fireblade-ecs/Sources/FirebladeECS/Nexus.swift

119 lines
4.7 KiB
Swift

//
// Nexus.swift
// FirebladeECS
//
// Created by Christian Treffs on 09.10.17.
//
public final class Nexus {
/// Static version string.
public static let version: String = "1.0.0"
/// Main entity storage.
/// Entities are tightly packed by EntityIdentifier.
@usableFromInline final var entityStorage: UnorderedSparseSet<EntityIdentifier>
/// Entity ids that are currently not used.
@usableFromInline final var freeEntities: [EntityIdentifier]
/// - Key: ComponentIdentifier aka component type.
/// - Value: Array of component instances of same type (uniform).
/// New component instances are appended.
@usableFromInline final var componentsByType: [ComponentIdentifier: UnorderedSparseSet<Component>]
/// - Key: EntityIdentifier aka entity index
/// - Value: Set of unique component types (ComponentIdentifier).
/// Each element is a component identifier associated with this entity.
@usableFromInline final var componentIdsByEntity: [EntityIdentifier: Set<ComponentIdentifier>]
/// - Key: A parent entity id.
/// - Value: Adjacency Set of all associated children.
@usableFromInline final var childrenByParentEntity: [EntityIdentifier: Set<EntityIdentifier>]
/// - Key: FamilyTraitSet aka component types that make up one distinct family.
/// - Value: Tightly packed EntityIdentifiers that represent the association of an entity to the family.
@usableFromInline final var familyMembersByTraits: [FamilyTraitSet: UnorderedSparseSet<EntityIdentifier>]
public final weak var delegate: NexusEventDelegate?
public convenience init() {
self.init(entityStorage: UnorderedSparseSet<EntityIdentifier>(),
componentsByType: [:],
componentsByEntity: [:],
freeEntities: [],
familyMembersByTraits: [:],
childrenByParentEntity: [:])
}
internal init(entityStorage: UnorderedSparseSet<EntityIdentifier>,
componentsByType: [ComponentIdentifier: UnorderedSparseSet<Component>],
componentsByEntity: [EntityIdentifier: Set<ComponentIdentifier>],
freeEntities: [EntityIdentifier],
familyMembersByTraits: [FamilyTraitSet: UnorderedSparseSet<EntityIdentifier>],
childrenByParentEntity: [EntityIdentifier: Set<EntityIdentifier>]) {
self.entityStorage = entityStorage
self.componentsByType = componentsByType
self.componentIdsByEntity = componentsByEntity
self.freeEntities = freeEntities
self.familyMembersByTraits = familyMembersByTraits
self.childrenByParentEntity = childrenByParentEntity
}
deinit {
clear()
}
public final func clear() {
entityStorage.forEach { destroy(entityId: $0) }
entityStorage.removeAll()
freeEntities.removeAll()
componentsByType.removeAll()
componentIdsByEntity.removeAll()
familyMembersByTraits.removeAll()
childrenByParentEntity.removeAll()
}
public static var knownUniqueComponentTypes: Set<ComponentIdentifier> {
return Set<ComponentIdentifier>(componentDecoderMap.keys)
}
internal static var componentDecoderMap: [ComponentIdentifier: (Decoder) throws -> Component] = [:]
/// Register a component type uniquely with the Nexus implementation.
/// - Parameters:
/// - componentType: The component meta type.
/// - identifier: The unique identifier.
internal static func register<C>(component componentType: C.Type, using identifier: ComponentIdentifier) where C: Component {
precondition(componentDecoderMap[identifier] == nil, "Component type collision: \(identifier) already in use.")
componentDecoderMap[identifier] = { try C(from: $0) }
}
}
// MARK: - Errors
extension Nexus {
public enum Error: Swift.Error {
case versionMismatch(required: String, provided: String)
}
}
// MARK: - Equatable
extension Nexus: Equatable {
@inlinable
public static func == (lhs: Nexus, rhs: Nexus) -> Bool {
return lhs.entityStorage == rhs.entityStorage &&
lhs.componentIdsByEntity == rhs.componentIdsByEntity &&
lhs.freeEntities == rhs.freeEntities &&
lhs.familyMembersByTraits == rhs.familyMembersByTraits &&
lhs.componentsByType.keys == rhs.componentsByType.keys &&
lhs.childrenByParentEntity == rhs.childrenByParentEntity
// NOTE: components are not equatable (yet)
}
}
// MARK: - CustomDebugStringConvertible
extension Nexus: CustomDebugStringConvertible {
public var debugDescription: String {
return "<Nexus entities:\(numEntities) components:\(numComponents) families:\(numFamilies)>"
}
}