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

  Program:   Visualization Toolkit
  Module:    vtkAffineRepresentation.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   vtkAffineRepresentation
 * @brief   abstract class for representing affine transformation widgets
 *
 * This class defines an API for affine transformation widget
 * representations. These representations interact with vtkAffineWidget. The
 * basic functionality of the affine representation is to maintain a
 * transformation matrix.
 *
 * This class may be subclassed so that alternative representations can
 * be created.  The class defines an API and a default implementation that
 * the vtkAffineWidget interacts with to render itself in the scene.
 *
 * @warning
 * The separation of the widget event handling and representation enables
 * users and developers to create new appearances for the widget. It also
 * facilitates parallel processing, where the client application handles
 * events, and remote representations of the widget are slaves to the
 * client (and do not handle events).
 *
 * @sa
 * vtkAffineWidget vtkWidgetRepresentation vtkAbstractWidget
*/

#ifndef vtkAffineRepresentation_h
#define vtkAffineRepresentation_h

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

class vtkTransform;

class VTKINTERACTIONWIDGETS_EXPORT vtkAffineRepresentation : public vtkWidgetRepresentation
{
public:
  //@{
  /**
   * Standard methods for instances of this class.
   */
  vtkTypeMacro(vtkAffineRepresentation,vtkWidgetRepresentation);
  void PrintSelf(ostream& os, vtkIndent indent) VTK_OVERRIDE;
  //@}

  /**
   * Retrieve a linear transform characterizing the affine transformation
   * generated by this widget. This method copies its internal transform into
   * the transform provided. The transform is relative to the initial placement
   * of the representation (i.e., when PlaceWidget() is invoked).
   */
  virtual void GetTransform(vtkTransform *t) = 0;

  //@{
  /**
   * The tolerance representing the distance to the widget (in pixels)
   * in which the cursor is considered near enough to the widget to
   * be active.
   */
  vtkSetClampMacro(Tolerance,int,1,100);
  vtkGetMacro(Tolerance,int);
  //@}

  // Enums define the state of the representation relative to the mouse pointer
  // position. Used by ComputeInteractionState() to communicate with the
  // widget.
  enum _InteractionState
  {
    Outside=0, Rotate, Translate, TranslateX, TranslateY, ScaleWEdge, ScaleEEdge,
    ScaleNEdge, ScaleSEdge, ScaleNE, ScaleSW, ScaleNW, ScaleSE,
    ShearEEdge, ShearWEdge, ShearNEdge, ShearSEdge,
    MoveOriginX, MoveOriginY, MoveOrigin
  };

  /**
   * Methods to make this class properly act like a vtkWidgetRepresentation.
   */
  void ShallowCopy(vtkProp *prop) VTK_OVERRIDE;

protected:
  vtkAffineRepresentation();
  ~vtkAffineRepresentation() VTK_OVERRIDE;

  // The tolerance for selecting different parts of the widget.
  int Tolerance;

  // The internal transformation matrix
  vtkTransform *Transform;

private:
  vtkAffineRepresentation(const vtkAffineRepresentation&) VTK_DELETE_FUNCTION;
  void operator=(const vtkAffineRepresentation&) VTK_DELETE_FUNCTION;
};

#endif
