created enemy class

src/tanks/Enemy.java

@@ -5,8 +5,72 @@
 */
 package tanks;
 
+import javax.swing.JFrame;
+
 
 public class Enemy extends Living
 {
+    public Enemy
+    {
+        super();        
+    }
+    
+    
+   /*
+    enemy spawns at a random location on boarder of map. Random number 1-4 
+    to determine which edge of map enemy spawns. Random number code to
+    determine how far down or how far over player spawns on given edge.
+    */
+    public void spawn(JFrame frame)
+    {
+        int temp=(int)(Math.random()*(5));
+        if(temp==1)
+        {
+            y=0;
+            x=(int)(Math.random()*(frame.getWidth()+1));
+        }
+        else if(temp==2)
+        {
+            y=(int)(Math.random()*(frame.getHeight()+1));
+            x=frame.getWidth();
+        }
+        else if(temp==3)
+        {
+            y=frame.getHeight();
+            x=(int)(Math.random()*(frame.getWidth()+1));
+        }
+        else if(temp==4)
+        {
+            x=0;
+            y=(int)(Math.random()*(frame.getHeight()+1));
+        }
+    }
+    
+    
+    /*
+    Used right triangle algebra to determine distance from x,y of enemy 
+    to x,y of player.
+    */
+    public double distToPlayer(Player p)
+    {
+        double d, a, b;
+        a=Math.abs(x-p.getX());
+        b=Math.abs(y-p.getY());
+        d=Math.sqrt(a*a+b*b);
+        return(d);
+    }
+    
     
+    /*
+    Found lengths of imaginary triangle between player and enemy. 
+    Then used inverse trig to determine angle.
+    */
+    public double angleToPlayer(Player p)
+    {
+        double a, b, ang;
+        a=Math.abs(x-p.getX());
+        b=Math.abs(y-p.getY());
+        ang=Math.atan(b/a);
+        return(ang);
+    }
 }