A Rust binding for the Flecs ECS library: https://github.com/SanderMertens/flecs
Wraps native Flecs v3.2.1
```rust use flecs::*;
struct Position { x: f32, y: f32, }
struct Walking { }
fn main() { let mut world = World::new();
// We have to manually register all components
world.component::<Position>();
world.component::<Walking>();
// Create an entity with name Bob
let bob = world.entity().named("Bob")
.set(Position { x: 10.0, y: 20.0 })
.add::<Walking>();
// Get the value for the Position component
let pos = bob.get::<Position>();
println!("Bob position: {}, {}", pos.x, pos.y);
// Overwrite the value of the Position component
bob.set(Position { x: 20.0, y: 30.0 });
println!("Bob position: {}, {}", pos.x, pos.y);
// Create another named entity
let alice = world.entity().named("Alice")
.set(Position { x: 10.0, y: 20.0 });
// Add a tag after entity is created
alice.add::<Walking>();
// Print all of the components the entity has. This will output:
// Position, Walking, (Identifier,Name)
println!("Alice type = [ {} ]", alice.type_info().to_str());
// Remove tag
alice.remove::<Walking>();
// Iterate all entities with Position
world.each1(|e: flecs::Entity, p: &Position| {
println!("{}: {}, {}", e.name(), p.x, p.y);
});
} ```
bash
git clone https://github.com/jazzay/flecs-rs
cd flecs-rs
cargo build --release
Main examples are located in the examples directory. These can be run like so:
```bash cargo test
cargo run --example hello_world cargo run --example prefabs ```
Compiling with WebAssembly requires using the wasm32-unknown-emscripten target.
This is because there is no official toolchain for C/C++ targeting wasm32-unknown-unknown, which means that C/C++ bindings with do not work with this target and will result in unresolved symbols.
The Emscripten target which is not as well supported as the wasm32-unknown-unknown, which means that wasm-bindgen and some other popular Rust libraries that target WebAssembly will not work. So be sure to keep that in mind.
Create a directory to be statically served:
bash
mkdir static
Create a file called index.html under static/:
html
<html>
<body>
<script type="module">
import init from './systems.js'
await init()
</script>
</body>
</html>
Emscripten Setup: A specific version of the Emscripten SDK is required. Newer versions will usually cause build or runtime errors.
On Mac you may need to make sure your Python3 SSL certs are setup: https://bugs.python.org/issue43404
make setup_emsdk EMSDK=/your/install/directory
If necessary, you can override the standard library path:
export STDLIB=/usr/include
By default it uses the EMSDK's sysroot for includes.
On some platforms you may get linker errors:
https://stackoverflow.com/questions/67474533/error-in-compiling-rust-into-webassembly-using-emscripten-on-windows
To avoid this run this prior to building: (TODO make this automatic)
bash
emcc -c gxx_personality_v0_stub.cpp
Build WASM binary:
bash
cargo build --example systems --target wasm32-unknown-emscripten
cp ./target/wasm32-unknown-emscripten/debug/examples/systems.js ./static/
cp ./target/wasm32-unknown-emscripten/debug/examples/systems.wasm ./static/
Serve static file locally with any HTTP server tool, for example basic-http-server:
bash
cargo install basic-http-server
basic-http-server ./static/