// Created on: 1996-12-05
// Created by: Jean-Pierre COMBE/Odile Olivier
// Copyright (c) 1996-1999 Matra Datavision
// Copyright (c) 1999-2014 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 _PrsDim_TangentRelation_HeaderFile
#define _PrsDim_TangentRelation_HeaderFile

#include "PrsDim_Relation.hxx"

//! A framework to display tangency constraints between
//! two or more Interactive Objects of the datum type.
//! The datums are normally faces or edges.
class PrsDim_TangentRelation : public PrsDim_Relation
{
  DEFINE_STANDARD_RTTIEXT(PrsDim_TangentRelation, PrsDim_Relation)
public:
  //! TwoFacesTangent or TwoEdgesTangent relation
  //! Constructs an object to display tangency constraints.
  //! This object is defined by the first shape aFShape, the
  //! second shape aSShape, the plane aPlane and the index anExternRef.
  //! aPlane serves as an optional axis.
  //! anExternRef set to 0 indicates that there is no relation.
  Standard_EXPORT PrsDim_TangentRelation(const TopoDS_Shape&            aFShape,
                                         const TopoDS_Shape&            aSShape,
                                         const occ::handle<Geom_Plane>& aPlane,
                                         const int                      anExternRef = 0);

  //! Returns the external reference for tangency.
  //! The values are as follows:
  //! -   0 - there is no connection;
  //! -   1 - there is a connection to the first shape;
  //! -   2 - there is a connection to the second shape.
  //! This reference is defined at construction time.
  int ExternRef() { return myExternRef; }

  //! Sets the external reference for tangency, aRef.
  //! The values are as follows:
  //! -   0 - there is no connection;
  //! -   1 - there is a connection to the first shape;
  //! -   2 - there is a connection to the second shape.
  //! This reference is initially defined at construction time.
  void SetExternRef(const int aRef) { myExternRef = aRef; }

private:
  Standard_EXPORT void Compute(const occ::handle<PrsMgr_PresentationManager>& thePrsMgr,
                               const occ::handle<Prs3d_Presentation>&         thePrs,
                               const int                                      theMode) override;

  Standard_EXPORT void ComputeSelection(const occ::handle<SelectMgr_Selection>& theSel,
                                        const int                               theMode) override;

  Standard_EXPORT void ComputeTwoFacesTangent(const occ::handle<Prs3d_Presentation>& aPresentation);

  Standard_EXPORT void ComputeTwoEdgesTangent(const occ::handle<Prs3d_Presentation>& aPresentation);

private:
  gp_Pnt myAttach;
  gp_Dir myDir;
  double myLength;
  int    myExternRef;
};

#endif // _PrsDim_TangentRelation_HeaderFile