// Created on: 1992-01-30
// Created by: Didier PIFFAULT
// Copyright (c) 1992-1999 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 _TopTrans_SurfaceTransition_HeaderFile
#define _TopTrans_SurfaceTransition_HeaderFile

#include "Standard.hxx"
#include "Standard_DefineAlloc.hxx"

#include "gp_Dir.hxx"
#include "NCollection_Array2.hxx"
#include "TopAbs_Orientation.hxx"
#include "TopAbs_State.hxx"

//! This algorithm is used to compute the transition
//! of a 3D surface intersecting a topological surfacic
//! boundary on a 3D curve ( intersection curve ).
//! The boundary is described by a set of faces
//! each face is described by
//! - its support surface,
//! - an orientation defining its matter side.
//! The geometric elements are described locally at the
//! intersection point by a second order development.
//! A surface is described by the normal vector, the
//! principal directions and the principal curvatures.
//! A curve is described by the tangent, the normal
//! and the curvature.
//! The algorithm keeps track of the two faces elements
//! closest to the part of the curve "before" and "after"
//! the intersection, these two elements are updated
//! for each new face.
//! The position of the curve can be computed when at
//! least one surface element has been given, this
//! position is "In","Out" or "On" for the part of the
//! curve "Before" or "After" the intersection.
class TopTrans_SurfaceTransition
{
public:
  DEFINE_STANDARD_ALLOC

  //! Create an empty Surface Transition.
  Standard_EXPORT TopTrans_SurfaceTransition();

  //! Initialize a Surface Transition with the local
  //! description of the intersection curve and of the
  //! reference surface.
  //! PREQUESITORY : Norm oriented OUTSIDE "geometric matter"
  Standard_EXPORT void Reset(const gp_Dir& Tgt,
                             const gp_Dir& Norm,
                             const gp_Dir& MaxD,
                             const gp_Dir& MinD,
                             const double  MaxCurv,
                             const double  MinCurv);

  //! Initialize a Surface Transition with the local
  //! description of a straight line.
  Standard_EXPORT void Reset(const gp_Dir& Tgt, const gp_Dir& Norm);

  //! Add a face element to the boundary.
  //!
  //! - S defines topological orientation for the face :
  //! S FORWARD means: along the intersection curve on the
  //! reference surface, transition states while crossing
  //! the face are OUT,IN.
  //! S REVERSED means states are IN,OUT.
  //! S INTERNAL means states are IN,IN.
  //!
  //! - O defines curve's position on face :
  //! O FORWARD means the face is before the intersection
  //! O REVERSED means the face is AFTER
  //! O INTERNAL means the curve intersection is in the face.
  //! PREQUESITORY : Norm oriented OUTSIDE "geometric matter"
  Standard_EXPORT void Compare(const double             Tole,
                               const gp_Dir&            Norm,
                               const gp_Dir&            MaxD,
                               const gp_Dir&            MinD,
                               const double             MaxCurv,
                               const double             MinCurv,
                               const TopAbs_Orientation S,
                               const TopAbs_Orientation O);

  //! Add a plane or a cylindric face to the boundary.
  Standard_EXPORT void Compare(const double             Tole,
                               const gp_Dir&            Norm,
                               const TopAbs_Orientation S,
                               const TopAbs_Orientation O);

  //! Returns the state of the reference surface before
  //! the interference, this is the position relative to
  //! the surface of a point very close to the intersection
  //! on the negative side of the tangent.
  Standard_EXPORT TopAbs_State StateBefore() const;

  //! Returns the state of the reference surface after
  //! interference, this is the position relative to the
  //! surface of a point very close to the intersection
  //! on the positive side of the tangent.
  Standard_EXPORT TopAbs_State StateAfter() const;

  Standard_EXPORT static TopAbs_State GetBefore(const TopAbs_Orientation Tran);

  Standard_EXPORT static TopAbs_State GetAfter(const TopAbs_Orientation Tran);

private:
  Standard_EXPORT void UpdateReference(const double             Tole,
                                       const bool               isInfRef,
                                       double&                  CosInf,
                                       double&                  CosSup,
                                       const TopAbs_Orientation Tran,
                                       TopAbs_Orientation&      TranRef);

  Standard_EXPORT double ComputeCos(const double             Tole,
                                    const gp_Dir&            Norm,
                                    const TopAbs_Orientation O,
                                    bool&                    isleft) const;

  gp_Dir                                 myTgt;
  gp_Dir                                 myNorm;
  gp_Dir                                 beafter;
  double                                 myCurvRef;
  NCollection_Array2<double>             myAng;
  NCollection_Array2<double>             myCurv;
  NCollection_Array2<TopAbs_Orientation> myOri;
  bool                                   myIsDefined;
  bool                                   myTouchFlag;
};

#endif // _TopTrans_SurfaceTransition_HeaderFile