shinyPlasticBag

SuperHappyDevHouse #34 was today, and I had an absolutely amazing time. This was the best devhouse ever for me — huge thanks to Tom’s Mom for letting us trash their palatial estate yet again. Take a look at some photos from SHDH 34.

This was the first devhouse where I’ve ever actually successfully made anything. It’s an implementation of one-dimensional cellular automata in JavaScript, which was really just an excuse to learn more about the <canvas> tag. Check it out: CA-nvas. Use the little drop-down at the top to choose between a few interesting patterns. If you’re not using Chrome or Safari, it’s gonna be slow. Even Firefox 3.5 chokes a bit.

I was inspired to do so by the first available chapter of Dive Into HTML 5 (“Let’s Call It a Draw(ing Surface)“) of , recently released by Mark Pilgrim. It’s absolutely gorgeous to look at, and incredibly well-written. It gave me all of the information I needed to get started.

Now, as for the one-dimensional cellular automata bit. It sounds really complicated, but it’s actually stupid simple.

Imagine a sheet graph paper. Each row is a “generation”. For the first row, just fill in some blocks at random. That’s the “seed”. Now, to figure out what the next row should look like, you just apply this rule to each of the blocks: look at the three blocks above it — that is, the one directly above it and the ones to the left and right of that one. You have 8 possible combinations for these “ancestors” — all of them are off, just the one to the right is on, the one in the middle is on, etc. For each of these combinations, you have a rule to tell you whether the block in the next row should be turned on. It’s these different rules that lead to different patterns on your sheet of paper.

That’s it! AMAZING patterns just fall out of this thing. It’s even been speculated that the patterns on mollusk shells are generated by an algorithm similar to this. I love this stuff. You should take a few minutes to learn a bit more about cellular automata, because they’re easy to understand, and will blow your mind.

And on that note, I’m out of here.