entity_data

A container for entity component data.

An entity is an opaque identifier for an object. Each entity can have multiple components associated with it. Storage is based on ECS technique, but the main purpose is to efficiently store and access individual components without Boxing them.

The approach used in this library is superior to Rust's dynamic dispatch because components can have their separate fields and components of the same type are stored in a contiguous vector.

Example

```rust use entitydata::EntityStorageLayout; use entitydata::EntityStorage; use entitydata::entitystate;

struct Barks { bark_sound: String, }

impl Barks { fn bark(&self) { println!("{}", self.bark_sound); } }

[derive(Clone)]

struct Eats { eaten_food: Vec, }

impl Eats { fn eat(&mut self, food: String) { self.eaten_food.push(food); } }

struct Dog { favorite_food: String, }

struct Bird { weight: f32, habitat: String, }

fn main() { let mut layout = EntityStorageLayout::new(); let typedog = layout.addarchetype().with::().with::().with::().build(); let typebird = layout.addarchetype().with::().with::().build();

let mut storage = EntityStorage::new(&layout);

let eats = Eats { eaten_food: vec![] };

let super_dog = storage.add_entity(type_dog, entity_state!(
    Dog = Dog { favorite_food: "meat".to_string(), },
    Eats = eats.clone(),
    Barks = Barks { bark_sound: "bark.ogg".to_string() },
));

let hummingbird = storage.add_entity(type_bird, entity_state!(
    Bird = Bird { weight: 0.07, habitat: "gardens".to_string() },
    Eats = eats
));


let super_dog_barks = storage.get::<Barks>(&super_dog).unwrap();
super_dog_barks.bark();

let super_dog_props = storage.get_mut::<Dog>(&super_dog).unwrap();
super_dog_props.favorite_food = "beans".to_string();

let hummingbird_eats = storage.get_mut::<Eats>(&hummingbird).unwrap();
hummingbird_eats.eat("seeds".to_string());

} ```