Method init

crawl-ref/source/viewmap.cc:418–426

public:
    void init()
    {
        for (vector<cglyph_t> &groupdata : data)
            groupdata.clear();
        for (rectangle_iterator ri(0); ri; ++ri)
            maybe_add(*ri);
        for (vector<cglyph_t> &groupdata : data)
            sort(begin(groupdata), end(groupdata), _comp_glyphs);
    }

    formatted_string format() const
    {