Function m_postmove_effect

src/monmove.c:671–683

do whatever effects monster has after moving. called for both monsters and polyed hero. for hero, called after location changes, to prevent spam messages for hero getting enveloped in a cloud. for monsters, called before location changes, because monsters don't have "previous location" field */

   for monsters, called before location changes,
   because monsters don't have "previous location" field */
void
m_postmove_effect(struct monst *mtmp)
{
    boolean is_u = (mtmp == &gy.youmonst) ? TRUE : FALSE;
    coordxy x = is_u ? u.ux0 : mtmp->mx,
            y = is_u ? u.uy0 : mtmp->my;

    /* Hezrous create clouds of stench. This does not cost a move. */
    if (mtmp->data == &mons[PM_HEZROU]) /* stench */
        create_gas_cloud(x, y, 1, 8);
    else if (mtmp->data == &mons[PM_STEAM_VORTEX] && !mtmp->mcan)
        create_gas_cloud(x, y, 1, 0); /* harmless vapor */
}

/* returns 1 if monster died moving, 0 otherwise */
/* The whole dochugw/m_move/distfleeck/mfndpos section is serious spaghetti