centipede

A Centipede Game source: Katrin Becker 2002

But hey, how often are you going to get an assignment that starts off with:
Go Play.
I really mean it too. The best way to get a feel for what your program is supposed to do and how it's supposed to work is to actually play the game for a while. On-line versions are linked below.
CONTENTS of THIS PAGE...
Introduction & Background (just below)
Description of Our Version
The OBJECTS
GameClass ThingClass GunClass BugsClass MissileClass
Summary of "Things on the Screen"
Minimal Solution & A-B-C Requirements
Testing and Marking Bonuses

The Original Centipede (info)
A Java-Version you can play
See the Lab Notes for background information.

The following files will be available in the course directory:

~becker/Courses/233/A5

Centipede.Play (Documentation: game options)
easyCurses.help (Documentation: easycurses )
myRand.java
GameVal.java (constants, all static)
Point.java ( X and Y coordinates together in one object )
Thing.java ( the base class for the guys on the screen )
play (maybe: sample to run )

play.java (a sample main)

the easyCurses Classes:(window stuff)

easyCurses.class
trackerUtil.class
ucAnswer.class
ucError.class

Problem Statement:

Write a program to play a simple version of the old classic arcade game, "Centipede".
Background & History
Centipede, completed in 1981, was an Atari coin-operated game that swiftly won a wide following in the arcades. Apart from its smooth game play, Centipede was praised for its refreshing approach to screen colors and for its whimsical mushroom world.

The Creation of Centipede

Centipede was written by veteran Atari designer Ed Logg, who has become something of a legend in the world of video games, and a young game programmer who was credited with bringing a gentler touch to the world of video games with the enchanted mushroom patch.

Steve Calfee: "Ed Logg is the world's greatest games designer. He's done the most, the best games. His line up starts with Asteroids, which probably still is the biggest run we ever did. He's in [a long line of games]. He's kind of like Pete Rose; he has the most hits and he's also probably got the most strike outs. He just goes up to bat."

Remembrances from the Video Game Masters

The mushroom patch with its tenacious, never-say-die centipedes, bouncing Bugs, mushroom-laying fleas and transforming scorpions provided an imaginative leap for players, just as did the hoards of aliens in Tempest, the outer space adventures of Asteroids, the eerie battlefields of Battlezone and even the frightful scenarios of Missile Command. Of these times, and the games that emerged from Atari, Rich Adam said: "We were a young group of fun people who were sort of treading on untrodden territory. We were out exploring what technology could do to entertain adolescent minds, and we were adolescent minds."

In the early days of personal computers, before they became commonplace, and before sophisticated gaming programs were available for them, the arcades (and wherever else the coin-operated games were located) were the portals into these new fantasy worlds. And a river of quarters carried players into the electronic realms. Dan Pliskin described the coin-operated video game business as follows:"It was a wacky, extremely competitive business. I was there when coin-operated games were earning $8 billion in quarters a year. These games were outgrossing the record industry and the movie industry combined, in quarters! And when you looked at who was manufacturing these games, it was just a couple of Japanese companies and a few American companies. . . . There was incredible competition, all for kids' lunch and church money!

The quarters are still rolling in. Dan Plishkin continued: "People say that video games have already seen their heyday and business has definitely gone downhill. Maybe it has gone downhill. Maybe it's only $4 billion worth of quarters now. It's still one heck of an industry."

Popular from the Start

The prototype games were hand-built, wire-wrapped, one-of-a kinds that were created by the development team prior to ordering the circuit boards for the mass-produced versions. With just a single machine, people would come in at all hours of the night to play a new game. Dan Plishkin: "One of the things that kind of allowed everybody at Atari to have kind of a loose and enjoyable relationship was that management was kind of loose, too. An example of that happened with one of Howard Delman's games. I can't remember which one it was, but we sent the one and only prototype wire-wrapped version of Howie's game off to the AMOA (Amusement and Music Operators Association) show with strict orders not to sell it."

Of course the game was sold anyway, and a new prototype had to be assembled back at the labs. Dan Plishkin continued:"Several months later Howie gets a call from the person who bought this game. It had stopped collecting money and he wanted to know how to change the settings to make it play longer, or something, to see if it would earn more money. Howie had to tell the guy that if it ever collected any money at all, it was a miracle because it didn't have any coin routines at all. It had none, because we had wired it for free-play when we sent it to the AMOA show!"

The Great 25-Cent Escape

Especially in the early 1980s a great many newspaper and magazine articles were written about the meaning of and possible consequences of the wave of video games that seemed to allure so many kids, and adults, to the arcades. But at the heart of it might have been the promise of a quick escape into another world. Rich Adam: "I kind of figured out, maybe years after the fact, what I think the lure of video games is. It's because people have so little control over their lives. This is especially true with kids, but even adults often have little controlover the day-to-day part of their lives. You have to go to work. You don't get to control that much of your life. But for a quarter you can control this very complex machine. You can command it. For a quarter that's quite a bargain, to be able to do that for five minutes. . . . When you're good at a game it gives you an incredible sense of power over the whole environment."

Description of Our Version:
- no sound
- ASCII graphics

our game will consist of a WINDOW defined using "easycurses" and marks displayed in the window will be standard ASCII characters (size: 80W X 24H)

- graphics done using easycurses
- our "universe" is two dimensional

Since we do not yet have the experience to create a full-blown event-driven system our game will run as "snapshots in time". This is similar to the approach used in BATTLESHIP last term.

Game Basics:

The game consists of a screen, on which we 'draw' numerous Things. Some Things can move and others not. One of the Things is controllable by user input (we can make it move and shoot).

We will create an initial configuration at the start of the game consisting of a number of different Bugs. When we have destroyed them all, we win. If we get destroyed first, we loose.


- just as in BATTLESHIP each object will respond to the conditions as they were at the end of the previous time interval.

At each time interval: - each object will make a move based on the screen as it was last - Bugs continue to move - we retrieve input from the user to tell us what the "Gun" (that's the player) should do (which could be null meaning don't move the Gun)
Running the Game:

- ( optional ) can have command line arguments for game "parameters":

- level of difficulty (affects # of "Mushrooms", Bugs, Gun's range, etc.)
- or could allow user to specify range, etc.

- with no arguments, it would be run like:

java Play

- can have a restart option or can simply require the user to quit and start again
(suggested) user input: (everyone but Gun moves EACH "turn")

q	= Quit	s	= Shoot
<blank>	= move everyone but Gun	o	= mOve and shoot
z	= move Gun left	.	= move right and shoot
/	= move Gun right	x	= move left and shoot
j	= make Gun Jump (like hyperspace i.e. move several squares at once)	u	= jUmp and shoot

A Missile Class?
Some of the "things" can shoot, others leave mushroom (droppings?). There are many ways to handle this. To handle shooting, most include "plotting" some sort of missile path and then checking to see if there is anyone at any of the locations along the missile path (only the closest thing will get blown up unless your missile/laser is reeely strong). The missile path can easily be stored as an array of Points. It gets created when as thing shoots: the path is "plotted" and drawn, and then on the next 'turn' it can be erased. It too could be a thing. Once fired, it can look after plotting its own path: the thing that shot it keeps a pointer to a missile; if not NULL there is an active missile
A new missile would need to 'know':

- its range (set in constructor)
- its origin(set in constructor)
- its orientation (which direction it's going)(set in constructor)
- the endpath (the actual length of the path as opposed to the range - the actual path 'ends' when it hits something) - this value is calculated
- a flag that remembers if it hit something
- a pointer to the thing it hit

It needs to be able to:

plot the missile path
erase the missile path
say whether or not it hit something (access function)
say who it hit (access function)

If the missile is a proper sub-class of thing which is created by the Gun, then it basically has a life of it's own: it moves, maybe hits something, and dies. Once fired, the shooter no longer cares about it so it needn't keep track of it. This would make it behave more like a proper missile, whereas the other description above (which includes a path) is perhaps more like a laser.

Summary of "Things" on the Screen:

--	asst level	move?	direction	action	when shot
Mushrooms	C	no	---	obstacle	disappear
Gun	C	yes	E-W	move, and shoot	--
Bug: Scorpion	B	yes	E-W	mushrooms encountered are changed to poison mushrooms (which make the centipede drop)	disappear
Bug: Flea	B	yes	S	when < X mushrooms, it drops and leaves mushrooms behind	disappear
Bug: Spider	A	yes	diagonal	collisions w/ mushrooms make the mushrooms disappear AND make spider change direction	disappear
Bug: Centipede	A (simple version)	yes	'serpentine', changes direction when it encounters something	eats other bugs, but not mushrooms, still changes direction [moves E-W but when it changes, it moves one row down too]	[A] disappear /or/ [Bonus] splits into 2 centipedes [Bonus] drop when it encounters a poison mushroom
Missiles	C	yes	N	when they encounter an obstacle, that obstacle is destroyed	n/a

Sample Mark Guide Here

Notes on Marking:
We will be looking for the usual good, clean design; documentation, etc. as always.
In order to pass it must work. (Some marks will be given to all *reasonable* attempts, working or not)
Specifics we will be looking for when marking:
Initial Configuration

is everyone inside the lines?

Mushrooms

drawn correctly?
do they explode when shot or hit?

Gun

initial position correct?
can the player move him?
can the player make him shoot?
does he explode when hit?
is it possible to win?

Bugs

How to submit your assignment:
This assignment SHOULD be 'demo'ed for your TA. Be sure to arrange a time IN LAB (or when your TA is scheduled in CT or MS218) with your TA.

This assignment can be submitted electronically using submit.
Include:

- all '.java' files
- all '.class' files
- javadoc documentation
- your external documentation, including a diagramatical form of your classes

BONUSES:
1. [up to 10 points] Make a "full-function" centipede
2. [2-3 points] Detect "Game Over": when Gun dead; or when all Bugs gone.
3. [2 points] Keep score. (one point per thing or allow a certain number of points for certain kinds of things).
4. [2-5 points, per level] Allow different levels of difficulty (different #'s of things, different ranges, etc.)
5. [2 points] Set up "key bindings" so player can use the arrow keys, etc.
6. [4-? points] Make it Interrupt Driven

CHALLENGE:
1. [4-? points] Add sound.
2. [4-? points] Create a full GUI
3. [5-? points] Do it in colour
4. [5-? points] 3-D