OCCT/src/SelectMgr/SelectMgr_RectangularFrustum.hxx

// Created on: 2014-05-22
// Created by: Varvara POSKONINA
// Copyright (c) 2005-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#ifndef _SelectMgr_RectangularFrustum_HeaderFile
#define _SelectMgr_RectangularFrustum_HeaderFile

#include <SelectMgr_Frustum.hxx>

//! This class contains representation of rectangular selecting frustum, created in case
//! of point and box selection, and algorithms for overlap detection between selecting
//! frustum and sensitive entities. The principle of frustum calculation:
//! - for point selection: on a near view frustum plane rectangular neighborhood of
//!                        user-picked point is created according to the pixel tolerance
//!                        given and then this rectangle is projected onto far view frustum
//!                        plane. This rectangles define the parallel bases of selecting frustum;
//! - for box selection: box points are projected onto near and far view frustum planes.
//!                      These 2 projected rectangles define parallel bases of selecting frustum.
//! Overlap detection tests are implemented according to the terms of separating axis
//! theorem (SAT).
class SelectMgr_RectangularFrustum : public SelectMgr_Frustum<4>
{
public:

  SelectMgr_RectangularFrustum() {};

  //! Builds volume according to the point and given pixel tolerance
  virtual void Build (const gp_Pnt2d& thePoint) Standard_OVERRIDE;

  //! Builds volume according to the selected rectangle
  virtual void Build (const gp_Pnt2d& theMinPnt,
                      const gp_Pnt2d& theMaxPnt) Standard_OVERRIDE;

  //! Returns a copy of the frustum transformed according to the matrix given
  virtual NCollection_Handle<SelectMgr_BaseFrustum> Transform (const gp_Trsf& theTrsf) Standard_OVERRIDE;


  // SAT Tests for different objects

  //! SAT intersection test between defined volume and given axis-aligned box
  virtual const Standard_Boolean Overlaps (const BVH_Box<Standard_Real, 3>& theBox,
                                           Standard_Real& theDepth) Standard_OVERRIDE;

  //! Returns true if selecting volume is overlapped by axis-aligned bounding box
  //! with minimum corner at point theMinPt and maximum at point theMaxPt
  virtual const Standard_Boolean Overlaps (const SelectMgr_Vec3& theMinPnt,
                                           const SelectMgr_Vec3& theMaxPnt) Standard_OVERRIDE;

  //! Intersection test between defined volume and given point
  virtual const Standard_Boolean Overlaps (const gp_Pnt& thePnt,
                                           Standard_Real& theDepth) Standard_OVERRIDE;

  //! SAT intersection test between defined volume and given ordered set of points,
  //! representing line segments. The test may be considered of interior part or
  //! boundary line defined by segments depending on given sensitivity type
  virtual const Standard_Boolean Overlaps (const Handle(TColgp_HArray1OfPnt)& theArrayOfPnts,
                                           Select3D_TypeOfSensitivity theSensType,
                                           Standard_Real& theDepth) Standard_OVERRIDE;

  //! Checks if line segment overlaps selecting frustum
  virtual const Standard_Boolean Overlaps (const gp_Pnt& thePnt1,
                                           const gp_Pnt& thePnt2,
                                           Standard_Real& theDepth) Standard_OVERRIDE;

  //! SAT intersection test between defined volume and given triangle. The test may
  //! be considered of interior part or boundary line defined by triangle vertices
  //! depending on given sensitivity type
  virtual const Standard_Boolean Overlaps (const gp_Pnt& thePnt1,
                                           const gp_Pnt& thePnt2,
                                           const gp_Pnt& thePnt3,
                                           Select3D_TypeOfSensitivity theSensType,
                                           Standard_Real& theDepth) Standard_OVERRIDE;

  //! Measures distance between 3d projection of user-picked
  //! screen point and given point theCOG
  virtual const Standard_Real DistToGeometryCenter (const gp_Pnt& theCOG) Standard_OVERRIDE;

  //! Calculates the point on a view ray that was detected during the run of selection algo by given depth
  virtual SelectMgr_Vec3 DetectedPoint (const Standard_Real theDepth) const Standard_OVERRIDE;

  //! Checks if the point of sensitive in which selection was detected belongs
  //! to the region defined by clipping planes
  virtual const Standard_Boolean IsClipped (const Graphic3d_SequenceOfHClipPlane& thePlanes,
                                            const Standard_Real theDepth) Standard_OVERRIDE;

protected:

  void segmentSegmentDistance (const gp_Pnt& theSegPnt1,
                               const gp_Pnt& theSegPnt2,
                               Standard_Real& theDepth);

  void segmentPlaneIntersection (const SelectMgr_Vec3& thePlane,
                                 const gp_Pnt& thePntOnPlane,
                                 Standard_Real& theDepth);

private:

  SelectMgr_Vec3 myNearPickedPnt;             //!< 3d projection of user-picked selection point onto near view plane
  SelectMgr_Vec3 myFarPickedPnt;               //!< 3d projection of user-picked selection point onto far view plane
  SelectMgr_Vec3 myViewRayDir;
};

#endif // _SelectMgr_RectangularFrustum_HeaderFile