2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2011, Dave Pare, Jeff Bailey, Thomas Ruschak,
4 * Ken Stevens, Steve McClure, Markus Armbruster
6 * Empire 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 3 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, see <http://www.gnu.org/licenses/>.
21 * See files README, COPYING and CREDITS in the root of the source
22 * tree for related information and legal notices. It is expected
23 * that future projects/authors will amend these files as needed.
27 * aircombat.c: Deal with air to air combat
29 * Known contributors to this file:
31 * Thomas Ruschak, 1992
33 * Markus Armbruster, 2006-2011
50 #include "prototypes.h"
55 #define FLAK_GUN_MAX 14
57 static void sam_intercept(struct emp_qelem *, struct emp_qelem *,
58 natid, natid, coord, coord, int);
59 static void ac_intercept(struct emp_qelem *, struct emp_qelem *,
60 struct emp_qelem *, natid, coord, coord, int);
61 static void ac_combat_headers(natid, natid);
62 static void ac_airtoair(struct emp_qelem *, struct emp_qelem *);
63 static void ac_dog(struct plist *, struct plist *);
64 static void ac_putplane(struct plist *, int);
65 static void ac_doflak(struct emp_qelem *, struct sctstr *);
66 static void ac_landflak(struct emp_qelem *, coord, coord);
67 static void ac_shipflak(struct emp_qelem *, coord, coord);
68 static void ac_fireflak(struct emp_qelem *, natid, int);
69 static void getilists(struct emp_qelem *, unsigned char *, natid);
70 static int do_evade(struct emp_qelem *, struct emp_qelem *);
73 ac_encounter(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
74 coord x, coord y, char *path, int mission_flags)
78 unsigned char gotships[MAXNOC];
79 unsigned char gotlands[MAXNOC];
80 unsigned char rel[MAXNOC];
83 struct emp_qelem ilist[MAXNOC];
92 struct shiplist *head = NULL;
94 /* We want to only intercept once per sector per owner. So, if we overfly
95 a sector, and then overfly some land units or ships, we don't want to
96 potentially intercept 3 times. */
98 plp = (struct plist *)bomb_list->q_forw;
99 plane_owner = plp->plane.pln_own;
101 memset(overfly, 0, sizeof(overfly));
102 getilists(ilist, rel, plane_owner);
104 if (CANT_HAPPEN(mission_flags && plane_owner != player->cnum))
107 if (mission_flags & PM_R) {
108 flags = pln_caps(bomb_list);
110 pr("\nSPY Plane report\n");
113 } else if (flags & P_A) {
114 pr("\nAnti-Sub Patrol report\n");
116 pr("\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 = pln_caps(bomb_list);
141 setcont(player->cnum, sect.sct_own, FOUND_FLY);
142 if (sect.sct_type == SCT_WATER)
143 pr("flying over %s at %s\n",
144 dchr[sect.sct_type].d_name, xyas(x, y, player->cnum));
145 else if (flags & P_S)
146 satdisp_sect(§, flags & P_I ? 10 : 50);
148 look_at_sect(§, 25);
151 satdisp_units(sect.sct_x, sect.sct_y);
153 for (cn = 1; cn < MAXNOC; cn++) {
154 if (cn == player->cnum)
157 pr("Flying over %s ships in %s\n",
158 cname(cn), xyas(x, y, player->cnum));
160 pr("Flying over %s land units in %s\n",
161 cname(cn), xyas(x, y, player->cnum));
165 mpr(plane_owner, "flying over %s at %s\n",
166 dchr[sect.sct_type].d_name, xyas(x, y, plane_owner));
167 changed += map_set(plane_owner, sect.sct_x, sect.sct_y,
168 dchr[sect.sct_type].d_mnem, 0);
170 evaded = do_evade(bomb_list, esc_list);
172 overfly[sect.sct_own]++;
173 for (cn = 1; cn < MAXNOC; cn++) {
174 if (rel[cn] == ALLIED)
176 if (cn != sect.sct_own && !gotships[cn] && !gotlands[cn])
178 mpr(cn, "%s planes spotted over %s\n",
179 cname(plane_owner), xyas(x, y, cn));
181 setcont(cn, plane_owner, FOUND_FLY);
185 if (rel[sect.sct_own] <= HOSTILE)
186 ac_doflak(bomb_list, §);
187 /* If bombers left, fire flak from units and ships */
188 if (!QEMPTY(bomb_list))
189 ac_landflak(bomb_list, x, y);
190 if (!QEMPTY(bomb_list))
191 ac_shipflak(bomb_list, x, y);
192 /* mission planes aborted due to flak -- don't send escorts */
193 if (QEMPTY(bomb_list))
196 for (cn = 1; cn < MAXNOC && !QEMPTY(bomb_list); cn++) {
197 if (rel[cn] > HOSTILE)
199 ac_intercept(bomb_list, esc_list, &ilist[cn], cn, x, y,
201 || gotships[cn] || gotlands[cn]));
205 if (mission_flags & PM_R) {
206 flags = pln_caps(bomb_list);
207 if (sect.sct_type == SCT_WATER && mission_flags & PM_S)
208 plane_sweep(bomb_list, x, y);
209 if (sect.sct_type == SCT_WATER && flags & P_A)
210 plane_sona(bomb_list, x, y, &head);
214 if (!dir || QEMPTY(bomb_list) || (val = diridx(dir)) == DIR_STOP)
216 x = xnorm(x + diroff[val][0]);
217 y = ynorm(y + diroff[val][1]);
220 /* Let's report all of the overflights even if aborted */
221 for (cn = 1; cn < MAXNOC; cn++) {
222 if (overfly[cn] > 0 && rel[cn] != ALLIED)
223 nreport(plane_owner, N_OVFLY_SECT, cn, overfly[cn]);
225 /* If the map changed, update it */
227 writemap(plane_owner);
229 free_shiplist(&head);
230 for (cn = 1; cn < MAXNOC; cn++)
235 sam_intercept(struct emp_qelem *att_list, struct emp_qelem *def_list,
236 natid def_own, natid plane_owner, coord x, coord y,
239 struct emp_qelem *aqp;
240 struct emp_qelem *anext;
241 struct emp_qelem *dqp;
242 struct emp_qelem *dnext;
248 for (aqp = att_list->q_forw,
249 dqp = def_list->q_forw;
250 aqp != att_list && dqp != def_list; aqp = anext) {
252 aplp = (struct plist *)aqp;
253 if (aplp->pcp->pl_cost < 1000)
255 for (; dqp != def_list; dqp = dnext) {
257 dplp = (struct plist *)dqp;
259 if (!(dplp->pcp->pl_flags & P_M))
261 if (only_mission && !pp->pln_mission)
263 if (pp->pln_range < mapdist(x, y, pp->pln_x, pp->pln_y))
266 && pp->pln_radius < mapdist(x, y, pp->pln_opx, pp->pln_opy))
268 if (CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED)
269 || mission_pln_equip(dplp, NULL, 0) < 0) {
274 pp->pln_flags |= PLN_LAUNCHED;
275 putplane(pp->pln_uid, pp);
278 mpr(plane_owner, "%s launches SAMs!\n", cname(def_own));
279 mpr(def_own, "Launching SAMs at %s planes over %s!\n",
280 cname(plane_owner), xyas(x, y, def_own));
281 ac_combat_headers(plane_owner, def_own);
289 mpr(plane_owner, "\n");
295 ac_intercept(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
296 struct emp_qelem *def_list, natid def_own, coord x, coord y,
302 struct emp_qelem *next;
303 struct emp_qelem *qp;
304 struct emp_qelem int_list;
309 plp = (struct plist *)bomb_list->q_forw;
310 plane_owner = plp->plane.pln_own;
312 sam_intercept(bomb_list, def_list, def_own, plane_owner, x, y,
314 sam_intercept(esc_list, def_list, def_own, plane_owner, x, y,
318 for (qp = bomb_list->q_forw; qp != bomb_list; qp = qp->q_forw)
320 for (qp = esc_list->q_forw; qp != esc_list; qp = qp->q_forw)
325 emp_initque(&int_list);
327 for (qp = def_list->q_forw; qp != def_list; qp = next) {
329 plp = (struct plist *)qp;
331 /* SAMs interdict separately */
332 if (plp->pcp->pl_flags & P_M)
334 if (only_mission && !pp->pln_mission)
336 dist = mapdist(x, y, pp->pln_x, pp->pln_y) * 2;
337 if (pp->pln_range < dist)
340 && pp->pln_radius < mapdist(x, y, pp->pln_opx, pp->pln_opy))
342 if (CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED)
343 || mission_pln_equip(plp, NULL, 0) < 0) {
348 /* got one; delete from def_list, add to int_list */
350 emp_insque(qp, &int_list);
351 pp->pln_flags |= PLN_LAUNCHED;
352 pp->pln_mobil -= pln_mobcost(dist, pp, 0);
353 putplane(pp->pln_uid, pp);
355 if (icount > att_count)
360 mpr(plane_owner, "%d %s fighter%s rising to intercept!\n",
361 icount, cname(def_own), icount == 1 ? " is" : "s are");
362 mpr(def_own, "%d fighter%s intercepting %s planes over %s!\n",
363 icount, icount == 1 ? " is" : "s are", cname(plane_owner),
364 xyas(x, y, def_own));
365 ac_combat_headers(plane_owner, def_own);
366 ac_airtoair(esc_list, &int_list);
367 ac_airtoair(bomb_list, &int_list);
368 mpr(plane_owner, "\n");
374 ac_combat_headers(natid plane_owner, natid def_own)
377 " %-10.10s %-10.10s strength int odds damage results\n",
378 cname(plane_owner), cname(def_own));
380 " %-10.10s %-10.10s strength int odds damage results\n",
381 cname(def_own), cname(plane_owner));
388 ac_airtoair(struct emp_qelem *att_list, struct emp_qelem *int_list)
390 struct plist *attacker;
391 struct plist *interceptor;
392 struct emp_qelem *att;
393 struct emp_qelem *in;
396 struct emp_qelem *att_next;
397 struct emp_qelem *in_next;
399 att = att_list->q_forw;
400 in = int_list->q_forw;
403 if (QEMPTY(att_list) || QEMPTY(int_list)) {
407 while (more_att || more_int) {
408 in_next = in->q_forw;
409 att_next = att->q_forw;
410 attacker = (struct plist *)att;
411 interceptor = (struct plist *)in;
412 ac_dog(attacker, interceptor);
415 if (att == att_list) {
417 if (QEMPTY(att_list))
422 if (in == int_list) {
424 if (QEMPTY(int_list))
433 ac_dog_report(natid to, int intensity, double odds,
434 struct plist *p1, int val1, int dam1, char *dam_mesg1,
435 struct plist *p2, int val2, int dam2, char *dam_mesg2)
437 mpr(to, " %3.3s #%-4d %3.3s #%-4d %3d/%-3d %3d %3.2f %3d/%-3d"
438 "%-13.13s %-13.13s\n",
439 p1->pcp->pl_name, p1->plane.pln_uid,
440 p2->pcp->pl_name, p2->plane.pln_uid,
441 val1, val2, intensity, odds, dam1, dam2,
442 dam_mesg1, dam_mesg2);
446 ac_dog(struct plist *ap, struct plist *dp)
451 natid att_own, def_own;
452 int adam, ddam, adisp, ddisp;
453 char adam_mesg[14], ddam_mesg[14];
455 att_own = ap->plane.pln_own;
456 def_own = dp->plane.pln_own;
458 att = pln_att(&ap->plane);
460 att = pln_def(&ap->plane);
461 att = att * ap->plane.pln_effic / 100;
462 att = MAX(att, ap->pcp->pl_def / 2);
464 def = pln_def(&dp->plane) * dp->plane.pln_effic / 100;
465 def = MAX(def, dp->pcp->pl_def / 2);
467 if ((ap->pcp->pl_flags & P_F) && ap->load != 0)
469 if ((dp->pcp->pl_flags & P_F) && dp->load != 0)
471 att += ap->pcp->pl_stealth / 25.0;
472 def += dp->pcp->pl_stealth / 25.0;
481 odds = ((double)att / ((double)def + (double)att));
484 intensity = roll(20) + roll(20) + roll(20) + roll(20) + 1;
488 for (i = 0; i < intensity; i++) {
491 if (dp->plane.pln_effic - ddam < PLANE_MINEFF)
495 if (ap->plane.pln_effic - adam < PLANE_MINEFF)
500 if (dp->pcp->pl_flags & P_M)
503 adisp = ac_damage_plane(&ap->plane, def_own, adam, 0, adam_mesg);
504 ddisp = ac_damage_plane(&dp->plane, att_own, ddam, 0, ddam_mesg);
505 ac_dog_report(att_own, intensity, odds,
506 ap, att, adam, adam_mesg,
507 dp, def, ddam, ddam_mesg);
508 ac_dog_report(def_own, intensity, odds,
509 dp, def, ddam, ddam_mesg,
510 ap, att, adam, adam_mesg);
511 ac_putplane(ap, adisp);
512 ac_putplane(dp, ddisp);
515 setcont(att_own, def_own, FOUND_FLY);
516 setcont(def_own, att_own, FOUND_FLY);
521 ac_damage_plane(struct plnstr *pp, natid from, int dam, int flak,
529 snprintf(mesg, 14, " no damage");
533 eff = pp->pln_effic - dam;
538 if (eff < PLANE_MINEFF) {
539 snprintf(mesg, 14, " shot down");
541 } else if (eff < 80 && chance((80 - eff) / 100.0)) {
542 snprintf(mesg, 14, " aborted @%2d%%", eff);
545 snprintf(mesg, 14, " cleared");
548 pp->pln_mobil -= MIN(32 + pp->pln_mobil, dam / 2);
550 if (disp == 1 && from != 0 && !(plchr[pp->pln_type].pl_flags & P_M))
551 nreport(from, N_DOWN_PLANE, pp->pln_own, 1);
556 * NOTE: This routine may remove the appropriate plane element from the
557 * queue if it gets destroyed. That means that the caller must assume
558 * that the current queue pointer is invalid on return from the
559 * call. (this has caused bugs in the past)
562 ac_putplane(struct plist *plp, int disp)
567 putplane(plp->plane.pln_uid, &plp->plane);
571 ac_doflak(struct emp_qelem *list, struct sctstr *from)
577 plp = (struct plist *)list->q_forw;
578 plane_owner = plp->plane.pln_own;
580 gun = MIN(FLAK_GUN_MAX, from->sct_item[I_GUN]);
581 gun = roundavg(tfact(from->sct_own, 2.0 * gun));
583 mpr(plane_owner, "firing %d flak guns in %s...\n",
584 gun, xyas(from->sct_x, from->sct_y, plane_owner));
585 mpr(from->sct_own, "firing %d flak guns in %s...\n",
586 gun, xyas(from->sct_x, from->sct_y, from->sct_own));
587 ac_fireflak(list, from->sct_own, gun);
592 ac_shipflak(struct emp_qelem *list, coord x, coord y)
597 double flak, total, ngun;
603 plp = (struct plist *)list->q_forw;
604 plane_owner = plp->plane.pln_own;
607 snxtitem_xy(&ni, EF_SHIP, x, y);
608 while (!QEMPTY(list) && nxtitem(&ni, &ship)) {
609 if (ship.shp_own == 0 || ship.shp_own == plane_owner)
611 mcp = &mchr[(int)ship.shp_type];
612 if (mcp->m_flags & M_SUB)
614 if (relations_with(ship.shp_own, plane_owner) > HOSTILE)
616 gun = shp_usable_guns(&ship);
619 flak = gun * (ship.shp_effic / 100.0);
621 total += techfact(ship.shp_tech, flak * 2.0);
623 mpr(ship.shp_own, "firing %.0f flak guns from %s...\n",
624 flak, prship(&ship));
628 /* Limit to FLAK_GUN_MAX guns of average tech factor */
629 if (ngun > FLAK_GUN_MAX)
630 total *= FLAK_GUN_MAX / ngun;
632 gun = roundavg(total);
634 mpr(plane_owner, "Flak! Ships firing %d flak guns...\n", gun);
635 ac_fireflak(list, from, gun);
640 ac_landflak(struct emp_qelem *list, coord x, coord y)
645 double flak, total, ngun;
651 plp = (struct plist *)list->q_forw;
652 plane_owner = plp->plane.pln_own;
655 snxtitem_xy(&ni, EF_LAND, x, y);
656 while (!QEMPTY(list) && nxtitem(&ni, &land)) {
657 if (land.lnd_own == 0 || land.lnd_own == plane_owner)
659 lcp = &lchr[(int)land.lnd_type];
660 aaf = lnd_aaf(&land);
661 if ((lcp->l_flags & L_FLAK) == 0 || aaf == 0)
663 if (land.lnd_ship >= 0 || land.lnd_land >= 0)
665 if (relations_with(land.lnd_own, plane_owner) > HOSTILE)
667 flak = aaf * 1.5 * land.lnd_effic / 100.0;
669 total += techfact(land.lnd_tech, flak * 2.0);
671 mpr(land.lnd_own, "firing flak guns from unit %s (aa rating %d)\n",
676 /* Limit to FLAK_GUN_MAX guns of average tech factor */
677 if (ngun > FLAK_GUN_MAX)
678 total *= FLAK_GUN_MAX / ngun;
680 gun = roundavg(total);
682 mpr(plane_owner, "Flak! Land units firing %d flak guns...\n", gun);
683 ac_fireflak(list, from, gun);
688 * Called from shipflak, landflak, and doflak.
691 ac_fireflak(struct emp_qelem *list, natid from, int guns)
695 struct emp_qelem *qp;
696 struct emp_qelem *next;
699 for (qp = list->q_forw; qp != list; qp = next) {
701 plp = (struct plist *)qp;
702 n = ac_flak_dam(guns, pln_def(&plp->plane), plp->pcp->pl_flags);
703 disp = ac_damage_plane(&plp->plane, from, n, 1, msg);
704 mpr(plp->plane.pln_own, " %s takes %d%s%s.\n",
705 prplane(&plp->plane), n, *msg ? " --" : "", msg);
706 ac_putplane(plp, disp);
711 * Calculate flak damage
714 ac_flak_dam(int guns, int def, int pl_flags)
718 /* <-7 -7 -6 -5 -4 */
719 static float flaktable[18] = { 0.132f, 0.20f, 0.20f, 0.25f, 0.30f,
720 /* -3 -2 -1 0 +1 +2 +3 +4 */
721 0.35f, 0.40f, 0.45f, 0.50f, 0.50f, 0.55f, 0.60f, 0.65f,
722 /* +5 +6 +7 +8 >+8 */
723 0.70f,0.75f, 0.80f, 0.85f, 1.1305f };
724 enum { FLAK_MAX = sizeof(flaktable)/sizeof(flaktable[0]) - 1 };
727 if ((pl_flags & P_T) == 0)
731 mult = flaktable[FLAK_MAX];
736 mult = flaktable[flak];
739 dam = (int)((roll(8) + 2) * mult);
746 * Get planes available for interception duties.
749 getilists(struct emp_qelem *list, unsigned char *rel, natid intruder)
752 struct plchrstr *pcp;
758 for (cn = 1; cn < MAXNOC; cn++) {
759 rel[cn] = relations_with(cn, intruder);
760 emp_initque(&list[cn]);
763 snxtitem_all(&ni, EF_PLANE);
764 while (nxtitem(&ni, &plane)) {
765 if (rel[plane.pln_own] > HOSTILE)
767 pcp = &plchr[(int)plane.pln_type];
768 if ((pcp->pl_flags & P_F) == 0)
770 if (plane.pln_flags & PLN_LAUNCHED)
772 if (plane.pln_mission && plane.pln_mission != MI_AIR_DEFENSE)
774 if (plane.pln_mobil <= 0)
776 if (plane.pln_effic < 40)
779 if (ontradingblock(EF_PLANE, &plane))
782 if (!pln_airbase_ok(&plane, 0, 0))
785 ip = malloc(sizeof(*ip));
787 ip->pcp = &plchr[(int)plane.pln_type];
789 emp_insque(&ip->queue, &list[plane.pln_own]);
794 do_evade(struct emp_qelem *bomb_list, struct emp_qelem *esc_list)
796 struct emp_qelem *qp;
801 for (qp = bomb_list->q_forw; qp != bomb_list; qp = qp->q_forw) {
802 plp = (struct plist *)qp;
803 if (evade > plp->pcp->pl_stealth / 100.0)
804 evade = plp->pcp->pl_stealth / 100.0;
806 for (qp = esc_list->q_forw; qp != esc_list; qp = qp->q_forw) {
807 plp = (struct plist *)qp;
808 if (evade > plp->pcp->pl_stealth / 100.0)
809 evade = plp->pcp->pl_stealth / 100.0;