// Copyright 2011 Fotios Sioutis (sfotis@gmail.com)
//
//This file is part of pythonOCC.
//
//pythonOCC is free software: you can redistribute it and/or modify
//it under the terms of the GNU Lesser General Public License as published by
//the Free Software Foundation, either version 3 of the License, or
//(at your option) any later version.
//
//pythonOCC is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//GNU Lesser General Public License for more details.
//
//You should have received a copy of the GNU Lesser General Public License
//along with pythonOCC.  If not, see <http://www.gnu.org/licenses/>.

//---------------------------------------------------------------------------
#include "Tesselator.h"
//---------------------------------------------------------------------------
#include <TopExp_Explorer.hxx>
#include <Bnd_Box.hxx>
#include <StdPrs_ToolShadedShape.hxx>
#include <BRepMesh.hxx>
#include <Poly_Connect.hxx>
#include <Poly_Triangulation.hxx>
#include <TColgp_Array1OfPnt.hxx>
#include <TColgp_Array1OfDir.hxx>
#include <TColgp_Array1OfPnt2d.hxx>
#include <BRepTools.hxx>
#include <BRepBndLib.hxx>
//---------------------------------------------------------------------------
Tesselator::Tesselator(TopoDS_Shape   aShape,
                       theTextureMappingRule            aTxtMapType,
                       Standard_Real                    anAutoScaleSizeOnU,
                       Standard_Real                    anAutoScaleSizeOnV,
                       Standard_Real                    aDeviation,
                       Standard_Real                    aUOrigin,
                       Standard_Real                    aVOrigin,
                       Standard_Real                    aURepeat,
                       Standard_Real                    aVRepeat,
                       Standard_Real                    aScaleU,
                       Standard_Real                    aScaleV,
                       Standard_Real                    aRotationAngle) :
  //set local variables
  myDeviation(aDeviation),
  myUOrigin(aUOrigin),
  myVOrigin(aVOrigin),
  myURepeat(aURepeat),
  myVRepeat(aVRepeat),
  myScaleU(aScaleU),
  myScaleV(aScaleV),
  myAutoScaleSizeOnU(anAutoScaleSizeOnU),
  myAutoScaleSizeOnV(anAutoScaleSizeOnV),
  myTxtMapType(aTxtMapType),
  myShape(aShape),
  myRotationAngle(aRotationAngle)
{
  //prepare bbox tex coords
  if (myTxtMapType == atCube) {
    //create a compound for bbox
    //prepare bbox tex coords
    PrepareBoxTextureCoordinates(myShape);
  }

    locVertexcoord = NULL;
    locNormalcoord = NULL;
    locTexcoord    = NULL;
    // compute default deviation
    ComputeDefaultDeviation();
    
    //Tesselate();
    TesselateWithUVCoords();
}

Tesselator::Tesselator(TopoDS_Shape   aShape) :
  //set local variables
  myDeviation(1.0),
  myUOrigin(0.),
  myVOrigin(0.),
  myURepeat(1.),
  myVRepeat(1.),
  myScaleU(1.),
  myScaleV(1.),
  myAutoScaleSizeOnU(1.),
  myAutoScaleSizeOnV(1.),
  myTxtMapType(atNormal),
  myShape(aShape),
  myRotationAngle(0.)
{
    locVertexcoord = NULL;
    locNormalcoord = NULL;
    locTexcoord    = NULL;
    // compute default deviation
    ComputeDefaultDeviation();
    
    TesselateWithUVCoords();
}
//---------------------------------------------------------------------------
Tesselator::~Tesselator()
{
    if (locVertexcoord)
      delete [] locVertexcoord;

    if (locNormalcoord)
      delete [] locNormalcoord;

    if (locTexcoord)
      delete [] locTexcoord;
}

//---------------------------------------------------------------------------
void Tesselator::SetDeviation(Standard_Real aDeviation)
{
    myDeviation = aDeviation;   
}


//---------------------------------------------------------------------------
void Tesselator::Tesselate()
{
    Standard_Real Umin;
    Standard_Real Umax;
    Standard_Real Vmin;
    Standard_Real Vmax;

    Standard_Real dUmax;
    Standard_Real dVmax;

    TopExp_Explorer       ExpFace;
    StdPrs_ToolShadedShape   SST;

    gp_Dir d;
    gp_Pnt p;

    gp_Vec2d theCoord_p;
    gp_Pnt2d d_coord;

    //Triangulate
    BRepMesh::Mesh(myShape, myDeviation);

    for (ExpFace.Init(myShape, TopAbs_FACE); ExpFace.More(); ExpFace.Next()) {
      const TopoDS_Face&    myFace    = TopoDS::Face(ExpFace.Current());
      TopLoc_Location aLocation;

      Handle(Poly_Triangulation) myT = BRep_Tool::Triangulation(myFace, aLocation);

      if (!myT.IsNull()) {
        Poly_Connect pc(myT);

        aface *this_face = new aface;

        //write vertex buffer
        const TColgp_Array1OfPnt& Nodes = myT->Nodes();
        this_face->vertex_coord = new float[Nodes.Length() * 3];
        this_face->number_of_coords = Nodes.Length();
        for (int i = Nodes.Lower(); i <= Nodes.Upper(); i++) {
          p = Nodes(i).Transformed(aLocation.Transformation());
          this_face->vertex_coord[((i-1) * 3)+ 0] = p.X();
          this_face->vertex_coord[((i-1) * 3)+ 1] = p.Y();
          this_face->vertex_coord[((i-1) * 3)+ 2] = p.Z();
        }

        //write normal buffer
        TColgp_Array1OfDir myNormal(Nodes.Lower(), Nodes.Upper());
        SST.Normal(myFace, pc, myNormal);
        this_face->normal_coord = new float[myNormal.Length() * 3];
        this_face->number_of_normals = myNormal.Length();
        for (int i = myNormal.Lower(); i <= myNormal.Upper(); i++) {
          d = myNormal(i).Transformed(aLocation.Transformation());
          this_face->normal_coord[((i-1) * 3)+ 0] = d.X();
          this_face->normal_coord[((i-1) * 3)+ 1] = d.Y();
          this_face->normal_coord[((i-1) * 3)+ 2] = d.Z();
        }

        // set uvcoords buffers to NULL
        // necessary for JoinPrimitive to be performed
        this_face->tex_coord = NULL;
        this_face->number_of_texcoords = 0;
        
        //write triangle buffer
        Standard_Integer validFaceTriCount = 0;
        Standard_Integer n1 , n2 , n3;
        TopAbs_Orientation orient = myFace.Orientation();
        const Poly_Array1OfTriangle&   triangles   = myT->Triangles();
        this_face->tri_indexes  = new int  [triangles.Length()* 3];
        for (int nt = 1; nt <= myT->NbTriangles(); nt++) {
          triangles(nt).Get(n1,n2,n3);
          if (orient != TopAbs_FORWARD) {
              Standard_Integer tmp=n1;
              n1 = n2;
              n2 = tmp;
          }
          if (TriangleIsValid(Nodes(n1),Nodes(n2),Nodes(n3))) {
            this_face->tri_indexes[(validFaceTriCount * 3)+ 0] = n1;
            this_face->tri_indexes[(validFaceTriCount * 3)+ 1] = n2;
            this_face->tri_indexes[(validFaceTriCount * 3)+ 2] = n3;
            validFaceTriCount++;
          }
        }
        this_face->number_of_triangles = validFaceTriCount;
        facelist.push_back(this_face);
      }
    }
    JoinPrimitives();    
}

//---------------------------------------------------------------------------
void Tesselator::TesselateWithUVCoords()
{
  Standard_Real Umin;
  Standard_Real Umax;
  Standard_Real Vmin;
  Standard_Real Vmax;

  Standard_Real dUmax;
  Standard_Real dVmax;

  TopExp_Explorer       ExpFace;
  StdPrs_ToolShadedShape   SST;

  gp_Dir d;
  gp_Pnt p;

  gp_Vec2d theCoord_p;
  gp_Pnt2d d_coord;
  cout << "Tesselate with UV coords\n";
  //Triangulate
  BRepMesh::Mesh(myShape, myDeviation);

  for (ExpFace.Init(myShape, TopAbs_FACE); ExpFace.More(); ExpFace.Next()) {
    const TopoDS_Face&    myFace    = TopoDS::Face(ExpFace.Current());
    TopLoc_Location aLocation;

    Handle(Poly_Triangulation) myT = BRep_Tool::Triangulation(myFace, aLocation);

    if (!myT.IsNull()) {
      Poly_Connect pc(myT);

      aface *this_face = new aface;

      //write vertex buffer
      const TColgp_Array1OfPnt& Nodes = myT->Nodes();
      this_face->vertex_coord = new float[Nodes.Length() * 3];
      this_face->number_of_coords = Nodes.Length();
      for (int i = Nodes.Lower(); i <= Nodes.Upper(); i++) {
        p = Nodes(i).Transformed(aLocation.Transformation());
        this_face->vertex_coord[((i-1) * 3)+ 0] = p.X();
        this_face->vertex_coord[((i-1) * 3)+ 1] = p.Y();
        this_face->vertex_coord[((i-1) * 3)+ 2] = p.Z();
      }

      //write normal buffer
      TColgp_Array1OfDir myNormal(Nodes.Lower(), Nodes.Upper());
      SST.Normal(myFace, pc, myNormal);
      this_face->normal_coord = new float[myNormal.Length() * 3];
      this_face->number_of_normals = myNormal.Length();
      for (int i = myNormal.Lower(); i <= myNormal.Upper(); i++) {
        d = myNormal(i).Transformed(aLocation.Transformation());
        this_face->normal_coord[((i-1) * 3)+ 0] = d.X();
        this_face->normal_coord[((i-1) * 3)+ 1] = d.Y();
        this_face->normal_coord[((i-1) * 3)+ 2] = d.Z();
      }

      //write uvcoord buffer
      int id1 = 0, id2 = 2, idNull = 1;

      if (myTxtMapType == atNormal || myTxtMapType == atNormalAutoScale) {
        BRepTools::UVBounds(myFace,Umin, Umax, Vmin, Vmax);
        dUmax = (Umax - Umin);
        dVmax = (Vmax - Vmin);
        if (myTxtMapType == atNormalAutoScale) {
          myScaleU = myAutoScaleSizeOnU/dUmax;
          myScaleV = myAutoScaleSizeOnV/dVmax;
        }
      }
      const TColgp_Array1OfPnt2d& UVNodes = myT->UVNodes();
      this_face->tex_coord = new float[UVNodes.Length()  * 3];
      this_face->number_of_texcoords = UVNodes.Length();
      for (int i = UVNodes.Lower(); i <= UVNodes.Upper();i++) {
        if (myTxtMapType == atCube) {
          GetBoxTextureCoordinate(  Nodes(i).Transformed(aLocation.Transformation()),
                                    myNormal(i).Transformed(aLocation.Transformation()),
                                    theCoord_p);
          d_coord.SetX((-myUOrigin+(myURepeat*theCoord_p.X())/aBndBoxSz)/myScaleU);
          d_coord.SetY((-myVOrigin+(myVRepeat*theCoord_p.Y())/aBndBoxSz)/myScaleV);
        }
        else {
          d_coord = UVNodes(i);
          d_coord.SetX((-myUOrigin+(myURepeat*(d_coord.X()-Umin))/dUmax)/myScaleU);
          d_coord.SetY((-myVOrigin+(myVRepeat*(d_coord.Y()-Vmin))/dVmax)/myScaleV);
        }
        d_coord.Rotate(gp::Origin2d(), myRotationAngle);  
        this_face->tex_coord[((i-1) * 3)+ id1] = d_coord.X();
        this_face->tex_coord[((i-1) * 3)+ id2] = d_coord.Y();
        this_face->tex_coord[((i-1) * 3)+ idNull] = 0;
      }

      //write triangle buffer
      Standard_Integer validFaceTriCount = 0;
      Standard_Integer n1 , n2 , n3;
      TopAbs_Orientation orient = myFace.Orientation();
      const Poly_Array1OfTriangle&   triangles   = myT->Triangles();
      this_face->tri_indexes  = new int  [triangles.Length()* 3];
      for (int nt = 1; nt <= myT->NbTriangles(); nt++) {
        triangles(nt).Get(n1,n2,n3);
        if (orient != TopAbs_FORWARD) {
            Standard_Integer tmp=n1;
            n1 = n2;
            n2 = tmp;
        }
        if (TriangleIsValid(Nodes(n1),Nodes(n2),Nodes(n3))) {
          this_face->tri_indexes[(validFaceTriCount * 3)+ 0] = n1;
          this_face->tri_indexes[(validFaceTriCount * 3)+ 1] = n2;
          this_face->tri_indexes[(validFaceTriCount * 3)+ 2] = n3;
          validFaceTriCount++;
        }
      }
      this_face->number_of_triangles = validFaceTriCount;
      facelist.push_back(this_face);
    }
  }
  JoinPrimitivesWithUVCoords();
}

//---------------------------INTERFACE---------------------------------------
void Tesselator::ComputeDefaultDeviation()
{
    // This method automatically computes precision from the bounding box of the shape
    Bnd_Box aBox;
    Standard_Real aXmin,aYmin ,aZmin ,aXmax ,aYmax ,aZmax;

    //calculate the bounding box
    BRepBndLib::Add(myShape, aBox);
    aBox.Get(aXmin, aYmin, aZmin, aXmax, aYmax, aZmax);

    Standard_Real xDim = abs((long)aXmax - (long)aXmin);
    Standard_Real yDim = abs((long)aYmax - (long)aYmin);
    Standard_Real zDim = abs((long)aZmax - (long)aZmin);

    Standard_Real adeviation = std::max(aXmax-aXmin, std::max(aYmax-aYmin, aZmax-aZmin)) * 1e-2 ;
    myDeviation = adeviation;
}

void Tesselator::ExportShapeToX3D(char * filename, int diffR, int diffG, int diffB)
{
    ofstream X3Dfile;
    int *vertices_idx = new int[3];
    int *texcoords_idx = new int[3];
    int *normals_idx = new int[3];
    X3Dfile.open (filename);
    // write header
    X3Dfile << "<?xml version='1.0' encoding='UTF-8'?>" ;
    X3Dfile << "<!DOCTYPE X3D PUBLIC 'ISO//Web3D//DTD X3D 3.1//EN' 'http://www.web3d.org/specifications/x3d-3.1.dtd'>";
    X3Dfile << "<X3D>";
    X3Dfile << "<Head>";
    X3Dfile << "<meta name='generator' content='pythonOCC, http://www.pythonocc.org'/>";
    X3Dfile << "</Head>";
    X3Dfile << "<Scene><Shape><Appearance><Material DEF='Shape_Mat' diffuseColor='0.65 0.65 0.65' ";
    X3Dfile << "shininess='0.9' specularColor='1 1 1'></Material></Appearance>";
    // export faces indices
    X3Dfile << "<IndexedFaceSet coordIndex='";
    for (int i=0;i<tot_triangle_count;i++) {
        ObjGetTriangle(i, vertices_idx, texcoords_idx, normals_idx);
        // vertex indices
        X3Dfile << i*3 << " " << 1+i*3 << " " << 2+i*3 << " -1 ";
    } 
    X3Dfile << "' solid='false'>";
    // write points coordinates
    X3Dfile << "<Coordinate point='";
    for (int i=0;i<tot_triangle_count;i++) {
        ObjGetTriangle(i, vertices_idx, texcoords_idx, normals_idx);
        X3Dfile <<locVertexcoord[vertices_idx[0]]<< " " <<locVertexcoord[vertices_idx[0]+1]<<" "
            << locVertexcoord[vertices_idx[0]+2]<<" ";
        // Second vertex
        X3Dfile <<locVertexcoord[vertices_idx[1]]<<" "<<locVertexcoord[vertices_idx[1]+1]<<" "
            << locVertexcoord[vertices_idx[1]+2]<<" ";
        // Third vertex
        X3Dfile << locVertexcoord[vertices_idx[2]]<<" "<<locVertexcoord[vertices_idx[2]+1]<<" "
            << locVertexcoord[vertices_idx[2]+2]<<" ";
    }
    X3Dfile << "' containerField='coord'></Coordinate>";
    // write normals
    X3Dfile << "<Normal vector='";
    for (int i=0;i<tot_triangle_count;i++) {
        ObjGetTriangle(i, vertices_idx, texcoords_idx, normals_idx);
        // First normal
        X3Dfile << locNormalcoord[normals_idx[0]]<<" "<<locNormalcoord[normals_idx[0]+1]<<" "
            << locNormalcoord[normals_idx[0]+2]<<" ";
        // Second normal
        X3Dfile << locNormalcoord[normals_idx[1]]<<" "<<locNormalcoord[normals_idx[1]+1]<<" "
            << locNormalcoord[normals_idx[1]+2]<<" ";
        // Third normal
        X3Dfile << locNormalcoord[normals_idx[2]]<<" "<<locNormalcoord[normals_idx[2]+1]<<" "
            << locNormalcoord[normals_idx[2]+2] << " ";
    }
    X3Dfile << "' containerField='normal'></Normal>";
    // close all markups
    X3Dfile << "</IndexedFaceSet></Shape></Scene></X3D>\n"; 
    X3Dfile.close();
    delete [] vertices_idx;
    delete [] texcoords_idx;
    delete [] normals_idx;

}

void Tesselator::ExportShapeToJSON(char * filename)
{
    ofstream JSONObject;
    int *vertices_idx = new int[3];
    int *texcoords_idx = new int[3];
    int *normals_idx = new int[3];
    JSONObject.open (filename);
    // write header
    JSONObject << "var Shape = function () {\n";
    JSONObject << "var scope = this;\n";
    JSONObject << "THREE.Geometry.call( this );\n";
    // first write vertices coords
    for (int i=0;i<tot_triangle_count;i++) {
        ObjGetTriangle(i, vertices_idx, texcoords_idx, normals_idx);
        // First vertex
        JSONObject << "v("<<locVertexcoord[vertices_idx[0]]<<","<<locVertexcoord[vertices_idx[0]+1]<<","
            << locVertexcoord[vertices_idx[0]+2]<<");\n";
        // Second vertex
        JSONObject << "v("<<locVertexcoord[vertices_idx[1]]<<","<<locVertexcoord[vertices_idx[1]+1]<<","
            << locVertexcoord[vertices_idx[1]+2]<<");\n";
        // Third vertex
        JSONObject << "v("<<locVertexcoord[vertices_idx[2]]<<","<<locVertexcoord[vertices_idx[2]+1]<<","
            << locVertexcoord[vertices_idx[2]+2]<<");\n";
        
    
    }
    // write normals
    for (int i=0;i<tot_triangle_count;i++) {
        ObjGetTriangle(i, vertices_idx, texcoords_idx, normals_idx);
        // vertex indices
        JSONObject << "f3("<<i*3<<","<<1+i*3<<","<<2+i*3<<",";
        // First normal
        JSONObject << locNormalcoord[normals_idx[0]]<<","<<locNormalcoord[normals_idx[0]+1]<<","
            << locNormalcoord[normals_idx[0]+2]<<",";
        // Second normal
        JSONObject << locNormalcoord[normals_idx[1]]<<","<<locNormalcoord[normals_idx[1]+1]<<","
            << locNormalcoord[normals_idx[1]+2]<<",";
        // Third normal
        JSONObject << locNormalcoord[normals_idx[2]]<<","<<locNormalcoord[normals_idx[2]+1]<<","
            << locNormalcoord[normals_idx[2]+2];
        JSONObject << ");\n";
    }

    // at last, write texcoords
    for (int i=0;i<tot_triangle_count;i++) {
        ObjGetTriangle(i, vertices_idx, texcoords_idx, normals_idx);
        JSONObject << "uvs(";
        JSONObject << locTexcoord[texcoords_idx[0]]<<","<<locTexcoord[texcoords_idx[0]+2]<<",";
        JSONObject << locTexcoord[texcoords_idx[1]]<<","<<locTexcoord[texcoords_idx[1]+2]<<",";
        JSONObject << locTexcoord[texcoords_idx[2]]<<","<<locTexcoord[texcoords_idx[2]+2];
        JSONObject << ");\n";
    }

    // footer
    JSONObject << "function v( x, y, z ) {\n";
    JSONObject<< "  scope.vertices.push(new THREE.Vector3(x,y,z));\n";
    JSONObject<<"}\n";
    JSONObject <<"function f3( a, b, c, n1_x,n1_y,n1_z,n2_x,n2_y,n2_z,n3_x,n3_y,n3_z ) {\n";
    JSONObject << "  scope.faces.push(new THREE.Face3(a,b,c,[new THREE.Vector3(n1_x,n1_y,n1_z),\n";
    JSONObject << "new THREE.Vector3( n2_x, n2_y, n2_z ), new THREE.Vector3( n3_x, n3_y, n3_z ) ]  ) );\n";
    JSONObject << "}\n";
    JSONObject << "function uvs(a,b,c,d,e,f) {\n";
    JSONObject << "scope.faceVertexUvs[ 0 ].push( [new THREE.Vector2(a,b), new THREE.Vector2(c,d), new THREE.Vector2(e,f)] );\n";
    JSONObject << "}\n}\n";
    JSONObject << "Shape.prototype = new THREE.Geometry();\n";
    JSONObject << "Shape.prototype.constructor = Shape;\n";
    JSONObject.close();
    delete [] vertices_idx;
    delete [] texcoords_idx;
    delete [] normals_idx;
}

//---------------------------------------------------------------------------
float* Tesselator::VerticesList()
{
  return locVertexcoord;
}
//---------------------------------------------------------------------------
float* Tesselator::NormalsList()
{
  return locNormalcoord;
}
//---------------------------------------------------------------------------
float* Tesselator::TextureCoordinatesList()
{
  return locTexcoord;
}

//---------------------------------------------------------------------------
int Tesselator::ObjGetTriangleCount()
{
  return  tot_triangle_count;
}
//---------------------------------------------------------------------------
int Tesselator::ObjGetVertexCount()
{
  return  tot_vertex_count;
}
//---------------------------------------------------------------------------
int Tesselator::ObjGetNormalCount()
{
  return  tot_normal_count;
}
//---------------------------------------------------------------------------
int Tesselator::ObjGetTexCoordCount()
{
  return  tot_texcoord_count;
}
//---------------------------------------------------------------------------
void Tesselator::ObjGetTriangle(int trianglenum, int *vertices, int *texcoords, int *normals)
{
  int pID = loc_tri_indexes[(trianglenum * 3) + 0] * 3;
  int qID = loc_tri_indexes[(trianglenum * 3) + 1] * 3;
  int rID = loc_tri_indexes[(trianglenum * 3) + 2] * 3;

  vertices[0] = pID;
  vertices[1] = qID;
  vertices[2] = rID;

  normals[0] = pID;
  normals[1] = qID;
  normals[2] = rID;

  texcoords[0] = pID;
  texcoords[1] = qID;
  texcoords[2] = rID;
}
//---------------------------------------------------------------------------
//---------------------------------HELPERS-----------------------------------
//---------------------------------------------------------------------------
void Tesselator::JoinPrimitives()
{
  int obP = 0;
  int obN = 0;
  int obT = 0;
  int obTR = 0;

  int advance = 0;

  int total_poly_count = 0;
  int total_vertex_count = 0;
  int total_normal_count = 0;

  std::vector<aface*>::iterator anIterator = facelist.begin();

  while (anIterator != facelist.end()) {

    aface* myface = *anIterator;

    total_poly_count =  total_poly_count + myface->number_of_triangles;
    total_vertex_count = total_vertex_count + myface->number_of_coords;
    total_normal_count = total_normal_count + myface->number_of_normals;

    anIterator++;
  }

  loc_tri_indexes= new int[total_poly_count * 3 ];
  locVertexcoord = new float[total_vertex_count * 3 ];
  locNormalcoord = new float[total_normal_count * 3 ];

  tot_triangle_count = total_poly_count;
  tot_vertex_count   = total_vertex_count;
  tot_normal_count   = total_normal_count;

  anIterator = facelist.begin();
  while (anIterator != facelist.end()) {
    aface* myface = *anIterator;
    for (int x = 0; x < myface->number_of_coords; x++) {
      locVertexcoord[(obP * 3) + 0] = myface->vertex_coord[(x * 3) + 0];
      locVertexcoord[(obP * 3) + 1] = myface->vertex_coord[(x * 3) + 1];
      locVertexcoord[(obP * 3) + 2] = myface->vertex_coord[(x * 3) + 2];
      obP++;
    }

    for (int x = 0; x < myface->number_of_normals; x++) {
      locNormalcoord[(obN * 3) + 0] = myface->normal_coord[(x * 3) + 0];
      locNormalcoord[(obN * 3) + 1] = myface->normal_coord[(x * 3) + 1];
      locNormalcoord[(obN * 3) + 2] = myface->normal_coord[(x * 3) + 2];
      obN++;
    }

    for (int x = 0; x < myface->number_of_triangles; x++) {
      loc_tri_indexes[(obTR * 3) + 0] = myface->tri_indexes[(x * 3) + 0] + advance - 1;
      loc_tri_indexes[(obTR * 3) + 1] = myface->tri_indexes[(x * 3) + 1] + advance - 1;
      loc_tri_indexes[(obTR * 3) + 2] = myface->tri_indexes[(x * 3) + 2] + advance - 1;
      obTR++;
    }

    advance = obP;

    delete [] myface->vertex_coord;
    myface->vertex_coord = NULL;

    delete [] myface->normal_coord;
    myface->normal_coord = NULL;

    delete [] myface->tri_indexes;
    myface->tri_indexes = NULL;

    delete myface;
    myface = NULL;

    anIterator++;
  }
}

void Tesselator::JoinPrimitivesWithUVCoords()
{
  int obP = 0;
  int obN = 0;
  int obT = 0;
  int obTR = 0;

  int advance = 0;

  int total_poly_count = 0;
  int total_vertex_count = 0;
  int total_normal_count = 0;
  int total_texcoord_count = 0;

  std::vector<aface*>::iterator anIterator = facelist.begin();

  while (anIterator != facelist.end()) {

    aface* myface = *anIterator;

    total_poly_count =  total_poly_count + myface->number_of_triangles;
    total_vertex_count = total_vertex_count + myface->number_of_coords;
    total_normal_count = total_normal_count + myface->number_of_normals;
    total_texcoord_count = total_texcoord_count + myface->number_of_texcoords;

    anIterator++;
  }

  loc_tri_indexes= new int[total_poly_count * 3 ];
  locVertexcoord = new float[total_vertex_count * 3 ];
  locNormalcoord = new float[total_normal_count * 3 ];
  locTexcoord    = new float[total_texcoord_count * 3 ];

  tot_triangle_count = total_poly_count;
  tot_vertex_count   = total_vertex_count;
  tot_normal_count   = total_normal_count;
  tot_texcoord_count = total_texcoord_count;
  anIterator = facelist.begin();
  while (anIterator != facelist.end()) {
    aface* myface = *anIterator;
    for (int x = 0; x < myface->number_of_coords; x++) {
      locVertexcoord[(obP * 3) + 0] = myface->vertex_coord[(x * 3) + 0];
      locVertexcoord[(obP * 3) + 1] = myface->vertex_coord[(x * 3) + 1];
      locVertexcoord[(obP * 3) + 2] = myface->vertex_coord[(x * 3) + 2];
      obP++;
    }

    for (int x = 0; x < myface->number_of_normals; x++) {
      locNormalcoord[(obN * 3) + 0] = myface->normal_coord[(x * 3) + 0];
      locNormalcoord[(obN * 3) + 1] = myface->normal_coord[(x * 3) + 1];
      locNormalcoord[(obN * 3) + 2] = myface->normal_coord[(x * 3) + 2];
      obN++;
    }

    for (int x = 0; x < myface->number_of_texcoords; x++) {
      locTexcoord[(obT * 3) + 0] = myface->tex_coord[(x * 3) + 0];
      locTexcoord[(obT * 3) + 1] = myface->tex_coord[(x * 3) + 1];
      locTexcoord[(obT * 3) + 2] = myface->tex_coord[(x * 3) + 2];
      obT++;
    }

    for (int x = 0; x < myface->number_of_triangles; x++) {
      loc_tri_indexes[(obTR * 3) + 0] = myface->tri_indexes[(x * 3) + 0] + advance - 1;
      loc_tri_indexes[(obTR * 3) + 1] = myface->tri_indexes[(x * 3) + 1] + advance - 1;
      loc_tri_indexes[(obTR * 3) + 2] = myface->tri_indexes[(x * 3) + 2] + advance - 1;
      obTR++;
    }

    advance = obP;

    delete [] myface->vertex_coord;
    myface->vertex_coord = NULL;

    delete [] myface->normal_coord;
    myface->normal_coord = NULL;

    delete [] myface->tex_coord;
    myface->tex_coord = NULL;

    delete [] myface->tri_indexes;
    myface->tri_indexes = NULL;

    delete myface;
    myface = NULL;

    anIterator++;
  }
}

//---------------------------------------------------------------------------
Standard_Boolean Tesselator::TriangleIsValid(const gp_Pnt& P1, const gp_Pnt& P2, const gp_Pnt& P3) const
{
  gp_Vec V1(P1,P2);
  gp_Vec V2(P2,P3);
  gp_Vec V3(P3,P1);

  if ((V1.SquareMagnitude() > 1.e-10) && (V2.SquareMagnitude() > 1.e-10) && (V3.SquareMagnitude() > 1.e-10)) {
    V1.Cross(V2);
    if (V1.SquareMagnitude() > 1.e-10)
      return Standard_True;
    else
      return Standard_False;
  }
  else
    return Standard_False;
}

//---------------------------------------------------------------------------
void Tesselator::PrepareBoxTextureCoordinates(const TopoDS_Shape& aShape)
{
  //declare local variables
  Bnd_Box aBox;
  Standard_Real aXmin,aYmin ,aZmin ,aXmax ,aYmax ,aZmax;
  Standard_Real aUmaxBack, aVmaxBack;
  Standard_Real aUmaxLeft, aVmaxLeft;
  Standard_Real aUmaxBottom, aVmaxBottom;

  //calculate the bounding box
  BRepBndLib::Add(aShape, aBox);
  aBox.Get(aXmin, aYmin, aZmin, aXmax, aYmax, aZmax);

  //enlarge the bb so all edges have the size of the biggest one
  Standard_Real xDim = abs((long)aXmax - (long)aXmin);
  Standard_Real yDim = abs((long)aYmax - (long)aYmin);
  Standard_Real zDim = abs((long)aZmax - (long)aZmin);

  if ((xDim > yDim) && (xDim > zDim)) {
    aYmin -= (xDim - yDim) / 2;
    aYmax += (xDim - yDim) / 2;

    aZmin -= (xDim - zDim) / 2;
    aZmax += (xDim - zDim) / 2;
  }
  else if ((yDim > xDim) && (yDim > zDim)) {
    aXmin -= (yDim - xDim) / 2;
    aXmax += (yDim - xDim) / 2;

    aZmin -= (yDim - zDim) / 2;
    aZmax += (yDim - zDim) / 2;
  }
  else {
    aXmin -= (zDim - xDim) / 2;
    aXmax += (zDim - xDim) / 2;

    aYmin -= (zDim - yDim) / 2;
    aYmax += (zDim - yDim) / 2;
  }

  aBndBoxSz = aXmax-aXmin;
}

//---------------------------------------------------------------------------
void Tesselator::GetBoxTextureCoordinate(const gp_Pnt& p, const gp_Dir& N1, gp_Vec2d& theCoord_p)
{
  Standard_Real x = abs(N1.X());
  Standard_Real y = abs(N1.Y());
  Standard_Real z = abs(N1.Z());

  if (x >= y && x >= z) {
    if (N1.X() > 0) { //right
      theCoord_p.SetX(p.Y() - aYmin);
      theCoord_p.SetY(p.Z() - aZmin);
      theCoord_p.Rotate(M_PI/2.);
    }
    else { //left
      theCoord_p.SetX(p.Z() - aZmin);
      theCoord_p.SetY(p.Y() - aYmin);
    }
  }
  else if ((y >= z) && (y >= x)) {
    if (N1.Y() > 0) { //top
      theCoord_p.SetX(p.X() - aXmin);
      theCoord_p.SetY(-(p.Z() - aZmin));
    }
    else { //bottom
      theCoord_p.SetY(p.Z() - aZmin);
      theCoord_p.SetX(p.X() - aXmin);
      theCoord_p.Rotate( M_PI);
    }
  }
  else {
    if (N1.Z() > 0) {  //front
      theCoord_p.SetX(p.X() - aXmin);
      theCoord_p.SetY(p.Y() - aYmin);
    }
    else { //back
      theCoord_p.SetX(p.Y() - aYmin);
      theCoord_p.SetY(p.X() - aXmin);
      theCoord_p.Rotate(M_PI/2.);
    }
  }
}