libsrc/stlgeom/stltopology.cpp

#include <mystdlib.h>

#include <myadt.hpp>
#include <linalg.hpp>
#include <gprim.hpp>

#include <meshing.hpp>

#include "stlgeom.hpp"

namespace netgen
{


STLTopology :: STLTopology()
  : trias(), topedges(), points(), ht_topedges(NULL),
    neighbourtrigs(), trigsperpoint()
{
  ;
}

STLTopology :: ~STLTopology()
{
  ;
}


STLGeometry *  STLTopology :: LoadBinary (istream & ist)
{
  STLGeometry * geom = new STLGeometry();
  ARRAY<STLReadTriangle> readtrigs;

  PrintMessage(1,"Read STL binary file");

  if (sizeof(int) != 4 || sizeof(float) != 4)
    {
      PrintWarning("for stl-binary compatibility only use 32 bit compilation!!!");
    }

  //specific settings for stl-binary format
  const int namelen = 80; //length of name of header in file
  const int nospaces = 2; //number of spaces after a triangle

  //read header: name
  char buf[namelen+1];
  FIOReadStringE(ist,buf,namelen);
  PrintMessage(5,"header = ",buf);

  //Read Number of facets
  int nofacets;
  FIOReadInt(ist,nofacets);
  PrintMessage(5,"NO facets = ",nofacets);

  Point<3> pts[3];
  Vec<3> normal;

  int cntface, j;
  //int vertex = 0;
  float f;
  char spaces[nospaces+1];

  for (cntface = 0; cntface < nofacets; cntface++)
    {
      if (cntface % 10000 == 9999) { PrintDot(); }

      FIOReadFloat(ist,f); normal(0) = f;
      FIOReadFloat(ist,f); normal(1) = f;
      FIOReadFloat(ist,f); normal(2) = f;

      for (j = 0; j < 3; j++)
	{
	  FIOReadFloat(ist,f); pts[j](0) = f;
	  FIOReadFloat(ist,f); pts[j](1) = f;
	  FIOReadFloat(ist,f); pts[j](2) = f;
	}

      readtrigs.Append (STLReadTriangle (pts, normal));
      FIOReadString(ist,spaces,nospaces);
    }


  geom->InitSTLGeometry(readtrigs);

  return geom;
}


void STLTopology :: SaveBinary (const char* filename, const char* aname)
{
  ofstream ost(filename);
  PrintFnStart("Write STL binary file '",filename,"'");

  if (sizeof(int) != 4 || sizeof(float) != 4)
    {PrintWarning("for stl-binary compatibility only use 32 bit compilation!!!");}

  //specific settings for stl-binary format
  const int namelen = 80; //length of name of header in file
  const int nospaces = 2; //number of spaces after a triangle

  //write header: aname
  int i, j;
  char buf[namelen+1];
  int strend = 0;
  for(i = 0; i <= namelen; i++)
    {
      if (aname[i] == 0) {strend = 1;}
      if (!strend) {buf[i] = aname[i];}
      else {buf[i] = 0;}
    }

  FIOWriteString(ost,buf,namelen);
  PrintMessage(5,"header = ",buf);

  //RWrite Number of facets
  int nofacets = GetNT();
  FIOWriteInt(ost,nofacets);
  PrintMessage(5,"NO facets = ", nofacets);

  float f;
  char spaces[nospaces+1];
  for (i = 0; i < nospaces; i++) {spaces[i] = ' ';}
  spaces[nospaces] = 0;

  for (i = 1; i <= GetNT(); i++)
    {
      const STLTriangle & t = GetTriangle(i);

      const Vec<3> & n = t.Normal();
      f = n(0); FIOWriteFloat(ost,f);
      f = n(1); FIOWriteFloat(ost,f);
      f = n(2); FIOWriteFloat(ost,f);

      for (j = 1; j <= 3; j++)
	{
	  const Point3d p = GetPoint(t.PNum(j));

	  f = p.X(); FIOWriteFloat(ost,f);
	  f = p.Y(); FIOWriteFloat(ost,f);
	  f = p.Z(); FIOWriteFloat(ost,f);
	}
      FIOWriteString(ost,spaces,nospaces);
    }
  PrintMessage(5,"done");
}


void STLTopology :: SaveSTLE (const char* filename)
{
  ofstream outf (filename);
  int i, j;

  outf << GetNT() << endl;
  for (i = 1; i <= GetNT(); i++)
    {
      const STLTriangle & t = GetTriangle(i);
      for (j = 1; j <= 3; j++)
	{
	  const Point3d p = GetPoint(t.PNum(j));
	  outf << p.X() << " " << p.Y() << " " << p.Z() << endl;
	}
    }


  int ned = 0;
  for (i = 1; i <= GetNTE(); i++)
    {
      if (GetTopEdge (i).GetStatus() == ED_CONFIRMED)
	ned++;
    }

  outf << ned << endl;

  for (i = 1; i <= GetNTE(); i++)
    {
      const STLTopEdge & edge = GetTopEdge (i);
      if (edge.GetStatus() == ED_CONFIRMED)
	for (j = 1; j <= 2; j++)
	  {
	    const Point3d p = GetPoint(edge.PNum(j));
	    outf << p.X() << " " << p.Y() << " " << p.Z() << endl;
	  }
    }
}


STLGeometry *  STLTopology :: LoadNaomi (istream & ist)
{
  int i;
  STLGeometry * geom = new STLGeometry();
  ARRAY<STLReadTriangle> readtrigs;

  PrintFnStart("read NAOMI file format");

  char buf[100];
  Vec<3> normal;

  //int cntface = 0;
  //int cntvertex = 0;
  double px, py, pz;


  int noface, novertex;
  ARRAY<Point<3> > readpoints;

  ist >> buf;
  if (strcmp (buf, "NODES") == 0)
    {
      ist >> novertex;
      PrintMessage(5,"nuber of vertices = ", novertex);
      for (i = 0; i < novertex; i++)
	{
	  ist >> px;
	  ist >> py;
	  ist >> pz;
	  readpoints.Append(Point<3> (px,py,pz));
	}
    }
  else
    {
      PrintFileError("no node information");
    }


  ist >> buf;
  if (strcmp (buf, "2D_EDGES") == 0)
    {
      ist >> noface;
      PrintMessage(5,"number of faces=",noface);
      int dummy, p1, p2, p3;
      Point<3> pts[3];

      for (i = 0; i < noface; i++)
	{
	  ist >> dummy; //2
	  ist >> dummy; //1
	  ist >> p1;
	  ist >> p2;
	  ist >> p3;
	  ist >> dummy; //0

	  pts[0] = readpoints.Get(p1);
	  pts[1] = readpoints.Get(p2);
	  pts[2] = readpoints.Get(p3);

	  normal = Cross (pts[1]-pts[0], pts[2]-pts[0]) . Normalize();

	  readtrigs.Append (STLReadTriangle (pts, normal));

	}
      PrintMessage(5,"read ", readtrigs.Size(), " triangles");
    }
  else
    {
      PrintMessage(5,"read='",buf,"'\n");
      PrintFileError("ERROR: no Triangle information");
    }

  geom->InitSTLGeometry(readtrigs);

  return geom;
}

void STLTopology :: Save (const char* filename)
{
  PrintFnStart("Write stl-file '",filename, "'");

  ofstream fout(filename);
  fout << "solid\n";

  char buf1[50];
  char buf2[50];
  char buf3[50];

  int i, j;
  for (i = 1; i <= GetNT(); i++)
    {
      const STLTriangle & t = GetTriangle(i);

      fout << "facet normal ";
      const Vec3d& n = GetTriangle(i).Normal();

      sprintf(buf1,"%1.9g",n.X());
      sprintf(buf2,"%1.9g",n.Y());
      sprintf(buf3,"%1.9g",n.Z());

      fout << buf1 << " " << buf2 << " " << buf3 << "\n";
      fout << "outer loop\n";

      for (j = 1; j <= 3; j++)
	{
	  const Point3d p = GetPoint(t.PNum(j));

	  sprintf(buf1,"%1.9g",p.X());
	  sprintf(buf2,"%1.9g",p.Y());
	  sprintf(buf3,"%1.9g",p.Z());

	  fout << "vertex " << buf1 << " " << buf2 << " " << buf3 << "\n";
	}

      fout << "endloop\n";
      fout << "endfacet\n";
    }
  fout << "endsolid\n";


  // write also NETGEN surface mesh:
  ofstream fout2("geom.surf");
  fout2 << "surfacemesh" << endl;
  fout2 << GetNP() << endl;
  for (i = 1; i <= GetNP(); i++)
    {
      for (j = 0; j < 3; j++)
	{
	  fout2.width(8);
	  fout2 << GetPoint(i)(j);
	}

      fout2 << endl;
    }

  fout2 << GetNT() << endl;
  for (i = 1; i <= GetNT(); i++)
    {
      const STLTriangle & t = GetTriangle(i);
      for (j = 1; j <= 3; j++)
	{
	  fout2.width(8);
	  fout2 << t.PNum(j);
	}
      fout2 << endl;
    }
}


STLGeometry *  STLTopology ::Load (istream & ist)
{
  size_t i;
  STLGeometry * geom = new STLGeometry();

  ARRAY<STLReadTriangle> readtrigs;

  char buf[100];
  Point<3> pts[3];
  Vec<3> normal;

  int cntface = 0;
  int vertex = 0;
  bool badnormals = 0;

  while (ist.good())
    {
      ist >> buf;

      size_t n = strlen (buf);
      for (i = 0; i < n; i++)
	buf[i] = tolower (buf[i]);

      if (strcmp (buf, "facet") == 0)
	{
	  cntface++;
	}

      if (strcmp (buf, "normal") == 0)
	{
	  ist >> normal(0)
	      >> normal(1)
	      >> normal(2);
	  normal.Normalize();
	}

      if (strcmp (buf, "vertex") == 0)
	{
	  ist >> pts[vertex](0)
	      >> pts[vertex](1)
	      >> pts[vertex](2);

	  vertex++;

	  if (vertex == 3)
	    {
	      if (normal.Length() <= 1e-5)

		{
		  normal = Cross (pts[1]-pts[0], pts[2]-pts[0]);
		  normal.Normalize();
		}

	      else

		{
		  Vec<3> hnormal;
		  hnormal = Cross (pts[1]-pts[0], pts[2]-pts[0]);
		  hnormal.Normalize();

		  if (normal * hnormal < 0.5)
		    {
		      badnormals = 1;
		    }
		}

	      vertex = 0;

	      if ( (Dist2 (pts[0], pts[1]) > 1e-16) &&
		   (Dist2 (pts[0], pts[2]) > 1e-16) &&
		   (Dist2 (pts[1], pts[2]) > 1e-16) )

		readtrigs.Append (STLReadTriangle (pts, normal));
	    }
	}
    }

  if (badnormals)
    {
      PrintWarning("File has normal vectors which differ extremly from geometry->correct with stldoctor!!!");
    }

  geom->InitSTLGeometry(readtrigs);
  return geom;
}


void STLTopology :: InitSTLGeometry(const ARRAY<STLReadTriangle> & readtrigs)
{
  int i, k;

  // const double geometry_tol_fact = 1E6;
  // distances lower than max_box_size/tol are ignored

  trias.SetSize(0);
  points.SetSize(0);

  PrintMessage(3,"number of triangles = ", readtrigs.Size());

  if (!readtrigs.Size())
    return;


  boundingbox.Set (readtrigs[0][0]);
  for (i = 0; i < readtrigs.Size(); i++)
    for (k = 0; k < 3; k++)
      boundingbox.Add (readtrigs[i][k]);

  PrintMessage(5,"boundingbox: ", Point3d(boundingbox.PMin()), " - ",
	       Point3d(boundingbox.PMax()));

  Box<3> bb = boundingbox;
  bb.Increase (1);

  pointtree = new Point3dTree (bb.PMin(), bb.PMax());


  ARRAY<int> pintersect;

  pointtol = boundingbox.Diam() * stldoctor.geom_tol_fact;
  PrintMessage(5,"point tolerance = ", pointtol);

  for(i = 0; i < readtrigs.Size(); i++)
    {
      const STLReadTriangle & t = readtrigs[i];
      STLTriangle st;
      Vec<3> n = t.Normal();
      st.SetNormal (t.Normal());

      for (k = 0; k < 3; k++)
	{
	  Point<3> p = t[k];

	  Point<3> pmin = p - Vec<3> (pointtol, pointtol, pointtol);
	  Point<3> pmax = p + Vec<3> (pointtol, pointtol, pointtol);

	  pointtree->GetIntersecting (pmin, pmax, pintersect);

	  if (pintersect.Size() > 1)
	    PrintError("too many close points");
	  int foundpos = -1;
	  if (pintersect.Size())
	    foundpos = pintersect[0];

	  if (foundpos == -1)
	    {
	      foundpos = AddPoint(p);
	      pointtree->Insert (p, foundpos);
	    }
	  st[k] = foundpos;
	}

      if ( (st[0] == st[1]) ||
	   (st[0] == st[2]) ||
	   (st[1] == st[2]) )
	{
	  PrintError("STL Triangle degenerated");
	}
      else
	{
	  AddTriangle(st);
	}

    }

  FindNeighbourTrigs();
}


int STLTopology :: GetPointNum (const Point<3> & p)
{
  Point<3> pmin = p - Vec<3> (pointtol, pointtol, pointtol);
  Point<3> pmax = p + Vec<3> (pointtol, pointtol, pointtol);

  ARRAY<int> pintersect;

  pointtree->GetIntersecting (pmin, pmax, pintersect);
  if (pintersect.Size() == 1)
    return pintersect[0];
  else
    return 0;
}


void STLTopology :: FindNeighbourTrigs()
{
  //  if (topedges.Size()) return;

  PushStatusF("Find Neighbour Triangles");

  int i, j, k, l;

  // build up topology tables

  //int np = GetNP();
  int nt = GetNT();

  INDEX_2_HASHTABLE<int> * oldedges = ht_topedges;
  ht_topedges = new INDEX_2_HASHTABLE<int> (GetNP()+1);
  topedges.SetSize(0);

  for (i = 1; i <= nt; i++)
    {
      STLTriangle & trig = GetTriangle(i);


      for (j = 1; j <= 3; j++)
	{
	  int pi1 = trig.PNumMod (j+1);
	  int pi2 = trig.PNumMod (j+2);

	  INDEX_2 i2(pi1, pi2);
	  i2.Sort();

	  int enr;
	  int othertn;

	  if (ht_topedges->Used(i2))
	    {
	      enr = ht_topedges->Get(i2);
	      topedges.Elem(enr).TrigNum(2) = i;

	      othertn = topedges.Get(enr).TrigNum(1);
	      STLTriangle & othertrig = GetTriangle(othertn);

	      trig.NBTrigNum(j) = othertn;
	      trig.EdgeNum(j) = enr;
	      for (k = 1; k <= 3; k++)
		if (othertrig.EdgeNum(k) == enr)
		  othertrig.NBTrigNum(k) = i;
	    }
	  else
	    {
	      enr = topedges.Append (STLTopEdge (pi1, pi2, i, 0));
	      ht_topedges->Set (i2, enr);
	      trig.EdgeNum(j) = enr;
	    }
	}
    }


  PrintMessage(5,"topology built, checking");

  topology_ok = 1;
  int ne = GetNTE();

  for (i = 1; i <= nt; i++)
    GetTriangle(i).flags.toperror = 0;

  for (i = 1; i <= nt; i++)
    for (j = 1; j <= 3; j++)
      {
	const STLTopEdge & edge = GetTopEdge (GetTriangle(i).EdgeNum(j));
	if (edge.TrigNum(1) != i && edge.TrigNum(2) != i)
	  {
	    topology_ok = 0;
	    GetTriangle(i).flags.toperror = 1;
	  }
      }

  for (i = 1; i <= ne; i++)
    {
      const STLTopEdge & edge = GetTopEdge (i);
      if (!edge.TrigNum(2))
	{
	  topology_ok = 0;
	  GetTriangle(edge.TrigNum(1)).flags.toperror = 1;
	}
    }

  if (topology_ok)
    {
      orientation_ok = 1;
      for (i = 1; i <= nt; i++)
	{
	  const STLTriangle & t = GetTriangle (i);
	  for (j = 1; j <= 3; j++)
	    {
	      const STLTriangle & nbt = GetTriangle (t.NBTrigNum(j));
	      if (!t.IsNeighbourFrom (nbt))
		orientation_ok = 0;
	    }
	}
    }
  else
    orientation_ok = 0;


  status = STL_GOOD;
  statustext = "";
  if (!topology_ok || !orientation_ok)
    {
      status = STL_ERROR;
      if (!topology_ok)
	statustext = "Topology not ok";
      else
	statustext = "Orientation not ok";
    }


  PrintMessage(3,"topology_ok = ",topology_ok);
  PrintMessage(3,"orientation_ok = ",orientation_ok);
  PrintMessage(3,"topology found");

  // generate point -> trig table

  trigsperpoint.SetSize(GetNP());
  for (i = 1; i <= GetNT(); i++)
    for (j = 1; j <= 3; j++)
      trigsperpoint.Add1(GetTriangle(i).PNum(j),i);


  //check trigs per point:
  /*
  for (i = 1; i <= GetNP(); i++)
    {
      if (trigsperpoint.EntrySize(i) < 3)
	{
	  (*testout) << "ERROR: Point " << i << " has " << trigsperpoint.EntrySize(i) << " triangles!!!" << endl;
	}
    }
  */
  topedgesperpoint.SetSize (GetNP());
  for (i = 1; i <= ne; i++)
    for (j = 1; j <= 2; j++)
      topedgesperpoint.Add1 (GetTopEdge (i).PNum(j), i);

  PrintMessage(5,"point -> trig table generated");


  // transfer edge data:
  // .. to be done
  delete oldedges;


  for (STLTrigIndex ti = 0; ti < GetNT(); ti++)
    {
      STLTriangle & trig = trias[ti];
      for (k = 0; k < 3; k++)
	{
	  STLPointIndex pi = trig[k] - STLBASE;
	  STLPointIndex pi2 = trig[(k+1)%3] - STLBASE;
	  STLPointIndex pi3 = trig[(k+2)%3] - STLBASE;

	  // vector along edge
	  Vec<3> ve = points[pi2] - points[pi];
	  ve.Normalize();

	  // vector along third point
	  Vec<3> vt = points[pi3] - points[pi];
	  vt -= (vt * ve) * ve;
	  vt.Normalize();

	  Vec<3> vn = trig.GeomNormal (points);
	  vn.Normalize();

	  double phimin = 10, phimax = -1; // out of (0, 2 pi)

	  for (j = 0; j < trigsperpoint[pi].Size(); j++)
	    {
	      STLTrigIndex ti2 = trigsperpoint[pi][j] - STLBASE;
	      const STLTriangle & trig2 = trias[ti2];

	      if (ti == ti2) continue;

	      bool hasboth = 0;
	      for (l = 0; l < 3; l++)
		if (trig2[l] - STLBASE == pi2)
		  {
		    hasboth = 1;
		    break;
		  }
	      if (!hasboth) continue;

	      STLPointIndex pi4(0);
	      for (l = 0; l < 3; l++)
		if (trig2[l] - STLBASE != pi && trig2[l] - STLBASE != pi2)
		  pi4 = trig2[l] - STLBASE;

	      Vec<3> vt2 = points[pi4] - points[pi];

	      double phi = atan2 (vt2 * vn, vt2 * vt);
	      if (phi < 0) phi += 2 * M_PI;

	      if (phi < phimin)
		{
		  phimin = phi;
		  trig.NBTrig (0, (k+2)%3) = ti2 + STLBASE;
		}
	      if (phi > phimax)
		{
		  phimax = phi;
		  trig.NBTrig (1, (k+2)%3) = ti2 + STLBASE;
		}
	    }
	}
    }


  if (status == STL_GOOD)
    {
      // for compatibility:
      neighbourtrigs.SetSize(GetNT());
      for (i = 1; i <= GetNT(); i++)
	for (k = 1; k <= 3; k++)
	  AddNeighbourTrig (i, GetTriangle(i).NBTrigNum(k));
    }
  else
    {
      // assemble neighbourtrigs (should be done only for illegal topology):

      neighbourtrigs.SetSize(GetNT());

      int tr, found;
      int wrongneighbourfound = 0;
      for (i = 1; i <= GetNT(); i++)
	{
	  SetThreadPercent((double)i/(double)GetNT()*100.);
	  if (multithread.terminate)
	    {
	      PopStatus();
	      return;
	    }

	  for (k = 1; k <= 3; k++)
	    {
	      for (j = 1; j <= trigsperpoint.EntrySize(GetTriangle(i).PNum(k)); j++)
		{
		  tr = trigsperpoint.Get(GetTriangle(i).PNum(k),j);
		  if (i != tr && (GetTriangle(i).IsNeighbourFrom(GetTriangle(tr))
				  || GetTriangle(i).IsWrongNeighbourFrom(GetTriangle(tr))))
		    {
		      if (GetTriangle(i).IsWrongNeighbourFrom(GetTriangle(tr)))
			{
			  /*(*testout) << "ERROR: triangle " << i << " has a wrong neighbour triangle!!!" << endl;*/
			  wrongneighbourfound ++;
			}

		      found = 0;
		      for (int ii = 1; ii <= NONeighbourTrigs(i); ii++)
			{if (NeighbourTrig(i,ii) == tr) {found = 1;break;};}
		      if (! found) {AddNeighbourTrig(i,tr);}
		    }
		}
	    }
	  if (NONeighbourTrigs(i) != 3)
	    {
	      PrintError("TRIG ",i," has ",NONeighbourTrigs(i)," neighbours!!!!");
	      for (int kk=1; kk <= NONeighbourTrigs(i); kk++)
		{
		  PrintMessage(5,"neighbour-trig",kk," = ",NeighbourTrig(i,kk));
		}
	    };
	}
      if (wrongneighbourfound)
	{
	  PrintError("++++++++++++++++++++\n");
	  PrintError(wrongneighbourfound, " wrong oriented neighbourtriangles found!");
	  PrintError("try to correct it (with stldoctor)!");
	  PrintError("++++++++++++++++++++\n");

	  status = STL_ERROR;
	  statustext = "STL Mesh not consistent";

	  multithread.terminate = 1;
#ifdef STAT_STREAM
	  (*statout) << "non-conform stl geometry \\hline" << endl;
#endif
	}
    }

  TopologyChanged();

  PopStatus();
}


void STLTopology :: GetTrianglesInBox (/*
					  const Point<3> & pmin,
					  const Point<3> & pmax,
				       */
				       const Box<3> & box,
				       ARRAY<int> & btrias) const
{
  if (searchtree)

    searchtree -> GetIntersecting (box.PMin(), box.PMax(), btrias);

  else
    {
      int i;
      Box<3> box1 = box;
      box1.Increase (1e-4);

      btrias.SetSize(0);

      int nt = GetNT();
      for (i = 1; i <= nt; i++)
	{
	  if (box1.Intersect (GetTriangle(i).box))
	    {
	      btrias.Append (i);
	    }
	}
    }
}


void STLTopology :: AddTriangle(const STLTriangle& t)
{
  trias.Append(t);

  const Point<3> & p1 = GetPoint (t.PNum(1));
  const Point<3> & p2 = GetPoint (t.PNum(2));
  const Point<3> & p3 = GetPoint (t.PNum(3));

  Box<3> box;
  box.Set (p1);
  box.Add (p2);
  box.Add (p3);
  /*
  //  Point<3> pmin(p1), pmax(p1);
  pmin.SetToMin (p2);
  pmin.SetToMin (p3);
  pmax.SetToMax (p2);
  pmax.SetToMax (p3);
  */

  trias.Last().box = box;
  trias.Last().center = Center (p1, p2, p3);
  double r1 = Dist (p1, trias.Last().center);
  double r2 = Dist (p2, trias.Last().center);
  double r3 = Dist (p3, trias.Last().center);
  trias.Last().rad = max2 (max2 (r1, r2), r3);

  if (geomsearchtreeon)
    {searchtree->Insert (box.PMin(), box.PMax(), trias.Size());}
}


int STLTopology :: GetLeftTrig(int p1, int p2) const
{
  int i;
  for (i = 1; i <= trigsperpoint.EntrySize(p1); i++)
    {
      if (GetTriangle(trigsperpoint.Get(p1,i)).HasEdge(p1,p2)) {return trigsperpoint.Get(p1,i);}
    }
  PrintSysError("ERROR in GetLeftTrig !!!");

  return 0;
}

int STLTopology :: GetRightTrig(int p1, int p2) const
{
  return GetLeftTrig(p2,p1);
}


int STLTopology :: NeighbourTrigSorted(int trig, int edgenum) const
{
  int i, p1, p2;
  int psearch = GetTriangle(trig).PNum(edgenum);

  for (i = 1; i <= 3; i++)
    {
      GetTriangle(trig).GetNeighbourPoints(GetTriangle(NeighbourTrig(trig,i)),p1,p2);
      if (p1 == psearch) {return NeighbourTrig(trig,i);}
    }

  PrintSysError("ERROR in NeighbourTrigSorted");
  return 0;
}


int STLTopology :: GetTopEdgeNum (int pi1, int pi2) const
{
  if (!ht_topedges) return 0;

  INDEX_2 i2(pi1, pi2);
  i2.Sort();

  if (!ht_topedges->Used(i2)) return 0;
  return ht_topedges->Get(i2);
}


void STLTopology :: InvertTrig (int trig)
{
  if (trig >= 1 && trig <= GetNT())
    {
      GetTriangle(trig).ChangeOrientation();
      FindNeighbourTrigs();
    }
  else
    {
      PrintUserError("no triangle selected!");
    }
}


void STLTopology :: DeleteTrig (int trig)
{
  if (trig >= 1 && trig <= GetNT())
    {
      trias.DeleteElement(trig);
      FindNeighbourTrigs();
    }
  else
    {
      PrintUserError("no triangle selected!");
    }
}


void STLTopology :: OrientAfterTrig (int trig)
{
  int starttrig = trig;

  if (starttrig >= 1 && starttrig <= GetNT())
    {

      ARRAY <int> oriented;
      oriented.SetSize(GetNT());
      int i;
      for (i = 1; i <= oriented.Size(); i++)
	{
	  oriented.Elem(i) = 0;
	}

      oriented.Elem(starttrig) = 1;

      int k;

      ARRAY <int> list1;
      list1.SetSize(0);
      ARRAY <int> list2;
      list2.SetSize(0);
      list1.Append(starttrig);

      int cnt = 1;
      int end = 0;
      int nt;
      while (!end)
	{
	  end = 1;
	  for (i = 1; i <= list1.Size(); i++)
	    {
	      const STLTriangle& tt = GetTriangle(list1.Get(i));
	      for (k = 1; k <= 3; k++)
		{
		  nt = tt.NBTrigNum (k); // NeighbourTrig(list1.Get(i),k);
		  if (oriented.Get(nt) == 0)
		    {
		      if (tt.IsWrongNeighbourFrom(GetTriangle(nt)))
			{
			  GetTriangle(nt).ChangeOrientation();
			}
		      oriented.Elem(nt) = 1;
		      list2.Append(nt);
		      cnt++;
		      end = 0;
		    }
		}
	    }
	  list1.SetSize(0);
	  for (i = 1; i <= list2.Size(); i++)
	    {
	      list1.Append(list2.Get(i));
	    }
	  list2.SetSize(0);
	}

      PrintMessage(5,"NO corrected triangles = ",cnt);
      if (cnt == GetNT())
	{
	  PrintMessage(5,"ALL triangles oriented in same way!");
	}
      else
	{
	  PrintWarning("NOT ALL triangles oriented in same way!");
	}

      //      topedges.SetSize(0);
      FindNeighbourTrigs();
    }
  else
    {
      PrintUserError("no triangle selected!");
    }
}


}