Interaction/Widgets/vtkConstrainedPointHandleRepresentation.h

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

  Program:   Visualization Toolkit
  Module:    vtkConstrainedPointHandleRepresentation.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   vtkConstrainedPointHandleRepresentation
 * @brief   point representation constrained to a 2D plane
 *
 * This class is used to represent a vtkHandleWidget. It represents a
 * position in 3D world coordinates that is constrained to a specified plane.
 * The default look is to draw a white point when this widget is not selected
 * or active, a thin green circle when it is highlighted, and a thicker cyan
 * circle when it is active (being positioned). Defaults can be adjusted - but
 * take care to define cursor geometry that makes sense for this widget.
 * The geometry will be aligned on the constraining plane, with the plane
 * normal aligned with the X axis of the geometry (similar behavior to
 * vtkGlyph3D).
 *
 * TODO: still need to work on
 * 1) translation when mouse is outside bounding planes
 * 2) size of the widget
 *
 * @sa
 * vtkHandleRepresentation vtkHandleWidget
 */

#ifndef vtkConstrainedPointHandleRepresentation_h
#define vtkConstrainedPointHandleRepresentation_h

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

class vtkProperty;
class vtkActor;
class vtkPolyDataMapper;
class vtkPolyData;
class vtkGlyph3D;
class vtkPoints;
class vtkPolyData;
class vtkPlane;
class vtkPlaneCollection;
class vtkPlanes;
class vtkRenderer;

class VTKINTERACTIONWIDGETS_EXPORT vtkConstrainedPointHandleRepresentation
  : public vtkHandleRepresentation
{
public:
  /**
   * Instantiate this class.
   */
  static vtkConstrainedPointHandleRepresentation* New();

  ///@{
  /**
   * Standard methods for instances of this class.
   */
  vtkTypeMacro(vtkConstrainedPointHandleRepresentation, vtkHandleRepresentation);
  void PrintSelf(ostream& os, vtkIndent indent) override;
  ///@}

  using vtkHandleRepresentation::Translate;

  ///@{
  /**
   * Specify the cursor shape. Keep in mind that the shape will be
   * aligned with the constraining plane by orienting it such that
   * the x axis of the geometry lies along the normal of the plane.
   */
  void SetCursorShape(vtkPolyData* cursorShape);
  vtkPolyData* GetCursorShape();
  ///@}

  ///@{
  /**
   * Specify the shape of the cursor (handle) when it is active.
   * This is the geometry that will be used when the mouse is
   * close to the handle or if the user is manipulating the handle.
   */
  void SetActiveCursorShape(vtkPolyData* activeShape);
  vtkPolyData* GetActiveCursorShape();
  ///@}

  ///@{
  /**
   * Set the projection normal to lie along the x, y, or z axis,
   * or to be oblique. If it is oblique, then the plane is
   * defined in the ObliquePlane ivar.
   */
  vtkSetClampMacro(ProjectionNormal, int, vtkConstrainedPointHandleRepresentation::XAxis,
    vtkConstrainedPointHandleRepresentation::Oblique);
  vtkGetMacro(ProjectionNormal, int);
  ///@}

  void SetProjectionNormalToXAxis()
  {
    this->SetProjectionNormal(vtkConstrainedPointHandleRepresentation::XAxis);
  }
  void SetProjectionNormalToYAxis()
  {
    this->SetProjectionNormal(vtkConstrainedPointHandleRepresentation::YAxis);
  }
  void SetProjectionNormalToZAxis()
  {
    this->SetProjectionNormal(vtkConstrainedPointHandleRepresentation::ZAxis);
  }
  void SetProjectionNormalToOblique()
  {
    this->SetProjectionNormal(vtkConstrainedPointHandleRepresentation::Oblique);
  }

  ///@{
  /**
   * If the ProjectionNormal is set to Oblique, then this is the
   * oblique plane used to constrain the handle position
   */
  void SetObliquePlane(vtkPlane*);
  vtkGetObjectMacro(ObliquePlane, vtkPlane);
  ///@}

  ///@{
  /**
   * The position of the bounding plane from the origin along the
   * normal. The origin and normal are defined in the oblique plane
   * when the ProjectionNormal is Oblique. For the X, Y, and Z
   * axes projection normals, the normal is the axis direction, and
   * the origin is (0,0,0).
   */
  void SetProjectionPosition(double position);
  vtkGetMacro(ProjectionPosition, double);
  ///@}

  ///@{
  /**
   * A collection of plane equations used to bound the position of the point.
   * This is in addition to confining the point to a plane - these constraints
   * are meant to, for example, keep a point within the extent of an image.
   * Using a set of plane equations allows for more complex bounds (such as
   * bounding a point to an oblique reliced image that has hexagonal shape)
   * than a simple extent.
   */
  void AddBoundingPlane(vtkPlane* plane);
  void RemoveBoundingPlane(vtkPlane* plane);
  void RemoveAllBoundingPlanes();
  virtual void SetBoundingPlanes(vtkPlaneCollection*);
  vtkGetObjectMacro(BoundingPlanes, vtkPlaneCollection);
  void SetBoundingPlanes(vtkPlanes* planes);
  ///@}

  /**
   * Overridden from the base class. It converts the display
   * co-ordinates to world co-ordinates. It returns 1 if the point lies
   * within the constrained region, otherwise return 0
   */
  int CheckConstraint(vtkRenderer* renderer, double pos[2]) override;

  ///@{
  /**
   * Set/Get the position of the point in display coordinates.  These are
   * convenience methods that extend the superclasses' GetHandlePosition()
   * method. Note that only the x-y coordinate values are used
   */
  void SetPosition(double x, double y, double z);
  void SetPosition(double xyz[3]);
  double* GetPosition();
  void GetPosition(double xyz[3]);
  ///@}

  ///@{
  /**
   * This is the property used when the handle is not active
   * (the mouse is not near the handle)
   */
  vtkGetObjectMacro(Property, vtkProperty);
  ///@}

  ///@{
  /**
   * This is the property used when the mouse is near the
   * handle (but the user is not yet interacting with it)
   */
  vtkGetObjectMacro(SelectedProperty, vtkProperty);
  ///@}

  ///@{
  /**
   * This is the property used when the user is interacting
   * with the handle.
   */
  vtkGetObjectMacro(ActiveProperty, vtkProperty);
  ///@}

  ///@{
  /**
   * Subclasses of vtkConstrainedPointHandleRepresentation must implement these methods. These
   * are the methods that the widget and its representation use to
   * communicate with each other.
   */
  void SetRenderer(vtkRenderer* ren) override;
  void BuildRepresentation() override;
  void StartWidgetInteraction(double eventPos[2]) override;
  void WidgetInteraction(double eventPos[2]) override;
  int ComputeInteractionState(int X, int Y, int modify) override;
  ///@}

  /**
   * Method overridden from Superclass. computes the world
   * co-ordinates using GetIntersectionPosition()
   */
  void SetDisplayPosition(double pos[3]) override;

  ///@{
  /**
   * Methods to make this class behave as a vtkProp.
   */
  void GetActors(vtkPropCollection*) override;
  void ReleaseGraphicsResources(vtkWindow*) override;
  int RenderOverlay(vtkViewport* viewport) override;
  int RenderOpaqueGeometry(vtkViewport* viewport) override;
  int RenderTranslucentPolygonalGeometry(vtkViewport* viewport) override;
  vtkTypeBool HasTranslucentPolygonalGeometry() override;
  void ShallowCopy(vtkProp* prop) override;
  ///@}

  enum
  {
    XAxis = 0,
    YAxis,
    ZAxis,
    Oblique
  };

  void Highlight(int highlight) override;

protected:
  vtkConstrainedPointHandleRepresentation();
  ~vtkConstrainedPointHandleRepresentation() override;

  // Render the cursor
  vtkActor* Actor;
  vtkPolyDataMapper* Mapper;
  vtkGlyph3D* Glypher;
  vtkPolyData* CursorShape;
  vtkPolyData* ActiveCursorShape;
  vtkPolyData* FocalData;
  vtkPoints* FocalPoint;

  // Support picking
  double LastPickPosition[3];
  double LastEventPosition[2];

  // Methods to manipulate the cursor
  void Translate(const double* eventPos) override;
  void Scale(const double* eventPos);

  // Properties used to control the appearance of selected objects and
  // the manipulator in general.
  vtkProperty* Property;
  vtkProperty* SelectedProperty;
  vtkProperty* ActiveProperty;
  void CreateDefaultProperties();

  // Controlling vars
  int ProjectionNormal;
  double ProjectionPosition;
  int ProjectToPlane;
  vtkPlane* ObliquePlane;

  vtkPlaneCollection* BoundingPlanes;

  // Internal method for computing 3D location from 2D screen position
  int GetIntersectionPosition(const double eventPos[2], double worldPos[3], double tolerance = 0.0,
    vtkRenderer* renderer = nullptr);

  // Internal method for getting the project normal as a vector
  void GetProjectionNormal(double normal[3]);

  // Internal method for getting the origin of the
  // constraining plane as a 3-tuple
  void GetProjectionOrigin(double origin[3]);

  // Distance between where the mouse event happens and where the
  // widget is focused - maintain this distance during interaction.
  double InteractionOffset[2];

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

#endif