// read_stl.java   read a  .stl  file

import java.io.*;
import java.util.*;
import java.text.*;
import java.awt.*;
import java.awt.event.*;


// solid rect
//   facet normal 0.0 0.0 -1.0
//     outer loop
//       vertex 1.0 1.0 1.0
//       vertex 5.0 4.0 1.0
//       vertex 1.0 4.0 1.0
//     endloop
//   endfacet
//   facet normal 0.0 0.0 -1.0
//     outer loop
//       vertex 1.0 1.0 1.0
//       vertex 5.0 1.0 1.0
//       vertex 5.0 4.0 1.0
//    endloop
//   endfacet
//...
// endsolid

class read_stl
{
  Boolean debug = false;
  double xmin, xmax, ymin, ymax, zmin, zmax;
 
  public read_stl(String filein, double stl[][], int num_ptv[])
  {

    int num_tri = 0;
    int num_pt = 0;
    StringTokenizer T;
    String token;
    String solid = "solid";
    String facet = "facet";
    String normal = "normal";
    String outer = "outer";
    String loop = "loop";
    String vertex = "vertex";
    String endloop = "endloop";
    String endfacet = "endfacet";
    String endsolid = "endsolid";
      
    if(debug) System.out.println("read_stl.java reading "+filein);
    try
    {
      FileReader fin = new FileReader(filein);
      BufferedReader in = new BufferedReader(fin);
      String input_line;
      int len;

      while(true) // to  endsolid
      {
        input_line = in.readLine(); // 
        len = input_line.length();
        if(debug) System.out.println("input:"+input_line+"  len="+len);
        T = new StringTokenizer(input_line," ");
        token = T.nextToken(); // ?
        if(debug) System.out.println("token:"+token);
	if(token.equals(endsolid)) break;
	if(token.equals(endloop))
	{
	  num_tri++;
	  num_pt = 0;
	  continue;
	}
	if(token.equals(endfacet)) continue;
	if(token.equals(vertex))
	{
          token = T.nextToken(); // x
          if(debug) System.out.println("token:"+token);
          stl[num_tri][num_pt] = Double.parseDouble(token);
          token = T.nextToken(); // y
          if(debug) System.out.println("token:"+token);
          stl[num_tri][num_pt+1] = Double.parseDouble(token);
          token = T.nextToken(); // z
          if(debug) System.out.println("token:"+token);
          stl[num_tri][num_pt+2] = Double.parseDouble(token);
	  num_pt = num_pt + 3;
	}
	if(token.equals(facet))
	{
          if(debug) System.out.println("num_tri="+num_tri);
          token = T.nextToken(); // normal
          if(debug) System.out.println("token:"+token);
          token = T.nextToken(); // nx
          if(debug) System.out.println("token:"+token);
          stl[num_tri][9] = Double.parseDouble(token);
          token = T.nextToken(); // ny
          if(debug) System.out.println("token:"+token);
          stl[num_tri][10] = Double.parseDouble(token);
          token = T.nextToken(); // nz
          if(debug) System.out.println("token:"+token);
          stl[num_tri][11] = Double.parseDouble(token);
	}
      } // end while      
    } // end try
    catch(IOException exception)
    {
      System.out.println("read stl.java "+exception);
    }
    xmin = stl[0][0];
    xmax = stl[0][0];
    ymin = stl[0][1];
    ymax = stl[0][1];
    zmin = stl[0][2];
    zmax = stl[0][2];
    for(int i=1; i<num_tri; i++)
    {
      xmin = Math.min(xmin, stl[i][0]);
      xmax = Math.max(xmax, stl[i][0]);
      ymin = Math.min(ymin, stl[i][1]);
      ymax = Math.max(ymax, stl[i][1]);
      zmin = Math.min(zmin, stl[i][2]);
      zmax = Math.max(zmax, stl[i][2]);
    }
    System.out.println("num_tri="+num_tri);
    System.out.println("xmin="+xmin+", xmax="+xmax+
		       "\nymin="+ymin+", ymax="+ymax+
		       "\nzmin="+zmin+", zmax="+zmax);
    num_ptv[0] = num_tri;
  } // end read_stl
    
  void normal(double x0, double y0, double z0,
              double x1, double y1, double z1,
              double x2, double y2, double z2)
  {
    double ax, ay, az, bx, by, bz, nx, ny, nz, denom;
    float red, grn, blu; 
    ax = x2 - x0;
    ay = y2 - y0;
    az = z2 - z0;
    bx = x1 - x0;
    by = y1 - y0;
    bz = z1 - z0;
    nx = ay*bz-az*by;
    ny = az*bx-ax*bz;
    nz = ax*by-ay*bx;

    denom = Math.sqrt(nx*nx+ny*ny+nz*nz);
    nx = nx/denom;
    ny = ny/denom;
    nz = nz/denom;
    // System.out.println(x0+y0+z0);
    // System.out.println(x1+y1+z1);
    // System.out.println(x2+y2+z2);
    // System.out.println("nx="+nx+", ny="+ny+", nz="+nz);
  } // end normal
} // end class read_stl