Intersection of line segment with axis-aligned box in C#

public static List<Point3D> IntersectionOfLineSegmentWithAxisAlignedBox(

    Point3D segmentBegin, Point3D segmentEnd, Point3D boxCenter, Size3D boxSize)

{

    var beginToEnd = segmentEnd - segmentBegin;

    var minToMax = new Vector3D(boxSize.X, boxSize.Y, boxSize.Z);

    var min = boxCenter - minToMax / 2;

    var max = boxCenter + minToMax / 2;

    var beginToMin = min - segmentBegin;

    var beginToMax = max - segmentBegin;

    var tNear = double.MinValue;

    var tFar = double.MaxValue;

    var intersections = new List<Point3D>();

    foreach (Axis axis in Enum.GetValues(typeof(Axis)))

    {

        if (beginToEnd.GetCoordinate(axis) == 0) // parallel

        {

            if (beginToMin.GetCoordinate(axis) > 0 || beginToMax.GetCoordinate(axis) < 0)

                return intersections; // segment is not between planes

        }

        else

        {

            var t1 = beginToMin.GetCoordinate(axis) / beginToEnd.GetCoordinate(axis);

            var t2 = beginToMax.GetCoordinate(axis) / beginToEnd.GetCoordinate(axis);

            var tMin = Math.Min(t1, t2);

            var tMax = Math.Max(t1, t2);

            if (tMin > tNear) tNear = tMin;

            if (tMax < tFar) tFar = tMax;

            if (tNear > tFar || tFar < 0) return intersections;

        }

    }

    if (tNear >= 0 && tNear <= 1) intersections.Add(segmentBegin + beginToEnd * tNear);

    if (tFar >= 0 && tFar <= 1) intersections.Add(segmentBegin + beginToEnd * tFar);

    return intersections;

}

public enum Axis

{

    X,

    Y,

    Z

}

public static double GetCoordinate(this Point3D point, Axis axis)

{

    switch (axis)

    {

        case Axis.X:

            return point.X;

        case Axis.Y:

            return point.Y;

        case Axis.Z:

            return point.Z;

        default:

            throw new ArgumentException();

    }

}

public static double GetCoordinate(this Vector3D vector, Axis axis)

{

    switch (axis)

    {

        case Axis.X:

            return vector.X;

        case Axis.Y:

            return vector.Y;

        case Axis.Z:

            return vector.Z;

        default:

            throw new ArgumentException();

    }

}