using UnityEngine;
/// <summary>
/// Tween the object's position.
/// </summary>
public class TweenPosition : Tweener
{
    public Vector3 from;
    public Vector3 to;
    Transform mTrans;

    public Transform cachedTransform {
        get {
            if (mTrans == null)
                mTrans = transform;
            return mTrans;
        }
    }

    /// <summary>
    /// Tween's current value.
    /// </summary>

    public Vector3 value {
        get {
            return cachedTransform.localPosition;
        }
        set {
            cachedTransform.localPosition = value;
        }
    }

    /// <summary>
    /// Tween the value.
    /// </summary>

    protected override void OnUpdate(float factor, bool isFinished)
    {
        value = from * (1f - factor) + to * factor;
    }

    /// <summary>
    /// Start the tweening operation.
    /// </summary>

    static public TweenPosition Begin(GameObject go, float duration, Vector3 pos)
    {
        TweenPosition comp = Tweener.Begin<TweenPosition>(go, duration);
        comp.from = comp.value;
        comp.to = pos;

        if (duration <= 0f)
        {
            comp.Sample(1f, true);
            comp.enabled = false;
        }
        return comp;
    }

    [ContextMenu("Set 'From' to current value")]
    public override void SetStartToCurrentValue()
    {
        from = value;
    }

    [ContextMenu("Set 'To' to current value")]
    public override void SetEndToCurrentValue()
    {
        to = value;
    }

    [ContextMenu("Assume value of 'From'")]
    void SetCurrentValueToStart()
    {
        value = from;
    }

    [ContextMenu("Assume value of 'To'")]
    void SetCurrentValueToEnd()
    {
        value = to;
    }
}