Add WaypointMoveComponent

[AlmasB]

To go to fxgl module under dsl.components. The component moves the entity using provided Point2D waypoints.

Existing move-related components can be studied: https://github.com/AlmasB/FXGL/tree/dev/fxgl/src/main/kotlin/com/almasb/fxgl/dsl/components

Please provide API design first, before implementation.

[AlmasB]

To complete, we should also add an option that rotates the entity along the movement vector.

[Kuhsea]

Hi, I would like to work on this issue as part of a optional contribution task.

Looking at the existing movement components like ProjectileComponent, I want to propose the following API design:

WaypointMoveComponent(
    private val waypoints: List<Point2D>,
    speed: Double
)

Proposed behaviour:
The component will move the entity towards each Point2D waypoint in order.
When the entity reaches the current waypoint, it will move to the next one.
When the waypoints have been reached, movement will stop.
The component will use speed to control movement distance per second.
Rotation can be optional, like ProjectileComponent, with a method like allowRotation(true/false).

Possible usage:

entity.addComponent(
    WaypointMoveComponent(
        listOf(Point2D(100.0, 100.0), Point2D(300.0, 200.0)),
        150.0
    )
)

Would this API design fit the expected style for FXGL, or would you prefer a different approach before I start implementation?

[AlmasB]

Hi, thanks for this. If you check the commit referenced above, there is a base implementation available now, though I think it's still missing the optional rotation, which is needed as part of this issue.

See if you can add an extra sample (to go to fxgl-samples) that uses this component and shows how the new rotation works.

[Kuhsea]

Thanks, I’ll work on adding optional rotation to the existing WaypointMoveComponent.

My plan is to add a allowRotation(boolean) like ProjectileComponent, and rotate the entity with rotateToVector() based on the vector from the entitys current position to the next waypoint.

I’m will add a sample under fxgl-samples using a non symmetrical arrow shaped entity moving between multiple waypoints so the rotation behaviour is visible.

[Kuhsea]

The above changes have been made in the pull request