Darwin's World

Darwin's World is a two dimensional grid filled with creatures.  Each creature lives in a single square of the grid, and faces in one of the 4 major compas directions, North, South, East, or West, and belongs to a Species, which determines how the creature behaves.





 This world has 20 creatures, 10 Flytraps (the blue F's) and 10 Rovers (the Light purple R's).   The orientation of each creature is shown by the arrow which points in the direction that the creature is facing.  At each step of the simulation, each creature performs one of 4 actions:

• LEFT:  Rotate left 90 degrees
• RIGHT: Rotate right 90 degrees
• HOP: Move forward one square, if the square in front of the creature is empty
  
• INFECT:  If the square in front of the creature is of a different species, convert that creature to my species
  

The goal of each creature is to infect as many different other creatures as possible, to increase the population of its species

Species Programming

In order to know what to do at each simulation step, each creature executes a number of instructions of the program for its species.  For example, the Flytrap code is:

Step	Instruction	Comment
0	ifenemy 3	If there is an enemy ahead, go to step 3
1	left	Turn left
2	go 0	Go to step 0
3	infect	Infect the adjacant creature
4	go 0	Go to step 0

The step numbers are not part of the actual program (step numbers are implicit), but are included here to make the code easier to follow.  On each turn, the flytrap checks to see if there is an enemy immediately ahead.  If there is an enemy, it jumps to step 3, where it infects the enemy, and then contines to step 0. If there is no enemy, it continues on to step 1, where it turns left before jumping back to step 0.


The instructions that can appear in a creature's program are:
 

hop	Move forward one square.  If the next space is either outside the world, or contains another creature, then the hop command does nothing
left	Rotate left 90 degrees
right	Rotate right 90 degrees
infect n	If the space immediately in front of the creature is occupied by an enemy, that creature is infected.  The infected creature maintains its orientation and position, but changes its species to the species of the infecting creature.  On its next turn, the infected creature will start executing code starting at step n.  If n is not given, then the infected creature starts at step 0.  That is, infect is equivalent to infect 0.  If there is not an enemy immediately in front of the creature, then infect does nothing.
ifempty n	If the next square is empty, the next instruction to be executed is at step n.  If the next square is not empty, continue on to the next step
ifwall n	If the creature is facing the border of the world, go to step n.  If not, go on to the next step
ifsame n	If the creature is facing another creature of the same species, go to step n.  If not, go on to the next step
ifenemy n	If the creature is facing another creature of a different species, go to step n.  If not, go on to the next step
ifrandom n	Go to step n with probability 0.5, and go on to the next step with probability 0.5
go n	Go to step n

A creature can exeucte any number of if or go instructions in a single turn.  The turn ends when the program exectutes a hop, left, right, or infect.  On subequent turns, the program starts up from the point in the program at which it ended its previous turn.  Note that even an
unsucessful hop or infect will end the creature's turn

Species File Format

Each species is described in a file which consists of the species name, followed by the steps in the species program, in order.  The program ends with a blank line or end of file.  Comments may appear after the blank line, or at the end of each instruction line.  For example, the program file for the Flytrap creature is:

---

Flytrap
ifenemy 4
left
go 1
infect
go 1

The flytrap sits in one place and spins.
It infects anything that comes in font.
Flytraps do well when they clump.

---

Some basic creatures are provided:

Food	This creature does nothing but spin around waiting to be infeced by another creature.
Hop	This creature hops forward until it hits a wall.  Not very smart.
Flytrap	This creature spins in place, infecting any enemy that it sees.   Works well against Rovers, not so well against food, since it never goes looking for other creatures to infect.
Rover	This creature walks in a straight line until it is blocked, infecting any creature that it sees.  If it can move forward, it turns in a random direction.  Does very well in the presence of food.
Landmine	This creature is much like the flytrap:  it sits in one place, looking to infect.  Unlike the flytrap, it only turns if it is facing a wall or another landmine.  When landmines clump together, they can be formitable.  Like the flytrap, it is not really helped by food.

You are also encouraged to create your own creatures.  Can you combine the food-finding ability of the Rover, with the clumping ability of the Flytrap or Landmine?

Assignment

Your assignment is to program Darwin's world.  This is a long, complicated program, split up into several classes,  4 that we will provide, and 4 that you need to write yourself. 

Provided files:

• Instruction.java  Simple class that encapsulates a single instruction, which consists of an OpCode (hop, left, right, go, etc) and an address.  The address is only used by ifempty, ifenemy, ifwall, ifsame, infect, and go
  
• Point.java Simple class that encapsulates a point with integer coordinates and some utility functions
  
• Direction.java Enumerated type that represents the 4 compass directions (North/South/East/West), and some utility functions
  
• WorldDisplay.java Class that handles all of the GUI elements for Darwin's World
  
  You are allowed (but not required) to modify the provided files if you would like.  For instance, you could add to the WorldDisplay class so that it shows a count of the number of individuals of each species, so you can see who is winning.  The WorldDisplay class is pretty similar to the other Swing GUI stuff we've seen, see me if you have questions.
  

• Creature.java A class that represents a single creature.  The main interpreter loop is handled here
  
• Species.java A class that represents a species.  Programs are stored in the Species class
  
• World.java A class that represents the positions of the creatures in the world.  Note that while the world is logically a 2D grid, you probably don't want to represent it that way ...
  
• Darwin.java Main program, which sets up the initial state of the word, and then repeatedly calls the takeOneTurn of each creature and updates the display.  Your main should take the following command line parameters (found in args[0], args[1], etc):
  
  <width of world> <height of world> <number of creatures of each species> <list of species files>
  
  For instance, a  valid set of command line parameters might be:
  
  20 20 10 flytrap rover
  
  or
  
  30 30 10 flytrap rover food landmine
  
  Your main program should:
  
  Parse the command line parameters
  Set up the World, Creatues, and WorldDisplay
  Go into an infinite loop:
      take one step for each creature
      call the displayWorld method of the WorldDisplay class

You do not need to start from scratch -- we have provided a jar file for each of the required classes, so you can get Darwin's world up and running right away.  All you need to do is replace the .jar files with your own .java files.  There are two ways to do this:

1. Using the command line:  Create a folder that contains all of the provided jars.  Add this folder to your classpath.  You can run the provided main program using java  -jar Darwin.jar.  As you write your own versions, remove the .jar files from the directory in your classpath
   
   
2. Using Eclipse: Save the .jar files to any folder on your machine.  Create a project that contains all of the provided .java files.  Right-click on your project, go to Build Path -> Configure Build Path, then select Add External Jars (under the Librarys tab), and add the provided .jar files. You can run the provided main program by finding it in the package explorer (under referenced libraries) and running it.  As you write your own versions of the classes, remove the approprate jars from your project
   

Part I:  Due Wednesday, April 2

For part I of this assignment, you must complete the main class Darwin, as well as the World and Species classes.

Part II Due Wednesday, April 9

For part II of this assignment, you must complete the Creature class, and write your own creature, to compete against the rest of the class.