protected override void OnUpdate()
{
// Need a list because slot 0 is for the default value of SharedComponentData.
// It's only there because of API limitations. We only care about the SharedComponentData in slot 1.
var uniqueSpawners = new List <HelloSpawner>(2);
// Get all the spawners in the scene.
// In this case, there's only 1, but you could potentially have several spawners with, for example, different prefabs.
EntityManager.GetAllUniqueSharedComponentData(uniqueSpawners);
HelloSpawner spawner = uniqueSpawners[1];
// Filter the component group so we're only looking at entities with shared component data we set in the editor.
// In this case, it's only 1 entity, and it corresponds to the CubeSpawner game object in the scene.
m_Spawners.SetFilter(spawner);
// Create an entity from the prefab set on the spawner component.
// This can't be called from a job, which is why we're doing this in a ComponentSystem on the main thread.
Entity spawnedCubeEntity = EntityManager.Instantiate(spawner.prefab);
// Set the position of the newly spawned cube to the origin.
var position = new Position
{
Value = float3.zero
};
EntityManager.SetComponentData(spawnedCubeEntity, position);
// Destroy the spawner so this system only runs once.
var spawnerEntity = m_Spawners.GetEntityArray()[0];
EntityManager.DestroyEntity(spawnerEntity);
}
// Lets you convert the editor data representation to the entity optimal runtime representation
public void Convert(Entity entity, EntityManager dstManager, GameObjectConversionSystem conversionSystem)
{
var spawnerData = new HelloSpawner
{
// The referenced prefab will be converted due to DeclareReferencedPrefabs.
// So here we simply map the game object to an entity reference to that prefab.
Prefab = conversionSystem.GetPrimaryEntity(Prefab),
};
dstManager.AddComponentData(entity, spawnerData);
}
