My Sunday afternoon project wasn't something that I could just let lie and it didn't take long for work to start on it again. Using the list of improvements I had identified, I began with the aesthetics and then moved on to other, more number intensive areas of research.

Before even touching the code I subsumed everything into a Git repository; I'm a long time Subversion user but relatively new to Git so I still regularly refer back to the "Git - SVN Crash Course" which is pleasantly concise. With this done, I attacked the GIF output method first:

First was visibly increasing the size of the cells, I had originally used a multiplier of four for previous iterations but that made them very indistinct, and with only fifty generations it meant a large portion of the space wasn't used. The result was an increase in cell size to seven with a one pixel border: this was the result of a happy accident while crafting the previous post and resulted in the introductory images, however the calculations for the edge cells was incorrect which is why those animations don't appear to "loop"  at the edges as they should. This implementation fixed that and with a vastly smaller environment (only 8x8 with a 5x5 seed), each generation of cells and their progression is easier to see. Next was addressing the colour issue, generating both a background and foreground colour met with mixed results so taking a leaf from WP_Identicon's book, I kept the background colour constant and generated the foreground colour only:

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As a way of spending my bank holiday Sunday afternoon, I decided to embark on a small project; I didn't know what the project would be when I first began browsing through Wikipedia but eventually I ended up in About.com's C++ challenge section, one of which concerned John Horton Conway's "Game of Life": a rudimentary cellular automaton which, after its inception in 1970, had immeasurable impact on fields as diverse as philosophy and theology. After toying with some ideas, I decided to build a script which automatically creates animations of a number of generations of the game. From that seed the project grew into the first steps towards an avatar system, much like the automatically generated Gravatars that currently adorn so many Wordpress based blogs.

The first step was getting the algorithm working, and as I had already decided to make it web-based, that meant a PHP implementation. Using only the Wikipedia page as reference, I threw together a very basic script that allowed me to enter in some settings (grid dimensions, seed and generation limit) and for it to spit out the states between the seed and the generation cut off. After some wrangling with minor bugs (spelling errors, incorrect typing etc.) an unoptimised first version of the algorithm was complete:

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Evangelion occupies a very special place in my heart: I watched the series on VHS in 1997 when I was fourteen and - without hyperbole - it was a life changing experience. A series that was smart and brutally obtuse and flitted from Jungian psychology to religious dogma was revelatory for me at the time and it questioned a lot of what I had not yet fully formed questions about; so as well as being gob-smackingly awesome, it changed who I was and consequently who I am. For those reasons I am utterly fanatical about the franchise and concept. Like a delusional lover I put up with a lot of the nonsense that GAINAX throws: I own the original series on twelve VHS tapes which I upgraded to DVD when they were first released, then upgraded them to the Platinum DVDs; I did manage to stay away from the deluge of tat that has been continuously released but it's fair to say my own lot of Evangelion merchandise is not insignificant. In what is a truly savvy move, just as patience for the constant re-releases was beginning to wane news came of the Rebuild project.

Not just a fresh coat of paint but a fresh take - that was the promise at least. It was hard to get excited, especially when there was also word of a live action Hollywood adaptation bolstered by some mightily uninspiring concept art - the only promise being that WETA are on the case. Regardless, the news came out over a year before the first Rebuild release so there was plenty of time to build up my scepticism. The first movie, "Evangelion 1.0: You Are (Not) Alone" released in 2007, deserves a post of its own and the number of pages I've devoted to notes and thoughts and theories bordering on absurd. The second movie, "Evangelion 2.0: You Can (Not) Advance" released just this summer is easy to write about because I have not yet had a chance to analyse and unpick it as I am wont to do. For want of a better description, this is a review rather than an unravelling.

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The newest addition to chaostangent.com is the carousel nestling comfortably at the foot of every page. Sporting a variety of "social media" feeds as well as other morsels, it showcases a number of interesting technologies and techniques including: a fully looping carousel (JavaScript and CSS), integration with numerous external APIs (PHP, Zend Framework), screen-scraping and local caching of results to name but a few. It successfully fulfils the primary goal I had for it: cramming as much functionality into a contained a space as reasonably possible.

JavaScript

The carousel interface is design du-jour at the moment - sported by sites such as Apple, BBC iPlayer and Gametrailers - they manage selective display of information while still providing a high degree of interactivity. In short: they're swish and solve the problem of too much to feature in too little space. The carousel library I am using is a simplified, stripped-down version of one I developed for a large work project - for this reason I'm unable to release it under any kind of license. The original has a number of features that I wouldn't be using including automated construction of a "jump to" control and being able to navigate over a number of entries at once. My library is the only one I know of which successfully loops, providing an "infinite" carousel of sorts; other publicly available libraries cease at either end of the carousel which in some situations is more intuitive but the challenge of making one not do this was posed to me, and I couldn't very well pass it up.

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These are some of the neater parts of gallery.chaostangent.com that don't warrant a full exploration on their own but serve the goal of making the application more streamlined. I've crafted these examples to be focused so they don't contain superfluous details like error checking, timestamp columns and the like.

Database

The gallery schema is as follows:

CREATE TABLE IF NOT EXISTS `galleries` (
  `id` int(10) unsigned NOT NULL auto_increment,
  `left` int(10) unsigned NOT NULL default '0',
  `right` int(10) unsigned NOT NULL default '0',
  `parent` int(10) unsigned NOT NULL default '0',
  `title` tinytext NOT NULL,
  `directory` tinytext NOT NULL,
  PRIMARY KEY  (`id`),
  KEY `parent` (`parent`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 ;

This covers both the Modified Preorder Tree Traversal (`left` and `right` columns) model as well as the more standard hierarchical model (`parent` column). I'm still undecided as to whether indexing the `left` and `right` columns provides any benefits. Most of the queries on the gallery table involve getting the direct children of a particular node; the breadcrumb trail at the top of the page however is built using the `left` and `right` columns:

SELECT * FROM `galleries` WHERE (`left` >= ?) AND (`right` <= ?) ORDER BY `left`

Doing a multi-column index in MySQL works from the left column onwards, so for the above query, indexing on `left` and `right` would be a benefit. However when inserting and deleting nodes, queries are done singularly e.g. one for `left` and one for `right` which having an index on one and not the other may turn out to be detrimental in terms of update times. I could always do two indexes:

ALTER TABLE `galleries` ADD INDEX ( `left` , `right` ) ;
ALTER TABLE `galleries` ADD INDEX ( `right` , `left` ) ;

This runs the risk though of having a table that's more index than data. I haven't done a full benchmark of the different queries for each scenario but I would imagine only for large trees would indexing provide any tangible benefit.

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