sed page 16 - Dave's Blog

Generating N-D Tetris Pieces

2008 Jun 1, 7:27

When I woke up this morning for some reason I was thinking about Polytope Tetris, my N-D Tetris game, and specifically generating Tetris pieces in various number of dimensions. When I first wrote PTT I thought that as the number of dimensions increased you could end up with an infinite number of non-equivalent crazy Tetris pieces. However this morning I realized that because you only get four blocks per piece there are only a possible three joints in a single Tetris piece which means that you only need three dimensions to represent all possible distinct N-D Tetris pieces.

Below is the table of the various possible pieces per number of dimensions and sorted by the number of joints in the piece. Notice that the 'J' and 'L' become equivalent in 3D because you can rotate the 'J' through the third dimension to make it an 'L'. The same happens for 'S' and 'Z' in 3D, and 'S+' and 'Z+' in 4D.

Joints	Name	1D	2D	3D	+
1	I
2	J
	L
3	O
	T
	S
	Z
	T+
	S+
	Z+
	Total	1	7	8	7

As a consequence of not realizing there's a finite and small number of N-D Tetris pieces, I wrote code that would randomly generate pieces for a specified number of dimensions by wandering through Tetris space. This consists of first marking the current spot, then randomly picking a direction (a dimension and either forward or backward), going in that direction until hitting a previously unvisited spot and repeating until four spots are marked, forming a Tetris piece. However this morning I realized that continuing in the same direction until reaching am unvisited spot means I can't generate the 'T+' piece. I think the better way to go is keep the list of all possible pieces, pick one randomly, and rotate it randomly through the available dimensions. Doing this will also allow me to give distinct pieces their own specific color (like the classic Tetris games do) rather than picking the color randomly like I do now.

polytope tetris tetris

Leaking Information Through Delicious

2008 May 18, 6:45

While re-reading Cryptonomicon I thought about what kind of information I'm leaking by posting links on Delicious. At work I don't post any Intranet websites for fear of revealing anything but I wondered if not posting would reveal anything. For instance, if I'm particularly busy at work might I post less indicating something about the state of the things I work on? I got an archive of my Delicious posts via the Delicious API and then ran it through a tool I made to create a couple of tables which I've graphed on Many Eyes

I've graphed my posts per week and with red lines I've marked IE7 and IE8 releases as stated by Wikipedia. As you can see, there doesn't seem to be much of a pattern so I suppose my concerns we're unfounded. I use it for both work and non-work purposes and my use of Delicious isn't that consistent so I don't think it would be easy to find a pattern like I was thinking about. Perhaps if many people from my project used Delicious and that data could be compared together it might be easier. For fun I looked at my posts per day of week which starts off strong on Mondays and decreases as the week goes on, and my posts per hour of day. It looks like I mostly post around lunch and on the extremes I've only posted very late at night twice at 4am: converting media for the Zune, and Penn's archive of articles. In the morning at 7am I've posted only once: document introducing SGML.manyeyes graph cryptonomicon delicious

Finished Paper Mario Games

2008 May 12, 4:05

Sarah and I have finished playing through the games "Paper Mario", "Paper Mario: The Thousand-Year Door", and "Super Paper Mario" last week (including the various Pits of 100 Trials). We played them all on the Wii, because even though Super Paper Mario was the only one released explicitly for that platform, Wii maintains compatibility with Game Cube games such as Thousand-Year Door and Paper Mario although originally released for the Nintendo 64 is now available as a pay for download game on the Wii's Virtual Console. So, yay for Nintendo!

I think my favorite of the three is Thousand-Year Door mostly because of the RPG attack system. In Thousand-Year Door and Paper Mario when you come into contact with an enemy you go into an RPG style attack system where you take turns selecting actions. In Super Paper Mario you still have hit points and such, but you don't go into a turn based RPG style attack system, rather you do the regular Mario jumping on bad guys thing (or hitting them with a mallet etc...). Thousand-Year Door and Paper Mario are very similar in terms of game play but Thousand-Year Door looks very pretty and has made improvements to how your party-mates are handled in battle (they have HP and can fall as you would expect) and there's an audience that cheers you on during your battles.

Even if the gameplay sucked the humor throughout the series might be tempting enough. Mario's clothing and mustache are mocked throughout and standard RPG expectations are subverted. I hate to describe any of these moments for fear of ruining anything but, for instance, an optional and very difficult enemy who may only be killed after hours of work only results in one experience point, or a very intimidating enemy who you imagine you'll have to fight actually challenges you to a quiz.

Despite how I personally rank them, all the games are great and I'd recommend any of them.

mario videogame paper mario nontechnical

Finally finished Baroque Cycle Novels

2008 May 2, 10:20

I've finally finished the Baroque Cycle, a historical fiction series set in the 17th and 18th centuries by Neal Stephenson whose work I always enjoy. There were often delays where I'd forget about the books until I had to take plane somewhere, or get discouraged reading about the character's thoughts on economics, or have difficulty finding the next volume, or become more engrossed in other books, projects or video games, and leave the Baroque Cycle books untouched for many months at a time. Consequently, my reading of this series has, I'm ashamed to say, spanned years. After finishing some books which I enjoy I end up hungry for just a bit more to read. For this series I don't need a bit more to read, I'm done with that, but I do want a badge or maybe a medal. Or barring that, college credit in European History and Macro Economics. I can recommend this book to anyone who has enjoyed Neal Stephenson's other work and has a few years of free time to kill.

history neal stephenson baroque cycle book nontechnical