cirnogodot/GTweensGodot/GTweens/Source/Interpolators/SystemQuaternionInterpolator.cs

using System.Numerics;
using GTweens.Easings;

namespace GTweens.Interpolators
{
    public sealed class SystemQuaternionInterpolator : IInterpolator<Quaternion>
    {
        public static readonly SystemQuaternionInterpolator Instance = new();

        SystemQuaternionInterpolator()
        {

        }

        public Quaternion Evaluate(
            Quaternion initialValue,
            Quaternion finalValue,
            float time,
            EasingDelegate easingDelegate
            )
        {
            float curveTime = easingDelegate(0f, 1f, time);

            return Quaternion.Slerp(initialValue, finalValue, curveTime);
        }

        public Quaternion Subtract(Quaternion initialValue, Quaternion finalValue)
        {
            return Quaternion.Inverse(initialValue) * finalValue;
        }

        public Quaternion Add(Quaternion initialValue, Quaternion finalValue)
        {
            return initialValue * finalValue;
        }
    }
}