For the last few weeks I have been working on a personal game in haXe/NME that I will post about later. This weekend I got to the stage where I started to really think about user input. My goal for the game is to take full advantage of NME’s ability to target a bunch of platforms. I know I need to handle the game controls in a way that would allow for totally different input methods based on the target the game is published for i.e. keyboard for Flash/HTML5 in the browser, and accelerometer or touch screen controls for native iOS and Android apps.

This game is my first real project I have worked on by myself using both haXe and NME, so there has definitely been a learning curve. I felt like the way I would usually do keyboard input in a flash game would not be the best way to do things, mainly because of the multiple output targets. I needed a more object-orientated abstract way of handling the game controls. I also wanted something that would fit into my existing gameloop, and not force me to adopt some crazy bloated design pattern.

I am a huge fan of The Creative Coding Podcast, and basically everything that Iain Lobb and Seb Lee-Delisle get up to. So I remembered a little set of util classes Iain made in AS3 called Gamepad. I also remembered him mention on the podcast he was experimenting with haXe. I did a quick search but it seemed like no one had ported Gamepad over to haXe yet, and there didn’t even seem to be anything close to it for haxelib. I thought this was very strange for a language where game creation is one of it’s main uses.

I thought porting Gamepad would be a great way to learn a bit more about haXe, and get something useful at the end of it. It only took me a few hours, including testing it with my game, but by the end I had it working on Flash, C++, and HTML5 canvas. Check out adamharte/Gamepad-Haxe on GitHub, and don’t be afraid to fork it, and add issues to the issue tracker or just comment here. For the original ActionScript 3 version check out iainlobb/Gamepad on GitHub.

Some things I learned; A few small language differences coming from ActionScript. Such as there is no indexOf method of the Array class. Seems like the best way around this is to use a Lambda. The Lambda class has a bunch of static method for interacting with Iterable objects e.g. To get the index of an object in an array you might do:

[actionscript3]Lambda.indexOf(myItems, exampleItem);[/actionscript3]

That is a little less intuitive than the AS3 Array class, but fine once you know.

Now that I have the direct port and can start using it in my game, I will try to come up with ways I might improve on it, and make it work with other targets better. First I will try and get it working for touch screen controls on mobile devices, then maybe look into some strange behaviour I was getting with the HTML5 target.

So all round, I think I learnt a fair bit from porting Gamepad. It forced me to look deeper into some specifics that I needed to get to the end result. I will definitely be looking for other missing pieces that haXe can adopt. Big thanks to Iain Lobb for writing Gamepad in the first place, and especially for making it open-source.

Cheers,
Adam