Struct JoinIndex 

pub struct JoinIndex { /* private fields */ }

Entity to component-row index: which components an entity has, and where each one’s row sits in its column.

Implementations

impl JoinIndex

pub fn new() -> JoinIndex

An empty index.

pub fn set(&mut self, entity: Entity, id: ComponentId, row: u32)

Record that entity has component id, stored at row in that component’s column. If entity is a fresh occupant of its index (first use, or a recycled index), the previous occupant’s state is dropped first.

pub fn clear(&mut self, entity: Entity, id: ComponentId)

Forget that entity has component id. Frees the index slot once the entity has no components left, so the index reads as unused again.

pub fn clear_entity(&mut self, entity: Entity)

Forget every component of entity. Called when the entity is despawned.

pub fn mask(&self, entity: Entity) -> ComponentMask

The set of components entity has. An empty mask for a stale handle.

pub fn row(&self, entity: Entity, id: ComponentId) -> Option<u32>

The row of entity in component id’s column, or None if it lacks that component (or the handle is stale).

pub fn matches( &self, entity: Entity, required: ComponentMask, excluded: ComponentMask, ) -> bool

Whether entity has all of required and none of excluded.

Trait Implementations

impl Debug for JoinIndex

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for JoinIndex

fn default() -> JoinIndex

Returns the “default value” for a type.