Starfighter Gosu Tutorial

By masonhale Date 2011-01-24 15:04

Hello Gosu community!

I've been working with my teenage son on a game, as a learning project. As part of that process we reconfigured the Ruby Tutorial game into 2D Galaga-style shooter. We have posted the project on GitHub here: https://github.com/masonhale/Starfighter-Gosu-Tutorial and will be presenting it at the Austin on Rails meeting tomorrow night: http://austinonrails.org/past/2011/1/9/meeting_tuesday_january_25_2010_700900_pm/

Please have a look. We are looking for feedback to make for a better presentation.

We are still working on slides for the presentation. We will post those as well when they are completed.

Thanks for the awesome library!

By jlnr (dev) Date 2011-01-24 22:16

Hey, looking forward to seeing the slides! The whole final project of 300+ lines is pretty heavy to show around, maybe you should split it up into several files?

One thing is that's a bit quirky about Gosu is the 'tileable' argument in Image.new/load_tiles. It just affects the sharpness of the image borders when you stretch or rotate an image. So, if you fill the screen with zoomed-up map tiles, you should pass tileable=true. Conversely, the stars and player should be loaded with tileable=false, because if you zoom them up, even the border pixels should be uniformly 'blurred' (filtered).

Other than that, looks like a solid code base. If it bothers people, you can tell them that I am (still) working on getting all the 'window' arguments removed. They really ruin the beauty of your code in some places atm.

Have a good presentation :)

By masonhale Date 2011-01-25 00:45

Thanks for taking the time to review the code.

I've made the changes to the Image.new tileable parameters as you mentioned, and I also created a "final" version with a Main.rb file that loads additional classes from a new /lib/ directory. Should make things more manageable now.

Thanks again!

Will post the slides later tonight or early tomorrow.

By RavensKrag Date 2011-01-30 20:11

If the 'window' arguments are removed, will Gosu function in a manner similar to Chingu, with a global $window?

By jlnr (dev) Date 2011-01-31 09:34 Edited 2011-01-31 09:41

Well, yes and no. Internally, the graphics and audio contexts are global and independent from the window, so you can do stuff like that (complete program):

i = Image.new("Player.png")
puts i.width

Playing audio without a window is not as cute, sadly. You might have to call Song#update every now and then, something that Window does for you right now. The idea is not to have a global window, but to decouple things in general. Window#draw_quad will also be Gosu::draw_quad etc.

I don't think it matters a lot in game design, because at some point you have something like a "game" that owns the map and objects, be it the window, a Chingu state, or an abstract object. All game objects will want to access that, so you're back to having a global or passing stuff around.

But with Gosu 0.8, helper libraries are able to do "image = Image.new('my_helpful_overlay.png')" without support from the enclosing program (passing the window). Also, having just a simple constant "GOBLIN_IMAGE = Image.new('goblin.png')" is something that is not possible right now.

I didn't change the reference and examples right now, but Song and Sample don't need the window argument anymore as a first step.