Struct rin::ecs::operators::Ref

pub struct Ref<'a, T, R> where
    T: NToOneComponent<'a>,  { /* fields omitted */ }

Applies a component in another entity referenced through a component that Derefs to an Entity:

Entity A                           Entity C
Component(Entity) ───────────────► AnotherCompoenent
                                     ▲
                                     │
Entity B                             │
Component(Entity)  ──────────────────┘

Allows to create NToOne relations between entities components.

When the referenced operator accesses the component mutably, an iterator over Ref will return a StreamingIterator which can’t be used in for loops and instead has to be used with .for_each or .for_each_mut. The operations available on this iterators are also limited.

This is to ensure that two or more mutable references to the same data won’t be kept simultaneously. If you are only using the iterator in a for loop or similar and not keeping the returned mutable references then any of the unsafe_iter_mut methods in entities or storages can be used safely.

In the following example we create 2 entities that share a common geometry then access the geometry for each entity:

#[derive(Debug)]
struct Vertex;
#[derive(NToOneComponent, Debug)]
struct GeometryRef(Entity);

#[derive(Component, Debug)]
struct Geometry(Vec<Vertex>);

#[derive(Component, Debug)]
struct Position{x: f32, y: f32};

let mut world = World::new();
let geometry = world.new_entity().add(Geometry(vec![Vertex, Vertex, Vertex])).build();
let a = world.new_entity()
    .add(GeometryRef(geometry))
    .add(Position{x: 0.0, y: 0.0})
    .build();
let b = world.new_entity()
    .add(GeometryRef(geometry))
    .add(Position{x: 0.0, y: 0.0})
    .build();
let entities = world.entities();
for geometry in entities.iter_for::<Ref<GeometryRef, Read<Geometry>>>() {

}

Trait Implementations

impl<'a, T, R> DataAccesses for Ref<'a, T, R> where
    T: NToOneComponent<'a>,
    R: DataAccesses, 

pub fn reads() -> Vec<TypeId, Global>

pub fn writes() -> Vec<TypeId, Global>

impl<'a, T, R> Deref for Ref<'a, T, R> where
    T: NToOneComponent<'a>,
    R: UnorderedData<'a>, 

type Target = R

The resulting type after dereferencing.

pub fn deref(&self) -> &R

Dereferences the value.

impl<'a, T, R> DerefMut for Ref<'a, T, R> where
    T: NToOneComponent<'a>,
    R: UnorderedData<'a>, 

pub fn deref_mut(&mut self) -> &mut R

Mutably dereferences the value.

impl<'a, T, R> FromComponent<'a, <R as UnorderedData<'a>>::ComponentsRef> for Ref<'a, T, R> where
    T: NToOneComponent<'a>,
    R: UnorderedData<'a> + FromComponent<'a, <R as UnorderedData<'a>>::ComponentsRef>, 

pub fn from_component(
    component: <R as UnorderedData<'a>>::ComponentsRef
) -> Ref<'a, T, R>

impl<'a, T, R> UnorderedData<'a> for Ref<'a, T, R> where
    T: Deref<Target = Entity> + NToOneComponent<'a>,
    R: UnorderedData<'a>,
    <T as Component>::Storage: for<'s> Storage<'s, T>,
    <<T as Component>::Storage as Storage<'a, T>>::Get: Borrow<T>, 

type Iter = RefIter<'a, <Ref<'a, T, R> as UnorderedData<'a>>::Storage>

type IterMut = RefIterMut<'a, <Ref<'a, T, R> as UnorderedData<'a>>::Storage, <Ref<'a, T, R> as UnorderedData<'a>>::ComponentsRef>

type Components = <R as UnorderedData<'a>>::Components

type ComponentsRef = <R as UnorderedData<'a>>::ComponentsRef

type Storage = RefStorage<'a, ReadGuardRef<'a, <T as Component>::Storage>, T, <R as UnorderedData<'a>>::Storage, <R as UnorderedData<'a>>::Components, RefData, LazyIndexGuard<'a>>

pub fn query_mask<E>(entities: &E) -> Bitmask where
    E: EntitiesStorage, 

pub fn into_iter<E>(
    entities: &'a E
) -> <Ref<'a, T, R> as UnorderedData<'a>>::Iter where
    E: EntitiesStorage, 

pub fn into_iter_mut<E>(
    entities: &'a E
) -> <Ref<'a, T, R> as UnorderedData<'a>>::IterMut where
    E: EntitiesStorage, 

pub fn storage<E>(
    entities: &'a E
) -> Option<<Ref<'a, T, R> as UnorderedData<'a>>::Storage> where
    E: EntitiesStorage, 

impl<'a, T, R> SafeIter<'a> for Ref<'a, T, R> where
    T: NToOneComponent<'a>,
    R: ReadOnlyOp<'a>, 

impl<'a, T, R> SafeStreamingIter<'a> for Ref<'a, T, R> where
    T: NToOneComponent<'a>,