2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2008, Dave Pare, Jeff Bailey, Thomas Ruschak,
4 * Ken Stevens, Steve McClure
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * See files README, COPYING and CREDITS in the root of the source
23 * tree for related information and legal notices. It is expected
24 * that future projects/authors will amend these files as needed.
28 * shpsub.c: Ship subroutine stuff
30 * Known contributors to this file:
32 * Steve McClure, 1996-2000
33 * Markus Armbruster, 2006
49 #include "prototypes.h"
56 static int shp_check_one_mines(struct ulist *);
57 static int shp_hit_mine(struct shpstr *, struct mchrstr *);
58 static void shp_mess(char *, struct ulist *);
61 shp_sel(struct nstr_item *ni, struct emp_qelem *list)
73 while (nxtitem(ni, &ship)) {
76 mcp = &mchr[(int)ship.shp_type];
77 /* if (wantflags && (mcp->m_flags & wantflags) != wantflags)
79 if (nowantflags && mcp->m_flags & nowantflags)
83 if (ontradingblock(EF_SHIP, &ship)) {
84 pr("ship #%d inelligible - it's for sale.\n",
89 /* This abuse is better fixed by building a ship with the normal negative
90 mobility that everything else is built with */
93 if (ship.shp_effic < 21 &&
94 ship.shp_mobil < etu_per_update) {
95 pr("%s needs at least %d mob to navigate.\n",
96 prship(&ship), etu_per_update);
101 ship.shp_mission = 0;
103 memset(ship.shp_rpath, 0, sizeof(ship.shp_rpath));
104 putship(ship.shp_uid, &ship);
105 mlp = malloc(sizeof(struct ulist));
106 mlp->chrp = (struct empobj_chr *)mcp;
107 mlp->unit.ship = ship;
108 mlp->mobil = ship.shp_mobil;
109 emp_insque(&mlp->queue, list);
113 /* This function assumes that the list was created by shp_sel */
115 shp_nav(struct emp_qelem *list, double *minmobp, double *maxmobp,
116 int *togetherp, natid actor)
118 struct emp_qelem *qp;
119 struct emp_qelem *next;
130 for (qp = list->q_back; qp != list; qp = next) {
132 mlp = (struct ulist *)qp;
133 getship(mlp->unit.ship.shp_uid, &ship);
134 if (ship.shp_own != actor) {
135 mpr(actor, "%s was sunk at %s\n",
136 prship(&ship), xyas(ship.shp_x, ship.shp_y, actor));
137 emp_remque((struct emp_qelem *)mlp);
142 if (*ship.shp_path && !update_running) {
143 shp_mess("has a sail path", mlp);
144 mpr(actor, "Use `sail <#> -' to reset\n");
148 /* check crew - uws don't count */
149 if (ship.shp_item[I_MILIT] == 0 && ship.shp_item[I_CIVIL] == 0) {
150 shp_mess("is crewless", mlp);
153 if (!getsect(ship.shp_x, ship.shp_y, §)) {
154 shp_mess("was sucked into the sky by a strange looking spaceship", mlp); /* heh -KHS */
157 switch (shp_check_nav(§, &ship)) {
158 case CN_CONSTRUCTION:
159 shp_mess("is caught in a construction zone", mlp);
162 shp_mess("is landlocked", mlp);
168 shp_mess("was just swallowed by a big green worm", mlp);
176 if (ship.shp_x != allx || ship.shp_y != ally)
178 if (ship.shp_mobil + 1 < (int)mlp->mobil) {
179 mlp->mobil = ship.shp_mobil;
181 if (mlp->mobil < *minmobp)
182 *minmobp = mlp->mobil;
183 if (mlp->mobil > *maxmobp)
184 *maxmobp = mlp->mobil;
185 mlp->unit.ship = ship;
190 shp_sweep(struct emp_qelem *ship_list, int verbose, int takemob, natid actor)
192 struct emp_qelem *qp;
193 struct emp_qelem *next;
196 int mines, m, max, shells;
200 for (qp = ship_list->q_back; qp != ship_list; qp = next) {
202 mlp = (struct ulist *)qp;
203 if (!(((struct mchrstr *)mlp->chrp)->m_flags & M_SWEEP)) {
205 mpr(actor, "%s doesn't have minesweeping capability!\n",
206 prship(&mlp->unit.ship));
209 if (takemob && mlp->mobil <= 0.0) {
211 mpr(actor, "%s is out of mobility!\n",
212 prship(&mlp->unit.ship));
215 getsect(mlp->unit.ship.shp_x, mlp->unit.ship.shp_y, §);
216 if (sect.sct_type != SCT_WATER) {
218 mpr(actor, "%s is not at sea. No mines there!\n",
219 prship(&mlp->unit.ship));
223 mlp->mobil -= shp_mobcost(&mlp->unit.ship);
224 mlp->unit.ship.shp_mobil = (int)mlp->mobil;
226 putship(mlp->unit.ship.shp_uid, &mlp->unit.ship);
227 if (!(mines = sect.sct_mines))
229 max = ((struct mchrstr *)mlp->chrp)->m_item[I_SHELL];
230 shells = mlp->unit.ship.shp_item[I_SHELL];
231 for (m = 0; mines > 0 && m < 5; m++) {
233 mpr(actor, "Sweep...\n");
235 shells = MIN(max, shells + 1);
236 changed |= map_set(actor, sect.sct_x, sect.sct_y, 'X', 0);
239 sect.sct_mines = mines;
240 mlp->unit.ship.shp_item[I_SHELL] = shells;
241 if (shp_check_one_mines(mlp)) {
246 putship(mlp->unit.ship.shp_uid, &mlp->unit.ship);
255 shp_check_one_mines(struct ulist *mlp)
260 getsect(mlp->unit.ship.shp_x, mlp->unit.ship.shp_y, §);
261 if (sect.sct_type != SCT_WATER)
265 if (chance(DMINE_HITCHANCE(sect.sct_mines))) {
266 actor = mlp->unit.ship.shp_own;
267 shp_hit_mine(&mlp->unit.ship, ((struct mchrstr *)mlp->chrp));
269 if (map_set(actor, sect.sct_x, sect.sct_y, 'X', 0))
272 putship(mlp->unit.ship.shp_uid, &mlp->unit.ship);
273 if (!mlp->unit.ship.shp_own)
280 shp_check_mines(struct emp_qelem *ship_list)
282 struct emp_qelem *qp;
283 struct emp_qelem *next;
287 for (qp = ship_list->q_back; qp != ship_list; qp = next) {
289 mlp = (struct ulist *)qp;
290 if (shp_check_one_mines(mlp)) {
301 shp_mess(char *str, struct ulist *mlp)
303 mpr(mlp->unit.ship.shp_own, "%s %s & stays in %s\n",
304 prship(&mlp->unit.ship),
305 str, xyas(mlp->unit.ship.shp_x, mlp->unit.ship.shp_y,
306 mlp->unit.ship.shp_own));
307 mlp->unit.ship.shp_mobil = (int)mlp->mobil;
308 putship(mlp->unit.ship.shp_uid, &mlp->unit.ship);
309 emp_remque((struct emp_qelem *)mlp);
314 shp_check_nav(struct sctstr *sect, struct shpstr *shp)
316 switch (dchr[sect->sct_type].d_nav) {
320 if (mchr[(int)shp->shp_type].m_flags & M_CANAL) {
321 if (sect->sct_effic < 2)
322 return CN_CONSTRUCTION;
324 return CN_LANDLOCKED;
327 if (sect->sct_effic < 2)
328 return CN_CONSTRUCTION;
331 if (sect->sct_effic < 60)
332 return CN_CONSTRUCTION;
335 return CN_LANDLOCKED;
341 sect_has_dock(struct sctstr *sect)
343 switch (dchr[sect->sct_type].d_nav) {
353 shp_count(struct emp_qelem *list, int wantflags, int nowantflags,
356 struct emp_qelem *qp;
357 struct emp_qelem *next;
361 for (qp = list->q_back; qp != list; qp = next) {
363 mlp = (struct ulist *)qp;
364 if (mlp->unit.ship.shp_x != x || mlp->unit.ship.shp_y != y)
367 (((struct mchrstr *)mlp->chrp)->m_flags & wantflags) != wantflags)
370 ((struct mchrstr *)mlp->chrp)->m_flags & nowantflags)
378 shp_damage_one(struct ulist *mlp, int dam)
380 shipdamage(&mlp->unit.ship, dam);
381 putship(mlp->unit.ship.shp_uid, &mlp->unit.ship);
382 if (!mlp->unit.ship.shp_own) {
383 emp_remque((struct emp_qelem *)mlp);
389 shp_damage(struct emp_qelem *list, int totdam, int wantflags,
390 int nowantflags, int x, int y)
392 struct emp_qelem *qp;
393 struct emp_qelem *next;
399 || !(count = shp_count(list, wantflags, nowantflags, x, y)))
401 dam = ldround((double)totdam / count, 1);
402 for (qp = list->q_back; qp != list; qp = next) {
404 mlp = (struct ulist *)qp;
405 if (mlp->unit.ship.shp_x != x || mlp->unit.ship.shp_y != y)
408 (((struct mchrstr *)mlp->chrp)->m_flags & wantflags) != wantflags)
411 ((struct mchrstr *)mlp->chrp)->m_flags & nowantflags)
413 shp_damage_one(mlp, dam);
419 shp_contains(struct emp_qelem *list, int newx, int newy, int wantflags,
422 struct emp_qelem *qp;
423 struct emp_qelem *next;
426 for (qp = list->q_back; qp != list; qp = next) {
428 mlp = (struct ulist *)qp;
429 /* If the ship isn't in the requested sector, then continue */
430 if (newx != mlp->unit.ship.shp_x || newy != mlp->unit.ship.shp_y)
433 (((struct mchrstr *)mlp->chrp)->m_flags & wantflags) != wantflags)
436 ((struct mchrstr *)mlp->chrp)->m_flags & nowantflags)
443 static struct ulist *
444 most_valuable_ship(struct emp_qelem *list)
446 struct emp_qelem *qp;
447 struct emp_qelem *next;
449 struct ulist *mvs = 0;
451 for (qp = list->q_back; qp != list; qp = next) {
453 mlp = (struct ulist *)qp;
454 if (((struct mchrstr *)mlp->chrp)->m_flags & M_SUB)
456 if (!((struct mchrstr *)mlp->chrp)->m_nxlight &&
457 !((struct mchrstr *)mlp->chrp)->m_nchoppers &&
458 ((struct mchrstr *)mlp->chrp)->m_cost < 1000 &&
459 !((struct mchrstr *)mlp->chrp)->m_nplanes &&
460 !((struct mchrstr *)mlp->chrp)->m_nland)
466 if (((struct mchrstr *)mlp->chrp)->m_cost * mlp->unit.ship.shp_effic >
467 ((struct mchrstr *)mlp->chrp)->m_cost * mvs->unit.ship.shp_effic)
474 shp_easiest_target(struct emp_qelem *list, int wantflags, int nowantflags)
476 struct emp_qelem *qp;
477 struct emp_qelem *next;
480 int easiest = 9876; /* things start great for victim */
483 for (qp = list->q_back; qp != list; qp = next) {
485 mlp = (struct ulist *)qp;
487 (((struct mchrstr *)mlp->chrp)->m_flags & wantflags) != wantflags)
490 ((struct mchrstr *)mlp->chrp)->m_flags & nowantflags)
492 hard = shp_hardtarget(&mlp->unit.ship);
494 easiest = hard; /* things get worse for victim */
497 return easiest - count;
501 shp_missile_interdiction(struct emp_qelem *list, coord newx, coord newy,
507 struct emp_qelem msl_list, *qp, *newqp;
511 msl_sel(&msl_list, newx, newy, victim, P_T | P_MAR, 0, MI_INTERDICT);
514 while (!QEMPTY(&msl_list) && (mvs = most_valuable_ship(list))) {
515 sprintf(what, "%s", prship(&mvs->unit.ship));
516 dam = msl_launch_mindam(&msl_list, newx, newy,
517 shp_hardtarget(&mvs->unit.ship),
518 EF_SHIP, 1, what, victim, MI_INTERDICT);
521 "missile interdiction mission does %d damage to %s!\n",
523 shp_damage_one(mvs, dam);
526 } else if (++twotries >= 2) {
530 qp = msl_list.q_forw;
531 while (qp != msl_list.q_forw) {
541 /* Note that this function has a side effect - it uses coastwatch
542 * ranges to see if it should fire upon a ship. So, this function
543 * is expected to return positive if a ship is in range, and 0 if a
544 * ship is not in range. */
546 notify_coastguard(struct emp_qelem *list, int trange, struct sctstr *sectp)
548 struct emp_qelem *qp;
549 struct emp_qelem *next;
554 natp = getnatp(sectp->sct_own);
556 vrange = sectp->sct_type == SCT_RADAR ? 14 : 4;
557 vrange *= tfact(sectp->sct_own, 1.0) * sectp->sct_effic / 100.0;
565 for (qp = list->q_back; qp != list; qp = next) {
567 mlp = (struct ulist *)qp;
568 if (((struct mchrstr *)mlp->chrp)->m_flags & M_SUB)
570 if (natp->nat_flags & NF_COASTWATCH)
571 wu(0, sectp->sct_own,
572 "%s %s sighted at %s\n",
573 cname(mlp->unit.ship.shp_own),
574 prship(&mlp->unit.ship),
575 xyas(mlp->unit.ship.shp_x, mlp->unit.ship.shp_y,
578 setcont(sectp->sct_own, mlp->unit.ship.shp_own, FOUND_COAST);
585 shp_fort_interdiction(struct emp_qelem *list, coord newx, coord newy,
595 signed char notified[MAXNOC];
598 /* Inform neutral and worse */
599 for (i = 0; i < MAXNOC; ++i) {
600 if (getrel(getnatp(i), victim) <= NEUTRAL)
606 snxtsct_dist(&ns, newx, newy, fort_max_interdiction_range);
607 while (nxtsct(&ns, &fsect)) {
610 if (fsect.sct_own == victim)
612 if (notified[fsect.sct_own])
614 trange = mapdist(newx, newy, fsect.sct_x, fsect.sct_y);
615 if (notify_coastguard(list, trange, &fsect))
616 notified[fsect.sct_own] = 1;
618 if (opt_NO_FORT_FIRE)
619 return 0; /* Only coastwatch notify in nofortfire */
620 /* Only fire at Hostile ships */
621 for (i = 0; i < MAXNOC; ++i) {
622 if (getrel(getnatp(i), victim) >= NEUTRAL)
625 snxtsct_dist(&ns, newx, newy, fort_max_interdiction_range);
626 while (nxtsct(&ns, &fsect)) {
627 if (!notified[fsect.sct_own])
629 gun = fsect.sct_item[I_GUN];
632 range = roundrange(fortrange(&fsect));
633 trange = mapdist(newx, newy, fsect.sct_x, fsect.sct_y);
636 if (fsect.sct_item[I_MILIT] < 5)
638 shell = fsect.sct_item[I_SHELL];
640 shell += supply_commod(fsect.sct_own, fsect.sct_x, fsect.sct_y,
645 fsect.sct_item[I_SHELL] = shell;
649 guneff = landgun((int)fsect.sct_effic, gun);
652 mpr(victim, "Incoming fire does %d damage!\n", dam);
654 mpr(victim, "%s fires at you for %d!\n",
655 xyas(fsect.sct_x,fsect.sct_y,victim),
659 "%s fires at %s ships in %s for %d!\n",
660 xyas(fsect.sct_x, fsect.sct_y,
662 cname(victim), xyas(newx, newy, fsect.sct_own), dam);
663 nreport(fsect.sct_own, N_SHP_SHELL, victim, 1);
666 return shp_damage(list, totdam, 0, M_SUB, newx, newy);
671 shp_interdict(struct emp_qelem *list, coord newx, coord newy, natid victim)
675 if (shp_contains(list, newx, newy, 0, M_SUB)) {
676 stopping |= shp_fort_interdiction(list, newx, newy, victim);
678 if (shp_contains(list, newx, newy, 0, M_SUB)) {
681 unit_interdict(newx, newy, victim, "ships",
682 shp_easiest_target(list, 0, M_SUB),
684 0, M_SUB, newx, newy);
685 if (most_valuable_ship(list)) {
687 shp_missile_interdiction(list, newx, newy, victim);
691 if (shp_contains(list, newx, newy, M_SUB, 0)) {
694 unit_interdict(newx, newy, victim, "subs",
695 shp_easiest_target(list, M_SUB, 0),
697 M_SUB, 0, newx, newy);
702 /* high value of hardtarget is harder to hit */
704 shp_hardtarget(struct shpstr *sp)
708 struct mchrstr *mcp = mchr + sp->shp_type;
711 getsect(sp->shp_x, sp->shp_y, §);
712 onsea = sect.sct_type == SCT_WATER;
713 if (mcp->m_flags & M_SUB)
715 return (int)((sp->shp_effic / 100.0) *
716 (20 + sp->shp_speed * onsea / 2.0 - vis));
720 shp_hit_mine(struct shpstr *sp, struct mchrstr *mcp)
724 mpr(sp->shp_own, "Kawhomp! Mine detected in %s!\n",
725 xyas(sp->shp_x, sp->shp_y, sp->shp_own));
727 nreport(sp->shp_own, N_HIT_MINE, 0, 1);
730 if (mcp->m_flags & M_SWEEP)
733 shipdamage(sp, ldround(m, 1));
739 shp_nav_one_sector(struct emp_qelem *list, int dir, natid actor,
743 struct emp_qelem *qp;
744 struct emp_qelem *next;
746 struct emp_qelem done;
753 double tech; /* for mapping */
754 double tf; /* for mapping */
758 if (dir <= DIR_STOP || dir >= DIR_VIEW) {
759 unit_put(list, actor);
764 for (qp = list->q_back; qp != list; qp = next) {
766 mlp = (struct ulist *)qp;
767 newx = xnorm(mlp->unit.ship.shp_x + dx);
768 newy = ynorm(mlp->unit.ship.shp_y + dy);
769 getsect(newx, newy, §);
770 navigate = shp_check_nav(§, &mlp->unit.ship);
771 if (navigate != CN_NAVIGABLE ||
772 (sect.sct_own && actor != sect.sct_own &&
773 getrel(getnatp(sect.sct_own), actor) < FRIENDLY)) {
774 if (dchr[sect.sct_type].d_nav == NAV_CANAL &&
775 !(((struct mchrstr *)mlp->chrp)->m_flags & M_CANAL) &&
776 navigate == CN_LANDLOCKED)
778 "is too large to fit into the canal system at %s",
779 xyas(newx, newy, actor));
781 sprintf(dp, "can't go to %s", xyas(newx, newy, actor));
783 mpr(actor, "%s\n", dp);
791 if (mlp->mobil <= 0.0) {
792 shp_mess("is out of mobility", mlp);
795 mobcost = shp_mobcost(&mlp->unit.ship);
796 mlp->unit.ship.shp_x = newx;
797 mlp->unit.ship.shp_y = newy;
798 if (mlp->mobil - mobcost < -127) {
801 mlp->mobil -= mobcost;
803 mlp->unit.ship.shp_mobil = (int)mlp->mobil;
804 putship(mlp->unit.ship.shp_uid, &mlp->unit.ship);
806 /* Now update the map for this ship */
807 tech = techfact(mlp->unit.ship.shp_tech,
808 ((struct mchrstr *)mlp->chrp)->m_vrnge);
809 if (((struct mchrstr *)mlp->chrp)->m_flags & M_SONAR)
810 tf = techfact(mlp->unit.ship.shp_tech, 1.0);
813 radmapupd(mlp->unit.ship.shp_own,
814 mlp->unit.ship.shp_x, mlp->unit.ship.shp_y,
815 (int)mlp->unit.ship.shp_effic, (int)tech, tf);
819 stopping |= shp_sweep(list, 0, 0, actor);
822 stopping |= shp_check_mines(list);
826 /* interdict ships sector by sector */
828 while (!QEMPTY(list)) {
829 mlp = (struct ulist *)list->q_back;
830 newx = mlp->unit.ship.shp_x;
831 newy = mlp->unit.ship.shp_y;
832 stopping |= shp_interdict(list, newx, newy, actor);
833 /* move survivors in this sector to done */
834 for (qp = list->q_back; qp != list; qp = next) {
836 mlp = (struct ulist *)qp;
837 if (mlp->unit.ship.shp_x == newx &&
838 mlp->unit.ship.shp_y == newy) {
840 emp_insque(qp, &done);
844 /* assign surviving ships back to list */
845 emp_insque(list, &done);
853 * Check for incoming missiles with a P_MAR flag.
854 * Return True=1 if the missile was shotdown.
857 * Chad Zabel, July 95
861 shp_missile_defense(coord dx, coord dy, natid bombown, int hardtarget)
867 double gun, eff, teff;
869 snxtitem_dist(&ni, EF_SHIP, dx, dy, 1);
871 while (nxtitem(&ni, &ship)) {
875 if (!(mchr[(int)ship.shp_type].m_flags & M_ANTIMISSILE))
878 if (getrel(getnatp(ship.shp_own), bombown) >= NEUTRAL)
881 if (ship.shp_effic < 60)
884 shell = ship.shp_item[I_SHELL];
885 if (ship.shp_item[I_MILIT] < 1) /* do we have mil? */
887 if (shell < 2) { /* do we need shells */
888 shell += supply_commod(ship.shp_own, ship.shp_x, ship.shp_y,
893 if (ship.shp_item[I_GUN] < 1) /* we need at least 1 gun */
896 /* now calculate the odds */
897 gun = MIN(ship.shp_item[I_GUN], ship.shp_glim);
898 eff = ship.shp_effic / 100.0;
899 teff = ship.shp_tech / (ship.shp_tech + 200.0);
900 /* raise 4.5 for better interception -KHS */
901 hitchance = (int)(gun * eff * teff * 4.5) - hardtarget;
907 mpr(bombown, "%s anti-missile system activated...",
908 cname(ship.shp_own));
909 mpr(ship.shp_own, "Ship #%i anti-missile system activated!\n",
911 mpr(ship.shp_own, "%d%% hitchance...", hitchance);
913 ship.shp_item[I_SHELL] = shell - 2;
914 putship(ship.shp_uid, &ship);
916 if (roll(100) <= hitchance) {
917 mpr(bombown, "KABOOOM!! Missile destroyed\n\n");
919 "KABOOOM!! Incoming missile destroyed!\n\n");
922 mpr(bombown, "SWOOSH!! anti-missile system failed!!\n");
924 "SWOOSH!! Missile evades anti-missile systems\n\n");
927 return 0; /* all attempts failed */
931 /* Fire missiles at a ship which has fired shells */
933 shp_missdef(struct shpstr *sp, natid victim)
935 struct emp_qelem list;
942 mlp = malloc(sizeof(struct ulist));
943 mlp->chrp = (struct empobj_chr *)&mchr[(int)sp->shp_type];
944 mlp->unit.ship = *sp;
945 mlp->mobil = sp->shp_mobil;
946 emp_insque(&mlp->queue, &list);
947 sprintf(buf, "%s", prship(&mlp->unit.ship));
950 if (most_valuable_ship(&list)) {
951 shp_missile_interdiction(&list, sp->shp_x, sp->shp_y, sp->shp_own);
952 getship(sp->shp_uid, sp);
956 "missiles launched in defense did 100%% damage to %s\n",
958 wu(0, victim, "%s sunk!\n", buf);
959 } else if (eff > 0 && sp->shp_effic < eff) {
961 "missiles launched in defense did %d%% damage to %s\n",
962 100 * (eff - sp->shp_effic) / eff, buf);
970 shp_mobcost(struct shpstr *sp)
972 return speed_factor(sp->shp_effic * 0.01 * sp->shp_speed,
977 * Set SP's tech to TLEV along with everything else that depends on it.
980 shp_set_tech(struct shpstr *sp, int tlev)
982 struct mchrstr *mcp = mchr + sp->shp_type;
983 int tech_diff = tlev - mcp->m_tech;
985 if (CANT_HAPPEN(tech_diff < 0)) {
991 sp->shp_armor = (short)SHP_DEF(mcp->m_armor, tech_diff);
992 sp->shp_speed = (short)SHP_SPD(mcp->m_speed, tech_diff);
993 sp->shp_visib = (short)SHP_VIS(mcp->m_visib, tech_diff);
994 sp->shp_frnge = (short)SHP_RNG(mcp->m_frnge, tech_diff);
995 sp->shp_glim = (short)SHP_FIR(mcp->m_glim, tech_diff);