//ObjToPov.java 0.01
//Chris Jeppesen - chrisj@digiquill.com
//23 October 2001 - Mars Day!

//You are free to use or modify this code for any non-commercial use
//For any other use, contact me
//Please send me any patches you may make

import com.sun.j3d.utils.geometry.*;
import javax.vecmath.*;
import java.io.*;
import java.util.*;

public class ObjToPov {
  public static void main(String[] args) throws IOException {
    System.out.println("Kwan Systems ObjToPov: Wavefront .OBJ to POV-Ray mesh2 converter");
    if (args.length!=2) {
      System.out.println("usage: java ObjToPov infile.obj outfile.inc");
    } else {
      //get to work
      LineNumberReader Inf=new LineNumberReader(new FileReader(args[0]));
      String S=Inf.readLine();
      ArrayList V=new ArrayList();
      ArrayList Polys=new ArrayList();
      V.add(new Point3d());
      String Matl=null;
      Polyhedron CurrentPoly=null;
      while(S!=null) {
        if(S.length()>0) {
          switch(S.charAt(0)) {
            case 'v':
              int Pos1=1;
              int Pos2=S.indexOf(" ",Pos1+1);
              double X=Double.parseDouble(S.substring(Pos1,Pos2));
              Pos1=Pos2+1;
              Pos2=S.indexOf(" ",Pos1+1);
              double Y=Double.parseDouble(S.substring(Pos1,Pos2));
              Pos1=Pos2+1;
              double Z=Double.parseDouble(S.substring(Pos1));
              Point3d P=new Point3d(X,Y,Z);
              V.add(P);
  //            System.out.println(P);
              break;
            case 'u':
              //finish off old polyhedron
              //Initialize polyhedron
              if(CurrentPoly!=null) {
                CurrentPoly.finish(V);
//                System.out.println(CurrentPoly.toObj());
              }
              CurrentPoly=new Polyhedron(S);
              Polys.add(CurrentPoly);
              System.out.println(CurrentPoly);
              break;
            case 'f':
              CurrentPoly.Facets.add(Polyhedron.parseFacet(S));
              break;
          }
        }
        S=Inf.readLine();
      }
      if(CurrentPoly!=null) {
        CurrentPoly.finish(V);
      }
      System.out.println("Read "+(V.size()-1)+" vectors");
      Inf.close();
      PrintWriter Ouf=new PrintWriter(new FileWriter(args[1]));
      Ouf.println("//"+args[1]);
      Ouf.println("//Kwan Systems ObjToPov");
      Ouf.println("//Converted from "+args[0]);
      for(Iterator I=Polys.iterator();I.hasNext();) {
        Polyhedron F=(Polyhedron)I.next();
        Ouf.println(F.toPov());
      }
      Ouf.close();
    }
  }
}

class TaggedPoint3d extends Point3d {
  int Tag;
  public TaggedPoint3d(Point3d v, int t) {
    super(v);
    Tag=t;
  }
}

class Polyhedron {
  public ArrayList VertexList;        //Array of Point3d, Local Vertex List
  public ArrayList Facets=null;       //Array of int[]
  public ArrayList LocalFacets=null;  //array of int[3], local facet list, all should be triangles
  String Material;
  public static int[] parseFacet(String S) {
    int Pos1=S.indexOf(' ')+1;
    int Pos2=S.indexOf(' ',Pos1);
    int len=0;
    while(Pos2>0) {
      len++;
      Pos1=Pos2+1;
      Pos2=S.indexOf(' ',Pos1);
    }
    len++;
    int[] Result=new int[len];
    Pos1=S.indexOf(' ')+1;
    Pos2=S.indexOf(' ',Pos1);
    len=0;
    while(Pos2>0) {
      Result[len]=Integer.parseInt(S.substring(Pos1,Pos2));
      len++;
      Pos1=Pos2+1;
      Pos2=S.indexOf(' ',Pos1);
    }
    Result[len]=Integer.parseInt(S.substring(Pos1));
    len++;
    return Result;
  }
  public Polyhedron(String usemtl) {
    Material=usemtl.substring(7);
    Facets=new ArrayList();
    LocalFacets=new ArrayList();
    VertexList=new ArrayList();
  }
  public void AddFacet(String S) {
    Facets.add(parseFacet(S));
  }
  public void AddFacet(int[] I) {
    Facets.add(I);
  }
  public String toString() {
    return Material;
  }
  public static void PrintIntArray(int[]A) {
    for(int i=0;i<A.length;i++) System.out.print(A[i]+" ");
    System.out.println("");
  }
  public static int[][] ReshapeArray(int[]A) {
    int[][] Result=new int[A.length/3][3];
    for(int i=0;i<Result.length;i++) {
      Result[i][0]=A[i*3+0];
      Result[i][1]=A[i*3+1];
      Result[i][2]=A[i*3+2];
    }
    return Result;
  }
  public static int[][] triangulate(ArrayList V,int[] Facet) {
    if(Facet.length==3) {
      int[][] result=new int[1][];
      result[0]=Facet;
      return result;
    } else {
      //PrintIntArray(Facet);
      GeometryInfo G=new GeometryInfo(GeometryInfo.POLYGON_ARRAY);
      Point3d[] P=new Point3d[Facet.length];
      for(int i=0;i<Facet.length;i++) P[i]=(Point3d)V.get(Facet[i]);
      G.setCoordinates(P);
      int[] StripCounts={Facet.length};
      G.setStripCounts(StripCounts);
      int[] Indices=new int[Facet.length]; for(int i=0;i<Facet.length;i++) Indices[i]=Facet[i];
      int[] localIndices=new int[Facet.length]; for(int i=0;i<Facet.length;i++) localIndices[i]=i;
      G.setCoordinateIndices(localIndices);
      Triangulator T=new Triangulator();
      T.triangulate(G);
      int[] NewPoints=G.getCoordinateIndices();
      for(int i=0;i<NewPoints.length;i++)NewPoints[i]=Indices[NewPoints[i]];
      //PrintIntArray(NewPoints);
      return ReshapeArray(NewPoints);
    }
  }
  public String toObj() {
    StringBuffer S=new StringBuffer();
    S.append("g hga1\n");
    for(Iterator I=VertexList.iterator();I.hasNext();) {
      Point3d F=(Point3d)I.next();
      S.append("v "+F.x+" "+F.y+" "+F.z+"\n");
    }
    S.append("g hga1 ant\n");
    S.append("usemtl "+Material+"\n");
    for(Iterator I=LocalFacets.iterator();I.hasNext();) {
      int[] F=(int[])I.next();
      S.append("f "+(F[0]+1)+" "+(F[1]+1)+" "+(F[2]+1)+"\n");
    }
    return S.toString();
  }
  public String toPov() {
    StringBuffer S=new StringBuffer();
    S.append("mesh2 {\n");
    S.append("  vertex_vectors {\n");
    S.append("    "+VertexList.size()+"\n");
    for(Iterator I=VertexList.iterator();I.hasNext();) {
      Point3d F=(Point3d)I.next();
      S.append("    <"+F.x+","+F.y+","+F.z+">\n");
    }
    S.append("  }\n");
    S.append("  face_indices {\n");
    S.append("    "+LocalFacets.size()+"\n");
    for(Iterator I=LocalFacets.iterator();I.hasNext();) {
      int[] F=(int[])I.next();
      S.append("    <"+(F[0])+","+(F[1])+","+(F[2])+">\n");
    }
    S.append("  }\n");
    S.append("  texture {"+Material+"}\n");
    S.append("}\n");
    return S.toString();
  }
  public void finish(ArrayList V) {
    int[] maptolocal=new int[V.size()]; for(int i=0;i<maptolocal.length;i++) maptolocal[i]=-1;
    int mapused=0;
    if(Facets.size()>0) {
      System.out.print("Triangulating, "+Facets.size()+" to do");
      int count=0;
      for(Iterator I=Facets.iterator();I.hasNext();) {
        int[] F=(int[])I.next();
        int[][] tris=triangulate(V,F);
        for(int i=0;i<tris.length;i++) LocalFacets.add(tris[i]);
        count++;
        if((count % 100)==0) System.out.print(".");
      }
      System.out.println("");
      //build the map
      System.out.print("Local Mapping, "+LocalFacets.size()+" to do");
      count=0;
      for(int i=0;i<LocalFacets.size();i++) {
        int[] tri=(int[])LocalFacets.get(i);
        for(int j=0;j<3;j++) {
          if(maptolocal[tri[j]]<0) {
            maptolocal[tri[j]]=mapused;
            mapused++;
            //build the local vertex list
            VertexList.add(V.get(tri[j]));
          }
          //change tris to local
          tri[j]=maptolocal[tri[j]];
        }
        LocalFacets.set(i,tri);
        count++;
        if((count % 100)==0) System.out.print(".");
      }
      System.out.println("");
    }
  }
}