Merge branch 'feature/entity-identifier' into develop

Sources/FirebladeECS/ComponentIdentifier.swift

@@ -18,7 +18,12 @@ public struct ComponentIdentifier {
 extension ComponentIdentifier {
     @usableFromInline
     init<C>(_ componentType: C.Type) where C: Component {
-        self.hash = Nexus.makeOrGetComponentId(componentType)
+        self.hash = Self.makeRuntimeHash(componentType)
+    }
+
+    /// object identifier hash (only stable during runtime) - arbitrary hash is ok.
+    internal static func makeRuntimeHash<C>(_ componentType: C.Type) -> Hash where C: Component {
+        ObjectIdentifier(componentType).hashValue
     }
 }
 

Sources/FirebladeECS/EntityIdentifier.swift

@@ -21,4 +21,3 @@ public struct EntityIdentifier {
 
 extension EntityIdentifier: Equatable { }
 extension EntityIdentifier: Hashable { }
-extension EntityIdentifier: Codable { }

Sources/FirebladeECS/EntityIdentifierGenerator.swift

@@ -0,0 +1,35 @@
+//
+//  EntityIdentifierGenerator.swift
+//
+//
+//  Created by Christian Treffs on 26.06.20.
+//
+
+internal final class EntityIdentifierGenerator {
+    private var stack: [UInt32]
+
+    var count: Int {
+        stack.count
+    }
+
+    convenience init() {
+        self.init([EntityIdentifier(0)])
+    }
+
+    init(_ entityIds: [EntityIdentifier]) {
+        stack = entityIds.reversed().map { UInt32($0.id) }
+    }
+
+    func nextId() -> EntityIdentifier {
+        if stack.count == 1 {
+            defer { stack[0] += 1 }
+            return EntityIdentifier(stack[0])
+        } else {
+            return EntityIdentifier(stack.removeLast())
+        }
+    }
+
+    func freeId(_ entityId: EntityIdentifier) {
+        stack.append(UInt32(entityId.id))
+    }
+}

Sources/FirebladeECS/Nexus+Entity.swift

@@ -6,20 +6,12 @@
 //
 
 extension Nexus {
-    @inlinable
-    internal func nextEntityId() -> EntityIdentifier {
-        guard let nextReused: EntityIdentifier = freeEntities.popLast() else {
-            return EntityIdentifier(UInt32(entityStorage.count))
-        }
-        return nextReused
-    }
-
     @discardableResult
     public func createEntity() -> Entity {
-        let newEntityIdentifier: EntityIdentifier = nextEntityId()
+        let entityId: EntityIdentifier = entityIdGenerator.nextId()
-        entityStorage.insert(newEntityIdentifier, at: newEntityIdentifier.id)
+        entityStorage.insert(entityId, at: entityId.id)
-        delegate?.nexusEvent(EntityCreated(entityId: newEntityIdentifier))
+        delegate?.nexusEvent(EntityCreated(entityId: entityId))
-        return Entity(nexus: self, id: newEntityIdentifier)
+        return Entity(nexus: self, id: entityId)
     }
 
     @discardableResult
@@ -67,7 +59,7 @@ extension Nexus {
             update(familyMembership: entityId)
         }
 
-        freeEntities.append(entityId)
+        entityIdGenerator.freeId(entityId)
 
         delegate?.nexusEvent(EntityDestroyed(entityId: entityId))
         return true

Sources/FirebladeECS/Nexus.swift

@@ -11,7 +11,7 @@ public final class Nexus {
     @usableFromInline final var entityStorage: UnorderedSparseSet<EntityIdentifier, EntityIdentifier.Id>
 
     /// Entity ids that are currently not used.
-    @usableFromInline final var freeEntities: [EntityIdentifier]
+    let entityIdGenerator: EntityIdentifierGenerator
 
     /// - Key: ComponentIdentifier aka component type.
     /// - Value: Array of component instances of same type (uniform).
@@ -37,7 +37,7 @@ public final class Nexus {
         self.init(entityStorage: UnorderedSparseSet<EntityIdentifier, EntityIdentifier.Id>(),
                   componentsByType: [:],
                   componentsByEntity: [:],
-                  freeEntities: [],
+                  entityIdGenerator: EntityIdentifierGenerator(),
                   familyMembersByTraits: [:],
                   childrenByParentEntity: [:])
     }
@@ -45,15 +45,15 @@ public final class Nexus {
     internal init(entityStorage: UnorderedSparseSet<EntityIdentifier, EntityIdentifier.Id>,
                   componentsByType: [ComponentIdentifier: ManagedContiguousArray<Component>],
                   componentsByEntity: [EntityIdentifier: Set<ComponentIdentifier>],
-                  freeEntities: [EntityIdentifier],
+                  entityIdGenerator: EntityIdentifierGenerator,
                   familyMembersByTraits: [FamilyTraitSet: UnorderedSparseSet<EntityIdentifier, EntityIdentifier.Id>],
                   childrenByParentEntity: [EntityIdentifier: Set<EntityIdentifier>]) {
         self.entityStorage = entityStorage
         self.componentsByType = componentsByType
         self.componentIdsByEntity = componentsByEntity
-        self.freeEntities = freeEntities
         self.familyMembersByTraits = familyMembersByTraits
         self.childrenByParentEntity = childrenByParentEntity
+        self.entityIdGenerator = entityIdGenerator
     }
 
     deinit {
@@ -63,34 +63,11 @@ public final class Nexus {
     public final func clear() {
         entityStorage.forEach { destroy(entityId: $0) }
         entityStorage.removeAll()
-        freeEntities.removeAll()
         componentsByType.removeAll()
         componentIdsByEntity.removeAll()
         familyMembersByTraits.removeAll()
         childrenByParentEntity.removeAll()
     }
-
-    @available(swift, deprecated: 0.12.0)
-    public static var knownUniqueComponentTypes: Set<ComponentIdentifier> {
-        Set<ComponentIdentifier>(stableComponentIdentifierMap.keys.map { ComponentIdentifier(hash: $0) })
-    }
-}
-
-// MARK: - centralized component identifier mapping
-extension Nexus {
-    internal static var stableComponentIdentifierMap: [ComponentIdentifier.Hash: ComponentIdentifier.StableId] = [:]
-
-    internal static func makeOrGetComponentId<C>(_ componentType: C.Type) -> ComponentIdentifier.Hash where C: Component {
-        /// object identifier hash (only stable during runtime) - arbitrary hash is ok.
-        let objIdHash = ObjectIdentifier(componentType).hashValue
-        // if we do not know this component type yet - we register a stable identifier generator for it.
-        if stableComponentIdentifierMap[objIdHash] == nil {
-            let string = String(describing: C.self)
-            let stableHash = StringHashing.singer_djb2(string)
-            stableComponentIdentifierMap[objIdHash] = stableHash
-        }
-        return objIdHash
-    }
 }
 
 // MARK: - CustomDebugStringConvertible

Tests/FirebladeECSTests/EntityTests.swift

@@ -31,14 +31,56 @@ class EntityTests: XCTestCase {
 
         let entity = nexus.createEntity()
         entity.assign(pos)
-        entity.assign(name)
+        entity.assign(name, vel)
-        entity.assign(vel)
 
         let expectedComponents: [Component] = [pos, name, vel]
         let allComponents = entity.allComponents()
 
         XCTAssertTrue(allComponents.elementsEqualUnordered(expectedComponents) { $0 === $1 })
     }
+
+    func testEntityEquality() {
+        let nexus = Nexus()
+
+        let entityA = nexus.createEntity()
+        let entityB = nexus.createEntity()
+
+        XCTAssertEqual(entityA, entityA)
+        XCTAssertNotEqual(entityA, entityB)
+    }
+
+    func testRemoveAllComponentsFromEntity() {
+        let nexus = Nexus()
+
+        let entity = nexus.createEntity(with: Position(x: 1, y: 2), Name(name: "MyEntity"))
+        XCTAssertEqual(entity.numComponents, 2)
+        entity.removeAll()
+        XCTAssertEqual(entity.numComponents, 0)
+    }
+
+    func testEntityIdGenerator() {
+        let generator = EntityIdentifierGenerator()
+
+        XCTAssertEqual(generator.count, 1)
+
+        for _ in 0..<100 {
+            _ = generator.nextId()
+        }
+
+        XCTAssertEqual(generator.count, 1)
+
+        for i in 10..<60 {
+            generator.freeId(EntityIdentifier(UInt32(i)))
+        }
+
+        XCTAssertEqual(generator.count, 51)
+
+        for _ in 0..<50 {
+            _ = generator.nextId()
+        }
+
+        XCTAssertEqual(generator.count, 1)
+    }
 }
 
 extension Sequence {

Tests/FirebladeECSTests/SystemsTests.swift

@@ -38,7 +38,7 @@ class SystemsTests: XCTestCase {
         XCTAssertEqual(nexus.numEntities, 0)
         XCTAssertEqual(colorSystem.colors.memberIds.count, 0)
         XCTAssertEqual(positionSystem.positions.memberIds.count, 0)
-        XCTAssertEqual(nexus.freeEntities.count, 0)
+        XCTAssertEqual(nexus.entityIdGenerator.count, 1)
         XCTAssertEqual(nexus.familyMembersByTraits[posTraits]?.count, 0)
 
         batchCreateEntities(count: num)
@@ -47,7 +47,7 @@ class SystemsTests: XCTestCase {
         XCTAssertEqual(nexus.familyMembersByTraits[posTraits]?.count, num)
         XCTAssertEqual(colorSystem.colors.memberIds.count, num)
         XCTAssertEqual(positionSystem.positions.memberIds.count, num)
-        XCTAssertEqual(nexus.freeEntities.count, 0)
+        XCTAssertEqual(nexus.entityIdGenerator.count, 1)
 
         colorSystem.update()
         positionSystem.update()
@@ -56,7 +56,7 @@ class SystemsTests: XCTestCase {
         XCTAssertEqual(nexus.familyMembersByTraits[posTraits]?.count, num)
         XCTAssertEqual(colorSystem.colors.memberIds.count, num)
         XCTAssertEqual(positionSystem.positions.memberIds.count, num)
-        XCTAssertEqual(nexus.freeEntities.count, 0)
+        XCTAssertEqual(nexus.entityIdGenerator.count, 1)
 
         batchCreateEntities(count: num)
 
@@ -64,7 +64,7 @@ class SystemsTests: XCTestCase {
         XCTAssertEqual(nexus.familyMembersByTraits[posTraits]?.count, num * 2)
         XCTAssertEqual(colorSystem.colors.memberIds.count, num * 2)
         XCTAssertEqual(positionSystem.positions.memberIds.count, num * 2)
-        XCTAssertEqual(nexus.freeEntities.count, 0)
+        XCTAssertEqual(nexus.entityIdGenerator.count, 1)
 
         colorSystem.update()
         positionSystem.update()
@@ -73,12 +73,12 @@ class SystemsTests: XCTestCase {
         XCTAssertEqual(nexus.familyMembersByTraits[posTraits]?.count, num * 2)
         XCTAssertEqual(colorSystem.colors.memberIds.count, num * 2)
         XCTAssertEqual(positionSystem.positions.memberIds.count, num * 2)
-        XCTAssertEqual(nexus.freeEntities.count, 0)
+        XCTAssertEqual(nexus.entityIdGenerator.count, 1)
 
         batchDestroyEntities(count: num)
 
         XCTAssertEqual(nexus.familyMembersByTraits[posTraits]?.count, num)
-        XCTAssertEqual(nexus.freeEntities.count, num)
+        XCTAssertEqual(nexus.entityIdGenerator.count, 1 + num)
         XCTAssertEqual(nexus.numEntities, num)
         XCTAssertEqual(colorSystem.colors.memberIds.count, num)
         XCTAssertEqual(positionSystem.positions.memberIds.count, num)
@@ -90,7 +90,7 @@ class SystemsTests: XCTestCase {
         XCTAssertEqual(nexus.numEntities, num)
         XCTAssertEqual(colorSystem.colors.memberIds.count, num)
         XCTAssertEqual(positionSystem.positions.memberIds.count, num)
-        XCTAssertEqual(nexus.freeEntities.count, num)
+        XCTAssertEqual(nexus.entityIdGenerator.count, 1 + num)
 
         batchCreateEntities(count: num)
 
@@ -98,7 +98,7 @@ class SystemsTests: XCTestCase {
         XCTAssertEqual(nexus.numEntities, num * 2)
         XCTAssertEqual(colorSystem.colors.memberIds.count, num * 2)
         XCTAssertEqual(positionSystem.positions.memberIds.count, num * 2)
-        XCTAssertEqual(nexus.freeEntities.count, 0)
+        XCTAssertEqual(nexus.entityIdGenerator.count, 1)
     }
 
     func createDefaultEntity() {

Tests/FirebladeECSTests/XCTestManifests.swift

@@ -26,7 +26,10 @@ extension EntityTests {
     // to regenerate.
     static let __allTests__EntityTests = [
         ("testAllComponentsOfEntity", testAllComponentsOfEntity),
-        ("testEntityIdentifierAndIndex", testEntityIdentifierAndIndex)
+        ("testEntityEquality", testEntityEquality),
+        ("testEntityIdentifierAndIndex", testEntityIdentifierAndIndex),
+        ("testEntityIdGenerator", testEntityIdGenerator),
+        ("testRemoveAllComponentsFromEntity", testRemoveAllComponentsFromEntity)
     ]
 }