ISystem -> IJob

[cerulean plume]

I have 2 questions:
Part 1:
I am trying to get an entity from a system class using the GetSingleton method, but it seems like the system is running the command before it is created... how do I run the onCreate after the entity is created??

        playerEntity = SystemAPI.GetSingletonEntity<PlayerInputComponent>();
        inputEntity = SystemAPI.GetSingletonEntity<InputComponent>();
        playerComponent = entityManager.GetComponentData<PlayerInputComponent>(playerEntity);
        inputComponent = entityManager.GetComponentData<InputComponent>(inputEntity);

I had put these 2 lines before the struct's declaration

[UpdateInGroup(typeof(InitializationSystemGroup), OrderLast = true)]
[CreateAfter(typeof(InputComponentSystem))]

but it isn't enough... what should I do?

Part 2:
I have this I system code, I want to convert it to IjobEntity class Execute method

float3 moveDirection = float3.zero;
foreach (RefRO<InputComponent> input in SystemAPI.Query<RefRO<InputComponent>>())
{
    moveDirection.x = input.ValueRO.movement.x;
    moveDirection.z = input.ValueRO.movement.y;
}
foreach ((
    RefRW<LocalTransform> localTransform,
    RefRW<PhysicsVelocity> velocity,
    RefRO<PlayerMovementComponent> playerInputComponent)
    in SystemAPI.Query<
        RefRW<LocalTransform>,
        RefRW<PhysicsVelocity>,
        RefRO<PlayerMovementComponent>>())
{
                // do stuff like
                moveDirection = math.normalize(moveDirection);
                velocity.ValueRW.Linear = moveDirection * playerInputComponent.ValueRO.MovementSpeed;
}

as you can see I am getting values from a component and using them to move another component... what's the right way to convert this into a job

[frank panther]

!code

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[frank panther]

1: There's a CreateAfter attribute
2: In the job's execute method use ref LocalTrnasform localTransform for RW components, and PlayerMovementComponent playerInputComponent for ReadOnly components.

[cerulean plume]

• I have used the create after, the error still occurs (but this isn't important for now, let's focus on issue 2 please )
• For issue 2, the problem isn't using in or ref, the problem is I am using 2 queries... 1st query needs only 1 entity with a specific component (the input entity).
  Then i need the 2nd query to access other entities that have specific components
  how do i convert that into a IJobEntity?

[frank panther]

Oh, just make two different jobs

ah, wait, you're doing something weird

if InputComponent is a singleton, just get the singleton with SystemAPI.GetSingleton and pass the value into the job struct

[cerulean plume]

here's the thing, SystemApi.GetSingleton isn't getting the entity from OnCreate, even though I used CreateAfter.
It is necessary to mention that the entity that has inputcomponent is created in another system (I mention that in my question above)

and even if it did get the singleton, I dont know how to pass it to the IjobEntity that I made

[frank panther]

If it's created in OnCreate then all you need is CreateAfter. If it's still erroring then you're doing something else wrong.

But also, your whole setup doesn't really make sense. Is InputComponent and PlayerMovementComponent supposed to both be singletons? If that's the case then you don't need to do any jobs or queries at all, you should just be setting them in OnUpdate and have RequireForUpdate in OnCreate

[cerulean plume]

playermovementcomponent isn't a singleton

[frank panther]

So there's multiple player movements that are all controlled by the same InputComponent?

[cerulean plume]

there are several entities that act based on the same input from the same player

[frank panther]

In that case all you should need is a system with:
in OnCreate:

• state.RequireForUpdate<InputComponent>()
  In OnUpdate:
• SystemAPI.GetSingleton<InputComponent>()
• A job where one of the fields in the struct is float3 MoveDirection, then setting that value when you construct the job struct.

[cerulean plume]

I thought about this, but isn't SystemAPI.GetSingleton<InputComponent>() supposed to be only in the oncreate? i know that dots is way faster but isn't getting the inputcomponent in the onupdate unnecessary and wasteful?

[frank panther]

No, you should almost never be using it in OnCreate. Getting a singleton is incredibly quick and generally not something you need to worry about, especially if you're burst-compiling OnUpdate

[cerulean plume]

if my understanding is correct, my system code's on update will go something like this:

float3 moveDirection = float3.zero;
var input = SystemAPI.GetSingleton<InputComponent>();
{
    moveDirection.x = input.movement.x;
    moveDirection.z = input.movement.y;
}

        PlayerMoverJob job = new BotsMoverJob { inputvector = moveDirection};
        job.ScheduleParallel();

and the ijobidentity:

public void Execute(ref LocalTransform localTransform, ref PhysicsVelocity velocity, in PlayerMovementComponent robot)
    ```

I am sorry to ask a lot but i am new to dots

[cerulean plume]

Your solution worked perfectly, but if I may ask, i am using the new input system using dots (im creating an entity to get the input). My question is:
is it ok for me to subscribe to the input in the oncreate? or must i get the values in the onupdate?

[frank panther]

If it's an ISystem then subscribing to the input in OnCreate would probably not be ideal, since you wouldn't have a good way to store them? Personally I usually just bite the bullet and have an unbursted system read them (possibly with manual polling), but subscribing can be fine too if you're not breaking parallelism and make sure to unsubscribe in OnDestroy