fireblade-ecs/Sources/FirebladeECS/Nexus+Family.swift

106 lines
3.8 KiB
Swift

//
// Nexus+Family.swift
// FirebladeECS
//
// Created by Christian Treffs on 13.10.17.
//
extension Nexus {
/// Gets or creates (new) family with given traits.
///
/// - Parameters:
/// - allComponents: all component types are required in this family.
/// - noneComponents: none component type may appear in this family.
/// - oneComponents: at least one of component types must appear in this family.
/// - Returns: family with given traits.
public func family(requiresAll allComponents: [Component.Type], excludesAll noneComponents: [Component.Type], needsAtLeastOne oneComponents: [Component.Type] = []) -> Family {
let traits = FamilyTraitSet(requiresAll: allComponents, excludesAll: noneComponents, needsAtLeastOne: oneComponents)
guard let family: Family = get(family: traits) else {
return create(family: traits)
}
return family
}
public func canBecomeMember(_ entity: Entity, in family: Family) -> Bool {
let entityIdx: EntityIndex = entity.identifier.index
guard let componentSet: ComponentSet = componentIdsSetByEntity[entityIdx] else {
assert(false, "no component set defined for entity: \(entity)")
return false
}
return family.traits.isMatch(components: componentSet)
}
public func members(of family: Family) -> EntitySet {
let traitHash: FamilyTraitSetHash = family.traits.hashValue
return familyMembersByTraitHash[traitHash] ?? [] // FIXME: fail?
}
public func isMember(_ entity: Entity, in family: Family) -> Bool {
let traitHash: FamilyTraitSetHash = family.traits.hashValue
let entityId = entity.identifier
return familyMembersByTraitHash[traitHash]?.contains(entityId) ?? false
}
fileprivate func get(family traits: FamilyTraitSet) -> Family? {
let traitHash: FamilyTraitSetHash = traits.hashValue
return familiyByTraitHash[traitHash]
}
fileprivate func create(family traits: FamilyTraitSet) -> Family {
let traitHash: FamilyTraitSetHash = traits.hashValue
let family = Family(self, traits: traits)
let replaced = familiyByTraitHash.updateValue(family, forKey: traitHash)
assert(replaced == nil, "Family with exact trait hash already exists: \(traitHash)")
notify(FamilyCreated(family: traits))
// FIXME: update memberships for prior entites
return family
}
// FIXME: remove families?!
// MARK: - update family membership
func update(membership family: Family, for entity: Entity) {
let entityIdx: EntityIndex = entity.identifier.index
guard let componentsSet: ComponentSet = componentIdsSetByEntity[entityIdx] else { return }
let isMatch: Bool = family.traits.isMatch(components: componentsSet)
switch isMatch {
case true:
add(to: family, entity: entity)
case false:
remove(from: family, entity: entity)
}
}
fileprivate func add(to family: Family, entity: Entity) {
let traitHash: FamilyTraitSetHash = family.traits.hashValue
let entityId: EntityIdentifier = entity.identifier
if familyMembersByTraitHash[traitHash] != nil {
let (inserted, _) = familyMembersByTraitHash[traitHash]!.insert(entityId)
assert(inserted, "entity with id \(entityId) already in family")
} else {
familyMembersByTraitHash[traitHash] = EntitySet(minimumCapacity: 2)
familyMembersByTraitHash[traitHash]!.insert(entityId)
}
notify(FamilyMemberAdded(member: entityId, to: family.traits))
}
fileprivate func remove(from family: Family, entity: Entity) {
let traitHash: FamilyTraitSetHash = family.traits.hashValue
let entityId: EntityIdentifier = entity.identifier
guard let removed = familyMembersByTraitHash[traitHash]?.remove(entityId) else {
assert(false, "removing entity id \(entityId) that is not in family \(family)")
report("removing entity id \(entityId) that is not in family \(family)")
return
}
notify(FamilyMemberRemoved(member: removed, from: family.traits))
}
}