Function show_map_spot

src/detect.c:1371–1419

used by magic mapping, clairvoyance, and wand of probing */

/* used by magic mapping, clairvoyance, and wand of probing */
void
show_map_spot(coordxy x, coordxy y, boolean cnf)
{
    struct rm *lev;
    struct trap *t;
    struct engr *ep;
    int oldglyph;

    if (cnf && rn2(7))
        return;
    lev = &levl[x][y];

    lev->seenv = SVALL;

    /* Secret corridors are found, but not secret doors. */
    if (lev->typ == SCORR) {
        lev->typ = CORR;
        unblock_point(x, y);
    }

    /*
     * Force the real background, then if it's not furniture and there's
     * a known trap there, display the trap, else if there was an object
     * shown there, redisplay the object.  So during mapping, furniture
     * takes precedence over traps, which take precedence over objects,
     * opposite to how normal vision behaves.
     */
    oldglyph = glyph_at(x, y);
    if (svl.level.flags.hero_memory) {
        magic_map_background(x, y, 0);
        newsym(x, y); /* show it, if not blocked */
    } else {
        magic_map_background(x, y, 1); /* display it */
    }
    if (!IS_FURNITURE(lev->typ)) {
        if ((t = t_at(x, y)) != 0 && t->tseen) {
            map_trap(t, 1);
        } else if ((ep = engr_at(x, y)) != 0 && !cnf) {
            map_engraving(ep, 1);
        } else if (glyph_is_trap(oldglyph) || glyph_is_object(oldglyph)) {
            show_glyph(x, y, oldglyph);
            if (svl.level.flags.hero_memory)
                lev->glyph = oldglyph;
        }
    }
    /* possibly update #overview */
    if (!cnf && lev->roomno >= ROOMOFFSET)
        room_discovered(lev->roomno - ROOMOFFSET);
}

void
do_mapping(void)