Asteroids in under 600 lines of Common Lisp (uses SBCL and SDL)

https://github.com/andyhd/asteroids/blob/master/asteroids.lisp

by Charles__L • 14 years ago

83 37 14 years ago

github.com

sahat• 14 years ago

I didn't know what a beautiful code was, until I looked at this project.

andyhd6• 14 years ago

Thanks!

prospero3• 14 years ago

Here's an Asteroids clone I wrote in Clojure a few years back, which has less than 400 lines and some neat stuff like procedurally generated 3D asteroids: https://github.com/ztellman/penumbra/blob/master/test/exampl...

Some of the design decisions are discussed in detail at http://ideolalia.com/creating-a-simple-game-in-clojure

fusiongyro4• 14 years ago

The Lisp code used multiple dispatch to handle collisions between objects, whereas your Clojure code instead uses list comprehensions to generate pairs of colliding objects by type. I know Clojure also supports multiple dispatch, so I'm wondering if you could comment on this design decision.

prospero3• 14 years ago

The only collisions I care about in my implementation are asteroid/ship and bullet/asteroid, and they're easier to express directly. The OP's version appears to have many more types of collisions, which makes multiple dispatch a more obvious choice.

slig• 14 years ago

Thanks for the blog post. Very informative and concise.

nemoniac• 14 years ago

Could you update the penumbra README? I'd like to try it out but the instructions are outdated.

prospero3• 14 years ago

Outdated how? They were working the last time I made a commit a year ago, I'm not sure what could have changed.

notJim2• 14 years ago

It would be incredible to me if someone could write some commentary about this for the non-lisper. Skimming it now, it seems very familiar to me (as in, I don't really see anything about it that expresses anything particularly beautifully), but I might be missing some of the finer points. Overall, I recognize a lot of familiar code that I've written for games in javascript. It's hard to appreciate the aesthetics of this, since I'm not familiar with the language.

aidenn02• 14 years ago

My guess is that the author is new to common lisp. It's the only CL project in his github account, and he wrote it using vim. Most people who have been using SBCL for a while will use emacs with SLIME as it is the recommended IDE for using SBCL.

So I wouldn't expect it to contain any particularly awesome lisp-isms. My first read made me think it was using multiple-dispatch, but it isn't doing so in a way that wouldn't also be possible in a language with overloading, as no more than 1 parameter is ambiguously typed at function call time.

fusiongyro4• 14 years ago

I think it's a little disingenuous to expect less of someone for using a different editor. Good catch on the multiple dispatch though.

enduser• 14 years ago

Some of the best lispers use vim. cf Doug Hotye (antiweb, Let Over Lambda) and Paul Graham. I use vim + slimv to develop with SBCL.

andyhd6• 14 years ago

Hi, author here. I am new to Lisp (about 4 months in) and I've been a happy Vim user for many years, so I'm not finding the transition to Emacs very easy. I am trying, though.

andyhd6• 14 years ago

I was planning to write about my experience writing this, so I'll keep you posted.

It's really not elegant or special code at all, though, just something I used to learn some more about Lisp.

notJim2• 14 years ago

Please do!

Lisp has this reputation within the hacker community, and I'd love to hear some impressions from people who are new to it.

ken• 14 years ago

Looks pretty good overall, but there are a few little oddities.

Not to turn this into a design review, but using EQ to test for 0 seems like it's asking for trouble, and it looks like that * has only one argument.

andyhd6• 14 years ago

Thanks for the tip. I didn't realize numbers with the same value could be different to eq.

rwos• 14 years ago

This was on /r/programming and now it's here - I'm sorry, but I don't really understand what this is all about. 600 lines doesn't seem ultra-small to me. And Lisp - well sure, not too common a language for games, but it's not as if this was written in a purely functional style or something. In fact, it looks like pretty standard imperative programming to me - it wouldn't look much different in C.

Am I missing something here?

andyhd6• 14 years ago

I wasn't trying to write it in less than 600 lines, that's just what the OP used for an interesting title, I guess.

It's just a fun project I did to learn a bit of CL. I translated the code from a Python game, so it's not in pure functional style. Now that you mention it, though, I feel like I should try that.

rule30• 14 years ago

no macros? I'm no expert and I'm asking to experts: macros are one of the key features of Lisp. Should macros have helped reducing LOC or improving maintainability?

sp332• 14 years ago

Disclaimer: I'm not a lisper. But according to Paul Graham, Macros are harder to write than ordinary Lisp functions, and it's considered to be bad style to use them when they're not necessary. http://www.paulgraham.com/avg.html

justinhj• 14 years ago

Nice to see a project using http://code.google.com/p/lispbuilder/wiki/LispbuilderSDL which wraps the SDL library amongst others and works on Linux, Mac OS X and Windows.

swah• 14 years ago

"If the browser ran bytecodes instead of javascript..."

gawi• 14 years ago

Not even using libasteroid...

spaninispa• 14 years ago

great!

it's a nice project, it's free, it's modern, it works, it's an interactive-graphic-non-boring thing, it's a game!

lisp needs more of this.

party's open: more functional, macro wiser and skinnier ones are welcome.

vim should be welcome too as I run ASTeroids fine under vim+slimv (just like the terminal) while under emacs+slime it doesn't display some white line segments here and there... (same sbcl for all)

last thing, I scored 3432 (level 11) with the first coin...;)

andyhd6• 14 years ago

Thanks for your support! I totally agree with you - I put the code up on Github because I figured someone like me might want to improve it or take it in another direction.

prtamil3• 14 years ago

I just observed , whenever there is a discussion about Common Lisp , some how somebody would inject something about Clojure. Did anybody noticed that ?

prtamil3• 14 years ago

if I want to eat steak, i'd search about steak, why the hell i need to check about broccoli. Same thing if i want to learn Common Lisp, i need more info about Common Lisp, Why the hell i need info about Clojure.

prtamil3• 14 years ago

Its simple Logic,

Programmers Those who use C = C Programmers. Scheme = Scheme Programmers. Common Lisp = Common Lisp Programmers. Clojure = Clojure Programmers.

Programmers Who use Clojure != Common Lisp Programmers.

So Please, please stop posting about Clojure in Common Lisp Posts.

I don't want Clojure solution for Common Lisp problem.

Asteroids in under 600 lines of Common Lisp (uses SBCL and SDL)

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