GameObjectEx.cs

public static class GameObjectEx
{
    /// <summary>
    /// ComponentDataWrapper<T> の一覧を取得し、Archetypeを返す
    /// </summary>
    /// <returns></returns>
    public static EntityArchetype Archetype(this GameObject @this, EntityManager manager)
    {
        // Get All ComponentDataWrapperBase in GameObject
        var wrapper = @this.GetComponents<ComponentDataWrapperBase>();
        // get the BaseType GenericArguments
        var componentType = wrapper.Select(w => (ComponentType)w.GetType().BaseType.GetGenericArguments()[0]);
        // maybe gameobject has a MeshInstanceRendererComponent. so erase SharedComponentDataWrapper
        // and CreateArchetype
        return manager.CreateArchetype(componentType.Where(c => !c.IsSharedComponent).ToArray());
    }

    /// <summary>
    /// MeshInstanceRenderer を生成する
    /// </summary>
    /// <param name="this"></param>
    /// <returns></returns>
    public static MeshInstanceRenderer CreateMeshInstanceRenderer(this GameObject @this)
    {
        // 従来システムの MeshFilter や MeshRenderer を取得する
        var meshFilter = @this.GetComponent<MeshFilter>();
        var renderer = @this.GetComponent<MeshRenderer>();

        var res = new MeshInstanceRenderer();
        if (meshFilter != null && renderer != null)
        {
            res.mesh = meshFilter.sharedMesh;
            res.material = renderer.sharedMaterial;
        }
        return res;
    }
}