/*
   gremlin goes beserk, goblin goes after human
*/

import java.awt.*;
import java.awt.event.*;
import java.awt.Graphics;
import javax.swing.*;

public class goblinapp2b extends JFrame implements KeyListener
{
  private Graphics brush;
  private Graphics display;
  private Image canvas;    // off-screen graphics buffer
  private human professor;  // professor object
  private goblin stu;
  private goblin ent;
  private diamond treasure;
  private static final Color bkcolor = Color.black;
  private static final int XBOUND = 800;
  private static final int YBOUND = 600;
  private static final int STEP = 4;
  private static final int FDELAY = 50;

  public static void main(String[] args) // needed for application
  {
    goblinapp2b session  = new goblinapp2b();
    session.addWindowListener(new WindowAdapter() {
              public void windowClosing(WindowEvent e) {System.exit(0);} });
    session.init();
  }

   public void paint(Graphics g) {}  // overrides auto-update

   public void init()
    {
       setBounds(0,0,XBOUND,YBOUND);
       show();
       canvas = createImage(XBOUND,YBOUND);
       brush = canvas.getGraphics();
       display = this.getGraphics();
       brush.setColor(bkcolor);   // clear 
       brush.fillRect(0,0,XBOUND,YBOUND);   // with black background
       brush.setColor(Color.blue);  
       addKeyListener(this);
       requestFocus();		// keys go to applet
       animate();
    } // init

   public void clearbuffer()
    { Color old;
      old = brush.getColor();
      brush.setColor(bkcolor);   // clear 
      brush.fillRect(0,0,XBOUND,YBOUND);   // with black background
      brush.setColor(old);   //  restores color
    } // clearbuffer

   public void nextframe(int delay) // delay in ms
    {
       try { Thread.sleep(delay); } catch (InterruptedException IE) {}
       display.drawImage(canvas,0,0,null);  // draws to screen
       clearbuffer();
    } // nextframe with ms delay


    // event handling
   public void keyReleased(KeyEvent e) {}
   public void keyTyped(KeyEvent e) {}
   public void keyPressed(KeyEvent e)
    { int key = e.getKeyCode();       // key pressed
      if (key == KeyEvent.VK_UP) 
	  professor.setdirection(0,-1*STEP);  // move up
      if (key == KeyEvent.VK_DOWN) 
	  professor.setdirection(0,STEP);
      if (key == KeyEvent.VK_LEFT) 
	  professor.setdirection(-1*STEP,0);
      if (key == KeyEvent.VK_RIGHT) 
	  professor.setdirection(STEP,0);
      if (key == KeyEvent.VK_SPACE)
	  professor.setdirection(0,0);  // stop
      // else do nothing - direction remains the same
    }

    /* ----------------******************------------------ */

    public int randint(int min, int max) 
    { return (int) (Math.random() * (max-min+1) + min); }

   public void animate()
    {  int x1; int y1;   // hold numbers
       int x2; int y2;
       int dx; int dy;   // direction to set for goblin
       professor = new human(XBOUND-50,YBOUND-50,brush);
       stu = new goblin(50,50,brush,"gremlin1.gif");     
       goblin dent = new goblin(XBOUND-50,50,brush,"zerg1.gif");
       treasure = new diamond(XBOUND/2,YBOUND/2,brush);
       stu.setdirection(12,10);  
       try {Thread.sleep(1000);} catch (Exception ee) {}
       boolean stop = false;
       while (!stop)
	   {  
	       // goblin moves quickly
	       // set second goblin's course vector: moves faster!
	       x1 = dent.getx();   y1 = dent.gety();
	       x2 = professor.getx(); y2 = professor.gety();
	       if (x2>x1) dx = STEP+1; else dx = -1*(STEP+1);
	       if (y2>y1) dy = STEP+1; else dy = -1*(STEP+1);
	       dent.setdirection(dx,dy);  

	       stu.move();  dent.move();
	       treasure.move();
	       professor.move();
	       nextframe(FDELAY);
	       if (stu.overlap(professor) || dent.overlap(professor)) 
		   { display.setFont(new Font("Serif",Font.BOLD,24));
   		     display.setColor(Color.red);
		     display.drawString("The Goblins Win!",XBOUND/2-100,YBOUND/2);
		     stop = true;
		   }
	       if (treasure.overlap(professor))
		   { display.setFont(new Font("Serif",Font.BOLD,24));
   		     display.setColor(Color.red);
		     display.drawString("The Professor Wins!",XBOUND/2-100,YBOUND/2);
		     stop = true;
		   }
           }
    } // animate
} // class goblinapp2


/* ************************************************* */

class human
{
   private Image img;   // gif
   private int xcord, ycord;        // coordinates of center
   private int dx, dy;   // movement vector
   private Graphics brush;
   private int radius;
   private static final int XBOUND = 800;
   private static final int YBOUND = 600;   

    // accessor methods
    public int getx() { return xcord; }
    public int gety() { return ycord; }
    public int getr() { return radius; }
    public int getdx() { return dx; }
    public int getdy() { return dy; }
   
   public human(int x0, int y0, Graphics b0)  // constructor
    { 
      xcord = x0;
      ycord = y0;
      // change following line to correct location of gif:
      img = Toolkit.getDefaultToolkit().getImage("/shared/csc/local/stuff/man15.gif");
      radius = 15;
      brush = b0;
    }

    public void draw()
    {
	brush.drawImage(img,xcord-radius,ycord-radius,null);
	//brush.drawOval(xcord-radius,ycord-radius,2*radius,2*radius);
    }   

    public void setdirection(int newdx, int newdy)
    {  
	dx = newdx;
	dy = newdy;
    }

    public void move()
    {
	xcord = xcord + dx;
	if (xcord < radius/2) xcord = XBOUND-(radius/2);
	if (xcord > XBOUND-(radius/2)) xcord = radius/2;
	ycord = ycord + dy;
	if (ycord < radius/2) ycord = YBOUND-(radius/2);
	if (ycord > YBOUND-(radius/2)) ycord = radius/2;
	draw();
    }
    
} // end class human



class goblin
{
   private Image img;   // gif
   private int xcord, ycord;        // coordinates of center
   private int dx, dy;   // movement vector
   private Graphics brush;
   private int radius;
   private static final int XBOUND = 800;
   private static final int YBOUND = 600;   

    // accessor methods
    public int getx() { return xcord; }
    public int gety() { return ycord; }
    public int getr() { return radius; }
    public int getdx() { return dx; }
    public int getdy() { return dy; }
   
   public goblin(int x0, int y0, Graphics b0, String giffile)  // constructor
    { 
      xcord = x0;
      ycord = y0;
      img = Toolkit.getDefaultToolkit().getImage("/shared/csc/local/stuff/"+giffile);
      radius = 30;
      brush = b0;
    }

    public void draw()
    {
	brush.drawImage(img,xcord-radius,ycord-radius,null);
	//brush.drawOval(xcord-radius,ycord-radius,2*radius,2*radius);
    }   

    public void setdirection(int newdx, int newdy)
    {  
	dx = newdx;
	dy = newdy;
    }

    public void move()  // bounces off
    {
	if (xcord < radius) { xcord = radius; dx = -1 * dx; }
           else if (xcord > (XBOUND-radius))
	       { xcord = XBOUND-radius; dx = -1 * dx; }
            else xcord = xcord + dx;

	if (ycord < radius) { ycord = radius; dy = -1 * dy; }
            else if (ycord > (YBOUND-radius))
	       { ycord = YBOUND-radius; dy = -1 * dy; }
            else ycord = ycord + dy;
	draw();
    }

    public int randint(int min, int max) 
    { return (int) (Math.random() * (max-min+1) + min); }

    public double dist(int x1, int y1, int x2, int y2)
    {
	int dx = (x1-x2) * (x1-x2);
	int dy = (y1-y2) * (y1-y2);
	return Math.sqrt(dx+dy);
    }

    // detects if goblin's circle overlaps that of human:
    public boolean overlap(human h)
    {
	int x2, y2, r2;
	x2 = h.getx();
	y2 = h.gety();
	r2 = h.getr();
	return dist(xcord,ycord,x2,y2) <= (radius + r2 - 5);
    }
    
} // end class goblin



class diamond
{
   private Image img;   // gif
   private int xcord, ycord;        // coordinates of center
   private Graphics brush;
   private int radius;
   private static final int XBOUND = 800;
   private static final int YBOUND = 600;   

    // accessor methods
    public int getx() { return xcord; }
    public int gety() { return ycord; }
    public int getr() { return radius; }
   
   public diamond(int x0, int y0, Graphics b0)  // constructor
    { 
      xcord = x0;
      ycord = y0;
      img = Toolkit.getDefaultToolkit().getImage("/shared/csc/local/stuff/gem1.gif");
      radius = 12;
      brush = b0;
    }

    public void draw()
    {
	brush.drawImage(img,xcord-radius,ycord-radius,null);
	//brush.drawOval(xcord-radius,ycord-radius,2*radius,2*radius);
    }   

    public void move()  // bounces off
    {
	int dx, dy;
	dx = randint(-4,4);
	dy = randint(-4,4);
	if ((xcord+dx > radius/2) && (xcord+dx < XBOUND-(radius/2)))
 	  xcord = xcord + dx;
	if ((ycord+dy > radius/2) && (ycord+dy < YBOUND-(radius/2)))
	  ycord = ycord + dy;
	draw();
    }

    public int randint(int min, int max) 
    { return (int) (Math.random() * (max-min+1) + min); }

    public double dist(int x1, int y1, int x2, int y2)
    {
	int dx = (x1-x2) * (x1-x2);
	int dy = (y1-y2) * (y1-y2);
	return Math.sqrt(dx+dy);
    }

    // detects if diamond's circle overlaps that of human:
    public boolean overlap(human h)
    {
	int x2, y2, r2;
	x2 = h.getx();
	y2 = h.gety();
	r2 = h.getr();
	return dist(xcord,ycord,x2,y2) <= (radius + r2 - 5);
    }
    
} // end class diamond