Darwinbots 3

Check the following link for a real-time discussion of features and progress: IRC

Darwinbots 3 is a long term project to recode Darwinbots in C# as a brand new program. Every feature and aspect is going to be examined and refined as its added, in a framework that will ensure robustness and agility in handling bugs and new features. The code can be browsed: http://svn.darwinbots.com/Darwinbots3/

Compiling the code

Getting the compiler

You'll need a version of Visual C# 2010 (this all might run under Mono in Linux, but I don't have either so no promises). You can download C# express for free. The whole process will probably take several hours to do. The good news is that even if you never start programming Darwinbots, you just found a free high quality compiler :D

Downloading the dependencies

To compile the project, you need:

• XNA 3.1 - A game library released by Microsoft which is used for graphics.

To distribute the project (which you probably don't care about), you need:

• ILMerge - Allows multiple .NET assemblies (.DLLs) to be packaged into a single assembly.
• NETz - Allows packing of the exe to make it smaller.
• (TODO: Double check what needs to be installed .NET wise and XNA wise (redistributables)).

Get either Subversion or a Subversion client

For those unfamiliar with version control, it's basically a way to ensure that multiple people can work on the same source code. You "check out" a copy of the current source code from the repository and store it locally on your computer. You then change the source code in places and "commit" it back to the repository. If there have been changes in the mean time that conflict with your changes (should be a pretty rare occurrence), SVN will notify you and ask you to resolve the problem before the commit is applied to the central code repository. Another advantage of working this way is that the entire evolution of the code is tracked. If some bug is found that was introduced months ago, you can browse through the repository at different versions of the program to find what changes caused it.

You can either try one of the Subversion commandline builds if you're into that sort of thing, or try one of the GUI based Subversion clients. Numsgil uses SmartSVN, which he highly recommends.

Accessing the repository and committing

http://svn.darwinbots.com/Darwinbots3/ This is the link for the repository. It has anonymous access, so anyone can download and browse it. To commit changes, you need a username and password. Post a request for one here. If you haven't registered in the forum yet, please do so. It's important that progress is talked about so others can see what's going on.

How you should set up your SVN projects and local directories

You can dump the source whereever you want. Everything is set up with relative paths. I would suggest something like this just for sanity, though:

C:\

• \Darwinbots3
  • \Source <-- sync this to the trunk directory in the repository, or one of the tags or branches if you're working from them

Again, the source folder doesn't have to be inside your Darwinbots3 folder, but life will probably be easier if it is.

Visual Studio solution files

Instead of one large master solution file to build the entire project, each module maintains its own solution file for just that solution. Usually it will contain the module itself, some unit tests, and a test app. This is to make checking unit tests for errors simpler, among other purposes. All the modules spit out binaries in to the bin/Release directory, and these are checked in, so there's no need to rebuild everything very often (assuming source and binary and kept in sync, which will usually be true). To build the entire project, you'll need to run one of the build scripts in the Scripts directory. Note that you shouldn't need to do this very often.

Junk directories and bin folders

The projects are set up to place bulky build files in the Junk directory. This directory should always be empty on the repository, except for the "About This Folder.txt" file. Final EXEs are built to the Bin folder. Only release binaries are on the repository, and are what projects use when they want to import another (for instance, the release build of UnitTestSharp is used for the unit testing projects). Note that this can cause weird problems if you build a project in debug mode and not in release mode, and then submit code changes to the repository, since the binary and source code will be out of date.

Under the scripts directory, there are scripts for publishing from the Bin directory to the top level Darwinbots3 directory (essentially publishing locally) and scripts to clean the junk folders (delete files and such).

This setup is subject to change based on usability issues.

You have the code, now what?

Each module has its own solution file. Because many modules have interdependencies, the release libraries are on the repository so you shouldn't need to compile all the projects first time. You can just open one up randomly and compile it and it'll work. Alteratively, in the Scripts folder, there is a batch file called BuildAll-Release. Run that file. You might need to run it more than once depending on what order the batch file decides to build the modules in.

Where's the DB3 EXE?

There isn't one yet. The idea is that it's getting built from the ground up, one module at a time. So there's no central project yet that actually uses all the modules at once. Instead each module is tested and developed individually based on some simple use cases. At the end, there'll be a nice product suite that should combine fairly organically into a final EXE. With any luck, anyway :P

Coding standards

Basic Standards

Look at the code, and follow by example.

Repository etiquette

• Prefer to post lots of small, atomic changes over large, far-reaching changes. It's easier to integrate for other people, and minimizes the possibility of commit conflicts.

• Keep the repository's code running. Don't commit a change that would break the program, or worse, prevent it from compiling. If you do anyway, fix the problem immediately.

• Be careful what files you submit. If it's a large temporary file you accidentally submitted it will take up repository space for ever and ever, even if you remove it from the repository later.

Unit testing

Unit testing is a way to ensure that a function or section of code works like you think it should. It is immeasurably important for keeping the code robust and bug free. It also makes refactoring much easier. this site is an excellent introduction to Unit Testing for games.

Ideally, you would write the tests first and then "fix" the program to pass those tests. This requires some discipline that I personally don't always have, so I'm not going to strongly enforce this. Aim for this standard anyway. Definitely unit test as many aspects of the code you're working on as possible, even if it's after the fact.

If you want to submit code without tests, it'll probably end up in the trashcan, honestly, when time comes for me to figure out how it's supposed to work (and why it's currently not working).

Release pattern

When a new release is ready, it's given a version number. The format is:

• Darwinbots3 AXXXXX.exe - An alpha release. The XXXXX is the source control revision (ie: the changelist number in the SVN) corresponding to the executable
• Darwinbots3 BXXXXX.exe - A beta release. The XXXXX is the source control revision corresponding to the executable
• Darwinbots3.0.exe - The first feature complete and stable release.
• Darwinbots3.XXX RC1 - A release candidate. The number after RC is the release candidate version. The XXX is the version number (starts at 001, goes to 999).
• Darwinbots3.XXX - The stable release for version XXX.

Note that these files alphabetically sort according to when they are expected to release. This is important.

Design

Visit the wish list to see the major features under consideration from the point of view of the end result. Discuss them in the forum.

Milestones

Milestone 1 - Basic functionality version

Subarticles

• Physics explanation - An explanation in plain $LaTeX$ of how the physics engine works.
• Modules - A list of modules involved in Darwinbots3 and an explanation of how each works.
• Tasks - A list of relatively self contained tasks which need doing.

DNA

Visit the Robot DNA page to see how the DNA will work.