fireblade-ecs/Sources/FirebladeECS/Family.swift

70 lines
1.9 KiB
Swift

//
// Family.swift
//
//
// Created by Christian Treffs on 21.08.19.
//
public struct Family<R> where R: ComponentsProviding {
@usableFromInline unowned let nexus: Nexus
public let traits: FamilyTraitSet
public init(nexus: Nexus, requiresAll: @autoclosure () -> (R.ComponentTypes), excludesAll: [Component.Type]) {
let required = R(requiresAll())
self.nexus = nexus
traits = FamilyTraitSet(requiresAll: required.componentTypes, excludesAll: excludesAll)
}
@inlinable public var memberIds: UnorderedSparseSet<EntityIdentifier> {
return nexus.members(withFamilyTraits: traits)
}
@inlinable public var count: Int {
return memberIds.count
}
@inlinable public var isEmpty: Bool {
return memberIds.isEmpty
}
@inlinable public var entities: FamilyEntities {
return FamilyEntities(nexus, memberIds)
}
@inlinable
public func canBecomeMember(_ entity: Entity) -> Bool {
return nexus.canBecomeMember(entity, in: traits)
}
@inlinable
public func isMember(_ entity: Entity) -> Bool {
return nexus.isMember(entity, in: traits)
}
}
extension Family {
public struct FamilyIterator: IteratorProtocol {
@usableFromInline var memberIdsIterator: UnorderedSparseSetIterator<EntityIdentifier>
@usableFromInline unowned let nexus: Nexus
public init(family: Family<R>) {
self.nexus = family.nexus
memberIdsIterator = family.memberIds.makeIterator()
}
public mutating func next() -> R.Components? {
guard let entityId: EntityIdentifier = memberIdsIterator.next() else {
return nil
}
return R.getComponents(nexus: nexus, entityId: entityId)
}
}
}
extension Family: Sequence {
__consuming public func makeIterator() -> FamilyIterator {
return FamilyIterator(family: self)
}
}