Crate rusty_sword_arena[−][src]

💡 Did You Know? You can generate your own, offline version of this document by running this command in your own clone of the repository.

cargo doc --lib --no-deps --open

Other Tutorial References

Rusty Sword Arena - Game Design

Rusty Sword Arena is a networked, 2D, top-down, arena combat game. A server implementation and shared library is provided. Your task is to implement a game client in Rust using the provided shared library and the game design details below.

Note that while significant effort has been put into making the server robust and unlikely to crash, there has consciously been very little effort towards security, or pretty much any proper game engine architecture. In other words, this is a great way to learn Rust and have some fun at the same time, but this in no way pretends to be a substitute for a real game engine™. 😉

Basic Gameplay

The basic idea of the game is you are presented with the top-down view of a person (circle) in an arena (your window) who can swing his weapon (a rusty sword) around a certain distance (a larger [concentric] circle than the person himself). You can face any direction you like, in fact turning is instant as far as the server is concerned. You can move in any direction (which is not instant, the server implements some rudimentary movement physics) and attempt to attack other players with your sword. You will be limited to 50% movement speed while attacking, so it is to your benefit to try to time your attack attempts to when you are actually ready to attack.

You start with some health. When you are hit, you lose health. When the health runs out, you die and the person who killed you gets a point. After a respawn delay, you respawn with full health. If you attempt to run from the arena, you are likely to be eaten by a grue. Being eaten by a grue causes you to lose a point, but there is no point penalty when another player kills you.

Preparation

First, you should follow the instructions on the readme to install some prerequisites. Then come back here and keep going.

Creating Your Game Client

These are all things we will do together in the tutorial. Feel free to get ahead of the group if you can!

  • Pick a name for your client and create a Rust crate. Hint: use cargo
  • Obtain the player's desired name and the host to connect to.
    • One easy way is to get the name and host from the command-line.
    • See args for the code part.
  • Add rusty_sword_arena as a dependency in your Cargo.toml file.
  • Create a ServerConnection using the host
  • Use the ServerConnection to join the game
    • You should hold onto that ID so you know which player you are.
    • You should probably handle the possible didn't-join condition.
  • Use the ServerConnection to get a GameSetting. If version in game setting does not match VERSION in the rusty_sword_arena module you are using, you may want to abort the game...and then fix your Cargo.toml.
  • Add impose as a dependency.
  • Use impose to add your audio to an audio system. You can use these free placeholder sounds either individually or zipped up if you like, or record or create your own sounds! (Or you can skip sounds altogether, really).
  • Create a Window
  • IN YOUR MAIN GAME LOOP...
    • Gather any keyboard/mouse input from the Window you created, and then coalesce it into a persistent PlayerInput.
      • Every ~15ms, send the coalesced input to the server and reset your input
      • If the player wants to quit, here's the place to break out of the game loop
    • Get all the pending GameStates from the server.
      • FOR EACH GAME STATE (which represents the state of one frame)
      • Process all the PlayerStates into some local collection(s) that represent the client's view of players and their graphics.
      • Play sounds as desired, based on player events
    • Loop through your local state storage and draw a frame that represents the latest state of the players. ...

Challenges!

Here are some things we will NOT do together in the tutorial. If you are ahead of the class, or want to keep going after the class, here's some challenges you could take on!

  • Multiple players from one client - The server and networking protocol do not prevent a single client from adding multiple players to the game. Create some way to divide the keyboard/mouse input up among two or more local players who will play through the same client.
  • AI - Who says a human has to do the playing? The server is giving you all the information about all the players's states. Use that information to develop an AI player who plays by himself.
  • RTS - Who says you have to control everything yourself? Combine one or both of the above challenges to implement a real-time strategy interface, where you direct one (or more) players controlled by your client to achieve a goal (move somewhere, attack things, run away, etc) and then your controlled players autonomously attempt to achieve that goal until you specify otherwise.
  • Better Graphics - Improve on the graphics. Either make better use of the provided shapes to indicate more of what is going on, or dig into the RSA gfx.rs module and augment it with new and better graphical capabilities. Health indicators sure would be nice.
  • Better Sound - The sound library we used is pretty limited. Add new sounds, or improve the underlying sound system. The sound library that impose uses is called rodio -- you could use it directly. Or you could switch to a similar, but better high-level library like ears.
  • Improve Rusty Sword Arena Itself -- Fork Rusty Sword Arena. Add features, or fix bugs in the server.
    • Improve the reference client implementation.
    • Port the graphics subsystem from OpenGL to Vulkan.
    • Add more graphics primitives (rectangles for healthbars, for example).
    • Add the ability to render text.
    • Port the network subsystem from ZeroMQ to nanomsg.
    • Improve the network methods ability to indicate what exactly happened (was the name taken? was the game full?)
    • Port the sound subsystem from impose to something better.
    • Update the documentation to be clearer, more comprehensive, and have more useful links.
    • Add support for Game Modes (Teams? Capture the flag?).
    • Add Weapon Drops.
    • Add the ability to Parry (you can try to attack OR parry - a successful parry causes the attacking player to have a much larger delay than usual before the next attack attempt).
    • Create an issue if you have ideas you want to discuss, or need help.
    • Create a Pull Request if you would like feedback on your code, or if think your change is ready to contribute back to the main project.

Modules

game

Everything in the game module is shared by the server and the client
gfx

The graphics module that will be used by your client
net

The networking module that will be used by your client
timer

A timer module for general use

Constants

VERSION

The current version number. Your client should check this against the version the server sends in GameSettings