function export_case()
%EXPORT_CASE  按 case_config.m 导出本算例的 OpticsFEM JSON（含 ElementOrder=2）。
[phy, cfg] = case_config();
root = fileparts(mfilename('fullpath'));
addpath(fullfile(root, '..', 'common'));
jsonPath = fullfile(root, cfg.jsonFile);
export_phy_to_json(phy, jsonPath, cfg);

% Append ElementOrder (export_phy_to_json 目前未写该字段)
txt = fileread(jsonPath);
if ~contains(txt, '"ElementOrder"')
    txt = strrep(txt, sprintf('"EletricType": %d,', cfg.EletricType), ...
        sprintf('"EletricType": %d,\n  "ElementOrder": %d,', cfg.EletricType, cfg.ElementOrder));
    fid = fopen(jsonPath, 'w');
    fprintf(fid, '%s', txt);
    fclose(fid);
end
fprintf('已写出 %s\n', jsonPath);
fprintf('C++ 算例目录: 3D opticsfem-master\\scat3D_order2\\\n');
end