TweenLib is a tweening library for Unity ECS that enables field-level tweening of IComponentData. Instead of providing built-in tween logic, it allows you to define your own logic for full flexibility.
To install, paste the following URL into Unity's Package Manager:
- Open Package Manager.
- Click the + button.
- Select "Add package from git URL...".
- Enter:
https://github.com/hoangtongvu/com.darksun.tweenlib.git
TweenLib provides several ready-to-use Tweeners in the StandardTweeners assembly:
- TransformPositionTweener
- TransformRotationTweener
- (More coming soon...)
Or, you can create your own Tweener with custom logic:
- The Tweener must be partial struct.
- The Tweener must implements
ITweener<Component, Target>, where:Componentis theIComponentDatathat you want to tween on.Targetis the tween destination value.
A Tweener example (TransformPositionTweener):
[BurstCompile]
public partial struct TransformPositionTweener : ITweener<LocalTransform, float3>
{
[BurstCompile]
public bool CanStop(in LocalTransform componentData, in float lifeTimeSecond, in float baseSpeed, in float3 target)
{
return math.all(math.abs(target - componentData.Position) < new float3(Configs.Epsilon));
}
[BurstCompile]
public void Tween(ref LocalTransform componentData, in float baseSpeed, in float3 target)
{
componentData.Position =
math.lerp(componentData.Position, target, baseSpeed * this.DeltaTime);
}
}There are 2 components generated by source generator, named based on your Tweener name.
{tweenerName}_TweenDataCan_{tweenerName}_TweenTag
You can attach them into your entity using Authorings or Systems.
CubeAuthoring example:
public class CubeAuthoring : MonoBehaviour
{
private class Baker : Baker<CubeAuthoring>
{
public override void Bake(CubeAuthoring authoring)
{
Entity entity = GetEntity(authoring, TransformUsageFlags.Dynamic);
AddComponent<Can_TransformPositionTweener_TweenTag>(entity);
SetComponentEnabled<Can_TransformPositionTweener_TweenTag>(entity, false);
AddComponent<TransformPositionTweener_TweenData>(entity);
}
}
}To trigger tweening, use TweenBuilder in your systems, which can be accessed via Tweener.
A TweenBuilder usage example:
foreach (var (transformRef, moveStateRef, tweenDataRef, canTweenTag, moveStateChangedTag) in
SystemAPI.Query<
RefRO<LocalTransform>
, RefRO<MoveStateICD>
, RefRW<TransformPositionTweener_TweenData>
, EnabledRefRW<Can_TransformPositionTweener_TweenTag>
, EnabledRefRO<MoveStateChangedTag>>()
.WithOptions(EntityQueryOptions.IgnoreComponentEnabledState))
{
if (!moveStateChangedTag.ValueRO) continue;
if (moveStateRef.ValueRO.Value != MoveState.Right) continue;
const float rightX = 8f;
const float baseSpeed = 2f;
TransformPositionTweener.TweenBuilder.Create()
.WithBaseSpeed(baseSpeed)
.WithTarget(new float3(rightX, 0, 0))
.Build(ref tweenDataRef.ValueRW, canTweenTag);
}Note: Currently, TweenLib only support controling tween life time via BaseSpeed.
- Multiple Interface Implementation: If a Tweener implements multiple interfaces and ITweener is not the first one listed, the source generator may not work correctly.