diff options
Diffstat (limited to 'ecs/src')
| -rw-r--r-- | ecs/src/component/storage.rs | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/ecs/src/component/storage.rs b/ecs/src/component/storage.rs index 53b1168..cb219f1 100644 --- a/ecs/src/component/storage.rs +++ b/ecs/src/component/storage.rs @@ -127,10 +127,6 @@ impl Storage archetype.push_entity(entity_uid, components); - archetype - .entity_lookup - .insert(entity_uid, archetype.entities.len() - 1); - self.entity_archetype_lookup .insert(entity_uid, archetype_id); @@ -386,6 +382,7 @@ pub struct Archetype { component_ids: HashMap<Uid, usize>, entity_lookup: HashMap<Uid, usize>, + entity_uid_lookup: Vec<Uid>, entities: Vec<ArchetypeEntity>, } @@ -400,6 +397,7 @@ impl Archetype .map(|(index, component_id)| (component_id, index)) .collect(), entity_lookup: HashMap::new(), + entity_uid_lookup: Vec::new(), entities: Vec::new(), } } @@ -458,21 +456,32 @@ impl Archetype uid: entity_uid, components: components.into_iter().map(Into::into).collect(), }); + + let index = self.entities.len() - 1; + + self.entity_lookup.insert(entity_uid, index); + + self.entity_uid_lookup.push(entity_uid); } pub fn take_entity(&mut self, entity_uid: Uid) -> Option<ArchetypeEntity> { let entity_index = self.entity_lookup.remove(&entity_uid)?; - let entity = self.entities.remove(entity_index); + let last_entity_uid = *self + .entity_uid_lookup + .get(self.entities.len() - 1) + .expect("Entity UID lookup contains too few entity UIDS"); - for index in self.entity_lookup.values_mut() { - if *index > entity_index { - *index -= 1; - } - } + // By using swap_remove, no memory reallocation occurs and only one index in the + // entity lookup needs to be updated + let removed_entity = self.entities.swap_remove(entity_index); + + self.entity_lookup.insert(last_entity_uid, entity_index); + + self.entity_uid_lookup.swap_remove(entity_index); - Some(entity) + Some(removed_entity) } } |