OCCT/src/TopClass/TopClass_Classifier2d.gxx

// Created on: 1992-11-17
// Created by: Laurent BUCHARD
// 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.

// Modified:	Mon May 13 15:20:43 1996
//-- Reinitialisation des transitions complexes

//  Modified by skv - Wed Jul 12 15:20:58 2006 OCC12627


#include <IntRes2d_IntersectionSegment.hxx>
#include <IntRes2d_IntersectionPoint.hxx>
#include <gp_Vec2d.hxx>

//=======================================================================
//function : TopClass_Classifier2d
//purpose  : 
//=======================================================================

TopClass_Classifier2d::TopClass_Classifier2d() :
       myIsSet(Standard_False),
       myFirstCompare(Standard_True),
       myState(TopAbs_UNKNOWN),      // skv OCC12627
       myIsHeadOrEnd(Standard_False) // skv OCC12627
{
}

//=======================================================================
//function : Reset
//purpose  : 
//=======================================================================

void TopClass_Classifier2d::Reset(const gp_Lin2d& L,  
				  const Standard_Real P,
				  const Standard_Real Tol)
{
  myLin = L;
  myParam = P;
  myTolerance = Tol;
  myState = TopAbs_UNKNOWN;
  myFirstCompare = Standard_True;
  myFirstTrans = Standard_True;
  myClosest = 0;
  myIsSet = Standard_True;
//  Modified by skv - Wed Jul 12 15:20:58 2006 OCC12627 Begin
  myIsHeadOrEnd = Standard_False;
//  Modified by skv - Wed Jul 12 15:20:58 2006 OCC12627 End
}

//=======================================================================
//function : Compare
//purpose  : 
//=======================================================================

void TopClass_Classifier2d::Compare(const TheEdge& E,
				    const TopAbs_Orientation Or)
{
  // intersect the edge and the segment
  myClosest = 0;
  myIntersector.Perform(myLin,myParam,myTolerance,E);
  if (!myIntersector.IsDone()) return;
  if ((myIntersector.NbPoints()   == 0)&&
      (myIntersector.NbSegments() == 0)) return;

  // find the closest point
  Standard_Integer iPoint, iSegment, nbPoints, nbSegments;

  const IntRes2d_IntersectionPoint *PClosest = NULL;

  Standard_Real dMin = RealLast();
  nbPoints = myIntersector.NbPoints();
  for (iPoint = 1; iPoint <= nbPoints;  iPoint++)  {
    const IntRes2d_IntersectionPoint& PInter = myIntersector.Point(iPoint);
    // test for ON
    if (PInter.TransitionOfFirst().PositionOnCurve() == IntRes2d_Head) {
      myClosest = iPoint;
      myState = TopAbs_ON;
      return;
    }
    Standard_Real paramfirst = PInter.ParamOnFirst();
    if (paramfirst <  dMin) {
      myClosest = iPoint;
      PClosest = &PInter;
      dMin = paramfirst;
    }
  }

  // for the segments we only test the first point
  nbSegments = myIntersector.NbSegments();
  for (iSegment = 1; iSegment <= nbSegments;  iSegment++)  {
    const IntRes2d_IntersectionSegment& SegInter = 
      myIntersector.Segment(iSegment);
    const IntRes2d_IntersectionPoint& PInter = SegInter.FirstPoint();
    if (PInter.TransitionOfFirst().PositionOnCurve() == IntRes2d_Head) {
      myClosest = nbPoints + iSegment+  iSegment - 1;
      myState = TopAbs_ON;
      return;
    }
    Standard_Real paramfirst = PInter.ParamOnFirst();
    if (paramfirst <  dMin) {
      myClosest = nbPoints + iSegment+iSegment - 1;
      PClosest = &PInter;
      dMin = paramfirst;
    }
  }

  // if no point was found return
  if (myClosest == 0) return;

  // if the Edge is INTERNAL or EXTERNAL, no problem
  if (Or == TopAbs_INTERNAL) {
    myState = TopAbs_IN;
    return;
  }
  else if (Or == TopAbs_EXTERNAL) {
    myState = TopAbs_OUT;
    return;
  }


  if ( ! myFirstCompare ) {
    Standard_Boolean b = (dMin > myParam);
    if (b) {
      // dMin > myParam : le point le plus proche (dMin) trouve dans CETTE
      // intersection ligne,arete n'est pas le plus proche
      // de TOUS les points d'intersection avec les autres aretes (myParam).
      return;
    }
  }
  
  // process the closest point PClosest, found at dMin on line.
  myFirstCompare = Standard_False;

  if(myParam > dMin) {  //-- lbr le 13 mai 96 
    myFirstTrans = Standard_True; 
  } 
  
  myParam = dMin;
  const IntRes2d_Transition& T2 = PClosest->TransitionOfSecond();
//  Modified by skv - Wed Jul 12 15:20:58 2006 OCC12627 Begin
//   Standard_Boolean isHeadorEnd = (T2.PositionOnCurve() == IntRes2d_Head) ||
//                                  (T2.PositionOnCurve() == IntRes2d_End);
  myIsHeadOrEnd = (T2.PositionOnCurve() == IntRes2d_Head) ||
                  (T2.PositionOnCurve() == IntRes2d_End);
//  Modified by skv - Wed Jul 12 15:20:58 2006 OCC12627 End
  
  // transition on the segment

  TopAbs_Orientation SegTrans = TopAbs_FORWARD;

  const IntRes2d_Transition& T1 = PClosest->TransitionOfFirst();
  switch (T1.TransitionType()) {
  case IntRes2d_In :
    if (Or == TopAbs_REVERSED)   SegTrans = TopAbs_REVERSED;
    else                         SegTrans = TopAbs_FORWARD;
    break;
  case IntRes2d_Out :
    if (Or == TopAbs_REVERSED)   SegTrans = TopAbs_FORWARD;
    else                         SegTrans = TopAbs_REVERSED;
    break;
  case IntRes2d_Touch :
    switch (T1.Situation()) {
    case IntRes2d_Inside :
      if (Or == TopAbs_REVERSED) SegTrans = TopAbs_EXTERNAL;
      else                       SegTrans = TopAbs_INTERNAL;
      break;
    case IntRes2d_Outside :
      if (Or == TopAbs_REVERSED) SegTrans = TopAbs_INTERNAL;
      else                       SegTrans = TopAbs_EXTERNAL;
      break;
    case IntRes2d_Unknown :      return;
    }
    break;
  case IntRes2d_Undecided :      return;
  }

  // are we inside the Edge ?
  //  const IntRes2d_Transition& T2 = PClosest->TransitionOfSecond();
  if ( ! myIsHeadOrEnd ) {
    // PClosest is inside the edge
    switch (SegTrans) {

    case TopAbs_FORWARD :
    case TopAbs_EXTERNAL :
      myState = TopAbs_OUT;
      break;

    case TopAbs_REVERSED :
    case TopAbs_INTERNAL :
      myState = TopAbs_IN;
      break;
    }
  }
  else {
    // PClosest is Head or End of the edge : update the complex transition
    gp_Dir2d Tang2d,Norm2d;
    Standard_Real Curv;
    myIntersector.LocalGeometry
      (E,PClosest->ParamOnSecond(),Tang2d,Norm2d,Curv);
    gp_Dir Tang(Tang2d.X(),Tang2d.Y(),0.);
    gp_Dir Norm(Norm2d.X(),Norm2d.Y(),0.);
    if (myFirstTrans) {
      gp_Dir D(myLin.Direction().X(),myLin.Direction().Y(),0.);
      myTrans.Reset(D);
      myFirstTrans = Standard_False;
    }
    
    TopAbs_Orientation Ort;
    if (T2.PositionOnCurve() == IntRes2d_Head) Ort = TopAbs_FORWARD;
    else                                       Ort = TopAbs_REVERSED;
    myTrans.Compare(RealEpsilon(), Tang, Norm,  Curv, SegTrans, Ort);
    myState = myTrans.StateBefore();
  }
}