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

119 lines
4.3 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)
return family(with: traits)
}
public func family(with traits: FamilyTraitSet) -> Family {
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 componentIds: ComponentIdentifiers = componentIdsByEntity[entityIdx] else {
assert(false, "no component set defined for entity: \(entity)")
return false
}
// FIXME: may be a bottle neck
let componentSet: ComponentSet = ComponentSet.init(componentIds)
return family.traits.isMatch(components: componentSet)
}
public func members(of family: Family) -> UniformEntityIdentifiers {
let traitHash: FamilyTraitSetHash = family.traits.hashValue
return familyMembersByTraitHash[traitHash] ?? UniformEntityIdentifiers() // FIXME: fail?
}
public func isMember(_ entity: Entity, in family: Family) -> Bool {
return isMember(entity.identifier, in: family)
}
public func isMember(_ entityId: EntityIdentifier, in family: Family) -> Bool {
let traitHash: FamilyTraitSetHash = family.traits.hashValue
guard let members: UniformEntityIdentifiers = familyMembersByTraitHash[traitHash] else { return false }
return members.has(entityId.index)
}
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)")
// FIXME: this is costly for many entities
for entity: Entity in entityStorage {
update(membership: family, for: entity.identifier)
}
notify(FamilyCreated(family: traits))
return family
}
// FIXME: remove families?!
// MARK: - update family membership
fileprivate func calculateTraitEntityIdHash(traitHash: FamilyTraitSetHash, entityIdx: EntityIndex) -> TraitEntityIdHash {
return hash(combine: traitHash, entityIdx)
}
func update(membership family: Family, for entityId: EntityIdentifier) {
let entityIdx: EntityIndex = entityId.index
let traits: FamilyTraitSet = family.traits
let traitHash: FamilyTraitSetHash = traits.hashValue
guard let componentIds: ComponentIdentifiers = componentIdsByEntity[entityIdx] else { return }
let is_Member: Bool = isMember(entityId, in: family)
let componentsSet: ComponentSet = ComponentSet.init(componentIds)
let isMatch: Bool = traits.isMatch(components: componentsSet)
switch (isMatch, is_Member) {
case (true, false):
add(to: traitHash, entityId: entityId, entityIdx: entityIdx)
notify(FamilyMemberAdded(member: entityId, to: traits))
case (false, true):
remove(from: traitHash, entityId: entityId, entityIdx: entityIdx)
notify(FamilyMemberRemoved(member: entityId, from: traits))
default:
break
}
}
fileprivate func add(to traitHash: FamilyTraitSetHash, entityId: EntityIdentifier, entityIdx: EntityIndex) {
if familyMembersByTraitHash[traitHash] == nil {
familyMembersByTraitHash[traitHash] = UniformEntityIdentifiers()
}
familyMembersByTraitHash[traitHash]!.add(entityId, at: entityIdx)
}
fileprivate func remove(from traitHash: FamilyTraitSetHash, entityId: EntityIdentifier, entityIdx: EntityIndex) {
familyMembersByTraitHash[traitHash]?.remove(at: entityIdx)
}
}