Entity

Entity - serves to identify an object in the game world and access attached components

• Represented as a 4 byte structure

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By default an entity can be created and exist without components, also when the last component is deleted it is not deleted
If you want to override this, you must use the compiler directive FFS_ECS_LIFECYCLE_ENTITY
More info: Compiler directives

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Creation:

// Creating a single entity

// Method 1 - creating an “empty” entity
var entity = MyEcs.Entity.New();

// Method 2 - with component type (overload methods from 1-5 components)
var entity = MyEcs.Entity.New<Position>();
var entity = MyEcs.Entity.New<Position, Velocity, Name>();

// Method 3 - with component value (overload methods from 1-5 components)
var entity = MyEcs.Entity.New(new Position(x: 1, y: 1, z: 2));
var entity = MyEcs.Entity.New(
            new Name { Val = "SomeName" },
            new Velocity { Val = 1f },
            new Position { Val = Vector3.One }
);

// Creating multiple entities
// Method 1 - with component type (overload methods from 1-5 components)
int count = 100;
MyEcs.Entity.NewOnes<Position>(count);

// Method 2 - specifying component type (overload methods from 1-5 components) + delegate initialization of each entity
int count = 100;
Ecs.Entity.NewOnes<Position>(count, static entity => {
    // some init logic for each entity
});

// Method 3 - with component value (overload methods from 1-5 components)
int count = 100;
MyEcs.Entity.NewOnes(count, new Position(x: 1, y: 1, z: 2));

// Method 4 - with component value (overload methods from 1-5 components) + initialization delegate of each entity
int count = 100;
MyEcs.Entity.NewOnes(count, new Position(x: 1, y: 1, z: 2), static entity => {
    // some init logic for each entity
});

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Basic operations:

var entity = MyEcs.Entity.New(
            new Name { Val = "SomeName" },
            new Velocity { Val = 1f },
            new Position { Val = Vector3.One }
);

entity.Disable();                        // Disable entity (a disabled entity is not found by default in queries (see Query))
entity.Enable();                         // Enable entity

bool enabled = entity.IsEnabled();       // Check if the entity is enabled in the world
bool disabled = entity.IsDisabled();     // Check if the entity is disabled in the world

bool actual = entity.IsActual();         // Check if an entity has been deleted in the world
short version = entity.Version();        // Get entity version
var clone = entity.Clone();              // Clone the entity and all components, tags, masks
entity.Destroy();                        // Delete the entity and all components, tags, masks

var entity2 = MyEcs.Entity.New<Name>();
clone.CopyTo(entity2);                   // Copy all components, tags, masks to the specified entity

var entity3 = MyEcs.Entity.New<Name>();
entity2.MoveTo(entity3);                 // Move all components to the specified entity and delete the current entity

PackedEntity packed = entity3.Pack();  // Pack an entity with meta information about the version to be transmitted

var str = entity3.ToPrettyString();      // Get a string with all information about the entity