Custom propertiesCustom properties

When the catalog has no matching property, animate a callback value or supply your own getter and setter.

Examples use using Godot; and using tweens.gd; in a Node method, with targets inside the scene tree.

Callback values

label.Tween(new Tweens.Float
{
    From = 10,
    To = 100,
    Duration = 1,
    OnUpdate = (_, sample) => label.Text = Mathf.RoundToInt(sample).ToString(),
});

The label counts from 10 to 100. OnUpdate receives each value; the node you start on owns playback. Callback values lists the other value types.

Property bindings

HealthBar.cs

public partial class HealthBar : Node2D
{
    public float Fill { get; set; } = 1;

    static readonly Tweens.Property<HealthBar, float> Drain = new(
        bar => bar.Fill, (bar, value) => bar.Fill = value, Interpolators.Float)
        { Duration = 0.4, Ease = InOut.SmootherStep };

    public void SetHealth(float fraction) => this.Tween(Drain with { To = fraction });
}

1. Store. Any property or field works.
2. Define. A getter, a setter, and an interpolator, with the usual timing and easing.
3. Play. Each call sets a new destination with with.

Custom bindings

For storage independent of interpolation, derive from TweenBinding<TTarget, TValue>. Override Read and Write, with optional Prepare, Restore, and Release hooks. PropertyBinding<TTarget, TValue> supplies these operations from a getter and setter. The same binding works with PropertyTween<TTarget, TValue> for endpoints or Tweens.Sampled<TTarget, TValue> for a prepared keyframe curve.

Tweens.ColorProperty<TTarget> provides a shorter color definition: getter, setter, destination, and timing, with premultiplied OKLab supplied automatically. Its Through extension uses the same storage for several keys; see keyframes.

Deriving from TweenDefinition<TTarget, TValue> remains available when one class supplies both storage and custom interpolation. Each start works on a shallow copy, so referenced objects stay shared unless you copy them. Storage-only bindings can override Copy for custom mutable configuration.

Release only what your copy owns

Keep per-playback state on the playback copy, and release only resources that copy created.

Custom definitionsEvery hook, its order, and failed preparation.

Manual schedulingAdvance tweens yourself, for plain objects and tests.