TestSphereAABB

    static bool TestSphereAABB (Vector3 sphereCoords, double sphereRadius, Vector3 boxCoords, Vector2 boxSize) {
        // Compute squared distance between sphere center and AABB
        // the sqrt (dist) is fine to use as well, but this is faster.
        float sqDist = 0.0f;

        let diffCoords = level.Vec3Diff (sphereCoords, boxCoords);

        let bMin = (
            diffCoords.X - boxSize.X,
            diffCoords.Y - boxSize.X,
            diffCoords.Z
        );
        let bMax = (
            diffCoords.X + boxSize.X,
            diffCoords.Y + boxSize.X,
            diffCoords.Z + boxSize.Y
        );

        // For each axis count any excess distance outside box extents
        // X
        if (bMin.X > 0) sqDist += (bMin.X) * (bMin.X);
        if (bMax.X < 0) sqDist += (bMax.X) * (bMax.X);
        // Y
        if (bMin.Y > 0) sqDist += (bMin.Y) * (bMin.Y);
        if (bMax.Y < 0) sqDist += (bMax.Y) * (bMax.Y);
        // Z
        if (bMin.Z > 0) sqDist += (bMin.Z) * (bMin.Z);
        if (bMax.Z < 0) sqDist += (bMax.Z) * (bMax.Z);

        // Sphere and AABB intersect if the (squared) distance between them is
        // less than the (squared) sphere radius.
        return sqDist <= sphereRadius * sphereRadius;
    }