vtkBiDimensionalRepresentation2D.h

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

  Program:   Visualization Toolkit
  Module:    vtkBiDimensionalRepresentation2D.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.

=========================================================================*/
// .NAME vtkBiDimensionalRepresentation2D - represent the vtkBiDimensionalWidget
// .SECTION Description
// The vtkBiDimensionalRepresentation2D is used to represent the
// bi-dimensional measure in a 2D (overlay) context. This representation
// consists of two perpendicular lines defined by four
// vtkHandleRepresentations. The four handles can be independently
// manipulated consistent with the orthogonal constraint on the lines. (Note:
// the four points are referred to as Point1, Point2, Point3 and
// Point4. Point1 and Point2 define the first line; and Point3 and Point4
// define the second orthogonal line.)
//
// To create this widget, you click to place the first two points. The third
// point is mirrored with the fourth point; when you place the third point
// (which is orthogonal to the lined defined by the first two points), the
// fourth point is dropped as well. After definition, the four points can be
// moved (in constrained fashion, preserving orthogonality). Further, the
// entire widget can be translated by grabbing the center point of the widget;
// each line can be moved along the other line; and the entire widget can be
// rotated around its center point.

// .SECTION See Also
// vtkAngleWidget vtkHandleRepresentation vtkBiDimensionalRepresentation


#ifndef vtkBiDimensionalRepresentation2D_h
#define vtkBiDimensionalRepresentation2D_h

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

class vtkHandleRepresentation;
class vtkCellArray;
class vtkPoints;
class vtkPolyData;
class vtkPolyDataMapper2D;
class vtkTextMapper;
class vtkActor2D;
class vtkProperty2D;
class vtkTextProperty;


class VTKINTERACTIONWIDGETS_EXPORT vtkBiDimensionalRepresentation2D : public vtkBiDimensionalRepresentation
{
public:
  // Description:
  // Instantiate the class.
  static vtkBiDimensionalRepresentation2D *New();

  // Description:
  // Standard VTK methods.
  vtkTypeMacro(vtkBiDimensionalRepresentation2D,vtkBiDimensionalRepresentation);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Retrieve the property used to control the appearance of the two
  // orthogonal lines.
  vtkGetObjectMacro(LineProperty,vtkProperty2D);
  vtkGetObjectMacro(SelectedLineProperty,vtkProperty2D);

  // Description:
  // Retrieve the property used to control the appearance of the text
  // labels.
  vtkGetObjectMacro(TextProperty,vtkTextProperty);

//BTX -- used to communicate about the state of the representation
  enum {Outside=0,NearP1,NearP2,NearP3,NearP4,OnL1Inner,OnL1Outer,OnL2Inner,OnL2Outer,OnCenter};
//ETX

  // Description:
  // These are methods that satisfy vtkWidgetRepresentation's API.
  virtual void BuildRepresentation();
  virtual int ComputeInteractionState(int X, int Y, int modify=0);
  virtual void StartWidgetDefinition(double e[2]);
  virtual void Point2WidgetInteraction(double e[2]);
  virtual void Point3WidgetInteraction(double e[2]);
  virtual void StartWidgetManipulation(double e[2]);
  virtual void WidgetInteraction(double e[2]);
  virtual void Highlight(int highlightOn);

  // Description:
  // Methods required by vtkProp superclass.
  virtual void ReleaseGraphicsResources(vtkWindow *w);
  virtual int RenderOverlay(vtkViewport *viewport);

  // Description:
  // Get the text shown in the widget's label.
  char* GetLabelText();

  // Description:
  // Get the position of the widget's label in display coordinates.
  double* GetLabelPosition();
  void GetLabelPosition(double pos[3]);
  void GetWorldLabelPosition(double pos[3]);

protected:
  vtkBiDimensionalRepresentation2D();
  ~vtkBiDimensionalRepresentation2D();

  // Keep track if modifier is set
  int Modifier;

  // Geometry of the lines
  vtkCellArray        *LineCells;
  vtkPoints           *LinePoints;
  vtkPolyData         *LinePolyData;
  vtkPolyDataMapper2D *LineMapper;
  vtkActor2D          *LineActor;
  vtkProperty2D       *LineProperty;
  vtkProperty2D       *SelectedLineProperty;

  // The labels for the line lengths
  vtkTextProperty *TextProperty;
  vtkTextMapper   *TextMapper;
  vtkActor2D      *TextActor;

  // Internal variables
  double P1World[3];
  double P2World[3];
  double P3World[3];
  double P4World[3];
  double P21World[3];
  double P43World[3];
  double T21;
  double T43;
  double CenterWorld[3];
  double StartEventPositionWorld[4];

  // Helper method
  void ProjectOrthogonalPoint(double x[4], double y[3], double x1[3], double x2[3], double x21[3],
                              double dir, double xP[3]);

private:
  vtkBiDimensionalRepresentation2D(const vtkBiDimensionalRepresentation2D&);  //Not implemented
  void operator=(const vtkBiDimensionalRepresentation2D&);  //Not implemented
};

#endif