You can keep up with what I am up to over at my new blog HERE.

This blog has a lot of valuable content, and it will continue to be online for many years to come.  However, I will not write any posts here again.

In the last couple of days I have been trying to accurately simulate the movement of car (two steering wheels, and two fixed wheels).  This is more complicated than it first appears because, when the car is turning, it is actually rotating around a point which is outside itself.  The diagram to the right should help to show what I mean.

Getting this form of motion to work properly involves some complicated co-ordinate geometry to make points rotate around other points across multiple frames of reference.  It took me a while, but I finally managed to get it working today.  You can check out the result below

CLICK HERE TO VIEW SOURCE

People close to me know how often I complain about websites which install mobile versions.  “I paid $500 so I could have a device capable of viewing your regular website just fine. Why do you force me to use this broken, useless imitation of a website?”

Lifehacker.com is a classic example of a site which installed a mobile theme because it was trendy but which is also broken and unusable.  All links in the original post are removed from the mobile version (wtf?) and images are gone too.  To top it off they have a “view classic Lifehacker” link at the top but this takes you to the home page, not the post you were viewing.  Clicking on the post from the home page then takes you back to the mobile version >.<  I still go there on my iPhone from time to time, but a piece of me dies every time

You’ll be happy to know that my mobile version does not have any of these issues (if you find issues, please let me know).  I am using a very well made Wordpress plugin called WPtouch which does a great job of handling the mobile version of things without effecting my primary theme.  The best part is, if you don’t like the mobile version, you can simply turn it off (with the switch at the bottom) and you wont have to see it again

Yep, that’s right. In both the above images that little patch of green in background is New Zealand.  You’d have to say that the odds of the same country showing up twice in IIS images is fairly unlikely. Having the same part of that country appear, with the IIS in the same orientation is just amazing!

I realize I’m digging pretty deep here, but this is as close as New Zealand is ever going to get to being part of the space program…

Since my last post I have continued working on little ‘cat herding’ game as a way of learning about how a simple 2D game engine works.  It quickly became apparent to me however that I was going to need a tool to help me define levels for the game as manually typing out the level definition (several large int arrays) was becoming very tedious.

A ‘World Builder’ application is quite a different puzzle to building a game, because the world builder not only needs to be able to render the level to the screen, but it also needs to be able to update the level in a fast and elegant way.  These constraints are directly contradictory when you are trying to decide on the data structure to represent your world, and it took me several different attempts to get it right.  What I eventually settled on can be seen above, and you can download the source here.  Read on for an explanation of how it works.

Note: All of the tile assets used in this demo (and my previous one) have been borrowed from the application RPG Maker XP. It’s an awesome piece of software!

It’s All Just Grass and Sand

I spent most of a day brooding over this problem before I came up with a solution that worked.  I tried slicing the original assets (example shown on the right) up into 16×16 pixel slices rather than the original 32×32 pixels.  That only served to blow out the complexity of the problem. I tried having the application generate every possible combination of 16×16 slices during the application start up, which worked, but made the process of defining maps by dragging a mouse too hard.

Then suddenly it hit me and it was all too simple:

• It’s all just grass or sand
• Grass encroaches into sand

The fact that all tiles were either grass or sand meant I could stop storing the tile number for each cell and instead just store the texture for that cell (e.g. 0 = grass, 1 = sand).  This made updating the map using the mouse really simple. All I needed to do was update the target cell to either 1 or 0.

The fact that grass encroaches into sand meant that I now had a rule which I could use at runtime to determine how to draw each cell based on the value of that cell and the value of all of its immediate neighbours.  Armed with this knowledge I rebuilt by tiling system once more.

I needed one last bit of trickery to make the system work perfectly. This trickery was that even though I was now defining the map by storing one value for each 32×32 pixel cell, I needed to draw that cell using a 16×16 resolution.  This allowed me to slice my original asset up into 16×16 pixel slices (giving me every possible combination) but still have an elegant way to select each slice (because each slice could only fit in one of the four corners of a cell).  Each corner of a 32×32 pixel cell is defined by the value of the current cell, and the cells which border that corner.  With this knowledge I was able to define a set of rules for selecting the right tiles to draw a cell and everything else came out in the wash

If you want to know more about how things were done then feel free to grab the source from the link included above.  You are free to reuse this code in any way which you find helpful. I’ve tried to keep it clean and readable, but I make no promises.

Check back soon to follow me as I adventure further into trying to build a simple game engine from the ground up

Recently at work I haven’t been doing much actual Flex development.  Instead I have been spending my time working on a data mining/business intelligence system which is an intricate combination of some complex SQL, Ruby scripts and some software called Pentaho.  Long story short I was starting to miss the feeling of getting my hands dirty in Flex code, so a few days I go I started messing around with building my own rudimentary game engine from the group up.

Above you can see what I have built so far in about 3 hours total coding time spread over the last four days.  The age old adage “never re-invent the wheel, unless you want to learn something” has proven true here once again also.  There is quite a lot of trickery to get even this small number of objects to draw themselves onto the screen in a fast, efficient way.

I’ll probably release the source code pretty soon. It’s still a bit in a state of flux so I’m not ready to let other people read it just yet

If I continue to have a bit of free time up my sleeve in the next few weeks I hope to port this project to AIR and have a go at trying to construct the map and characters from a definition in a text file.  At present the layout is defined in a 2D int array, so the conversion will hopefully be fairly simple.  If that works out then I’ll probably try and remember some of the AI techniques I learnt back in university… Should be fun

I am amazed.  I cannot wait to start collaborating across the web using wave.  Being a web citizen is about to get much better!

Who will be the first to write an Adobe Air API for wave?

I hope everyone had a great day. St Patricks day is one of those days that has universal appeal with everyone, regardless of whether they are Irish or not. Kinda like Christmas

Quoted from original post: Haikus for a Dangerous World

I just finished teaching my first class on 3-D cinematography. For the final, I gave the students the option to answer 2 extra credit questions. Here’s the second one.

“A velociraptor is coming at you on a hoverboard. In a haiku, describe how you will survive.”

Some selected responses:

Shit Christopher Lloyd!
Back in the DeLorean!
This sequel will suck!

I use sticky web
Like Spidy and Green Goblin.
Take down that raptor.

Screaming to trees,
I’m not that good of a treat.
I have many fleas.

I would climb high
above the sharp reptile beast
and kick its face in.

Calmly explain that
he is an anachronism.
Then watch him die.

If you’re anything like me, you’re now wondering what ‘anachronism’ means. 
Here, let me Google that for you