/* * chase.c - Code for one object to chase another * * Advanced Rogue * Copyright (C) 1984, 1985, 1986 Michael Morgan, Ken Dalka and AT&T * All rights reserved. * * Based on "Rogue: Exploring the Dungeons of Doom" * Copyright (C) 1980, 1981 Michael Toy, Ken Arnold and Glenn Wichman * All rights reserved. * * See the file LICENSE.TXT for full copyright and licensing information. */ /* * Code for one object to chase another * */ #include #include #include #include "curses.h" #include "rogue.h" #define MAXINT INT_MAX #define MININT INT_MIN bool straight_shot(int ery, int erx, int eey, int eex, coord *shooting); /* * Canblink checks if the monster can teleport (blink). If so, it will * try to blink the monster next to the player. */ bool can_blink(struct thing *tp) { register int y, x, index=9; coord tryp; /* To hold the coordinates for use in diag_ok */ bool spots[9], found_one=FALSE; /* * First, can the monster even blink? And if so, there is only a 50% * chance that it will do so. And it won't blink if it is running or * held. */ if (off(*tp, CANBLINK) || (on(*tp, ISHELD)) || on(*tp, ISFLEE) || tp->t_action == A_FREEZE || (rnd(12) < 6)) return(FALSE); /* Initialize the spots as illegal */ do { spots[--index] = FALSE; } while (index > 0); /* Find a suitable spot next to the player */ for (y=hero.y-1; y= cols || index == 4) continue; /* Is it OK to move there? */ if (step_ok(y, x, NOMONST, tp) && (!isatrap(mvwinch(cw, y, x)) || rnd(10) >= tp->t_stats.s_intel || on(*tp, ISFLY))) { /* OK, we can go here. But don't go there if * monster can't get at player from there */ tryp.y = y; tryp.x = x; if (diag_ok(&tryp, &hero, tp)) { spots[index] = TRUE; found_one = TRUE; } } } /* If we found one, go to it */ if (found_one) { char rch; /* What's really where the creatures moves to */ /* Find a legal spot */ while (spots[index=rnd(9)] == FALSE) continue; /* Get the coordinates */ y = hero.y + (index/3) - 1; x = hero.x + (index % 3) - 1; /* Move the monster from the old space */ mvwaddch(cw, tp->t_pos.y, tp->t_pos.x, tp->t_oldch); /* Move it to the new space */ tp->t_oldch = CCHAR( mvwinch(cw, y, x) ); /* Display the creature if our hero can see it */ if (cansee(y, x) && off(*tp, ISINWALL) && !invisible(tp)) mvwaddch(cw, y, x, tp->t_type); /* Fix the monster window */ mvwaddch(mw, tp->t_pos.y, tp->t_pos.x, ' '); /* Clear old position */ mvwaddch(mw, y, x, tp->t_type); /* Record the new position */ tp->t_pos.y = y; tp->t_pos.x = x; /* If the monster is on a trap, trap it */ rch = CCHAR( mvinch(y, x) ); if (isatrap(rch)) { if (cansee(y, x)) tp->t_oldch = rch; be_trapped(tp, &(tp->t_pos)); } } return(found_one); } /* * Can_shoot determines if the monster (er) has a direct line of shot * at the prey (ee). If so, it returns the direction in which to shoot. */ coord * can_shoot(coord *er, coord *ee) { static coord shoot_dir; /* * They must be in the same room or very close (at door) */ if (roomin(er) != roomin(ee) && DISTANCE(er->y,er->x,ee->y,ee->x) > 1) return(NULL); /* Do we have a straight shot? */ if (!straight_shot(er->y, er->x, ee->y, ee->x, &shoot_dir)) return(NULL); else return(&shoot_dir); } /* * chase: * Find the spot for the chaser(er) to move closer to the * chasee(ee). Rer is the room of the chaser, and ree is the * room of the creature being chased (chasee). Flee is true if * destination (ee) is player and monster is running away * or the player is in a wall and the monster can't get to it */ void chase(struct thing *tp, coord *ee, struct room *rer, struct room *ree, bool flee) { int dist, thisdist, monst_dist = MAXINT; register coord *er = &tp->t_pos; struct thing *prey; /* What we are chasing */ coord ch_ret; /* Where chasing takes you */ char ch, mch; bool next_player = FALSE; /* * set the distance from the chas(er) to the chas(ee) here and then * we won't have to reset it unless the chas(er) moves (instead of shoots) */ dist = DISTANCE(er->y, er->x, ee->y, ee->x); /* * See if our destination is a monster or player. If so, make "prey" point * to it. */ if (ce(hero, *ee)) prey = &player; /* Is it the player? */ else if (tp->t_dest && ce(*(tp->t_dest), *ee)) { /* Is it a monster? */ struct linked_list *item; /* What is the monster we're chasing? */ item = find_mons(ee->y, ee->x); if (item != NULL) prey = THINGPTR(item); else prey = NULL; } else prey = NULL; /* We will use at least one movement period */ tp->t_no_move = movement(tp); if (on(*tp, ISFLY)) /* If the creature is flying, speed it up */ tp->t_no_move /= 2; /* * If the thing is confused or it can't see the player, * let it move randomly. */ if ((on(*tp, ISHUH) && rnd(10) < 8) || (prey && on(*prey, ISINVIS) && off(*tp, CANSEE))) { /* invisible prey */ /* * get a valid random move */ tp->t_newpos = *rndmove(tp); dist = DISTANCE(tp->t_newpos.y, tp->t_newpos.x, ee->y, ee->x); } /* * Otherwise, find the empty spot next to the chaser that is * closest to the chasee. */ else { register int ey, ex, x, y; int dist_to_old = MININT; /* Dist from goal to old position */ /* * This will eventually hold where we move to get closer * If we can't find an empty spot, we stay where we are. */ dist = flee ? 0 : MAXINT; ch_ret = *er; /* Are we at our goal already? */ if (!flee && ce(ch_ret, *ee)) { turn_off(*tp, ISRUN); /* So stop running! */ return; } ey = er->y + 1; ex = er->x + 1; /* Check all possible moves */ for (x = er->x - 1; x <= ex; x++) { if (x < 0 || x >= cols) /* Don't try off the board */ continue; for (y = er->y - 1; y <= ey; y++) { coord tryp; if ((y < 1) || (y >= lines - 2)) /* Don't try off the board */ continue; /* Don't try the player if not going after the player */ if ((flee || !ce(hero, *ee) || on(*tp, ISFRIENDLY)) && x == hero.x && y == hero.y) { next_player = TRUE; continue; } tryp.x = x; tryp.y = y; /* Is there a monster on this spot closer to our goal? * Don't look in our spot or where we were. */ if (!ce(tryp, *er) && !ce(tryp, tp->t_oldpos) && isalpha(mch = CCHAR( mvwinch(mw, y, x) ) )) { int test_dist; test_dist = DISTANCE(y, x, ee->y, ee->x); if (test_dist <= 25 && /* Let's be fairly close */ test_dist < monst_dist) { /* Could we really move there? */ mvwaddch(mw, y, x, ' '); /* Temporarily blank monst */ if (diag_ok(er, &tryp, tp)) monst_dist = test_dist; mvwaddch(mw, y, x, mch); /* Restore monster */ } } /* Can we move onto the spot? */ if (!diag_ok(er, &tryp, tp)) continue; ch = CCHAR( mvwinch(cw, y, x) ); /* Screen character */ /* * Stepping on player is NOT okay if we are fleeing. * If we are friendly to the player and there is a monster * in the way that is not of our race, it is okay to move * there. */ if (step_ok(y, x, FIGHTOK, tp) && (off(*tp, ISFLEE) || ch != PLAYER)) { /* * If it is a trap, an intelligent monster may not * step on it (unless our hero is on top!) */ if ((isatrap(ch)) && (rnd(10) < tp->t_stats.s_intel) && (!on(*tp, ISFLY)) && (y != hero.y || x != hero.x)) continue; /* * OK -- this place counts */ thisdist = DISTANCE(y, x, ee->y, ee->x); /* Adjust distance if we are being shot at */ if (tp->t_wasshot && tp->t_stats.s_intel > 5 && prey != NULL) { /* Move out of line of sight */ if (straight_shot(tryp.y, tryp.x, ee->y, ee->x, NULL)) { if (flee) thisdist -= SHOTPENALTY; else thisdist += SHOTPENALTY; } /* But do we want to leave the room? */ else if (rer && rer == ree && ch == DOOR) thisdist += DOORPENALTY; } /* Don't move to the last position if we can help it * (unless out prey just moved there) */ if (ce(tryp, tp->t_oldpos) && (flee || !ce(tryp, hero))) dist_to_old = thisdist; else if ((flee && (thisdist > dist)) || (!flee && (thisdist < dist))) { ch_ret = tryp; dist = thisdist; } } } } /* If we aren't trying to get the player, but he is in our way, * hit him (unless we have been turned or are friendly). next_player * being TRUE -> we are next to the player but don't want to hit him. * * If we are friendly to the player, following him, and standing next * to him, we will try to help him out in battle. */ if (next_player && off(*tp, WASTURNED)) { if (off(*tp, ISFRIENDLY) && ((flee && ce(ch_ret, *er)) || (!flee && DISTANCE(er->y, er->x, ee->y, ee->x) < dist)) && step_ok(tp->t_dest->y, tp->t_dest->x, NOMONST, tp)) { /* Okay to hit player */ debug("Switching to hero."); tp->t_newpos = hero; tp->t_action = A_MOVE; return; } else if (on(*tp, ISFRIENDLY) && !flee && ce(*ee, hero)) { /* * Look all around the player. If there is a fightable * creature next to both of us, hit it. Otherwise, if * there is a fightable creature next to the player, try * to move next to it. */ dist = MAXINT; for (x = hero.x - 1; x <= hero.x + 1; x++) { if (x < 0 || x >= cols) /* Don't try off the board */ continue; for (y = hero.y - 1; y <= hero.y + 1; y++) { if ((y < 1) || (y >= lines - 2)) /* Stay on the board */ continue; /* Is there a fightable monster here? */ if (isalpha(mvwinch(mw, y, x)) && step_ok(y, x, FIGHTOK, tp) && off(*tp, ISSTONE)) { thisdist = DISTANCE(er->y, er->x, y, x); if (thisdist < dist) { dist = thisdist; ch_ret.y = y; ch_ret.x = x; } } } } /* Are we next to a bad guy? */ if (dist <= 2) { /* Get him! */ tp->t_newpos = ch_ret; tp->t_action = A_MOVE; } /* Try to move to the bad guy */ else if (dist < MAXINT) chase(tp, &ch_ret, roomin(&tp->t_pos), roomin(&ch_ret), FALSE); else tp->t_action = A_NIL; return; } } /* * If we have decided that we can move onto a monster (we are * friendly to the player, go to it. */ if (!ce(ch_ret, *er) && isalpha(mvwinch(mw, ch_ret.y, ch_ret.x))) { debug("Attack monster"); tp->t_newpos = ch_ret; tp->t_action = A_MOVE; return; } /* If we can't get closer to the player (if that's our goal) * because other monsters are in the way, just stay put */ if (!flee && ce(hero, *ee) && monst_dist < MAXINT && DISTANCE(er->y, er->x, hero.y, hero.x) < dist) { tp->t_action = A_NIL; /* do nothing for awhile */ return; } /* Do we want to go back to the last position? */ else if (dist_to_old != MININT && /* It is possible to move back */ ((flee && dist == 0) || /* No other possible moves */ (!flee && dist == MAXINT))) { /* Do we move back or just stay put (default)? */ dist = DISTANCE(er->y, er->x, ee->y, ee->x); /* Current distance */ if (!flee || (flee && (dist_to_old > dist))) ch_ret = tp->t_oldpos; } /* Record the new destination */ tp->t_newpos = ch_ret; } /* * Do we want to fight or move? If our selected destination (ch_ret) * is our hero, then we want to fight. Otherwise, we want to move. */ if (ce(tp->t_newpos, hero)) { /* Fight! (or sell) */ if (on(*tp, CANSELL)) { tp->t_action = A_SELL; tp->t_no_move += movement(tp); /* takes a little time to sell */ } else { tp->t_action = A_ATTACK; /* * Try to find a weapon to wield. Wield_weap will return a * projector if weapon is a projectile (eg. bow for arrow). * If weapon is NULL (the case here), it will try to find * a suitable weapon. * * Add in rest of time. Fight is * movement() + weap_move() + FIGHTBASE */ tp->t_using = wield_weap(NULL, tp); if (tp->t_using == NULL) tp->t_no_move += weap_move(tp, NULL); else tp->t_no_move += weap_move(tp, OBJPTR(tp->t_using)); if (on(*tp, ISHASTE)) tp->t_no_move += FIGHTBASE/2; else if (on(*tp, ISSLOW)) tp->t_no_move += FIGHTBASE*2; else tp->t_no_move += FIGHTBASE; } } else { /* Move */ tp->t_action = A_MOVE; /* * Check if the creature is not next to the player. If it * is not and has held or suffocated the player, then stop it! * Note that this code should more appropriately appear in * the area that actually moves the monster, but for now it * is okay here because the player can't move while held or * suffocating. */ if (dist > 2) { if (on(*tp, DIDHOLD)) { turn_off(*tp, DIDHOLD); turn_on(*tp, CANHOLD); if (--hold_count == 0) turn_off(player, ISHELD); } /* If monster was suffocating, stop it */ if (on(*tp, DIDSUFFOCATE)) { turn_off(*tp, DIDSUFFOCATE); turn_on(*tp, CANSUFFOCATE); extinguish(suffocate); msg("You can breathe again.....Whew!"); } } } } /* * do_chase: * Make one thing chase another. */ void do_chase(struct thing *th) { register struct room *orig_rer, /* Original room of chaser */ *new_room; /* new room of monster */ char floor, rch, sch; coord old_pos, /* Old position of monster */ ch_ret; /* Where we want to go */ if (on(*th, NOMOVE)) return; ch_ret = th->t_newpos; /* Record our desired new position */ /* * Make sure we have an open spot (no other monster's gotten in our way, * someone didn't just drop a scare monster there, our prey didn't just * get there, etc.) */ if (!step_ok(th->t_newpos.y, th->t_newpos.x, FIGHTOK, th)) { /* * Most monsters get upset now. Guardians are all friends, * and we don't want to see 50 messages in a row! */ if (th->t_stats.s_intel > 4 && off(*th, ISUNDEAD) && off(*th, ISGUARDIAN) && off(*th, AREMANY) && off(*th, ISHUH) && off(player, ISBLIND) && cansee(unc(th->t_pos)) && !invisible(th)) msg("%s motions angrily.", prname(monster_name(th), TRUE)); return; } else if (ce(th->t_newpos, hero) || /* Player just got in our way */ isalpha(mvwinch(mw, th->t_newpos.y, th->t_newpos.x))) { bool fightplayer = ce(th->t_newpos, hero); /* If we were turned or are friendly, we just have to sit here! */ if (fightplayer && (on(*th, WASTURNED) || on(*th, ISFRIENDLY))) return; /* Do we want to sell something? */ if (fightplayer && on(*th, CANSELL)) { th->t_action = A_SELL; th->t_no_move += movement(th); /* takes a little time to sell */ return; } /* Let's hit him */ th->t_action = A_ATTACK; /* * Try to find a weapon to wield. Wield_weap will return a * projector if weapon is a projectile (eg. bow for arrow). * If weapon is NULL (the case here), it will try to find * a suitable weapon. */ th->t_using = wield_weap(NULL, th); /* * add in rest of time */ if (th->t_using == NULL) th->t_no_move += weap_move(th, NULL); else th->t_no_move += weap_move(th, OBJPTR(th->t_using)); if (on(*th, ISHASTE)) th->t_no_move += FIGHTBASE/2; else if (on(*th, ISSLOW)) th->t_no_move += FIGHTBASE*2; else th->t_no_move += FIGHTBASE; return; } /* * Blank out the old position and record the new position -- * the blanking must be done first in case the positions are the same. */ mvwaddch(mw, th->t_pos.y, th->t_pos.x, ' '); mvwaddch(mw, ch_ret.y, ch_ret.x, th->t_type); /* Get new and old rooms of monster */ new_room = roomin(&ch_ret); orig_rer = roomin(&th->t_pos); /* Store the critter's old position and update the current one */ old_pos = th->t_pos; th->t_pos = ch_ret; floor = (roomin(&ch_ret) == NULL) ? PASSAGE : FLOOR; /* If we have a scavenger, it can pick something up */ if (off(*th, ISGUARDIAN)) { register struct linked_list *n_item, *o_item; register int item_count = 0; bool want_something = FALSE; while ((n_item = find_obj(ch_ret.y, ch_ret.x)) != NULL) { register struct object *n_obj, *o_obj; bool wants_it; /* Does this monster want anything? */ if (want_something == FALSE) { if (on(*th, ISSCAVENGE) || on(*th, CARRYFOOD) || on(*th, CARRYGOLD) || on(*th, CARRYSCROLL) || on(*th, CARRYPOTION) || on(*th, CARRYRING) || on(*th, CARRYSTICK) || on(*th, CARRYMISC) || on(*th, CARRYWEAPON) || on(*th, CARRYARMOR) || on(*th, CARRYDAGGER)) { want_something = TRUE; /* * Blank the area. We have to do it only before the * first item in case an item gets dropped in same * place. We don't want to blank it out after it get * dropped. */ mvaddch(ch_ret.y, ch_ret.x, floor); /* Were we specifically after something here? */ if (ce(*th->t_dest, ch_ret)) { /* If we're mean, we go after the hero */ if (on(*th, ISMEAN)) runto(th, &hero); /* Otherwise just go back to sleep */ else { turn_off(*th, ISRUN); th->t_dest = NULL; } } } else break; } item_count++; /* Count the number of items */ /* * see if he's got one of this group already */ o_item = NULL; n_obj = OBJPTR(n_item); detach(lvl_obj, n_item); /* See if he wants it */ if (n_obj->o_type == SCROLL && n_obj->o_which == S_SCARE && th->t_stats.s_intel < 16) wants_it = FALSE; /* Most monsters don't want a scare monster */ else if (on(*th, ISSCAVENGE)) wants_it = TRUE; else { wants_it = FALSE; /* Default case */ switch (n_obj->o_type) { case FOOD: if(on(*th, CARRYFOOD)) wants_it = TRUE; when GOLD: if(on(*th, CARRYGOLD)) wants_it = TRUE; when SCROLL:if(on(*th, CARRYSCROLL)) wants_it = TRUE; when POTION:if(on(*th, CARRYPOTION)) wants_it = TRUE; when RING: if(on(*th, CARRYRING)) wants_it = TRUE; when STICK: if(on(*th, CARRYSTICK)) wants_it = TRUE; when MM: if(on(*th, CARRYMISC)) wants_it = TRUE; when ARMOR: if(on(*th, CARRYARMOR)) wants_it = TRUE; when WEAPON:if(on(*th, CARRYWEAPON) || (on(*th,CARRYDAGGER)&&n_obj->o_which==DAGGER)) wants_it = TRUE; } } /* * The quartermaster doesn't sell cursed stuff so he won't * pick it up */ if (on(*th, CANSELL) && (n_obj->o_flags & ISCURSED)) wants_it = FALSE; /* If he doesn't want it, throw it away */ if (wants_it == FALSE) { fall(n_item, FALSE); continue; } /* Otherwise, let's pick it up */ if (n_obj->o_group) { for(o_item = th->t_pack; o_item != NULL; o_item = next(o_item)){ o_obj = OBJPTR(o_item); if (o_obj->o_group == n_obj->o_group) { o_obj->o_count += n_obj->o_count; o_discard(n_item); break; } } } if (o_item == NULL) { /* didn't find it */ attach(th->t_pack, n_item); } } /* If there was anything here, we may have to update the screen */ if (item_count) { if (cansee(ch_ret.y, ch_ret.x)) mvwaddch(cw, ch_ret.y, ch_ret.x, mvinch(ch_ret.y, ch_ret.x)); updpack(TRUE, th); /* Update the monster's encumberance, too */ } } rch = CCHAR( mvwinch(stdscr, old_pos.y, old_pos.x) ); if (th->t_oldch == floor && rch != floor && !isatrap(rch)) mvwaddch(cw, old_pos.y, old_pos.x, rch); else mvwaddch(cw, old_pos.y, old_pos.x, th->t_oldch); sch = CCHAR( mvwinch(cw, ch_ret.y, ch_ret.x) ); /* What player sees */ rch = CCHAR( mvwinch(stdscr, ch_ret.y, ch_ret.x) ); /* What's really there */ /* If we have a tunneling monster, it may be making a tunnel */ if (on(*th, CANTUNNEL) && (rch == SECRETDOOR || rch == WALL || rch == '|' || rch == '-')) { char nch; /* The new look to the tunnel */ if (rch == WALL) nch = PASSAGE; else if (levtype == MAZELEV) nch = FLOOR; else nch = DOOR; addch(nch); if (cansee(ch_ret.y, ch_ret.x)) sch = nch; /* Can player see this? */ /* Does this make a new exit? */ if (rch == '|' || rch == '-') { struct linked_list *newroom; coord *exit; newroom = new_item(sizeof(coord)); exit = DOORPTR(newroom); *exit = ch_ret; attach(new_room->r_exit, newroom); } } /* Mark if the monster is inside a wall */ if (isrock(mvinch(ch_ret.y, ch_ret.x))) turn_on(*th, ISINWALL); else turn_off(*th, ISINWALL); /* If the monster can illuminate rooms, check for a change */ if (on(*th, HASFIRE)) { register struct linked_list *fire_item; /* Is monster entering a room? */ if (orig_rer != new_room && new_room != NULL) { fire_item = creat_item(); /* Get an item-only structure */ ldata(fire_item) = (char *) th; attach(new_room->r_fires, fire_item); new_room->r_flags |= HASFIRE; if (cansee(ch_ret.y, ch_ret.x) && next(new_room->r_fires) == NULL) light(&hero); } /* Is monster leaving a room? */ if (orig_rer != new_room && orig_rer != NULL) { /* Find the bugger in the list and delete him */ for (fire_item = orig_rer->r_fires; fire_item != NULL; fire_item = next(fire_item)) { if (THINGPTR(fire_item) == th) { /* Found him! */ detach(orig_rer->r_fires, fire_item); destroy_item(fire_item); if (orig_rer->r_fires == NULL) { orig_rer->r_flags &= ~HASFIRE; if (cansee(old_pos.y, old_pos.x)) light(&old_pos); } break; } } } } /* If monster is entering player's room and player can see it, * stop the player's running. */ if (new_room != orig_rer && new_room != NULL && new_room == roomin(th->t_dest) && cansee(unc(ch_ret)) && (off(*th, ISINVIS) || on(player, CANSEE)) && (off(*th, ISSHADOW) || on(player, CANSEE)) && (off(*th, CANSURPRISE) || ISWEARING(R_ALERT))) { running = FALSE; if (fight_flush) md_flushinp(); } th->t_oldch = sch; /* Let's display those creatures that we can see. */ if (cansee(unc(ch_ret)) && off(*th, ISINWALL) && !invisible(th)) mvwaddch(cw, ch_ret.y, ch_ret.x, th->t_type); /* Record monster's last position (if new one is different) */ if (!ce(ch_ret, old_pos)) th->t_oldpos = old_pos; /* If the monster is on a trap, trap it */ sch = CCHAR( mvinch(ch_ret.y, ch_ret.x) ); if (isatrap(sch)) { if (cansee(ch_ret.y, ch_ret.x)) th->t_oldch = sch; be_trapped(th, &ch_ret); } } /* * Get_hurl returns the weapon that the monster will "throw" if he has one */ struct linked_list * get_hurl(struct thing *tp) { struct linked_list *arrow=NULL, *bolt=NULL, *rock=NULL, *spear = NULL, *dagger=NULL, *dart=NULL, *aklad=NULL; register struct linked_list *pitem; register struct object *obj; bool bow=FALSE, crossbow=FALSE, sling=FALSE; for (pitem=tp->t_pack; pitem; pitem=next(pitem)) { obj = OBJPTR(pitem); if (obj->o_type == WEAPON) switch (obj->o_which) { case BOW: bow = TRUE; when CROSSBOW: crossbow = TRUE; when SLING: sling = TRUE; when ROCK: rock = pitem; when ARROW: arrow = pitem; when BOLT: bolt = pitem; when SPEAR: spear = pitem; when DAGGER: /* Don't throw the dagger if it's our last one */ if (obj->o_count > 1) dagger = pitem; when DART: dart = pitem; } else if (obj->o_type == RELIC && obj->o_which == AXE_AKLAD) aklad = pitem; } /* Do we have that all-powerful Aklad Axe? */ if (aklad) return(aklad); /* Use crossbow bolt if possible */ if (crossbow && bolt) return(bolt); if (bow && arrow) return(arrow); if (spear) return(spear); if (dagger) return(dagger); if (sling && rock) return(rock); if (dart) return(dart); return(NULL); } /* * runto: * Set a monster running after something */ void runto(struct thing *runner, coord *spot) { if (on(*runner, ISSTONE)) return; /* If we are chasing a new creature, forget about thrown weapons */ if (runner->t_dest && !ce(*runner->t_dest, *spot)) runner->t_wasshot=FALSE; /* * Start the beastie running */ runner->t_dest = spot; turn_on(*runner, ISRUN); turn_off(*runner, ISDISGUISE); } /* * straight_shot: * See if there is a straight line of sight between the two * given coordinates. If shooting is not NULL, it is a pointer * to a structure which should be filled with the direction * to shoot (if there is a line of sight). If shooting, monsters * get in the way. Otherwise, they do not. */ bool straight_shot(int ery, int erx, int eey, int eex, coord *shooting) { register int dy, dx; /* Deltas */ char ch; /* Does the monster have a straight shot at prey */ if ((ery != eey) && (erx != eex) && (abs(ery - eey) != abs(erx - eex))) return(FALSE); /* Get the direction to shoot */ if (eey > ery) dy = 1; else if (eey == ery) dy = 0; else dy = -1; if (eex > erx) dx = 1; else if (eex == erx) dx = 0; else dx = -1; /* Make sure we have free area all the way to the player */ ery += dy; erx += dx; while ((ery != eey) || (erx != eex)) { switch (ch = CCHAR( winat(ery, erx) )) { case '|': case '-': case WALL: case DOOR: case SECRETDOOR: case FOREST: return(FALSE); default: if (shooting && isalpha(ch)) return(FALSE); } ery += dy; erx += dx; } if (shooting) { /* If we are shooting -- put in the directions */ shooting->y = dy; shooting->x = dx; } return(TRUE); }