So .. I had a hard time resisting working on my 64k version of “python”. I’ve been able to get quite a few features into it and I’ve gotten my julia demo up to near-C speed as well as tamed the crazy memory problems I was having.
I suppose the question I ponder is “why bother”? Well:

• It’s fun 🙂
• I’m learning the basics of parsing, code generation.
• It might even be somewhat useful!

The first two don’t require much explanation, the third (usefulness?):

• By keeping the codebase < 64k, it will be readable by mortals
• By generating C code, it can build self-contained binaries easily
• It has a really simple “FFI” which auto-generates many of the “FFI” wrappers for you
• It’s sort of fast now (no promises for anything real)

It, of course, isn’t python, it just looks a bit like it. Notable differences are:

• Access to members is like lua / javascript. x[“y”] and x.y mean the same thing.
• Most infix operators only work with numbers. “x”+”y” won’t work. (Rational: makes numerical math fast)
• It’s missing (and will never have) a bunch of really nice features. Syntax checking is notably weak. Maybe I should scrap my parser, etc and just use python’s.
• No exception handling. Incorrect use of anything will result in a seg fault.

Notable similarities:

• Language contains separate list and dict types. I thought about doing like lua / javascript / php and having a single type, but it just didn’t feel right.
• It’s indented (duh)
• Garbage collection via libgc

Well .. that’s about it. I expect before I’m done I’ll make a game with it, to see how it works in the real world. I’ve got a few more things on my TODO list to get done first. If you are brave, check out svn://www.imitationpickles.org/tinypy/trunk and run ./run_julia (linux) to see the julia demo.

Oh, and for all you “test first” folks, I’ve (more or less) been doing that. It’s made development considerably easier. See the bottom of “pylang.py” “dumbparse.py” and “dumpout.py” for all the testing fun.

I’ve been a bit quiet the last couple weeks .. after my spree of “python->c” converter posts I got pretty busy working on the Ludum Dare 10 website.  Ludum Dare is a 48 hour game development competition.

I used WordPress as the basis for this project and I think it was a pretty good choice.  Generally anything I needed to do, there was a hook in the API to let me do it.  I was able to keep all my compo code (theme voting, trophies, rating of entries,  tag clouds, screenshot grids, security tweaks) all within a module I wrote without having to modify any of the core WordPress files 🙂

There were around 150 signups on the site and 50 people completed entries.  The theme was “Chain Reaction” which won even in the first round of voting .. and still won after the 2nd and 3rd rounds.  I spent most of the competition sitting around on IRC doing nothing and occasionally working on my game.

The one notable glitch in the compo was the announcement of the theme ceremony.  I switched the voting to closed so we could see the results and it showed several themes with almost nobody voting for them.  Turns out those were two themes which I initially had in the final round but removed (because they didn’t make the cut).  The results of a few people voting was stored in the database so they still showed up.  Anyway, that was easily fixed.

At the end of the compo it took me an hour or so to get the entry rating system set up.  I also added the ability to leave a comment along with your rating to encourage more people to leave comments.  (They could use the WordPress blog commenting system, but that would take a few extra clicks and thinking.)  This way seems much nicer.

I think the funnest feature I added to the site was the Trophy feature.  This feature lets users award each-other 64×64 pixel trophies at any time.  It’s a nice community feature because it lets people recognize cool things that people did out-side of the pre-set rating categories in the contest.  (For example, one entrant recorded a tuba solo for their game.  Although the compo has a sound category, several people felt that the tuba playing merited special tuba trophies.)

I don’t know if I’ll be running the Ludum Dare competition again or not, but I’m sure I’ll be hosting some others now that I’ve got this swell compo system written 🙂

Hey, more fractal fun tonight as I attack PyPy! I must admit, this effort was more challenging – PyPy is pretty big and scary, but I found the folks in #pypy to be quite helpful. exarkun helped me quite a bit in working out the details. (Apparently PyPy doesn’t use ctypes anymore, it uses rffi .. which is sparsely documented.) Anyway with exarkun’s help I got a crude SDL wrapper put together!

Initially I just implemented my julia demo again, but I figured it would make for a boring blog entry to have the same pictures two days in a row. As it turns out, the julia was about 30% faster in PyPy than in shed-skin. Both shed-skin and PyPy appear to have similar limitations. shed-skin’s error messages are less cryptic than PyPy’s. Both FFI’s were somewhat challenging to work with, though I think I prefer shed-skin’s.

If you want to give it a whirl, download PyPy and my junk. The NOTES.txt file lists the command I used to build the executable. Sorry if the mouse interface is a bit lousy, but it was the best I could do in 2 minutes.

There’s this swell python to c++ compiler called shedskin. It’s really interesting. I took a few hours tonight to make it do something:

Yep those are real-time julia fractals 🙂 If you dare – check it out (make sure python and SDL-devel are all setup):

wget http://www.imitationpickles.org/tmp/juliashed.zip ; unzip juliashed.zip ; cd juliashed ; python ss.py test.py ; make ; ./test

I’ve sent Mark an excessively long e-mail with my comments. I’ll spare you the trouble and just give the highlights:

• My C++ skills don’t exist
• python descriptors are probably the feature I would like to see most – so I could implement pygame.Rect style Rects!
• misc packaging issues (see his previous blog post)
• The README says it “does not scale very well beyond a few hundred lines” – so I guess I’ll wait a while before I try to make a game with it. (Even simple games I make are around 1500 lines.)

Anyway, it’s a cool project. I plan to keep an eye on it.

This just in – I made a python+pygame equivalent. The shed-skin version is ~100x faster! Also, the black areas in the middle of the shapes are caused by my access of out-of-bounds palette entries. I added the -b (bounds check) to the command line and fixed the bug. The bounds check gave me no noticeable speed penalty.

As far as code goes, I’ve usually been a do-it-yourself kind of guy. However, I’ve been so impressed with WordPress I’ve actually used it to implement four of my sites in the last couple months. WordPress is an easy to use, smart piece of blogging software. It really seems to have just the right set of features in its default installation to be useful for most cases out of the box.

However, there comes a time when what’s given just isn’t enough. Thankfully, its got an extensive collection of plugins! Everything from blog aggregation to voting to forms to photo galleries. Not all plugins are great, but usually if you check out a few you can find one that will do what you want.

That is .. until you want something different! I might be hosting the 10th Ludum Dare compo. For that I needed some special features for collecting ratings of contestants entries, showing screenshot grids, and giving trophies to entrants.

WordPress comes with a fairly nice themes and plugins system which made it possible to add all those features to my blog without modifying the core-code of WordPress. Frequently I would implement a feature, and after learning more about WP internals, I was able to refactor it to be simpler by using more of the existing WP framework.

It wasn’t all fun and games, though, the learning curve was a bit painful for some features. A couple WordPress features (like table deltas) seemed a bit too clever (not to mention broken) for their own good. Fortunately, I was able to get away with not using those features.

The other challenge I had was when I came across a bug in WordPress. I did my best to figure out the bug, but it appears to be some strange javascripty thing which was beyond me. So I’ve reported the bug, and according to their schedule, it probably won’t be fixed for about six months. Ah well, at least it’s pretty minor.

All that said, it has been a fairly enjoyable process. I’ve been able to develop more site in less time by working with the WordPress plugin system. I have *considerably* less code to maintain, since I’m only responsible for the plugins I’ve made. Had I created this from scratch, I wouldn’t have gotten even half as far given the amount of time I invested.

This just in, the WordPress spell checker chokes on the word “with” .. weirdness!

It’s time for the 10th Ludum Dare compo!

Dec. 7-14th – Registration and Theme Voting
Dec. 14 at 7pm PST and runs until the 16th at 7pm PST

Join the fun in irc.afternet.org #ludumdare
With luck, the compo will be held on www.ludumdare.com ..
Be sure to join the irc channel for the most up-to-date information.

– Phil

Marshie Attacks: Halloween Interactive Driveway Activity

Some really cool game dev going on there.  They used python, pygame, pysight, lasers, bedsheets and potato canons to create an interactive Halloween game!