🤖 CROBOTS2000 🤖

This is a remake of the vintage videogame CROBOTS by Tom Poindexter, made with the OCaml bindings for the raylib game engine.

Play

CROBOTS is played by programming your robot in a text editor of your choice using a friendly C-like language, then inputing its source code into the game.

You can go solo (boring) or match it against other robots (even itself) by providing more than one source file to the game.

Grab the binary under Releases (Linux only). The usage is pretty straightforward:

crobots.exe <robot-programs>

Where <robot-programs> is a list of file paths containing the source code of the robots that you want to match.

Robot source code is typically stored in text files with the .r extension. There are a few historical samples in the samples directory.

In the command line below, for example, we make two rabbits and a sniper fight:

crobots.exe samples/rabbit.r samples/rabbit.r samples/sniper.r

If you have a working installation of OCaml with dune, you can also start the game like this:

dune exec crobots samples/rabbit.r samples/rabbit.r samples/sniper.r

Enjoy watching the sample robots compete or have a go at creating your own robots!

Robot API

The robot programming language is a super barebones fragment of the C language, enriched with a number of intrinsic functions (a.k.a. the Robot API) that allow the robot to move, fire missiles and locate enemies. Check out the Robot API in the official CROBOTS documentation.

Differences from the original game

I've introduced a heading intrinsic function that can be used to get the robot's current heading.

Due to the different design approach to the physics engine, the programming style in this remake is a bit different than that of the original game, as explained below.

First, there is angular friction: when you set your robot's heading using the drive() intrinsic, it will take a few CPU cycles for you robot to reach the target angle. This is unlike the original game, where turning was instantaneous.

So, if you want your robot to travel on a precise route (e.g. diagonally towards the top left corner of the field at 135 degrees), you need to call the drive primitive with a target speed of 0 to begin turning it in place:

drive(course, 0);

Cycle until the target heading is reached:

while (heading() != course) ; // do nothing

Then set off with your desired speed:

drive(course, speed);

The effect of this procedure is shown in the right gif: the robot first rotates then moves in a clean straight line, whereas in the left gif the robot turns and accelerates at the same time, missing the top-left corner.

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Debugging

To debug or modify this game on your computer you need a working installation of OCaml with the opam package manager and the dune build system installed. Once you have that sorted, you can start the game by issuing the command:

dune exec crobots <robot-programs>

Acknowledgements

• CROBOTS home: http://tpoindex.github.io/crobots/
• raylib-ocaml
• Menhir
• Thanks to @bitbart for the idea