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 * aircombat.c: Deal with air to air combat
30 * Known contributors to this file:
32 * Thomas Ruschak, 1992
34 * Markus Armbruster, 2006-2008
50 #include "prototypes.h"
55 #define FLAK_GUN_MAX 14
57 static int plane_caps(struct emp_qelem *);
58 static void ac_intercept(struct emp_qelem *, struct emp_qelem *,
59 struct emp_qelem *, natid, coord, coord);
60 static void ac_dog(struct plist *, struct plist *);
61 static void ac_planedamage(struct plist *, natid, int, natid, int,
63 static void ac_doflak(struct emp_qelem *, struct sctstr *);
64 static void ac_landflak(struct emp_qelem *, coord, coord);
65 static void ac_shipflak(struct emp_qelem *, coord, coord);
66 static void ac_fireflak(struct emp_qelem *, natid, int);
67 static void getilist(struct emp_qelem *, natid);
68 static int do_evade(struct emp_qelem *, struct emp_qelem *);
71 ac_encounter(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
72 coord x, coord y, char *path, int mission_flags,
77 unsigned char gotships[MAXNOC];
78 unsigned char gotlands[MAXNOC];
80 unsigned char rel[MAXNOC];
83 struct emp_qelem ilist[MAXNOC];
93 struct shiplist *head = NULL;
95 /* We want to only intercept once per sector per owner. So, if we overfly
96 a sector, and then overfly some land units or ships, we don't want to
97 potentially intercept 3 times. */
99 plp = (struct plist *)bomb_list->q_forw;
100 plane_owner = plp->plane.pln_own;
102 memset(overfly, 0, sizeof(overfly));
103 memset(gotilist, 0, sizeof(gotilist));
104 for (cn = 0; cn < MAXNOC; cn++)
105 rel[cn] = getrel(getnatp(cn), plane_owner);
107 if (mission_flags & PM_R) {
108 flags = plane_caps(bomb_list);
110 PR(plane_owner, "\nSPY Plane report\n");
113 } else if (flags & P_A) {
114 PR(plane_owner, "\nAnti-Sub Patrol report\n");
116 PR(plane_owner, "\nReconnaissance report\n");
122 getsect(x, y, §);
123 memset(gotships, 0, sizeof(gotships));
124 snxtitem_xy(&ni, EF_SHIP, x, y);
125 while (nxtitem(&ni, &ship)) {
126 if (mchr[(int)ship.shp_type].m_flags & M_SUB)
128 gotships[ship.shp_own] = 1;
130 memset(gotlands, 0, sizeof(gotlands));
131 snxtitem_xy(&ni, EF_LAND, x, y);
132 while (nxtitem(&ni, &land)) {
133 if (land.lnd_ship >= 0 || land.lnd_land >= 0)
135 gotlands[land.lnd_own] = 1;
138 if (mission_flags & PM_R) {
139 flags = plane_caps(bomb_list);
141 setcont(plane_owner, sect.sct_own, FOUND_FLY);
142 if (sect.sct_type == SCT_WATER) {
143 PR(plane_owner, "flying over %s at %s\n",
144 dchr[sect.sct_type].d_name, xyas(x, y, plane_owner));
145 if (mission_flags & PM_S)
146 plane_sweep(bomb_list, x, y);
148 plane_sona(bomb_list, x, y, &head);
149 changed += map_set(plane_owner,
150 sect.sct_x, sect.sct_y,
151 dchr[sect.sct_type].d_mnem, 0);
152 } else if (flags & P_S) {
153 satdisp_sect(§, flags & P_I ? 10 : 50);
155 /* This is borrowed from lookout */
156 if (sect.sct_own == plane_owner)
157 PR(plane_owner, "Your ");
159 PR(plane_owner, "%s (#%d) ",
160 cname(sect.sct_own), sect.sct_own);
161 PR(plane_owner, "%s", dchr[sect.sct_type].d_name);
162 changed += map_set(plane_owner,
163 sect.sct_x, sect.sct_y,
164 dchr[sect.sct_type].d_mnem, 0);
165 PR(plane_owner, " %d%% efficient ",
166 (sect.sct_own == plane_owner) ?
167 sect.sct_effic : roundintby((int)sect.sct_effic, 25));
168 civ = sect.sct_item[I_CIVIL];
169 mil = sect.sct_item[I_MILIT];
171 PR(plane_owner, "with %s%d civ ",
172 (sect.sct_own == plane_owner) ?
174 (sect.sct_own == plane_owner) ?
175 civ : roundintby(civ, 25));
177 PR(plane_owner, "with %s%d mil ",
178 (sect.sct_own == plane_owner) ?
180 (sect.sct_own == plane_owner) ?
181 mil : roundintby(mil, 25));
182 PR(plane_owner, "@ %s\n", xyas(x, y, plane_owner));
185 satdisp_units(sect.sct_x, sect.sct_y);
187 for (cn = 1; cn < MAXNOC; cn++) {
188 if (cn == plane_owner)
191 PR(plane_owner, "Flying over %s ships in %s\n",
192 cname(cn), xyas(x, y, plane_owner));
194 PR(plane_owner, "Flying over %s land units in %s\n",
195 cname(cn), xyas(x, y, plane_owner));
199 PR(plane_owner, "flying over %s at %s\n",
200 dchr[sect.sct_type].d_name, xyas(x, y, plane_owner));
201 changed += map_set(plane_owner, sect.sct_x, sect.sct_y,
202 dchr[sect.sct_type].d_mnem, 0);
205 evaded = do_evade(bomb_list, esc_list);
207 overfly[sect.sct_own]++;
208 for (cn = 1; cn < MAXNOC; cn++) {
209 if (cn == plane_owner || rel[cn] == ALLIED)
211 if (cn != sect.sct_own && !gotships[cn] && !gotlands[cn])
213 PR(cn, "%s planes spotted over %s\n",
214 cname(plane_owner), xyas(x, y, cn));
216 setcont(cn, plane_owner, FOUND_FLY);
220 if (rel[sect.sct_own] <= HOSTILE)
221 ac_doflak(bomb_list, §);
222 /* If bombers left, fire flak from units and ships */
223 if (!QEMPTY(bomb_list))
224 ac_landflak(bomb_list, x, y);
225 if (!QEMPTY(bomb_list))
226 ac_shipflak(bomb_list, x, y);
227 /* mission planes aborted due to flak -- don't send escorts */
228 if (QEMPTY(bomb_list))
232 air_defense(x, y, plane_owner, bomb_list, esc_list);
234 for (cn = 1; cn < MAXNOC && !QEMPTY(bomb_list); cn++) {
235 if (rel[cn] > HOSTILE)
237 if (cn != sect.sct_own && !gotships[cn] && !gotlands[cn])
240 getilist(&ilist[cn], cn);
243 ac_intercept(bomb_list, esc_list, &ilist[cn], cn, x, y);
248 if (!dir || QEMPTY(bomb_list) || (val = diridx(dir)) == DIR_STOP)
250 x = xnorm(x + diroff[val][0]);
251 y = ynorm(y + diroff[val][1]);
254 /* Let's report all of the overflights even if aborted */
255 for (cn = 1; cn < MAXNOC; cn++) {
256 if (plane_owner == cn)
258 if (overfly[cn] > 0 && rel[cn] != ALLIED)
259 nreport(plane_owner, N_OVFLY_SECT, cn, overfly[cn]);
261 /* If the map changed, update it */
263 writemap(player->cnum);
265 free_shiplist(&head);
266 for (cn = 1; cn < MAXNOC; cn++) {
273 plane_caps(struct emp_qelem *list)
275 struct emp_qelem *qp;
280 for (qp = list->q_forw; qp != list; qp = qp->q_forw) {
281 plp = (struct plist *)qp;
282 fl |= plp->pcp->pl_flags;
289 sam_intercept(struct emp_qelem *att_list, struct emp_qelem *def_list,
290 natid def_own, natid plane_owner, coord x, coord y,
293 struct emp_qelem *aqp;
294 struct emp_qelem *anext;
295 struct emp_qelem *dqp;
296 struct emp_qelem *dnext;
301 for (aqp = att_list->q_forw,
302 dqp = def_list->q_forw;
303 aqp != att_list && dqp != def_list; aqp = anext) {
305 aplp = (struct plist *)aqp;
306 if (aplp->pcp->pl_cost < 1000)
308 for (; dqp != def_list; dqp = dnext) {
310 dplp = (struct plist *)dqp;
311 if (!(dplp->pcp->pl_flags & P_M))
314 if (dplp->plane.pln_range <
315 mapdist(x, y, dplp->plane.pln_x, dplp->plane.pln_y))
317 if (CANT_HAPPEN(dplp->plane.pln_flags & PLN_LAUNCHED)
318 || mission_pln_equip(dplp, 0, P_F, 0) < 0) {
323 dplp->plane.pln_flags |= PLN_LAUNCHED;
324 putplane(dplp->plane.pln_uid, &dplp->plane);
327 PR(plane_owner, "%s launches SAMs!\n", cname(def_own));
328 PR(def_own, "Launching SAMs at %s planes over %s!\n",
329 cname(plane_owner), xyas(x, y, def_own));
330 ac_combat_headers(plane_owner, def_own);
338 PR(plane_owner, "\n");
341 if (delete_missiles) {
342 for (; dqp != def_list; dqp = dnext) {
344 dplp = (struct plist *)dqp;
345 if (!(dplp->pcp->pl_flags & P_M))
355 ac_intercept(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
356 struct emp_qelem *def_list, natid def_own, coord x, coord y)
361 struct emp_qelem *next;
362 struct emp_qelem *qp;
363 struct emp_qelem int_list;
368 plp = (struct plist *)bomb_list->q_forw;
369 plane_owner = plp->plane.pln_own;
371 sam_intercept(bomb_list, def_list, def_own, plane_owner, x, y, 0);
372 sam_intercept(esc_list, def_list, def_own, plane_owner, x, y, 0);
375 for (qp = bomb_list->q_forw; qp != bomb_list; qp = qp->q_forw)
377 for (qp = esc_list->q_forw; qp != esc_list; qp = qp->q_forw)
382 emp_initque(&int_list);
384 for (qp = def_list->q_forw; qp != def_list; qp = next) {
386 plp = (struct plist *)qp;
388 /* SAMs interdict separately */
389 if (plp->pcp->pl_flags & P_M)
391 dist = mapdist(x, y, pp->pln_x, pp->pln_y) * 2;
392 if (pp->pln_range < dist)
394 if (CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED)
395 || mission_pln_equip(plp, 0, P_F, 0) < 0) {
400 /* got one; delete from def_list, add to int_list */
402 emp_insque(qp, &int_list);
403 pp->pln_flags |= PLN_LAUNCHED;
404 pp->pln_mobil -= pln_mobcost(dist, pp, P_F);
405 putplane(pp->pln_uid, pp);
407 if (icount > att_count)
412 PR(plane_owner, "%d %s fighter%s rising to intercept!\n",
413 icount, cname(def_own), icount == 1 ? " is" : "s are");
414 PR(def_own, "%d fighter%s intercepting %s planes over %s!\n",
415 icount, icount == 1 ? " is" : "s are", cname(plane_owner),
416 xyas(x, y, def_own));
417 ac_combat_headers(plane_owner, def_own);
418 ac_airtoair(esc_list, &int_list);
419 ac_airtoair(bomb_list, &int_list);
420 PR(plane_owner, "\n");
426 ac_combat_headers(natid plane_owner, natid def_own)
429 " %-10.10s %-10.10s strength int odds damage results\n",
430 cname(plane_owner), cname(def_own));
432 " %-10.10s %-10.10s strength int odds damage results\n",
433 cname(def_own), cname(plane_owner));
440 ac_airtoair(struct emp_qelem *att_list, struct emp_qelem *int_list)
442 struct plist *attacker;
443 struct plist *interceptor;
444 struct emp_qelem *att;
445 struct emp_qelem *in;
449 struct emp_qelem *att_next;
450 struct emp_qelem *in_next;
452 att = att_list->q_forw;
453 in = int_list->q_forw;
456 if (QEMPTY(att_list) || QEMPTY(int_list)) {
460 while (more_att || more_int) {
461 in_next = in->q_forw;
462 att_next = att->q_forw;
463 attacker = (struct plist *)att;
464 interceptor = (struct plist *)in;
465 nplanes = attacker->plane.pln_effic;
466 if (nplanes > interceptor->plane.pln_effic)
467 nplanes = interceptor->plane.pln_effic;
468 ac_dog(attacker, interceptor);
471 if (att == att_list) {
473 if (QEMPTY(att_list))
478 if (in == int_list) {
480 if (QEMPTY(int_list))
489 ac_dog(struct plist *ap, struct plist *dp)
494 natid att_own, def_own;
499 att_own = ap->plane.pln_own;
500 def_own = dp->plane.pln_own;
502 PR(att_own, " %3.3s #%-4d %3.3s #%-4d",
504 ap->plane.pln_uid, dp->pcp->pl_name, dp->plane.pln_uid);
506 PR(def_own, " %3.3s #%-4d %3.3s #%-4d",
508 dp->plane.pln_uid, ap->pcp->pl_name, ap->plane.pln_uid);
509 att = pln_att(&ap->plane);
511 att = pln_def(&ap->plane);
512 att = att * ap->plane.pln_effic / 100;
513 att = MAX(att, ap->pcp->pl_def / 2);
515 def = pln_def(&dp->plane) * dp->plane.pln_effic / 100;
516 def = MAX(def, dp->pcp->pl_def / 2);
518 if ((ap->pcp->pl_flags & P_F) && ap->bombs != 0)
520 if ((dp->pcp->pl_flags & P_F) && dp->bombs != 0)
522 att += ap->pcp->pl_stealth / 25.0;
523 def += dp->pcp->pl_stealth / 25.0;
532 odds = ((double)att / ((double)def + (double)att));
535 intensity = roll(20) + roll(20) + roll(20) + roll(20) + 1;
537 PR(att_own, " %3d/%-3d %3d %3.2f ", att, def, intensity, odds);
538 PR(def_own, " %3d/%-3d %3d %3.2f ", def, att, intensity, odds);
542 while ((intensity--) > 0) {
546 if ((dp->plane.pln_effic - ddam) < PLANE_MINEFF)
550 if ((ap->plane.pln_effic - adam) < PLANE_MINEFF)
555 if (dp->pcp->pl_flags & P_M)
558 PR(att_own, "%3d/%-3d", adam, ddam);
559 PR(def_own, "%3d/%-3d", ddam, adam);
560 ac_planedamage(ap, def_own, adam, def_own, 1, 0, mesg);
561 strncpy(temp, mesg, 14);
562 ac_planedamage(dp, att_own, ddam, att_own, 1, 0, mesg);
563 PR(att_own, "%-13.13s %-13.13s\n", temp, mesg);
564 PR(def_own, "%-13.13s %-13.13s\n", mesg, temp);
567 setcont(att_own, def_own, FOUND_FLY);
568 setcont(def_own, att_own, FOUND_FLY);
573 * zap plane associated with plp.
574 * Damaging country is "from", damage is "dam".
575 * def_own is the country on the other side of the conflict from the plane
576 * owner. The only time def_own != from is when the interceptor is getting
579 * NOTE: This routine removes the appropriate plane element from the
580 * queue if it gets destroyed. That means that the caller must assume
581 * that the current queue pointer is invalid on return from the ac_planedamage
582 * call. (this has caused bugs in the past)
585 ac_planedamage(struct plist *plp, natid from, int dam, natid other,
586 int checkabort, int show, char *mesg)
596 plane_owner = pp->pln_own;
598 sprintf(dmess, " no damage");
603 memset(dmess, 0, sizeof(dmess));
607 if (eff < PLANE_MINEFF) {
608 sprintf(dmess, " shot down");
610 } else if (eff < 80 && chance((80 - eff) / 100.0) && checkabort) {
611 sprintf(dmess, " aborted @%2d%%", eff);
613 } else if (show == 0) {
614 sprintf(dmess, " cleared");
617 if ((plp->pcp->pl_flags & P_M) == 0) {
619 PR(plane_owner, " %s %s takes %d%s.\n",
620 cname(pp->pln_own), prplane(pp), dam, dmess);
622 PR(other, " %s %s takes %d%s.\n",
623 cname(pp->pln_own), prplane(pp), dam, dmess);
626 if (show && checkabort == 1) {
627 PR(plane_owner, "\n");
633 pp->pln_mobil -= MIN(32 + pp->pln_mobil, dam / 2);
635 if (disp == 1 && from != 0 && (plp->pcp->pl_flags & P_M) == 0)
636 nreport(from, N_DOWN_PLANE, pp->pln_own, 1);
639 putplane(pp->pln_uid, pp);
644 ac_doflak(struct emp_qelem *list, struct sctstr *from)
651 plp = (struct plist *)list->q_forw;
652 plane_owner = plp->plane.pln_own;
654 gun = MIN(FLAK_GUN_MAX, from->sct_item[I_GUN]);
655 shell = from->sct_item[I_SHELL];
656 if (gun > shell * 2) {
657 shell += supply_commod(from->sct_own, from->sct_x, from->sct_y,
658 I_SHELL, (gun + 1) / 2 - shell);
659 from->sct_item[I_SHELL] = shell;
665 gun = roundavg(tfact(from->sct_own, 2.0 * gun));
667 PR(plane_owner, "firing %d flak guns in %s...\n",
668 gun, xyas(from->sct_x, from->sct_y, plane_owner));
669 if (from->sct_own != 0)
670 PR(from->sct_own, "firing %d flak guns in %s...\n",
671 gun, xyas(from->sct_x, from->sct_y, from->sct_own));
672 ac_fireflak(list, from->sct_own, gun);
677 ac_shipflak(struct emp_qelem *list, coord x, coord y)
682 double flak, total, ngun;
689 plp = (struct plist *)list->q_forw;
690 plane_owner = plp->plane.pln_own;
693 snxtitem_xy(&ni, EF_SHIP, x, y);
694 while (!QEMPTY(list) && nxtitem(&ni, &ship)) {
695 if (ship.shp_own == 0 || ship.shp_own == plane_owner)
697 mcp = &mchr[(int)ship.shp_type];
698 if (mcp->m_flags & M_SUB)
700 rel = getrel(getnatp(ship.shp_own), plane_owner);
704 gun = shp_usable_guns(&ship);
706 shell = ship.shp_item[I_SHELL];
708 shell = supply_commod(ship.shp_own, ship.shp_x, ship.shp_y,
710 ship.shp_item[I_SHELL] = shell;
711 putship(ship.shp_uid, &ship);
714 if (gun == 0 || shell == 0)
716 flak = gun * (ship.shp_effic / 100.0);
718 total += techfact(ship.shp_tech, flak * 2.0);
720 PR(ship.shp_own, "firing %.0f flak guns from %s...\n",
721 flak, prship(&ship));
725 /* Limit to FLAK_GUN_MAX guns of average tech factor */
726 if (ngun > FLAK_GUN_MAX)
727 total *= FLAK_GUN_MAX / ngun;
729 gun = roundavg(total);
731 PR(plane_owner, "Flak! Ships firing %d flak guns...\n", gun);
732 ac_fireflak(list, from, gun);
737 ac_landflak(struct emp_qelem *list, coord x, coord y)
742 double flak, total, ngun;
749 plp = (struct plist *)list->q_forw;
750 plane_owner = plp->plane.pln_own;
753 snxtitem_xy(&ni, EF_LAND, x, y);
754 while (!QEMPTY(list) && nxtitem(&ni, &land)) {
755 if (land.lnd_own == 0 || land.lnd_own == plane_owner)
757 lcp = &lchr[(int)land.lnd_type];
758 aaf = lnd_aaf(&land);
759 if ((lcp->l_flags & L_FLAK) == 0 || aaf == 0)
761 if (land.lnd_ship >= 0 || land.lnd_land >= 0)
763 rel = getrel(getnatp(land.lnd_own), plane_owner);
766 flak = aaf * 1.5 * land.lnd_effic / 100.0;
768 total += techfact(land.lnd_tech, flak * 2.0);
770 PR(land.lnd_own, "firing flak guns from unit %s (aa rating %d)\n",
775 /* Limit to FLAK_GUN_MAX guns of average tech factor */
776 if (ngun > FLAK_GUN_MAX)
777 total *= FLAK_GUN_MAX / ngun;
779 gun = roundavg(total);
781 PR(plane_owner, "Flak! Land units firing %d flak guns...\n", gun);
782 ac_fireflak(list, from, gun);
787 * Called from shipflak, landflak, and doflak.
790 ac_fireflak(struct emp_qelem *list, natid from, int guns)
794 struct emp_qelem *qp;
795 struct emp_qelem *next;
798 plp = (struct plist *)list->q_forw;
800 for (qp = list->q_forw; qp != list; qp = next) {
802 plp = (struct plist *)qp;
803 n = ac_flak_dam(guns, pln_def(&plp->plane), plp->pcp->pl_flags);
804 ac_planedamage(plp, from, n, 0, 2, 1, msg);
809 * Calculate flak damage
812 ac_flak_dam(int guns, int def, int pl_flags)
816 /* <-7 -7 -6 -5 -4 */
817 static float flaktable[18] = { 0.132f, 0.20f, 0.20f, 0.25f, 0.30f,
818 /* -3 -2 -1 0 +1 +2 +3 +4 */
819 0.35f, 0.40f, 0.45f, 0.50f, 0.50f, 0.55f, 0.60f, 0.65f,
820 /* +5 +6 +7 +8 >+8 */
821 0.70f,0.75f, 0.80f, 0.85f, 1.1305f };
822 enum { FLAK_MAX = sizeof(flaktable)/sizeof(flaktable[0]) - 1 };
825 if ((pl_flags & P_T) == 0)
833 mult = flaktable[FLAK_MAX];
838 mult = flaktable[flak];
841 dam = (int)((roll(8) + 2) * mult);
848 * Get a list of planes available for interception duties.
851 getilist(struct emp_qelem *list, natid own)
853 struct plchrstr *pcp;
859 snxtitem_all(&ni, EF_PLANE);
860 while (nxtitem(&ni, &plane)) {
861 if (plane.pln_own != own)
863 pcp = &plchr[(int)plane.pln_type];
864 if ((pcp->pl_flags & P_F) == 0)
866 if (plane.pln_flags & PLN_LAUNCHED)
868 if (plane.pln_mission != 0)
870 if (plane.pln_mobil <= 0)
872 if (plane.pln_effic < 40)
874 if (!pln_airbase_ok(&plane, 0, 0))
877 ip = malloc(sizeof(*ip));
880 ip->pcp = &plchr[(int)plane.pln_type];
882 emp_insque(&ip->queue, list);
887 do_evade(struct emp_qelem *bomb_list, struct emp_qelem *esc_list)
889 struct emp_qelem *qp;
894 for (qp = bomb_list->q_forw; qp != bomb_list; qp = qp->q_forw) {
895 plp = (struct plist *)qp;
896 if (evade > plp->pcp->pl_stealth / 100.0)
897 evade = plp->pcp->pl_stealth / 100.0;
899 for (qp = esc_list->q_forw; qp != esc_list; qp = qp->q_forw) {
900 plp = (struct plist *)qp;
901 if (evade > plp->pcp->pl_stealth / 100.0)
902 evade = plp->pcp->pl_stealth / 100.0;