import java.io.*;

class arc {
  static double[] xx;
  static double[] yy;
  static double r;    
  
  public static void main(String[] args) {
    /*
     *  Urs Oswald osurs@bluewin.ch, 18.11.2002  
     *  Eingabe: x1 y1 x2 y2 x3 y3 r
     *  schreibt arc.tex: LaTeX-Datei fuer Bogen  
     *  mit Radius r im Winkel P1-P2-P3 (Scheitel: P2)
     *  ueberschreibt allfaellig schon vorhandene Datei desselben Namens
     */
    if(args.length < 7) {
      System.out.println("Schreibt arc.tex für Bogen mit Radius r im Winkel P1-P2-P3");
      System.out.println("Gebrauch: java arc x1 y1 x2 y2 x3 y3 r");
      return;
    } 
    String outstring = "";
    double a, rot;
    double[] xy;
    xx = new double[4];                           // P3: mittlerer (Kontroll-)Punkt
    yy = new double[4];    
    xx[1] = Double.parseDouble(args[0]);          // P1 --> 1
    yy[1] = Double.parseDouble(args[1]);
    xx[0] = Double.parseDouble(args[2]);          // P2 --> 0
    yy[0] = Double.parseDouble(args[3]);
    xx[2] = Double.parseDouble(args[4]);          // P3 --> 2
    yy[2] = Double.parseDouble(args[5]);    
    r    = Double.parseDouble(args[6]);           // r    
    outstring += "% arc\n";
    outstring += "% P1 = ("+xx[1]+"/"+yy[1]+")";
    outstring += "  P2 = ("+xx[0]+"/"+yy[0]+")";
    outstring += "  P3 = ("+xx[2]+"/"+yy[2]+")";
    outstring += "  r = " + r ;    
    xx[1] = xx[1] - xx[0]; yy[1] = yy[1] - yy[0]; // Verschiebung des Scheitels
    xx[2] = xx[2] - xx[0]; yy[2] = yy[2] - yy[0]; // in den Ursprung    
    a = Math.sqrt(xx[1]*xx[1] + yy[1]*yy[1]);     // Einheitsvektor (xx[1], yy[1])
    xx[1] = xx[1] / a; yy[1] = yy[1] / a;    
    a = Math.sqrt(xx[2]*xx[2] + yy[2]*yy[2]);     // Einheitsvektor (xx[2], yy[2])
    xx[2] = xx[2] / a; yy[2] = yy[2] / a;
    
    rot = 0.5*( angle(xx[1], yy[1])               // rot: Neigungswinkel der 
               +angle(xx[2], yy[2]));             //      Winkelhalbierenden
    
    xy  = rotate(xx[1], yy[1], -rot);             // Rotation: Ziel ist
    xx[1] = xy[0]; yy[1] = xy[1];                 // Symmetrie zur x-Achse
    xy  = rotate(xx[2], yy[2], -rot);
    xx[2] = xy[0]; yy[2] = xy[1];    
    xx[3] = 1 / xx[1]; yy[3] = 0;                 // qbezier-Punktfolge: P1 P3 P2    
    for(int i=1;i<4;i++) { 
      xy = rotate(xx[i], yy[i], rot);             // Zurueckrotieren
      xx[i] = r * xy[0] + xx[0];                  // Strecken und Zurueckschieben 
      yy[i] = r * xy[1] + yy[0];         
    }
    outstring += "\n\\qbezier"
      + punkt(1)+punkt(3)+punkt(2);               // Anfuegen der 3 Punkte       
    File outfile = new File("arc.tex");           // in Datei schreiben    
    try{
      FileWriter out = 
        new FileWriter(outfile.getPath(), false); // ueberschreibt allfaellig schon
      out.write(outstring);                       // bestehende Datei "arc.tex"
      out.close();
    }
    catch(IOException e) {
    }
  }         
  static double angle(double x, double y) {
    /*
     *   Resultat: Radian, 0 <= phi < 2PI   
     */
    double phi = 0.0;
    double a = Math.sqrt(x*x + y*y);    
    x = x/a;
    y = y/a;
    phi = Math.acos(x);
    if(y<0)
      phi = 2*Math.PI-phi;
    return phi;
  }  
  static double[] rotate(double x, double y, double phi) {
    /*
     *  phi im Bogenmass
     */
    double[] xy = new double[2];    
    xy[0] = x * Math.cos(phi) - y * Math.sin(phi);
    xy[1] = x * Math.sin(phi) + y * Math.cos(phi);    
    return xy;
  }    
  static String runde(double t) {
    String s = "";
    int T = (int)(Math.round(10000 * t));
    double d = T/10000.0;
    s = String.valueOf(d);
    return s;
  }  
  static String punkt(int i) {
    String s;
    s="(" + runde(xx[i]) + ", " + runde(yy[i]) + ")";
    return s;
  }       
}