentation() override;

  /**
   * Convenience method to convert from world to display
   */
  void WorldToDisplay( double w[4], double d[4] );

  /**
   * Convenience method to convert from display to world
   */
  void DisplayToWorld( double d[4], double w[4] );

  vtkSphereSource *                           SphereSource;
  double                                      HandleSizeInPixels;
  double                                      HandleSizeToleranceInPixels;

private:
  vtkFixedSizeHandleRepresentation3D(const vtkFixedSizeHandleRepresentation3D&) = delete;
  void operator=(const vtkFixedSizeHandleRepresentation3D&) = delete;
};

#endif