public class DrawModule <T>
    {
        public GraphicsDevice Device;
        public VertexDeclaration VertexDeclaration;
        private VertexBuffer _vertexBuffer;
        private IndexBuffer _indexBuffer;
        private List<T> _vertices;
        private List<ushort> _indices;
        private const ushort MaxPrimitives = 65535;

        private ushort _primitiveCount;
        private bool _readyToDraw;

        public DrawModule(GraphicsDevice device, VertexDeclaration vertexDeclaration)
        {
            VertexDeclaration = vertexDeclaration;
            Device = device;

            _primitiveCount = 0;
            _readyToDraw = false;

           _vertices = new List<T>();
           _indices = new List<ushort>();
        }

        public bool HasSpace(List<ushort> indices)
        {
            return ((indices.Count + _indices.Count)/3 < MaxPrimitives);
        }

        public bool AddData(List<T> vertices, List<ushort> indices)
        {
            if (HasSpace(indices))
            {
                ushort offset = (ushort)_vertices.Count();

                _vertices.AddRange(vertices);

                foreach (ushort index in indices)
                {
                    _indices.Add((ushort)(index + offset));
                }
            }

            return false;
        }

        public void PrepareToDraw()
        {
            _vertexBuffer = new VertexBuffer(Device, VertexDeclaration, _vertices.Count, BufferUsage.WriteOnly);
            _vertexBuffer.SetData(_vertices.ToArray());

            _indexBuffer = new IndexBuffer(Device, typeof(ushort), _indices.Count, BufferUsage.WriteOnly);
        }

        public void Draw()
        {
            if (_readyToDraw)
            {
                // do stuffs
            }