baitcenter / ggez

Rust library to create a Good Game Easily

What is this?

ggez is a Rust library to create a Good Game Easily.

More specifically, ggez is a lightweight cross-platform game framework for making 2D games with minimum friction. It aims to implement an API based on (a Rustified version of) the LÖVE game framework. This means it contains basic and portable 2D drawing, sound, resource loading and event handling, but finer details and performance characteristics may be different than LÖVE.

ggez is not meant to be everything to everyone, but rather a good base upon which to build. Thus it takes a fairly batteries-included approach without needing a million additions and plugins for everything imaginable, but also does not dictate higher-level functionality such as physics engine or entity component system. Instead the goal is to allow you to use whichever libraries you want to provide these functions, or build your own libraries atop ggez.

Features

• Filesystem abstraction that lets you load resources from folders or zip files
• Hardware-accelerated 2D rendering built on the gfx-rs graphics engine
• Loading and playing .ogg, .wav and .flac files via the rodio crate
• TTF font rendering with rusttype and glyph_brush.
• Interface for handling keyboard and mouse events easily through callbacks
• Config file for defining engine and game settings
• Easy timing and FPS measurement functions.
• Math library integration with mint.
• Some more advanced graphics options: shaders, sprite batches and render targets

Supported platforms

• Fully supported: Windows, Linux
• Not officially supported but might work anyway: Mac, iOS
• Work in progress: WebAssembly
• Not officially supported yet (but maybe you can help!): Android

For details, see docs/BuildingForEveryPlatform.md

Who's using ggez?

Check out the projects list!

Usage

ggez requires rustc >= 1.33 and is distributed on crates.io. To include it in your project, just add the dependency line to your Cargo.toml file:

ggez = "0.5"

ggez consists of three main parts: A Context object which contains all the state required to interface with the computer's hardware, an EventHandler trait that the user implements to register callbacks for events, and various sub-modules such as graphics and audio that provide the functionality to actually get stuff done. The general pattern is to create a struct holding your game's data which implements the EventHandler trait. Create a new Context object with default objects from a ContextBuilder or Conf object, and then call event::run() with the Context and an instance of your EventHandler to run your game's main loop.

See the API docs for full documentation, or the examples directory for a number of commented examples of varying complexity. Most examples show off a single feature of ggez, while astroblasto and snake are a small but complete games.

Getting started

For a quick tutorial on ggez, see the Hello ggez guide in the docs/ directory.

Examples

See the examples/ directory in the source. Most examples show off a single feature of ggez, while astroblasto is a small but complete Asteroids-like game.

To run the examples, just check out the source and execute cargo run --example in the root directory:

git clone https://github.com/ggez/ggez.git
cd ggez
cargo run --example 05_astroblasto

If this doesn't work, see the FAQ for solutions to common problems.

Basic Project Template

use ggez::{graphics, Context, ContextBuilder, GameResult};
use ggez::event::{self, EventHandler};

fn main() {
    // Make a Context.
    let (mut ctx, mut event_loop) = ContextBuilder::new("my_game", "Cool Game Author")
		.build()
		.expect("aieee, could not create ggez context!");

    // Create an instance of your event handler.
    // Usually, you should provide it with the Context object to
    // use when setting your game up.
    let mut my_game = MyGame::new(&mut ctx);

    // Run!
    match event::run(&mut ctx, &mut event_loop, &mut my_game) {
        Ok(_) => println!("Exited cleanly."),
        Err(e) => println!("Error occured: {}", e)
    }
}

struct MyGame {
    // Your state here...
}

impl MyGame {
    pub fn new(_ctx: &mut Context) -> MyGame {
        // Load/create resources such as images here.
        MyGame {
		    // ...
		}
    }
}

impl EventHandler for MyGame {
    fn update(&mut self, _ctx: &mut Context) -> GameResult<()> {
        // Update code here...
		Ok(())
    }

    fn draw(&mut self, ctx: &mut Context) -> GameResult<()> {
		graphics::clear(ctx, graphics::WHITE);
        // Draw code here...
		graphics::present(ctx)
    }
}

Implementation details

ggez is built upon winit for windowing and events, rodio for sound, and a 2D drawing engine implemented in gfx using the OpenGL backend (which currently defaults to use OpenGL 3.2). It is entirely thread-safe (though platform constraints mean the event-handling loop and drawing must be done in the main thread), and portable to Windows and Linux.

ggez is Pure Rust(tm).

Help!

Sources of information:

• The FAQ has answers to common questions and problems.
• The API docs, a lot of design stuff is explained there.
• Check out the examples.

If you still have problems or questions, feel free to ask! Easiest ways are:

• open an issue on the Github issue tracker
• say hi on the unofficial Rust Discord server