def _create_rects(rect_list):
    """
    Create a vertex buffer for a set of rectangles.
    """

    v2f = []
    for shape in rect_list:
        v2f.extend([-shape.width / 2, -shape.height / 2,
                    shape.width / 2, -shape.height / 2,
                    shape.width / 2, shape.height / 2,
                    -shape.width / 2, shape.height / 2])

    return v2f