Jario Update: Kinda Working!

I’ve just pushed an update to Jario with some pretty nice changes since I last mentioned it. As usual, you can check out the source if you’re interested or just Launch Java Web Start button!

I’ll be quick:


  • All the important items – coins, mushrooms, fire flowers and stars.
  • Goombas, Koopas and even empt shells, with the ‘proper’ graphics and animations.
  • Vastly improved input and collision handling.
  • Added a marginally more satisfying ending, though it still doesn’t do anything.
  • Fixed many, many bugs (but not the intermittent collision mesh one yet).


  • Cleaned up collision handling systems into a hierarchy of similar handlers for increasingly concrete entity types. I’ve found it to be very flexible and reusable so far, which is nice, since the logic of a game is little more than input and collisions.
  • Refactored image and animation spatials into a hierarchy of intermediate abstract classes, and added a SpatialComposer to group the different spatials of individual entity types and handle different states.
  • Inserted a hierarchy layer for spatial effect handling. Currently only processes changes in rendering alpha value, but does so quite nicely.
  • Played around with a TimerSystem to be used in conjunction with a Timer component, allowing systems to easily register callbacks with individual entities to be executed after a given delay. Makes it very easy to add temporary properties to entities. For instance, giving the player X seconds of invulnerability (hurt with >1 health, or press I) reduces to a single static function call. Still need to play with Artemis’ DelayedEntityProcessingSystem to see if that does a similar thing.

That’s all the significant bits so far. Still plenty more to go, though! Some of the above will need to change in order to support a complete level, which will be interesting. I also need some better game state transitions, though that’s nothing to do with Artemis. I’ll talk a little bit about some of the more interesting points soon, such as the collision handling and spatials, since those two are key to getting a game working smoothly.

Introducing: Jario

Jario logoYou saw Hario, and you revelled in its technical prowess. Now, the summer (winter) blockbuster of 2011 has arrived.

Jario is a port of Hario, and is similarly a very basic Mario clone, the quintessential platformer. From Hario’s C++ and HGE, Jario is running with Java and the Slick game library, as well as the brilliant Artemis entity-component framework, and it is an exploration of how to apply such a framework to a platformer-style game.

It’s currently in its very early stages after about a week of development from scratch, but it runs, and it already has more features than Hario. And although you may not believe it when you see it, it has superior graphics as well. There is no art more noble than that of a programmer.

It’s important to note that Jario is not a game so much as a proof of technology for the foundation of a game. As features are implemented it will become more game-like, and if I ever ‘finish’ it then it will perhaps be a game, but in my eyes it is just a body of code. The good news is that I can now refer to this code as I discuss Artemis and entity-component frameworks in general, which I certainly will get around to now. Jario is just the first step on the path to bigger and better things.

As usual, you can download the Web Start or run it in your browser. In addition, since it’s basically a piece of tech, I figured I should release the source code on Bitbucket to get some feedback from those with a little more Artemis experience. Finally, for this release there’s also a bonus feature: a pretty button for launching the Web Start! Behold:

Launch Java Web Start button

NOTE: Google Chrome users (such as myself) may find this button just downloading a JNLP file rather than launching anything tangible. To resolve this, click the little down arrow next to the downloaded file on the downloads shelf (the toolbar across the bottom) and select “Always open files of this type”. This will tell Chrome to launch JNLPs automatically (as well as downloading) rather than making the user do it, just like the other browsers.

Retro-introducing: Shadow Quest

Shadow Quest iconA couple of years ago, I took a subject at uni called Object-Oriented Software Development (433-294). Although I had already introduced myself to OOP, this was the best subject I’d ever taken, because the OOP paradigm was my favourite thing about programming, and it’s always worthwhile learning important things formally. On top of this, we had a fantastic lecturer (Shanika Karunasekera) with a bold plan to inject some life into the otherwise tiresome semester project – instead of building a generic banking application or similar, we would be writing a game.

This was, of course, right up my alley, and ultimately the result was Shadow Quest. You can read more about it on the project page, but essentially we were given a set of specific requirements to build an RPG using the Slick game library, and that would be our assessment (though various stages of planning and development). Brilliant. Everyone loved it.

Of course some students found it less challenging than others, and for them the challenge was set to create the best game extension by the end of the semester. So long as the basic requirements were fulfilled, we could add anything we wanted, and the author of the best game would win a book voucher.

I leapt at this opportunity, and set about implementing a bunch of features from Diablo II, my favourite RPG (despite it being a hack’n'slash). I added player experience, levelling, stats, inventory and equipment, magic items, random item drops, gold drops, buying potions, and the thing I was most proud of was my randomly generated dungeon: five levels of caves procedurally generated by a cellular automaton. It took a lot of work, but worked a treat, and I felt like I was in with a chance for best game.

Unfortunately, come judgement day, there was some very impressive competition, including one game which blew all the competition away in terms of features and polish. A giant map, animations, weather, visual effects, magic spells, archery, horse-riding, a town with indoors in the buildings, a bunch of NPCs, and so on. It was the deserving winner, but I still reckon it was the work of more than one person.

Anyway, I dug out the code for my version of Shadow Quest the other day, and decided to post it up here for posterity, with a few tweaks for efficiency. Again, you can check out the project page, the source code on Bitbucket (don’t judge me, it’s old!), or more importantly play it in your browser or download the Web Start. Enjoy!

Introducing: Artemoids

As I mentioned previously, I’m back to work, and my first order of business is playing around with Slick and the Artemis framework. To that end, after a mere day or so of coding, I’m pleased to present Artemoids, a simple Asteroids clone using the Artemis framework. I’ll talk more about the framework soon, but suffice it to say that it is incredible, and exactly what I’ve been looking for on and off over the past couple of years.

So. Artemoids is a simple, top-down 2D game in which you fly a ship around in space (zero gravity) and shoot asteroids. If an asteroid hits your ship you die, and when you shoot an asteroid it splits into two smaller asteroids. That’s pretty much it. There’s really no win/lose conditions, because I don’t intend to make a full game out of it; it’s primarily a test and demo of the Artemis framework, and something easy to cut my teeth on to kick off the holidays.

That said, I am planning a much more sophisticated game with quite a few similarities to Asteroids, so the Artemoids code should serve as a good foundation when I kick that off (and hopefully that will be soon, with an accompanying announcement).

You can try it out for yourself right now in a browser applet, or download a JNLP Java Web Start file to run it a little more locally. I’m quite excited about finally getting both of these deployment methods to work happily, as it means I’ll be significantly more able to show off any future Java projects I create.

Also, notably, this is the first project I’ve ever open-sourced, not because I’ve been a selfish git all this time (well, not only because of that) but because my projects have typically been pretty small-scale and hacked together for personal use. Hopefully however Artemoids (and of the some games that follow) will help to serve as an example for how to use the fledgling Artemis framework, and I’ll be referring to some of my code in future posts/articles. You can check out my Artemoids Bitbucket repository to read the source, submit any issues (bugs/feature requests) you find, or even fork the code for your own project. I’m a big fan of FLOSS, and I’m more than happy to lend a hand to anyone with any interest in what I’m doing.