ecs-rust

ecu-rust is a tiny toy ECS (Entity Component System) library written in Rust.

Online demos

Online WebAssembly demos

Rust code is compiled to WebAssembly with wasm-bindgen and it runs even in web browsers.

Features

• Tiny ECS library
• Easy to use
• Memory safe with Rust
• Offers a clean design with ECS
• Web application compatible by compiling to WebAssembly

Documents

T.B.D.

Sample Code

```Rust // Import ecs-rust use ecsrust::world::World; use ecsrust::entitymanager::EntityManager; use ecsrust::component::Component; use ecs_rust::system::System;

// Define Components and Systems

struct Namable { name: &'static str }

struct Position { x: f32, y: f32 }

struct Velocity { x: f32, y: f32 }

struct Step { num: u32 }

struct PrintStepSystem; struct MoveSystem; struct PrintPositionSystem;

// Implement Components and Systems

impl Component for Namable {} impl Component for Position {} impl Component for Velocity {} impl Component for Step {}

impl System for PrintStepSystem { fn update(&mut self, manager: &mut EntityManager) { let steps = manager.borrowcomponentsmut::().unwrap(); for step in steps.iter_mut() { step.num += 1; println!("Step {}", step.num); } } }

impl System for MoveSystem { fn update(&mut self, manager: &mut EntityManager) { let entityids = manager.getentityidsforpair::(); for id in entityids.iter() { let (velocity, mut position) = manager.borrowcomponentpair_mut::(*id).unwrap(); position.x += velocity.x; position.y += velocity.y; } } }

impl System for PrintPositionSystem { fn update(&mut self, manager: &mut EntityManager) { let entityids = manager.getentityidsforpair::(); for id in entityids.iter() { let name = manager.borrowcomponent::(*id).unwrap(); let position = manager.borrowcomponent::(*id).unwrap(); println!("{} is at ({}, {})", name.name, position.x, position.y); } } }

// Build an application and Run

fn main() { // Create world let mut world = World::new();

// Register Components to world world .registercomponent::() .registercomponent::() .registercomponent::() .registercomponent::();

// Create Entities and add Components to them { let entityid = world.createentity(); world.addcomponenttoentity(entityid, Step {num: 0}); }

{ let entityid = world.createentity(); world .addcomponenttoentity(entityid, Namable {name: "Alice"}) .addcomponenttoentity(entityid, Position {x: 0.0, y: 0.0}) .addcomponenttoentity(entityid, Velocity {x: 1.0, y: 2.0}); }

{ let entityid = world.createentity(); world .addcomponenttoentity(entityid, Namable {name: "Bob"}) .addcomponenttoentity(entityid, Position {x: 0.0, y: 0.0}) .addcomponenttoentity(entityid, Velocity {x: -2.0, y: 1.0}); }

{ // Unmovable let entityid = world.createentity(); world .addcomponenttoentity(entityid, Namable {name: "Rock"}) .addcomponenttoentity(entityid, Position {x: 0.0, y: 0.0}); }

// Add Systems to world world .addsystem(PrintStepSystem {}) .addsystem(MoveSystem {}) .add_system(PrintPositionSystem {});

// Run for _i in 0..3 { world.update(); } }

/* * Result: * Step 1 * Alice is at (1, 2) * Bob is at (-2, 1) * Rock is at (0, 0) * Step 2 * Alice is at (2, 4) * Bob is at (-4, 2) * Rock is at (0, 0) * Step 3 * Alice is at (3, 6) * Bob is at (-6, 3) * Rock is at (0, 0) */ ```

How to import

The library is released at crates.io. Add the following line into Cargo.toml of your Rust project.

[dependencies] ecs_rust = "0.0.2"

And add the following lines in your Rust code to import the library.

Rust use ecs_rust::world::World; use ecs_rust::entity_manager::EntityManager; use ecs_rust::component::Component; use ecs_rust::system::System;

How to build the library locally

sh $ git clone https://github.com/takahirox/ecs-rust.git $ cd ecs-rust $ cargo build

How to run desktop examples locally

sh $ cd ecs-rust $ cargo run --example example_name

How to run web examles locally

Prerequirements - Install wasm-bindgen client - Install Rust wasm32-unknown-unknown target with $ rustup target add wasm32-unknown-unknown - Install http-server with $ npm install -g http-server, or other local servers

```sh $ cd ecs-rust/web $ bash build_examples.sh $ http-server . -p 8080 -c-1

Access http://localhost:8080/examples/index.html on your web browser

```

How to run tests

T.B.D.