/// <summary> /// Before to start a review of Svelto.ECS terminologies: /// - Entity: /// it must be a real and concrete entity that you can explain /// in terms of game design. The name of each entity should reflect /// a specific concept from the game design domain /// - Engines (Systems): /// Where all the logic lies. Engines operates on EntityViews or EntityStructs /// - EntityViews and EntitiyViewStructs: /// EntityViews maps Entity Components. The Engines can't /// access directly to each entity (as a single set of components), but /// through component sets defined by the EntityView. /// They act as component filters and expose only the entity components /// that the Engine is interested in. /// EntityViews are actually defined with the Engine so they /// come together with the engine and in the same namespace of the engine. /// EntityViewStructs should always be used, while EntityViews as /// class use should be considered an exception. /// - Component Interfaces: /// Components must be seen as data holders. There may be implementation /// exceptions, but the interface must declare a group /// of readable and/or writeable data. /// In Svelto.ECS components are always interfaces declaring /// Setters and Getters of Value Types. DispatchOnSet /// and DispatchOnChange must not be seen as events, but /// as pushing of data instead of data polling, similar /// to the concept of DataBinding. /// - Implementors: /// Being components interfaces, they must be implemented through /// Implementors. The relation Implementors to Components /// is not 1:1 so that you can group several /// components into fewer implementors. This allows to easily /// share data between components. Implementors also act /// as bridge between the platform and Svelto.ECS. /// Since Components can hold only value types, Implementors /// are the objects that can interact directly with the platform /// objects, I.E.: RigidBody, Transform and so on. /// Note: IComponents must hold only valuetypes for /// code design purposes and not optmization purposes. /// The reason is that all the logic must lie in the engines /// so Components cannot hold references to instances that can /// expose functions with logic. /// - EntityStructs: /// In order to write Data Oriented Cache Friendly and allocation 0 code, Svelto.ECS /// also supports EntityStructs. /// - EntityDescriptors: /// Gives a way to formalize your Entity in svelto.ECS, it also /// defoines the EntityViews, EntityStructs and EntityViewStructs that must be generated once the /// Entity is built /// </summary> void SetupEngines() { //The Engines Root is the core of Svelto.ECS. You must NEVER inject the EngineRoot //as it is, therefore the composition root must hold a reference or it will be //GCed. //the UnitySumbmissionEntityViewScheduler is the scheduler that is used by the EnginesRoot to know //when to inject the EntityViews. You shouldn't use a custom one unless you know what you //are doing or you are not working with Unity. _unityEntitySubmissionScheduler = new UnityEntitySubmissionScheduler(); _enginesRoot = new EnginesRoot(_unityEntitySubmissionScheduler); //Engines root can never be held by anything else than the context itself to avoid leaks //That's why the EntityFactory and EntityFunctions are generated. //The EntityFactory can be injected inside factories (or engine acting as factories) //to build new entities dynamically _entityFactory = _enginesRoot.GenerateEntityFactory(); //The entity functions is a set of utility operations on Entities, including //removing an entity. I couldn't find a better name so far. var entityFunctions = _enginesRoot.GenerateEntityFunctions(); //the ISequencer is one of the 2 official ways available in Svelto.ECS //to communicate. They are mainly used for two specific cases: //1) specify a strict execution order between engines (engine logic //is executed horizontally instead than vertically, I will talk about this //in my articles). 2) filter a data token passed as parameter through //engines. The ISequencer is also not the common way to communicate //between engines PlayerDeathSequencer playerDeathSequence = new PlayerDeathSequencer(); EnemyDeathSequencer enemyDeathSequence = new EnemyDeathSequencer(); //wrap non testable unity static classes, so that //can be mocked if needed. IRayCaster rayCaster = new RayCaster(); ITime time = new Time(); //Player related engines. ALL the dependencies must be solved at this point //through constructor injection. var playerShootingEngine = new PlayerGunShootingEngine(rayCaster, time); var playerMovementEngine = new PlayerMovementEngine(rayCaster, time); var playerAnimationEngine = new PlayerAnimationEngine(); var playerDeathEngine = new PlayerDeathEngine(playerDeathSequence, entityFunctions); //Enemy related engines var enemyAnimationEngine = new EnemyAnimationEngine(time, enemyDeathSequence, entityFunctions); var enemyAttackEngine = new EnemyAttackEngine(time); var enemyMovementEngine = new EnemyMovementEngine(); //GameObjectFactory allows to create GameObjects without using the Static //method GameObject.Instantiate. While it seems a complication //it's important to keep the engines testable and not //coupled with hard dependencies references (read my articles to understand //how dependency injection works and why solving dependencies //with static classes and singletons is a terrible mistake) GameObjectFactory gameObjectFactory = new GameObjectFactory(); //Factory is one of the few patterns that work very well with ECS. Its use is highly encouraged IEnemyFactory enemyFactory = new EnemyFactory(gameObjectFactory, _entityFactory); var enemySpawnerEngine = new EnemySpawnerEngine(enemyFactory, entityFunctions); var enemyDeathEngine = new EnemyDeathEngine(entityFunctions, enemyDeathSequence); //hud and sound engines var hudEngine = new HUDEngine(time); var damageSoundEngine = new DamageSoundEngine(); var scoreEngine = new ScoreEngine(); //The ISequencer implementation is very simple, but allows to perform //complex concatenation including loops and conditional branching. //These two sequencers are a real stretch and are shown only for explanatory purposes. //Please do not see sequencers as a way to dispatch or broadcast events, they are meant only and exclusively //to guarantee the order of execution of the involved engines. //For this reason the use of sequencers is and must be actually rare, as perfectly encapsulated engines //do not need to be executed in specific order. //a Sequencer can: //- ensure the order of execution through one step only (one step executes in order several engines) //- ensure the order of execution through several steps. Each engine inside each step has the responsibility //to trigger the next step through the use of the Next() function //- create paths with branches and loop using the Condition parameter. playerDeathSequence.SetSequence(playerDeathEngine, playerMovementEngine, playerAnimationEngine, enemyAnimationEngine, damageSoundEngine, hudEngine); enemyDeathSequence.SetSequence(enemyDeathEngine, scoreEngine, damageSoundEngine, enemyAnimationEngine, enemySpawnerEngine); //All the logic of the game must lie inside engines //Player engines _enginesRoot.AddEngine(playerMovementEngine); _enginesRoot.AddEngine(playerAnimationEngine); _enginesRoot.AddEngine(playerShootingEngine); _enginesRoot.AddEngine(new PlayerInputEngine()); _enginesRoot.AddEngine(new PlayerGunShootingFXsEngine()); _enginesRoot.AddEngine(playerDeathEngine); //enemy engines _enginesRoot.AddEngine(enemySpawnerEngine); _enginesRoot.AddEngine(enemyAttackEngine); _enginesRoot.AddEngine(enemyMovementEngine); _enginesRoot.AddEngine(enemyAnimationEngine); _enginesRoot.AddEngine(enemyDeathEngine); //other engines _enginesRoot.AddEngine(new ApplyingDamageToTargetsEngine()); _enginesRoot.AddEngine(new CameraFollowTargetEngine(time)); _enginesRoot.AddEngine(new CharactersDeathEngine()); _enginesRoot.AddEngine(damageSoundEngine); _enginesRoot.AddEngine(hudEngine); _enginesRoot.AddEngine(scoreEngine); }
/// <summary> /// Before to start, let's review some of the Svelto.ECS terms: /// - Entity: /// it must be a real and concrete entity that you can explain in terms of game design. The name of each /// entity should reflect a specific concept from the game design domain /// - Engines (Systems): /// Where all the logic lies. Engines operates on EntityViewStructs and EntityStructs /// - EntityStructs: /// EntityStructs is the preferred way to store entity data. They are just plain structs of pure data (no /// objects) /// - EntityViewStructs: /// EntityViewStructs are used to wrap Objects that come from OOP libraries. You will never use it unless /// you are forced to mix your ECS code with OOP code because of external libraries or platforms. /// The Objects are known to svelto through Component Interfaces. /// - Component Interfaces: /// Components must be seen as data holders. In Svelto.ECS components are always interfaces declaring /// Setters and Getters of Value Types coming from the Objects they wrap /// - Implementors: /// The components interfaces must be implemented through Implementors and the implementors are the /// Objects you need to wrap. /// - EntityDescriptors: /// Gives a way to formalise your Entity, it also defines the EntityStructs and EntityViewStructs that must /// be generated once the Entity is built /// </summary> void SetupEngines() { //The Engines Root is the core of Svelto.ECS. You shouldn't inject the EngineRoot, //therefore the composition root must hold a reference or it will be GCed. //the UnitySumbmissionEntityViewScheduler is the scheduler that is used by the EnginesRoot to know //when to submit the entities. Custom ones can be created for special cases. _unityEntitySubmissionScheduler = new UnityEntitySubmissionScheduler(); _enginesRoot = new EnginesRoot(_unityEntitySubmissionScheduler); //The EntityFactory can be injected inside factories (or engine acting as factories) to build new entities //dynamically _entityFactory = _enginesRoot.GenerateEntityFactory(); //The entity functions is a set of utility operations on Entities, including removing an entity. I couldn't //find a better name so far. var entityFunctions = _enginesRoot.GenerateEntityFunctions(); //Sequencers are the official way to guarantee order between engines, but may not be the best way for //your product. var playerDeathSequence = new PlayerDeathSequencer(); var enemyDeathSequence = new EnemyDeathSequencer(); //wrap non testable unity static classes, so that can be mocked if needed. IRayCaster rayCaster = new RayCaster(); ITime time = new Time(); //Player related engines. ALL the dependencies must be solved at this point through constructor injection. var playerShootingEngine = new PlayerGunShootingEngine(rayCaster, time); var playerMovementEngine = new PlayerMovementEngine(rayCaster, time); var playerAnimationEngine = new PlayerAnimationEngine(); var playerDeathEngine = new PlayerDeathEngine(playerDeathSequence, entityFunctions); //Enemy related engines var enemyAnimationEngine = new EnemyAnimationEngine(time, enemyDeathSequence, entityFunctions); var enemyAttackEngine = new EnemyAttackEngine(time); var enemyMovementEngine = new EnemyMovementEngine(); //GameObjectFactory allows to create GameObjects without using the Static method GameObject.Instantiate. //While it seems a complication it's important to keep the engines testable and not coupled with hard //dependencies var gameObjectFactory = new GameObjectFactory(); //Factory is one of the few patterns that work very well with ECS. Its use is highly encouraged var enemyFactory = new EnemyFactory(gameObjectFactory, _entityFactory); var enemySpawnerEngine = new EnemySpawnerEngine(enemyFactory, entityFunctions); var enemyDeathEngine = new EnemyDeathEngine(entityFunctions, enemyDeathSequence); //hud and sound engines var hudEngine = new HUDEngine(time); var damageSoundEngine = new DamageSoundEngine(); var scoreEngine = new ScoreEngine(); //The ISequencer implementation is very simple, but allows to perform //complex concatenation including loops and conditional branching. //These two sequencers are a real stretch and are shown only for explanatory purposes. //Please do not see sequencers as a way to dispatch or broadcast events, they are meant only and exclusively //to guarantee the order of execution of the involved engines. //For this reason the use of sequencers is and must be actually rare, as perfectly encapsulated engines //do not need to be executed in specific order. //a Sequencer can: //- ensure the order of execution through one step only (one step executes in order several engines) //- ensure the order of execution through several steps. Each engine inside each step has the responsibility //to trigger the next step through the use of the Next() function //- create paths with branches and loop using the Condition parameter. playerDeathSequence.SetSequence(playerDeathEngine, playerMovementEngine, playerAnimationEngine, enemyAnimationEngine, damageSoundEngine, hudEngine); enemyDeathSequence.SetSequence(enemyDeathEngine, scoreEngine, damageSoundEngine, enemyAnimationEngine, enemySpawnerEngine); //All the logic of the game must lie inside engines //Player engines _enginesRoot.AddEngine(playerMovementEngine); _enginesRoot.AddEngine(playerAnimationEngine); _enginesRoot.AddEngine(playerShootingEngine); _enginesRoot.AddEngine(new PlayerInputEngine()); _enginesRoot.AddEngine(new PlayerGunShootingFXsEngine()); _enginesRoot.AddEngine(playerDeathEngine); _enginesRoot.AddEngine(new PlayerSpawnerEngine(gameObjectFactory, _entityFactory)); //enemy engines _enginesRoot.AddEngine(enemySpawnerEngine); _enginesRoot.AddEngine(enemyAttackEngine); _enginesRoot.AddEngine(enemyMovementEngine); _enginesRoot.AddEngine(enemyAnimationEngine); _enginesRoot.AddEngine(enemyDeathEngine); //other engines _enginesRoot.AddEngine(new ApplyingDamageToTargetsEngine()); _enginesRoot.AddEngine(new CameraFollowTargetEngine(time)); _enginesRoot.AddEngine(new CharactersDeathEngine()); _enginesRoot.AddEngine(damageSoundEngine); _enginesRoot.AddEngine(hudEngine); _enginesRoot.AddEngine(scoreEngine); }
/// <summary> /// Before to start a review of Svelto.ECS terminologies: /// - Entity: /// it must be a real and concrete entity that you can explain /// in terms of game design. The name of each entity should reflect /// a specific concept from the game design domain /// - Engines (Systems): /// Where all the logic lies. Engines operates on EntityViews or EntityStructs /// - EntityViews and EntitiyViewStructs: /// EntityViews maps Entity Components. The Engines can't /// access directly to each entity (as a single set of components), but /// through component sets defined by the EntityView. /// They act as component filters and expose only the entity components /// that the Engine is interested in. /// EntityViews are actually defined with the Engine so they /// come together with the engine and in the same namespace of the engine. /// EntityViewStructs should always be used, while EntityViews as /// class use should be considered an exception. /// - Component Interfaces: /// Components must be seen as data holders. There may be implementation /// exceptions, but the interface must declare a group /// of readable and/or writeable data. /// In Svelto.ECS components are always interfaces declaring /// Setters and Getters of Value Types. DispatchOnSet /// and DispatchOnChange must not be seen as events, but /// as pushing of data instead of data polling, similar /// to the concept of DataBinding. /// - Implementors: /// Being components interfaces, they must be implemented through /// Implementors. The relation Implementors to Components /// is not 1:1 so that you can group several /// components into fewer implementors. This allows to easily /// share data between components. Implementors also act /// as bridge between the platform and Svelto.ECS. /// Since Components can hold only value types, Implementors /// are the objects that can interact directly with the platform /// objects, I.E.: RigidBody, Transform and so on. /// Note: IComponents must hold only valuetypes for /// code design purposes and not optmization purposes. /// The reason is that all the logic must lie in the engines /// so Components cannot hold references to instances that can /// expose functions with logic. /// - EntityStructs: /// In order to write Data Oriented Cache Friendly and allocation 0 code, Svelto.ECS /// also supports EntityStructs. /// - EntityDescriptors: /// Gives a way to formalize your Entity in svelto.ECS, it also /// defoines the EntityViews, EntityStructs and EntityViewStructs that must be generated once the /// Entity is built /// </summary> void SetupEngines() { //The Engines Root is the core of Svelto.ECS. You must NEVER inject the EngineRoot //as it is, therefore the composition root must hold a reference or it will be //GCed. //the UnitySumbmissionEntityViewScheduler is the scheduler that is used by the EnginesRoot to know //when to inject the EntityViews. You shouldn't use a custom one unless you know what you //are doing or you are not working with Unity. _enginesRoot = new EnginesRoot(new UnitySumbmissionEntityViewScheduler()); //Engines root can never be held by anything else than the context itself to avoid leaks //That's why the EntityFactory and EntityFunctions are generated. //The EntityFactory can be injected inside factories (or engine acting as factories) //to build new entities dynamically _entityFactory = _enginesRoot.GenerateEntityFactory(); //The entity functions is a set of utility operations on Entities, including //removing an entity. I couldn't find a better name so far. var entityFunctions = _enginesRoot.GenerateEntityFunctions(); //the ISequencer is one of the 2 official ways available in Svelto.ECS //to communicate. They are mainly used for two specific cases: //1) specify a strict execution order between engines (engine logic //is executed horizontally instead than vertically, I will talk about this //in my articles). 2) filter a data token passed as parameter through //engines. The ISequencer is also not the common way to communicate //between engines Sequencer playerDamageSequence = new Sequencer(); Sequencer enemyDamageSequence = new Sequencer(); //wrap non testable unity static classes, so that //can be mocked if needed. IRayCaster rayCaster = new RayCaster(); ITime time = new Time(); //Player related engines. ALL the dependecies must be solved at this point //through constructor injection. var playerHealthEngine = new HealthEngine(playerDamageSequence); var playerShootingEngine = new PlayerGunShootingEngine(enemyDamageSequence, rayCaster, time); var playerMovementEngine = new PlayerMovementEngine(rayCaster, time); var playerAnimationEngine = new PlayerAnimationEngine(); var playerDeathEngine = new PlayerDeathEngine(entityFunctions); //Enemy related engines var enemyAnimationEngine = new EnemyAnimationEngine(); //HealthEngine is a different object for the enemy because it uses a different sequence var enemyHealthEngine = new HealthEngine(enemyDamageSequence); var enemyAttackEngine = new EnemyAttackEngine(playerDamageSequence, time); var enemyMovementEngine = new EnemyMovementEngine(); //GameObjectFactory allows to create GameObjects without using the Static //method GameObject.Instantiate. While it seems a complication //it's important to keep the engines testable and not //coupled with hard dependencies references (read my articles to understand //how dependency injection works and why solving dependencies //with static classes and singletons is a terrible mistake) GameObjectFactory factory = new GameObjectFactory(); //Factory is one of the few patterns that work very well with ECS. Its use is highly encuraged IEnemyFactory enemyFactory = new EnemyFactory(factory, _entityFactory); var enemySpawnerEngine = new EnemySpawnerEngine(enemyFactory, entityFunctions); var enemyDeathEngine = new EnemyDeathEngine(entityFunctions, time, enemyDamageSequence); //hud and sound engines var hudEngine = new HUDEngine(time); var damageSoundEngine = new DamageSoundEngine(); var scoreEngine = new ScoreEngine(); //The ISequencer implementaton is very simple, but allows to perform //complex concatenation including loops and conditional branching. playerDamageSequence.SetSequence( new Steps //sequence of steps, this is a dictionary! { { //first step /*from: */ enemyAttackEngine, //this step can be triggered only by this engine through the Next function /*to: */ new To //this step can lead only to one branch { //this is the only engine that will be called when enemyAttackEngine triggers Next() playerHealthEngine } }, { //second step /*from: */ playerHealthEngine, //this step can be triggered only by this engine through the Next function /*to: */ new To <DamageCondition> //once the playerHealthEngine calls the Step method, //all these engines in the list will be called //depending the condition. The order of the engines triggered is guaranteed. { //these engines will be called when the Next function is called with the DamageCondition.damage set { DamageCondition.Damage, new IStep <DamageInfo, DamageCondition>[] { hudEngine, damageSoundEngine } }, //these engines will be called when the Next function is called with the DamageCondition.dead set { DamageCondition.Dead, new IStep <DamageInfo, DamageCondition>[] { hudEngine, damageSoundEngine, playerMovementEngine, playerAnimationEngine, enemyAnimationEngine, playerDeathEngine } } } } } ); enemyDamageSequence.SetSequence( new Steps { { playerShootingEngine, new To { //in every case go to enemyHealthEngine enemyHealthEngine } }, { enemyHealthEngine, new To <DamageCondition> { { DamageCondition.Damage, new IStep <DamageInfo, DamageCondition>[] { enemyAnimationEngine, damageSoundEngine } }, { DamageCondition.Dead, new IStep <DamageInfo, DamageCondition>[] { scoreEngine, enemyMovementEngine, enemyAnimationEngine, damageSoundEngine, enemyDeathEngine } } } }, { enemyDeathEngine, new To { enemySpawnerEngine } } } ); //Mandatory step to make engines work //Player engines _enginesRoot.AddEngine(playerMovementEngine); _enginesRoot.AddEngine(playerAnimationEngine); _enginesRoot.AddEngine(playerShootingEngine); _enginesRoot.AddEngine(playerHealthEngine); _enginesRoot.AddEngine(new PlayerInputEngine()); _enginesRoot.AddEngine(new PlayerGunShootingFXsEngine()); //enemy engines _enginesRoot.AddEngine(enemySpawnerEngine); _enginesRoot.AddEngine(enemyAttackEngine); _enginesRoot.AddEngine(enemyMovementEngine); _enginesRoot.AddEngine(enemyAnimationEngine); _enginesRoot.AddEngine(enemyHealthEngine); _enginesRoot.AddEngine(enemyDeathEngine); //other engines _enginesRoot.AddEngine(new CameraFollowTargetEngine(time)); _enginesRoot.AddEngine(damageSoundEngine); _enginesRoot.AddEngine(hudEngine); _enginesRoot.AddEngine(scoreEngine); }
/// <summary> /// Before to start, let's review some of the Svelto.ECS terms: /// - Entity: /// it must be a real and concrete entity that you can explain in terms of game design. The name of each /// entity should reflect a specific concept from the game design domain /// - Engines (Systems): /// Where all the logic lies. Engines operates on Entity Components /// - IEntityComponent: /// It's an Entity Component which can be used with Pure ECS /// - IEntityViewComponent: /// structs implementing this are used to wrap Objects that come from OOP libraries. You will never use it unless /// you are forced to mix your ECS code with OOP code because of external libraries or platforms. These special /// "Hybrid" component can hold only interfaces /// - Implementors: /// The EntityViewComponent exposed interfaces must be implemented by Implementors that are actually the /// Objects you need to wrap. /// - EntityDescriptors: /// Gives a way to formalise your Entity, it also defines the components that must /// be generated once the Entity is built /// </summary> void CompositionRoot(UnityContext contextHolder) { //the UnitySumbmissionEntityViewScheduler is the scheduler that is used by the EnginesRoot to know //when to submit the entities. Custom ones can be created for special cases. var unityEntitySubmissionScheduler = new UnityEntitiesSubmissionScheduler("survival"); //The Engines Root is the core of Svelto.ECS. You shouldn't inject the EngineRoot, //therefore the composition root class must hold a reference or it will be garbage collected. _enginesRoot = new EnginesRoot(unityEntitySubmissionScheduler); //The EntityFactory can be injected inside factories (or engine acting as factories) to build new entities //dynamically var entityFactory = _enginesRoot.GenerateEntityFactory(); //The entity functions is a set of utility operations on Entities, including removing an entity. I couldn't //find a better name so far. var entityFunctions = _enginesRoot.GenerateEntityFunctions(); var entityStreamConsumerFactory = _enginesRoot.GenerateConsumerFactory(); //wrap non testable unity static classes, so that can be mocked if needed (or implementation can change in general, without changing the interface). IRayCaster rayCaster = new RayCaster(); ITime time = new Time(); //GameObjectFactory allows to create GameObjects without using the Static method GameObject.Instantiate. //While it seems a complication it's important to keep the engines testable and not coupled with hard //dependencies var gameObjectFactory = new GameObjectFactory(); //Player related engines. ALL the dependencies must be solved at this point through constructor injection. var playerShootingEngine = new PlayerGunShootingEngine(rayCaster, time); var playerMovementEngine = new PlayerMovementEngine(rayCaster); var playerAnimationEngine = new PlayerAnimationEngine(); var playerDeathEngine = new PlayerDeathEngine(entityFunctions, entityStreamConsumerFactory); var playerInputEngine = new PlayerInputEngine(); var playerGunShootingFXsEngine = new PlayerGunShootingFXsEngine(entityStreamConsumerFactory); //Spawner engines are factories engines that can build entities var playerSpawnerEngine = new PlayerSpawnerEngine(gameObjectFactory, entityFactory); var restartGameOnPlayerDeath = new RestartGameOnPlayerDeathEngine(); //Player engines _enginesRoot.AddEngine(playerMovementEngine); _enginesRoot.AddEngine(playerAnimationEngine); _enginesRoot.AddEngine(playerShootingEngine); _enginesRoot.AddEngine(playerInputEngine); _enginesRoot.AddEngine(playerGunShootingFXsEngine); _enginesRoot.AddEngine(playerDeathEngine); _enginesRoot.AddEngine(playerSpawnerEngine); _enginesRoot.AddEngine(restartGameOnPlayerDeath); //Factory is one of the few OOP patterns that work very well with ECS. Its use is highly encouraged var enemyFactory = new EnemyFactory(gameObjectFactory, entityFactory); //Enemy related engines var enemyAnimationEngine = new EnemyChangeAnimationOnPlayerDeath(); var enemyDamageFX = new EnemySpawnEffectOnDamage(entityStreamConsumerFactory); var enemyAttackEngine = new EnemyAttackEngine(time); var enemyMovementEngine = new EnemyMovementEngine(); //Spawner engines are factories engines that can build entities var enemySpawnerEngine = new EnemySpawnerEngine(enemyFactory, entityFunctions); var enemyDeathEngine = new EnemyDeathEngine(entityFunctions, entityStreamConsumerFactory, time , new WaitForSubmissionEnumerator( unityEntitySubmissionScheduler)); //enemy engines _enginesRoot.AddEngine(enemySpawnerEngine); _enginesRoot.AddEngine(enemyAttackEngine); _enginesRoot.AddEngine(enemyMovementEngine); _enginesRoot.AddEngine(enemyAnimationEngine); _enginesRoot.AddEngine(enemyDeathEngine); _enginesRoot.AddEngine(enemyDamageFX); //abstract engines var applyDamageEngine = new ApplyDamageToDamageableEntitiesEngine(entityStreamConsumerFactory); var cameraFollowTargetEngine = new CameraFollowingTargetEngine(time); var deathEngine = new DispatchKilledEntitiesEngine(); //abstract engines (don't need to know the entity type) _enginesRoot.AddEngine(applyDamageEngine); _enginesRoot.AddEngine(deathEngine); _enginesRoot.AddEngine(cameraFollowTargetEngine); //hud and sound engines var hudEngine = new HUDEngine(entityStreamConsumerFactory); var damageSoundEngine = new DamageSoundEngine(entityStreamConsumerFactory); var scoreEngine = new UpdateScoreEngine(entityStreamConsumerFactory); //other engines _enginesRoot.AddEngine(damageSoundEngine); _enginesRoot.AddEngine(hudEngine); _enginesRoot.AddEngine(scoreEngine); var unsortedEngines = new SurvivalUnsortedEnginesGroup(new FasterList <IStepEngine>( new IStepEngine[] { playerMovementEngine, playerInputEngine, playerGunShootingFXsEngine, playerSpawnerEngine, playerAnimationEngine, enemySpawnerEngine, enemyMovementEngine, cameraFollowTargetEngine, hudEngine, restartGameOnPlayerDeath } )); var unsortedDamageEngines = new DamageUnsortedEngines(new FasterList <IStepEngine>( new IStepEngine[] { applyDamageEngine, damageSoundEngine, deathEngine } )); //Svelto ECS doesn't provide a tick system, hence it doesn't provide a solution to solve the order of execution //However it provides some option if you want to use them like the SortedEnginesGroup. _enginesRoot.AddEngine(new TickEnginesGroup(new FasterList <IStepEngine>(new IStepEngine[] { unsortedEngines , playerShootingEngine , enemyDamageFX , enemyAttackEngine , unsortedDamageEngines , playerDeathEngine , enemyDeathEngine , scoreEngine }))); BuildGUIEntitiesFromScene(contextHolder, entityFactory); }