CUDA port of OpenSteer now public
During the last months I was busy writing my bachelor's thesis about parallelizing the [OpenSteer](http://opensteer.sf.net) toolkit using [NVIDIA's CUDA](http://www.nvidia.com/object/cuda_home.html) technology to make use of the power of today's GPUs.
OpenSteer is an open-source toolkit to test and simulate [steering behaviors of autonomous characters](http://www.red3d.com/cwr/steer/) in animations or video games. Steering behaviors are responsible
to navigate a character around its world in a natural way while reacting on influences of its environment, for example to avoid collisions with obstacles.
The source code of this port is now available on [github](http://github.com/simonboots/OpenSteerCUDA/).
My bachelor's thesis about this project is also available and can be found [here](http://www.stiefels.net/wp-content/uploads/2009/08/Parallelizing-the-OpenSteer-toolkit-using-GPUs.pdf).
Pro Git book now available
The Pro Git book, written by Scott Chacon and published by [Apress](http://apress.com/) is [now available](http://progit.org) for free. A printed version will be released [soon](http://www.amazon.com/gp/product/1430218339?ie=UTF8&tag=prgi-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=1430218339).
Scott also [published](http://github.com/progit/progit) the "source code" of the book under a [Creative Commons license](http://creativecommons.org/licenses/by-nc-sa/3.0/us/).
New Project: Visualization of the Best-Fit Placement Heuristic
Often one has to solve the problem of arranging objects so that they use as less room as possible. In the days before Christmas, for example, people try to utilize the expensive wrapping paper fully in order to save to money for a second roll. Depending on the arrangement of the presents this may work, or not. In the industry, a can factory tries to stamp different sized cans out of a roll of sheet metal. To minimize the waste (and to save money) the company has to think about the cutting of the metal sheet.
Both of these examples describe a problem known as the [two-dimensional cutting stock problem](http://en.wikipedia.org/wiki/Cutting_stock_problem).
Projects Moved to Github
Just want to let you know that I've moved the repositories of some of my projects to [github](http://github.com/simonboots). I think they are better off there as they are here.
The [project](/projects) pages have already been updated.
More projects coming soon...
Getting Started with iPhone Development
This weekend I finally found some time to watch [Bill Dudney](http://bill.dudney.net/roller/bill/)'s screencasts about iPhone development.
The screencast series is called '[Writing your first iPhone Application](http://pragprog.com/screencasts/v-bdiphone/writing-your-first-iphone-application)' and it is an ideal way to get started with iPhone application development.
All you need is a recent version of Xcode and some basic knowledge about Objective-C and Cocoa.
In 2,5 hours Bill shows you how to create a simple but nice recipe application where you can store recipes and its ingredients (sure, it is NOT a full-blown recipe database application but it serves its purpose). You learn a lot about table views, view controllers, navigation controllers and how to store your entered data persistently by using [SQLite](http://sqlite.org/).
I really enjoyed watching it and I'd recommend to write the application in parallel while you are watching it. That way you'll think more about how all the stuff works.
Every episode (five in total) costs $5 but I think it's completely worth the money.
Moving from Subversion to Git
I started using version control management systems with [CVS](http://ximbiot.com/cvs/cvshome/dev/) several years ago.
But soon it was clear that using Subversion instead of CVS would make version control a lot less cumbersome and error prone process. And for the last years Subversion was the system of my choice.
But then I saw [Linus Torvalds' Tech Talk speak at Google](http://www.youtube.com/watch?v=4XpnKHJAok8) about his new version control system called [Git](http://www.git-scm.com).
Although Linus' talk was a little bit offensive on other version control systems I liked the idea of Git being a distributed system. Other features like the true ease of branching/merging or its speed made it even more attractive.
So I played around with it for a while and I started to like it. This weekend I decided to switch all my Subversion managed projects to Git.
There are some good tools that come with Git which make this process very easy. I don't want to give another tutorial how to move your Subversion to Git. There are a lot of websites that do that.
But here are some links which helped me doing the transition:
* [Git for SVN Users](http://git.or.cz/course/svn.html)
* [Git User's Manual](http://www.kernel.org/pub/software/scm/git/docs/user-manual.html)
* [Git Internals](http://peepcode.com/products/git-internals-pdf) (Recommended!)
* [Git Screencast](http://peepcode.com/products/git)
* [Git SVN Workflow](http://andy.delcambre.com/2008/3/4/git-svn-workflow)
* [Git Installer for Mac OS X Leopard](http://code.google.com/p/git-osx-installer/)
* [Installing Git on Mac OS X Leopard](http://dysinger.net/2007/12/30/installing-git-on-mac-os-x-105-leopard/)
iPhone SDK Beta Out!
Today Apple released a beta version of the iPhone/iPod touch SDK for developers to create their own applications for these devices. The final SDK is about to be released in June this year.
Unfortunately Apple's [ADC website](http://developer.apple.com) seems to be overstrained at the moment with all the developers trying to download the SDK.
Cocoa Dev House Munich
On March 8, 2008 the [Cocoa Dev House Munich](http://cocoadevhouse.org/wiki/index.php/Main/CocoaDevHouseMunich) will take place at [equinux AG](http://www.equinux.de/) in Munich. There are already nearly 30 attendees on the list and I hope that I can write my name on that list soon, too.
Syntax Highlighting for NSTextView with flex
Implementing syntax highlighting can be a painful task. Lots of regular expressions and thinking may be required to master this.
On the search for an easy way to implement a syntax highlighting mechanism for NSTextView I found an easy and fast (regarding runtime) way to do this. By using flex (a tool with its roots in the 1970's) defining the rules of what should be highlighted makes it a lot more easier and structured.
flex is the GNU version of lex, the lexical analyzer generator (Buzzword jackpot!) developed by Eric Schmidt and Mike Lesk in 1975. By defining some rules (mainly regular expressions) it generates a C program which allows us to scan through a text and do something with the text, e.g. divide it into tokens. Tokens are chunks of characters with a special meaning (as defined in our rules). Confused? Read on, this concept will become very clear soon.
In this article I want to show you how we can use this ancient but very powerful tool to implement a basic syntax highlighting within a NSTextView.
Third Party Applications on iPhone and iPod touch
Today, Steve Jobs [announced a native SDK](http://www.apple.com/hotnews/) for their mobile OS X devices (iPhone and iPod touch).
This SDK allows third-party developers to create their own applications running natively on the iPhone and iPod touch.
Apple plans "to have an SDK in developers’ hands in February". Well, that sounds very interesting. 
