Creating a Game with Rust and Bevy - A Step-by-Step Guide

rust bevygamedev indiedev

A concise, step-by-step guide to creating your first game, from setup to gameplay mechanics, using the powerful Rust language and the Bevy game engine.

Introduction

Welcome, brave game developers, to the exciting world of Rust and Bevy! If you're looking to craft a game with performance and safety in mind, you've hitched your wagon to the right star. Here's a whimsical yet comprehensive guide to get you from zero to hero in game development with Rust's modern game engine, Bevy.

Step 1: Setting Up Your Development Environment

Install Rust: If you haven't already, embrace the Rustacean life:
```
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
```
Follow the prompts, and don't forget to source your shell configuration or restart your terminal.
Verify Installation:
```
rustc --version
```
Install Bevy's Prerequisites: Bevy loves some extra tools:
- For Windows, consider WSL or install the Visual Studio build tools.
- On Linux, you might need libasound2-dev or similar for audio.

Step 2: Creating Your Game Project

Initialize a New Rust Project:

cargo new my_bevy_game --bin
cd my_bevy_game

Add Bevy to Your Cargo.toml:

[dependencies]
bevy = "0.11" # Check for the latest version!

Step 3: Your First Bevy App

Edit src/main.rs:

use bevy::prelude::*;
 
fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_system(hello_world)
        .run();
}
 
fn hello_world() {
    println!("Hello, brave new world!");
}

Run Your Project:
```
cargo run
```
If all goes well, you'll see your greeting in the console.

Step 4: Building the Game Basics

Create the Game Loop: Add a system to update game state:

fn setup(mut commands: Commands) {
    commands.spawn(Camera2dBundle::default());
}
 
fn move_player(time: Res<Time>, mut query: Query<&mut Transform, With<Player>>) {
    for mut transform in query.iter_mut() {
        transform.translation.x += 100.0 * time.delta_seconds();
    }
}
 
fn spawn_player(mut commands: Commands) {
    commands.spawn(SpriteBundle {
        sprite: Sprite {
            color: Color::rgb(0.25, 0.25, 0.75),
            custom_size: Some(Vec2::new(50.0, 50.0)),
            ..default()
        },
        ..default()
    }).insert(Player);
}
 
struct Player;
 
fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_startup_system(setup)
        .add_startup_system(spawn_player)
        .add_system(move_player)
        .run();
}

Step 5: Adding Interaction

Player Input:

fn player_input(keys: Res<Input<KeyCode>>, mut query: Query<&mut Transform, With<Player>>) {
    let mut direction = Vec3::ZERO;
    if keys.pressed(KeyCode::Left) {
        direction.x -= 1.0;
    }
    if keys.pressed(KeyCode::Right) {
        direction.x += 1.0;
    }
    // Normalize and update player position
    if direction != Vec3::ZERO {
        direction = direction.normalize();
    }
    for mut transform in query.iter_mut() {
        transform.translation += direction * 200.0 * TIME_STEP;
    }
}
 
const TIME_STEP: f32 = 1.0 / 60.0;
 
// Update the main function to include this system

Step 6: Debugging and Optimization

Use Bevy's Diagnostic Tools: Add plugins for frame time diagnostics to see how your game performs.

Step 7: From Prototype to Game

Assets Management: Use Bevy's asset system to load sprites, sounds, etc.
UI: Implement a simple UI for game state display.

Build for Release:
```
cargo build --release
```
Distribute: Package your game for different platforms. Remember, Rust makes cross-compilation a breeze!

Conclusion

Congratulations! You've navigated through the cosmos of game development with Rust and Bevy. From setting up your environment to creating interactive gameplay, you're now equipped to expand this into a full-fledged game. Remember, in the universe of game development, the only limit is your imagination (and perhaps Rust's borrow checker, but you'll learn to love it).

Keep iterating, keep debugging, and most importantly, keep having fun. Game on!