CPSC 215 Lab 6 and Reading Week Project:

				TANKS!

		(Due Thursday during reading week)

   Download the tanks.java program from the class webpage.  This
program creates a 500X400 pixel applet (also get tanks.html) in which
two tanks, tank 0 (black turret) and tank 1 (blue turret) fights to
destroy eachother.  Also download the gif image "skull9.gif" which is
used to display a skeleton when a target is destroyed.  You are to
find a competing team, and modify the tank1 (black) and tank2 (blue)
classes at the very end of the file.  These are the ONLY classes you
can modify.  The "manuver" method determines the algorithm your tank
follows.  I'm assuming you were in class when I gave the demonstration.

   Here are the methods and variables you can access in your tank subclass:


ID	 :	an integer identifying yourself (0 - black, 1 - blue);
xcord()  : 	method that returns your x coordinate
ycord()  : 	method that returns your y coordinate
		These methods ensure you can't change your position arbitrarily
gunposition :   Position of your high-velocity anti-tank laser cannon,
		expressed in degrees. 0 is down, 90 is right, etc...
	        The initial angle is set to 90;

A.Targ[0], A.Targ[1]:  two targets (see class target) with information
  you can use concerning the other tank.  If T is a target object, then

	T.ID   is ID of target  (remember one of these is you!)
        T.xpos is x coordinate of target
        T.ypos is y coordinate of target
        T.gunposition is gunposition of target relative to THAT target, not you
        T.destroyed is true if target has been destroyed.


move(dir)	:  move in direction dir, where dir can be north, east
	south, or west.  These are actually integers 0-3. any other value
	will have no effect.  You move 4 pixels each time.

rotateTurret(dir) :  rotates turret, dir can be left (1) or right (-1).
	You rotate the gun by 2 degrees each time.

inrange(t)  :  t is a target object; method will return true if tank is
	within range of your cannon (200 pixels).

insight(t)  :  t is a target object; method will return true if t
	is within range AND aligned with your cannon.

target_insight():  true if there's a target in sight that's not yourself.
	Since I'm restricting the program to two tanks, this is the same
	as "insight" except no argument is needed.

fire()	:	Fires your cannon.  This will have no effect if
	if target_insight() is false.  Be warned that very occassionally
	your shots may "glance off".  Also, sometimes your tank reacts
	too slowly, and may miss an opportunity to fire, depending on
	your program and what the operating system is doing at the time.
	This makes things more fun.

distanceTo(x,y)  :  returns distance in pixels to coordinate x,y.  Your
	position is the center point of your tank turret.


In addition, you should know about the Java's Math functions:

  Math.sin(r), (and cos, tan)  takes radians as their arguments, not
  degrees, but I used degrees because I think they're easier for humans.
  Math.atan(x) (and asin, acos) return radians as values.  
  Given your "gunposition" in degrees:

  double gundr = gunposition * 0.01745;    // converts it to radians
 
  and 

  int gx = xpos + ((int) (25.0 * Math.sin(gundr))); 
  int gy = ypos + ((int) (25.0 * Math.cos(gundr)));

  will calculate the x,y coordinates of the *tip* of your cannon.
  (25.0 is the length of the cannon from its tip to the center of turret).

  You may also call gunslope() to return the slope of your gun if
  you want to compute line of fire.  I'm not exactly sure if this will
  be really useful, however.
  I have several references on java library functions, and I'd be
  glad to make them available to you.


  * * * * * * * *

  I have tried to make sure you can't cheat by changing variables you're
not supposed to change, but I might have left some loopholes.  If you
use them, you will get credit for the assignment but you will be 
disqualified from winning the contest.

  First defeat the random tank before competing with another team.
The assignment will be graded as a regular lab, but those who do well
in the contest will receive extra credit.

  Please be aware that this program was written in a very short
ammount of time and may have bugs.  If unexpected things happen (e.g,
tank fires backwards) please let me know and I'll correct the problem.
If the program suddenly halts in the middle, just quit and start it up
again.  Also use Java 1.1 instead of 1.2 - I have not tested it with
1.2.  I may be posting updates to the program, so PLEASE check the
class webpage often.  Also check your email regularly for updates from
the TAs.

  Contest is next Thursday, regular lab time (attendance required unless
you have prior permission).