Some time before the event I also spent a moment to wade through Box2D physics engine documentation, and made a little prototype game called Luomuheinäseipääntapinheitto (a.k.a. Organic hay pole peg throwing), entering it also to the gamedev contest (placed 8/19). Background music is Test Drive by Zapac. Check out a video from Youtube, or download and try it (only for Windows).

Here’s links (mostly Youtube) to some other highlights from the event: XMunkki’s gamedev entry Raya Racer for N900, Evoflash’s winner Flash demo from wild compo, Archee’s 4k intro with physics and AI, winner 4k, Pier 64k from Hedelmae, Tricky truck – Archee’s winner entry from gamedev, 64k intro compo 1st and 2nd, Fairlight’s demo (2nd in compo), and finally ASD’s winning demo.

A common technique for me has been to just make zip files of whatever I want to backup. Simple snapshots of a project, so I end up with bunch of “projectname-YYYYMMDD.zip” files. Or altenatively a common zip of certain folder which gets updated over time. For example, before I moved to using cvs or svn for source code version control, I used a batch file like this to backup all my little coding projects:

backup.bat
@zip -u -r d:\backup\prog_c * -x *.ilk *.pdb *.idb *.ncb *.opt *.plg *.bsc *.sbr *.pch *.obj *.zip *.dll


As you can see, this just updates an existing zip and excludes bunch of unnecessary files which I didn’t want to keep bloating up the backup zip. A worthy note is that I have usually made sure I have two separate hard disks in a computer and put the backups on the other one from the original data. At some point I also tried to switch to using dar instead of the zip files, since it would have had some advantages over the zip files. I didn’t end up using that for long though.

Like I hinted above, nowadays I’m using version control for source code, so I don’t make such zips that frequently anymore. Instead I have made sure that the version control repository gets backed up somehow.

My first solution was to make nightly snapshots of the repository using a script on the server, and then occasionally copy a snapshot file back to my main computer. I used this solution for many years. Below is copy of the backup script I used, which creates a .tar.gz backup file with given prefix from a specified file mask, adding YYYY-MM-DD timestamp to the backup file name, and also keeps only given number of snapshots around cleaning up any older ones.

dobackup.sh
#!/bin/sh

if [[ ! $1 || ! $2 || ! $3 || ! $4 || ! $5 ]]
then
echo $0 destdir name execdir mask backups
echo $'\t'destdir = directory to put backups in
echo $'\t'name = file prefix name of this backup
echo $'\t'execdir = directory to run the backup tar command in
echo $'\t'mask = filemask to give for tar
echo $'\t'backups = number of backups of name to keep in destdir
exit
fi

DESTDIR=$1
NAME=$2
EXECDIR=$3
MASK=$4
BACKUPS=$5

DESTFILE=$DESTDIR/$NAME-`date +%F`.tar.gz

cd $EXECDIR
tar zcf $DESTFILE $MASK

EXTRAFILES=$((`ls $DESTDIR/$NAME-* | wc -l` - $BACKUPS))

if [[ $EXTRAFILES > 0 ]]
then
rm -f `ls -t $DESTDIR/$NAME-* | tail -$EXTRAFILES`
fi


I had then another script which called the above one to create backup files from a few places in the system, and was put in a cron job to be run once per night. The backup script looked something like this:

allbackups.sh
#!/bin/sh
# All automatic nightly backups
cd /home/user/bin
BACKUPDIR=/var/backups/user
umask 007
# /home/share (includes version control repository)
./dobackup.sh $BACKUPDIR share /home share 7
# misc stuff
./dobackup.sh $BACKUPDIR misc /home/user "bin bookmarks.html code" 7


More recently I have also moved to mirroring stuff over to another computer using rsync. This was something I needed to do to create an off-site remote backup for my workplace’s version control repository. To do this, I have simply put ssh-keys in place to allow automatic remote ssh login from a certain machine to run rsync over it, and then I have a cron job line like this to update the mirror every night:

nightly rsync mirror for cron job file:
30 5 * * * /usr/bin/rsync -avz -e ssh user@server:/path/* /backup/mirror/ > /backup/log/last_cron_mirror.txt 2>&1


Additionally I’m also backing up some paths of this web server every now and then using simple tar commands in a script, and the following command to back up a dump of the mysql database:

compressed mysql dump, must be run as root:
/usr/bin/mysqldump --defaults-file=/etc/mysql/debian.cnf -A -Q --opt | /bin/bzip2 > ~/db-mysql-`date +%Y%m%d`.sql.bz2


Finally, since there are multiple computers in our household, we have also been simply copying manually some files over to a share in another computer to have at least a single duplicate. These days I have also set Windows 7 backup software to maintain a backup of certain folders and system state to a share in my home Linux server. In the past I also sometimes made manually a backup of my Windows XP computer’s system state using the OS backup tool. Also recently when a brand new hard disk failed for me, I bought another one and after getting the warranty replacement I put the two into a mirrored RAID disk.

I have experienced so many hard disk crashes over time so I have learned to pay at least some attention to backing up the most important stuff, even if I really still tend to be a little bit lazy about it.

I remember hitting against this problem numerous times, always remembering that I have solved it previously but always seem unable to find the previous solution. And I still can’t just write it out by heart.

Once again I had to solve this, so this time I tried to Google for it (“angle wrap delta”), and found out that somebody named Jason S had posted a nice generalization to a related question in Stackoverflow.com.

For your convenience, I’m posting a modified C version of the code here.


// Fancy generalization for wrapping below (e.g. for angles).
// Original code found from:
// http://stackoverflow.com/questions/2500430/calculating-rotation-in-360-deg-situations

// Unwraps a value, used for e.g. angles.
// Caveat: Doesn't handle negative input values correctly.
// Workaround: Wrap original value prev to [0..range) before applying this.
//       e.g.: prev = fmodf(fmodf(prev, range) + range, range);
static float unwrap(float prev, float next, float range)
{
  return prev + smod(next - prev, range);
}


There’s one caveat: it doesn’t seem to work correctly for negative angles. Just now I don’t have the time now to figure that out. But an easy workaround is to wrap the original angle first with angle=fmodf(fmodf(angle,2*pi)+2*pi,2*pi) and then transition from that angle to the destination. If somebody posts a better version I’ll update the post. :)

Well, let’s think about what it means to build bug-free software. There actually exists some software, which is built with goal of “zero-defects”. By that, I’m not referring to the constant hype from latest agile method cult who may have some extravagant claims. I mean software where it’s of utmost importance to really have no bugs, no matter the costs. A case where a single bug may mean loss of lives or failure of the whole project. This kind of software is built for space missions, nuclear facilities, and so on. And such a policy on quality is inherently very very expensive.

Imagine if Windows, for example, would have been built with such policy. It’s a really complex and huge piece of software compared to ones normally built with zero-defect policy. But, given the option, would you pay $19,900 of your operating system, if it would never crash? It’s quite a no-brainer that “everybody” would rather pick the same software for $199 and just put up with the few problems they encounter. (The price difference was picked by Stetson-Harrison method. It’s a guess to illustrate the point. The difference could be actually lot worse for niche market software which isn’t aimed for mass market.)

I was away for about 2.5 weeks to visit Japan, more exactly Kyoto and Tokyo. The trip was excellent, and in retrospect it was clearly a good idea to visit both cities. While Kyoto is a modern city, it still has a bit more traditional feel to things. For example, the local laws forbid building tall skyscrapers, so there aren’t much taller buildings than we have in Helsinki.

Tokyo in other hand is very modern city with lots of skyscrapers. When going to see the city view from top of Mori building in Roppongi hills, you can see the city expands in every direction to the horizon as far as you can see. There is also extremely well developed public transportation, just check the Tokyo subway map (PDF). The public transportation in Helsinki is also quite good, but Helsinki is so tiny compared to a big metropolitan city so that our subway is tiny as well – just compare the above one to the current Helsinki metro map. ^_^

Interestingly when going to USA it feels that everything is bigger. When going to Japan, it feels the opposite. Maybe that’s partly because there is a whole different class of small cars which are narrower than we’re used to. I think the average width of streets is a bit less as well. There are also typical big western cars, so there’s just more variety of different sized cars. There’s even mini garbage trucks as you can see. However, not everything is small; I think in Japan they just tend to make things small by default, but aren’t afraid of making things big when there’s a reason to do so.

Also some things seemed to be done in an opposite way of what we’ve used to. Not just the left-hand driving and walking, but cars are also almost always parked backing to parking spot so that it’s slower to park car but easy to leave. And at least in Kyoto the buses worked so that you go in from a single back door and pay when you exit through the front door. Curiously in Japanese language the verb is also put last in sentences (think of Yoda-speak).

When writing you sometimes want to put a sidenote in parentheses, and then end it with a smiley.

This raises a question: Should you write one or two ending parentheses?

This seems to be an awkward problem for many. XKCD even made a comic about it (link at end of this post).

My solution is to use just a single parenthesis, so the ending parenthesis becomes part of the smiley. It just looks better that way! However, this way really sucks if you are writing in e.g. some chat system which automatically replaces smileys with small graphic icons. In that case the ending parenthesis just disappears and it feels like the sidenote keeps going on and on and the whole paragraph starts feeling unbalanced. So, if I know that the system will replace my smileys with icons, I will use double parenthesis.

At this point you’re probably wondering why I don’t show an example? I often overuse such sidenotes for some remarks, which is of course the reason I have even realized this earth-shattering problem. However, I have also realized that the best way to fix it is actually just to not use such sidenotes. Often the sidenote may actually be just a natural thing to say in the next sentence. Or perhaps you can consider using a footnote. I feel footnotes don’t work that well in web pages but I prefer them in print publications.

Anyway, I should save you the trouble (of constructing examples yourselves :).
Or maybe you already tried yourself (I know you did! :-) ).

XKCD comic

Various sites have embraced the news eagerly such as IGN Wireless, CNET and Kotaku, to name just a few.

Be sure to also check Mikko’s blog post about a cardboard prototype.

Update Apr 3, 2010: iPad is now available in the US, and so is Zen Bound 2. Go get it!

Update:
Turns out that Stair Dismount also won the award for Technical Achievement. ^_^
Read the announcement in igfmobile.com.

In other “news”, I didn’t end up making an entry for the last weekend’s Ludum Dare 48h game dev compo. The theme was “Exploration” – I wasn’t really fond of the theme, but I still had a solid idea very quickly I went forward with. However, I ended up honing gameplay nuances for too long in my head and without actually doing much of implementation. I ended up writing some level generator thing and the supporting draw code etc. Might come back to those later if I want to work more on the idea; or perhaps even integrate with my summer efforts for making a little game for Assembly which also turned out not to be.

On the other hand, at least there was nice chance to have sort of “role reversal” for the weekend, since I was the one who went to buy groceries and made some food, and my wife made a nice little game to entry in the same LD48 compo.