static bool place_feature_near( const coord_def &centre,
                                int radius,
                                dungeon_feature_type candidate,
                                dungeon_feature_type replacement,
                                int tries )
{
    const int radius2 = radius * radius + 1;
    for (int i = 0; i < tries; ++i)
    {
        const coord_def &cp =
            centre + coord_def(random_range(-radius, radius),
                               random_range(-radius, radius));
        if (cp == centre || (cp - centre).abs() > radius2 || !in_bounds(cp))
            continue;
        if (grd(cp) == candidate)
        {
#ifdef DEBUG_DIAGNOSTICS
            mprf(MSGCH_DIAGNOSTICS, "Placing %s at (%d,%d)",
                 dungeon_feature_name(replacement),
                 cp.x, cp.y);
#endif
            grd(cp) = replacement;
            return (true);
        }
    }
    return (false);
}

        grd[46][35] = DNGN_ALTAR_LUGONU;
}                               // end generate_abyss()

        place_feature_near( coord_def(45, 35), LOS_RADIUS,
                            DNGN_FLOOR, DNGN_ALTAR_LUGONU, 50 );
}

        grd[you.x_pos + 1][you.y_pos] = DNGN_ALTAR_LUGONU;

        place_feature_near( you.pos(), LOS_RADIUS,
                            DNGN_FLOOR, DNGN_ALTAR_LUGONU, 50 );