You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: draw_anatomical_roi_2008.m
    path of file: ./repos/CanlabCore/CanlabCore/ROI_drawing_tools
    
    the code of the file until where you have to start completion: function draw_anatomical_roi_2008(met
    
function draw_volume_render(addstr)

if nargin < 1, addstr = 'add'; end

data = get_gui_data;

cl = mask2clusters(data.Rvol, data.V.mat);
if isempty(cl)
    spm_image('init', data.ovl);
else
    cluster_orthviews(cl, {[0 1 0]}, addstr, 'overlay', data.ovl);
end