// Copyright (c) 1996  David Engberg  All rights reserved
// $Id$

import java.io.RandomAccessFile;

/**
 * This mini-program is used to spit out a panopticon VRML world with a
 * number of prisoners equal to the number of arguments given on the command-
 * line.
 */
public class Panopticon {

  public static final String kPrefixFileName = "prefix.wrl";

  /**
   * This static function is invoked when this program is run.
   * The output of the program is a VRML file.  The command-line is a
   * list of URLs.
   */
  public static void main(String arguments[]) {
    int prisonerCount = arguments.length;
    if (prisonerCount < 4) {
      System.err.println(">>> At least 4 URLs are required for a panopticon");
      return;
    }
    try {
      RandomAccessFile prefixFile = new RandomAccessFile(kPrefixFileName, "r");
      String line;
      while ((line = prefixFile.readLine()) != null) {
	System.out.println(line);
      }
    } catch (IOException exception) {
      System.err.println(">>> File error reading prefix file: " + exception);
      return;
    }
    double radius = 2 + 2 / Math.tan(Math.PI / prisonerCount);
    System.out.println("# Circle radius = " + radius);
    double increment = 2 * Math.PI / prisonerCount;
    System.out.println("# Increment = " + increment);
    double angle = 0;
    System.out.println("\nTransform {");
    double outer = radius + 2.5;
    System.out.println("   scale " + outer + " .1 " + outer);
    System.out.println("   translation 0 -1.1 0");
    System.out.println("   children [");
    System.out.println("      Shape {");
    System.out.println("         appearance Appearance {");
    System.out.println("            material Material {");
    System.out.println("               diffuseColor 0.5 0.5 0.5");
    System.out.println("               specularColor 0.3 0.3 0.3");
    System.out.println("               shininess 0.1");
    System.out.println("            }");
    System.out.println("	 }");
    System.out.println("         geometry Cylinder {}");
    System.out.println("      }");
    System.out.println("     ]");
    System.out.println("}");

    for (int argument = 0; argument < arguments.length; ++argument) {
      double z = -radius * Math.cos(angle);
      double x = -radius * Math.sin(angle);
      System.out.println("\nTransform {");
      System.out.println("   rotation 0 1 0 " + angle);
      System.out.println("   translation " + x + " 0 " + z);
      System.out.println("   children [");
      System.out.println("      Anchor {");
      System.out.println("         url \"" + arguments[argument] + "\"");
      System.out.println("         children [ USE Cell ]");
      System.out.println("      }");
      System.out.println("     ]");
      System.out.println("}");
      System.out.println("Transform {");
      System.out.println("   rotation 0 1 0 " + angle);
      System.out.println("   translation " + x + " 4 " + z);
      System.out.println("   children [");
      System.out.println("      Anchor {");
      System.out.println("         url \"" + arguments[argument] + "\"");
      System.out.println("         children [ USE Cell ]");
      System.out.println("      }");
      System.out.println("     ]");
      System.out.println("}");
      angle += increment;
    }
    System.out.println("# End panopticon");
  }

}