Using Subversion With the Kobold2D Game Engine and Xcode

I've been messing about with some basic MacOS and iOS game development lately, and at the moment I'm working with the Kobold2D game engine, which is (mostly) a refinement of cocos2d.  I've found however that in Kobold's quest to make initial setup of a project easier, it sidesteps some of the normal setup that Xcode does when you add a project or file.  Some of this, such as Project Summary info like the Application Category and Bundle Identifier is easily fixed after the fact.  Version control setup, on the other hand, is marginally more complicated than normal (at least with Subversion).

With a bit of trial and error I think I've got a working procedure to get a new Kobold project to play nicely with Subversion.  Here are my assumptions for these instructions; the more you deviate from these the less this will be relevant, and I'll leave variations as an exercise for the reader:

1. You're running Xcode 4.6 (I'm testing with 4.6.3)
2. You've got Kobold2D 2.1.0
3. You already have a repository set up and waiting at version 0 (zero)
4. We're creating a pong clone called  -- oddly enough -- "pong"

Any text here in fixed width is intended to be cut and pasted directly into your Terminal if you desire.  However, I won't be held responsible if anything goes awry... I'm trusting that you're using your head and paying attention before you run any of these commands.

Create a Kobold2D Project

Run the Kobold2d Project Starter app.  Select the appropriate template (I'm going with Physics-Box2D) and set the project name to 'pong'.  You can also set your own Workspace name here if you want.  Make sure you uncheck "Auto-Open Workspace" because we don't want to have that open quite yet.  Click on the "Create Project from Template" button.

Import the Project into Subversion

In Terminal, set ~/Kobold2D/Kobold2D-2.1.0 as your current directory

cd ~/Kobold2D/Kobold2D-2.1.0

Make a new directory structure with the usual 'trunk', 'branches', 'tags' directory structure in it

mkdir -p pong-import/{trunk,branches,tags}

 Move your new 'pong' project into the new trunk directory

mv pong pong-import/trunk/

Change directory into pong-import and import the project and directory structure into your repository

cd pong-import; svn import . https://svn.mydomain.com/pong/ -m "Initial import"

Now delete this directory structure

cd ..; rm -Rf pong-import

That's it for the Terminal.

Add The Repository to Xcode

This is the only step that's exactly as it would usually be.  Go to the Xcode Organizer (menu Window -> Organizer) and select the Repositories tab.   Click on the + in the bottom left corner of the window and select Add Repository.   Follow the prompts to name the repository, give it the URI to the repository, add your authentication credentials, etc..  For the purposes of the example, let's say the URI for your repository is "https://svn.mydomain.com/pong/".

Check Out a Working Copy

While still in the Xcode Organizer Repositories tab, click on the expander arrow to the left of your 'pong' repository.  It should show four folders:  'Root' in purple, and your 'Trunk', 'Branches' and 'Tags' directories in yellow.  Select 'Root' and then click on "Checkout" in the button bar across the bottom of the Organizer.

This will open a standard Save dialogue.  Browse your way to ~/Kobold2D/Kobold2D-2.1.0/, type 'pong' into the Save As field, and click on Checkout.

Clean Up Your Workspace

Return to your Kobold-2.1.0 folder in the Finder.  Open the "Kobold2D.xcworkspace" workspace, or your custom workspace if you created one.

You'll see your pong project listed, but it'll be in red.  That's because the files aren't where the automatically-created workspace expects to find them.   Right click on that and select Delete.

Then, right-click again and select Add Files to "Kobold2D" (or whatever the name of your workspace is).  Browse to ~/Kobold2D/Kobold2D-2.1.0/pong/trunk/pong, select 'pong.xcodeproj' and click on Add.

You're Done!

You should now have a functioning Kobold2D project with all of the usual Xcode internal Subversion support available.  You should be able to pick a random file from your 'pong' project files, right click it and go to Source Control -> Update Selected Files and cause Xcode to check if there are updates available for that file.  

Good luck, and good gaming.

The One Where I Talk About A BBS Game

20 years ago I was, along with many of my friends, spending quite a lot of time on computer Bulletin Board Systems (BBSs). Most of us had already been doing this for many years, and there were people out there who'd been doing it even longer. The BBS scene at the time was pretty sophisticated we thought.. it was becoming possible to do some really great things!

One of the things that I thought was really great was playing computer games against other people in different places. This idea was still pretty novel, as computer networking, the way we think of it today, simply wasn't possible with most home computers – what few even existed. Most BBSes only had a single phone line for people to connect, and so out of necessity virtually every BBS game was turn-based, usually allowing a single turn per day. So, every day, I had time set aside to dial in, see what had transpired since the previous day, and take my turns.

One of my favourite games, and one of the few that I remember in any detail, was Esterian Conquest. It was a multi-player take on some of the early empire-building 4X games, set in a small two-dimensional galaxy, where each player had to build a fleet of ships, and go forth and conquer by force or diplomacy. Don't let the simple idea fool you though.. EC was a beast of a game, with simple rules that allowed for a plethora of complex results. Early on, my nightly turn would take but a few minutes to think about and execute, but later in the game I could literally spend hours pouring over reports from my fleets, hand-drawing maps on graph paper based on the information they contained, and then planning out and tediously punching in new orders for all of my fleets and planets.

About four years ago, while cleaning out boxes that had been in storage for ages, I came across a folder containing papers from the last game of EC I ever played. There were printouts of reports covered in pencil notes about possible actions to take, maps with quick calculations of how long it would take my fleets to reach some hot-spot in the game galaxy, and sheet after sheet of new orders.

Fleet 66 join fleet 47

Fleet 32 reduce speed to 5

Fleet 73 move to star at (12,41)

Everything about the game came back, and I started to wonder if it could somehow be resurrected. I had heard years before that the source code to EC had been lost in an all-too-unfortunate hard drive crash, but digging around in more boxes I did manage to find a floppy disk with the copy I had for the BBS I'd briefly run myself. Sadly, it proved to be more work than I had time for to get a computer running that could both run modern networking and connect that to an old DOS game. So I decided that instead, I'd just write my own.

I spent the next few months mapping out the game I'd like to create.. what I thought at the time was probably the first ever Turn-based Strategy MMO. I started writing documentation: how would I like the game to work? After chatting about the idea with a friend of mine, he gave me a photo-copy of an old table-top game he'd played called Stonova for ideas (it was based on Chris Wilkes' "Nova"). I worked out plans; I taught myself the math I'd need for three dimensional navigation (I wanted my game to take place in a realistic three-dimensional galaxy). But, when I really got down to it the game I had in mind would have required programming skills, particularly in the area of graphics, that I just didn't have the time to acquire. The idea was grand, but it was beyond me at the time. So I put the idea away for a while.

A couple of days ago, for no particular reason I can recall, I started thinking about this again. My original idea had been too grand for my meagre programming skills. But what if I scaled it down? In the last few years it's been proven that web-based games can work, and do attract players. So what if I ditched the desktop game idea, and went with the much easier to program web-based game? Games like Travian certainly seem to attract players, and as the basic concepts go it isn't all that different from what I had in mind.

My game will be simpler than EC in places, and more involved in others.

In EC it was possible to send your ships to any point in the galaxy, and along the way they would send back reports if they came within sensor range of any other passing ship. You could interrupt their orders mid-trip and have them pursue whom they spotted, or run away, or slow down and quietly follow at the edge of sensor range. I think I will simplify that a lot, and very likely only allow travel to other stars, not the spaces between them. Fleets will report on other fleets they find in their current star system, but I think I will drop the requirement to calculate intersecting flight paths, and handle changes in destination mid-flight.

EC had a small number of fixed ship types that you could build, and assemble into fleets. I think I'd like to have a bit more range in this area, so I'm going to design a technology research system that will allow players to concentrate on improving certain aspects of their ships. Are you a fan of big weapons? What happens when you go up against your opponent who has put all their research into heavily armoured ships? Or, maybe you just want to build really fast ships that can run away easily when threatened.

EC had no system of trade that I can recall. My game will allow players to trade resources, and might even have some sort of in-game cash economy. Perhaps you won't build warships at all, but will instead build big, fast transport ships and survive by supplying everyone with what they need... and paying tribute for "protection" where necessary.

So, I've started working on the idea again. I have no idea what will come of it, or whether I'll even finish. I haven't even got a name for it yet.. but I'm curious to see what I can come up with.

On Joining the Jedi

Clearly I'm a few months late to the game here, if you'll excuse the pun, but I just had to share once I saw this:



I was a huge fan of KOTOR 1 and 2, and the idea of an MMO based on them is ... well... I can't wait!