Robocode

1
(No Transcript)
2
Great teaching/ learning aid

• OO
• Threading
• Packaging
• Inheritance
• Polymorphism
• Calling API code

• Event handling
• Inner classes
• Java docs
• How to duck
• Consume time
• Even more time...

3
Teamwork

• Sharing ideas techniques
• Participate internationally in leagues

• You can create your own Robots
• However can participate in a team
• Excellent team builder

4
Windows Robocode Installation
Two ways . via robocode.alphaworks.ibm.com -
download run robocode-setup.jar (autosetup)
5
Linux Robocode Installation
From robocode.alphaworks.ibm.com download run
java jar robocode-setup.jar
6
What you get
Heaps - a runtime environment
Battlefield - a development IDE - javadocs
covering the API - example robots - divorced

7
Skillset needed
Various levels catered for - from beginner
- to intermediate - to advanced hacker !!
8
The battlefield ..

• houses the main simulation engine
• allows you to create, save and open new or
  existing battles
• you can pause or resume a battle
• terminate the battle
• obtain statistics on any robot using controls
  available in main arena
• activate the IDE

9
The IDE

• the Robocode editor is a customised text editor
  for Java source files that make up a robot.
• it is integrated with the Java compiler
• customised Robot packager
• you can use any other editor Eclipse is very
  useful and . FREE ?

10
What is a Robot ?

• consists of one or more Java classes
• can be archived into a JAR package
• packager available from the Battlefield GUI
• they can range from blind ram em, shoot em
  types to devious little buggers
• they can work in teams
• they can control droid robots (these can act as
  decoys, battering rams etc but they last longer)

11
Robot anatomy 101

• Just like the real thing
• it has a gun that rotates
• a radar on top that also rotates
• tank, gun and radar can rotate independently
• default, all aligned
• sorry no sound .

12
Robot commands

• all documented in the Javadoc of the Robocode API
  
• public methods of the robocode.Robot class or
  derivations such as robocode.AdvancedRobot

13
moving your Robot
Some basic commands

• turnRight(double degree) and turnLeft(double
  degree) turn the robot by a specified degree.
• ahead(double distance) and back(double distance)
  move the robot by the specified pixel distance
  these two methods are completed if the robot hits
  a wall or another robot.
• turnGunRight(double degree) and
  turnGunLeft(double degree) turn the gun,
  independent of the vehicle's direction.
• turnRadarRight(double degree) and
  turnRadarLeft(double degree) turn the radar on
  top of the gun, independent of the gun's
  direction (and the vehicle's direction).
• None of these commands will return control to the
  program until they are completed.

14
Controlling the Gun, Radar Tank
When the vehicle is turned, the direction of the
gun (and radar) will also move, unless indicate
differently by calling the following methods

• setAdjustGunForRobotTurn(boolean flag) If the
  flag is set to true, the gun will remain in the
  same direction while the vehicle turns.
• setAdjustRadarForRobotTurn(boolean flag) If the
  flag is set to true, the radar will remain in the
  same direction while the vehicle (and the gun)
  turns.
• setAdjustRadarForGunTurn(boolean flag) If the
  flag is set to true, the radar will remain in the
  same direction while the gun turns. It will also
  act as if setAdjustRadarForRobotTurn(true) has
  been called.

15
Yo !....
Methods exist for getting information about the
robot

• getX() and getY() get the current coordinate of
  the robot.
• getHeading(), getGunHeading(), and
  getRadarHeading() get the current heading of the
  vehicle, gun, or radar in degrees.
• getBattleFieldWidth() and getBattleFieldHeight()
  get the dimension of the battlefield for the
  current round.

16
Firing ....

• Firing and controlling damage.
• each robot starts out with a default "energy
  level," and is considered destroyed when its
  energy level falls to zero.
• when firing, the robot can use up to three units
  of energy. The more energy supplied to the
  bullet, the more damage it will inflict on the
  target robot.
• fire(double power) and fireBullet(double power)
  are used to fire a bullet with the specified
  energy (fire power).
• the fireBullet() version of the call returns a
  reference to a robocode.Bullet object that can be
  used in advanced robots.

17
Events ....

• Here are some of the more frequently used events
  
• ScannedRobotEvent. Handle the ScannedRobotEvent
  by overriding the onScannedRobot() method this
  method is called when the radar detects a robot.
• HitByBulletEvent. Handle the HitByBulletEvent by
  overriding the onHitByBullet() method this
  method is called when the robot is hit by a
  bullet.
• HitRobotEvent. Handle the HitRobotEvent by
  overriding the onHitRobot() method this method
  is called when your robot hits another robot.
• HitWallEvent. Handle the HitWallEvent by
  overriding the onHitWall() method this method is
  called when your robot hits a wall.
• That's all we need to know to create some pretty
  complex robots

18
Creating a robot ....

• start the Robot Editor
• select File-gtNew-gtRobot
• when prompted, name your robot (this will become
  the Java class name e.g (DWStraight)
• when prompted, enter an initial (used for the
  name of the package e.g dw)

19
Generated code
package dw import robocode. / DWStraight
- a robot by (developerWorks) / public class
DWStraight extends Robot ... // ltltArea
1gtgt / run DWStraight's default behavior
/ public void run() ... // ltltArea
2gtgt while(true) ... // ltltArea 3gtgt
... // ltltArea 4gtgt public void
onScannedRobot(ScannedRobotEvent e)
fire(1)
20
Adding functionality
package dw import robocode. public class
DWStraight extends Robot public void run()
turnLeft(getHeading()) while(true)
ahead(1000) turnRight(90)
public void onScannedRobot(ScannedRobotEvent e)
fire(1) public void onHitByBullet(HitByBu
lletEvent e) turnLeft(180)
21
Compiling testing your robot

• From the Robot Editor menu
• select Compiler-gtCompile to compile your robot
  code.
• We are now ready to try our first battle.
• switch back to the battlefield and select menu
  Battle-gtNew

22
Robot support classes

• Design of Robots rapidly gets complex.
• Modularity is a good aim
• Decompose into separate Java classes
• Bundle into a single JAR file (using supplied
  packager)
• Robocode will automatically handle class
  dependencies

23
Battle simulator features

• sophisticated simulation engine
• high performance (in order to render the battle
  at realistic speed)
• flexible (enabling the creation of complex
  robotics logic without getting in the way)
• design that leverages the Java platform

24
Battle simulator architecture

• non-preemptive threading
• coupled with the rendering capabilities provided
  by the JDK GUI and 2D graphics libraries

25
Battle simulator features

• sophisticated simulation engine
• high performance (in order to render the battle
  at realistic speed)
• flexible (enabling the creation of complex
  robotics logic without getting in the way)
• design that leverages the Java platform

26
Battle simulator psuedo code logic
while (round is not over) do call the
rendering subsystem to draw robots, bullets,
explosions for each robot do wake up
the robot wait for it to make a blocking
call, up to a max time interval end for
clear all robot event queue move bullets, and
generate event into robots' event queue if
applicable move robots, and generate event
into robots' event queue if applicable do
battle housekeeping and generate event into
robots' event queue if applicable
delay for frame rate if necessary end do
27
Getting more sophisticated

• so far the Robots are relatively simple
• restrictive Robot class ... blocking
• methods do not return control to our code until
  they finish operation
• we are essentially passing up on the ability to
  make decisions on every turn

enter AdvancedRobot
28
AdvancedRobot
while (round is not over) do call the
rendering subsystem to draw robots, bullets,
explosions for each robot do wake up
the robot wait for it to make a blocking
call, up to a max time interval end for
clear all robot event queue move bullets, and
generate event into robots' event queue if
applicable move robots, and generate event
into robots' event queue if applicable do
battle housekeeping and generate event into
robots' event queue if applicable
delay for frame rate if necessary end do
29
Inheritance relationships
If we want to create a robot called MultiMoveBot
that inherits from AdvancedRobot, we'd use the
following code public class MultiMoveBot extends
AdvancedRobot Note AdvancedRobot is actually
a subclass of Robot, and our own MultiMoveBot is
in turn a subclass of AdvancedRobot, as
illustrated in the class hierarchy shown
30
Exploring AdvancedRobot

• has non blocking API calls
• can change the robot's action on every turn
• a turn in Robocode is called a tick (as in a
  clock tick), and relates to a graphical frame
  that is displayed on the battlefield

31
Blocking vs non-blocking methods

• Robot class
• turnRight()
• turnLeft()
• turnGunRight()
• turnGunLeft()
• turnRadarRight()
• turnRadarLeft()
• ahead()
• back()

• AdvancedRobot class
• setTurnRight()
• setTurnLeft()
• setTurnGunRight()
• setTurnGunLeft()
• setTurnRadarRight()
• setTurnRadarLeft()
• setAhead()
• setback()

32
Working with non-blocking method calls
public class MultiMoveBot extends AdvancedRobot
... public void run() ... setTurnRight(fu
llTurn) setAhead(veryFar) setTurnGunLeft(ful
lTurn)
33
The execute() method
Giving control back to Robocode with a blocking
method call while(true) waitFor(new
TurnCompleteCondition(this)) toggleDirection()

34
The toggleDirection() method
private void toggleDirection() if (clockwise)
setTurnLeft(fullTurn) setBack(veryFar) s
etTurnGunRight(fullTurn) else
setTurnRight(fullTurn) setAhead(veryFar)
setTurnGunLeft(fullTurn) clockwise !
clockwise
35
Custom events
public class CustomEventBot extends
AdvancedRobot ... public void run()
... addCustomEvent( new
Condition("LeftLimit") public boolean
test() return (getHeading() lt
quarterTurn) )
addCustomEvent( new Condition("RightLimit")
public boolean test() return
(getHeading() gt threeQuarterTurn)
)
36
coordinates and direction

37
Handling custom events
public void onCustomEvent(CustomEvent ev)
Condition cd ev.getCondition()
System.out.println("event with "
cd.getName()) if (cd.getName().equals("RightLimi
t")) setTurnLeft(fullTurn) setTurnGunRigh
t(fullTurn) else setTurnRight(fullTurn)
setTurnGunLeft(fullTurn)
38
Interfaces and inner classes

• The three key new features provided by
  AdvancedRobot are the ability to
• Carry out multiple movements simultaneously
• Decide on the robot's action or strategy at every
  clock tick
• Define and handle custom events

39
Looking at the DuckSeekerBot
public class DuckSeekerBot extends AdvancedRobot
implements DuckConstants boolean
targetLocked false Target curTarget
null
40
The Target member class
class Target ... public Target(String
inname, boolean inalive, boolean inlocked)
... public boolean isAlive() ... public
boolean isLocked() ... ... // of Target
41
Homing in on our target
stop() turnRight(evt.getBearing()) if
(evt.getDistance() gt safeDistance)
ahead(evt.getDistance() - safeDistance)
42
Ok Lets wrap up for now
Getting the big picture on the battlefield
Vector, polymorphism, and java.MathThe
DuckSeekerBot Scans for a duck target Zooms
in and roasts the target Repeats until the
entire flock is gone An alternative approach to
the same problem is this Scan for all the ducks
that can be seen in the battlefield and build an
"intelligence map" Zoom in on the flock one at
a time to eliminate them Update the "map"
constantly from scan information This second
approach achieves the same result as the first,
but uses more intelligence. Most advanced robots
use this sort of "big picture" information in
formulating an instantaneous strategic decision.
Learning how to maintain such a map will allow us
to create robots with more sophisticated
intelligence. Get the idea ? Robocode really
does expand your Java knowledge ?
43
Extra Resources

1. Strategies .
2. Tutorials
3. Leagues
4. Forums
5. On-Line help
6. Web Sites