2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2009, 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
51 #include "prototypes.h"
56 #define FLAK_GUN_MAX 14
58 static int plane_caps(struct emp_qelem *);
59 static void sam_intercept(struct emp_qelem *, struct emp_qelem *,
60 natid, natid, coord, coord, int);
61 static void ac_intercept(struct emp_qelem *, struct emp_qelem *,
62 struct emp_qelem *, natid, coord, coord, int);
63 static void ac_combat_headers(natid, natid);
64 static void ac_airtoair(struct emp_qelem *, struct emp_qelem *);
65 static void ac_dog(struct plist *, struct plist *);
66 static void ac_planedamage(struct plist *, natid, int, natid, int,
68 static void ac_doflak(struct emp_qelem *, struct sctstr *);
69 static void ac_landflak(struct emp_qelem *, coord, coord);
70 static void ac_shipflak(struct emp_qelem *, coord, coord);
71 static void ac_fireflak(struct emp_qelem *, natid, int);
72 static void getilists(struct emp_qelem *, unsigned char *, natid);
73 static int do_evade(struct emp_qelem *, struct emp_qelem *);
76 ac_encounter(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
77 coord x, coord y, char *path, int mission_flags)
81 unsigned char gotships[MAXNOC];
82 unsigned char gotlands[MAXNOC];
83 unsigned char rel[MAXNOC];
86 struct emp_qelem ilist[MAXNOC];
96 struct shiplist *head = NULL;
98 /* We want to only intercept once per sector per owner. So, if we overfly
99 a sector, and then overfly some land units or ships, we don't want to
100 potentially intercept 3 times. */
102 plp = (struct plist *)bomb_list->q_forw;
103 plane_owner = plp->plane.pln_own;
105 memset(overfly, 0, sizeof(overfly));
106 getilists(ilist, rel, plane_owner);
108 if (mission_flags & PM_R) {
109 flags = plane_caps(bomb_list);
111 PR(plane_owner, "\nSPY Plane report\n");
114 } else if (flags & P_A) {
115 PR(plane_owner, "\nAnti-Sub Patrol report\n");
117 PR(plane_owner, "\nReconnaissance report\n");
123 getsect(x, y, §);
124 memset(gotships, 0, sizeof(gotships));
125 snxtitem_xy(&ni, EF_SHIP, x, y);
126 while (nxtitem(&ni, &ship)) {
127 if (mchr[(int)ship.shp_type].m_flags & M_SUB)
129 gotships[ship.shp_own] = 1;
131 memset(gotlands, 0, sizeof(gotlands));
132 snxtitem_xy(&ni, EF_LAND, x, y);
133 while (nxtitem(&ni, &land)) {
134 if (land.lnd_ship >= 0 || land.lnd_land >= 0)
136 gotlands[land.lnd_own] = 1;
139 if (mission_flags & PM_R) {
140 flags = plane_caps(bomb_list);
142 setcont(plane_owner, sect.sct_own, FOUND_FLY);
143 if (sect.sct_type == SCT_WATER) {
144 PR(plane_owner, "flying over %s at %s\n",
145 dchr[sect.sct_type].d_name, xyas(x, y, plane_owner));
146 if (mission_flags & PM_S)
147 plane_sweep(bomb_list, x, y);
149 plane_sona(bomb_list, x, y, &head);
150 changed += map_set(plane_owner,
151 sect.sct_x, sect.sct_y,
152 dchr[sect.sct_type].d_mnem, 0);
153 } else if (flags & P_S) {
154 satdisp_sect(§, flags & P_I ? 10 : 50);
156 /* This is borrowed from lookout */
157 if (sect.sct_own == plane_owner)
158 PR(plane_owner, "Your ");
160 PR(plane_owner, "%s (#%d) ",
161 cname(sect.sct_own), sect.sct_own);
162 PR(plane_owner, "%s", dchr[sect.sct_type].d_name);
163 changed += map_set(plane_owner,
164 sect.sct_x, sect.sct_y,
165 dchr[sect.sct_type].d_mnem, 0);
166 PR(plane_owner, " %d%% efficient ",
167 (sect.sct_own == plane_owner) ?
168 sect.sct_effic : roundintby((int)sect.sct_effic, 25));
169 civ = sect.sct_item[I_CIVIL];
170 mil = sect.sct_item[I_MILIT];
172 PR(plane_owner, "with %s%d civ ",
173 (sect.sct_own == plane_owner) ?
175 (sect.sct_own == plane_owner) ?
176 civ : roundintby(civ, 25));
178 PR(plane_owner, "with %s%d mil ",
179 (sect.sct_own == plane_owner) ?
181 (sect.sct_own == plane_owner) ?
182 mil : roundintby(mil, 25));
183 PR(plane_owner, "@ %s\n", xyas(x, y, plane_owner));
186 satdisp_units(sect.sct_x, sect.sct_y);
188 for (cn = 1; cn < MAXNOC; cn++) {
189 if (cn == plane_owner)
192 PR(plane_owner, "Flying over %s ships in %s\n",
193 cname(cn), xyas(x, y, plane_owner));
195 PR(plane_owner, "Flying over %s land units in %s\n",
196 cname(cn), xyas(x, y, plane_owner));
200 PR(plane_owner, "flying over %s at %s\n",
201 dchr[sect.sct_type].d_name, xyas(x, y, plane_owner));
202 changed += map_set(plane_owner, sect.sct_x, sect.sct_y,
203 dchr[sect.sct_type].d_mnem, 0);
206 evaded = do_evade(bomb_list, esc_list);
208 overfly[sect.sct_own]++;
209 for (cn = 1; cn < MAXNOC; cn++) {
210 if (cn == plane_owner || rel[cn] == ALLIED)
212 if (cn != sect.sct_own && !gotships[cn] && !gotlands[cn])
214 PR(cn, "%s planes spotted over %s\n",
215 cname(plane_owner), xyas(x, y, cn));
217 setcont(cn, plane_owner, FOUND_FLY);
221 if (rel[sect.sct_own] <= HOSTILE)
222 ac_doflak(bomb_list, §);
223 /* If bombers left, fire flak from units and ships */
224 if (!QEMPTY(bomb_list))
225 ac_landflak(bomb_list, x, y);
226 if (!QEMPTY(bomb_list))
227 ac_shipflak(bomb_list, x, y);
228 /* mission planes aborted due to flak -- don't send escorts */
229 if (QEMPTY(bomb_list))
232 for (cn = 1; cn < MAXNOC && !QEMPTY(bomb_list); cn++) {
233 if (rel[cn] > HOSTILE)
235 ac_intercept(bomb_list, esc_list, &ilist[cn], cn, x, y,
237 || gotships[cn] || gotlands[cn]));
242 if (!dir || QEMPTY(bomb_list) || (val = diridx(dir)) == DIR_STOP)
244 x = xnorm(x + diroff[val][0]);
245 y = ynorm(y + diroff[val][1]);
248 /* Let's report all of the overflights even if aborted */
249 for (cn = 1; cn < MAXNOC; cn++) {
250 if (plane_owner == cn)
252 if (overfly[cn] > 0 && rel[cn] != ALLIED)
253 nreport(plane_owner, N_OVFLY_SECT, cn, overfly[cn]);
255 /* If the map changed, update it */
257 writemap(player->cnum);
259 free_shiplist(&head);
260 for (cn = 1; cn < MAXNOC; cn++)
265 plane_caps(struct emp_qelem *list)
267 struct emp_qelem *qp;
272 for (qp = list->q_forw; qp != list; qp = qp->q_forw) {
273 plp = (struct plist *)qp;
274 fl |= plp->pcp->pl_flags;
281 sam_intercept(struct emp_qelem *att_list, struct emp_qelem *def_list,
282 natid def_own, natid plane_owner, coord x, coord y,
285 struct emp_qelem *aqp;
286 struct emp_qelem *anext;
287 struct emp_qelem *dqp;
288 struct emp_qelem *dnext;
294 for (aqp = att_list->q_forw,
295 dqp = def_list->q_forw;
296 aqp != att_list && dqp != def_list; aqp = anext) {
298 aplp = (struct plist *)aqp;
299 if (aplp->pcp->pl_cost < 1000)
301 for (; dqp != def_list; dqp = dnext) {
303 dplp = (struct plist *)dqp;
305 if (!(dplp->pcp->pl_flags & P_M))
307 if (only_mission && !pp->pln_mission)
309 if (pp->pln_range < mapdist(x, y, pp->pln_x, pp->pln_y))
312 && pp->pln_radius < mapdist(x, y, pp->pln_opx, pp->pln_opy))
314 if (CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED)
315 || mission_pln_equip(dplp, 0, P_F, 0) < 0) {
320 pp->pln_flags |= PLN_LAUNCHED;
321 putplane(pp->pln_uid, pp);
324 PR(plane_owner, "%s launches SAMs!\n", cname(def_own));
325 PR(def_own, "Launching SAMs at %s planes over %s!\n",
326 cname(plane_owner), xyas(x, y, def_own));
327 ac_combat_headers(plane_owner, def_own);
335 PR(plane_owner, "\n");
341 ac_intercept(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
342 struct emp_qelem *def_list, natid def_own, coord x, coord y,
348 struct emp_qelem *next;
349 struct emp_qelem *qp;
350 struct emp_qelem int_list;
355 plp = (struct plist *)bomb_list->q_forw;
356 plane_owner = plp->plane.pln_own;
358 sam_intercept(bomb_list, def_list, def_own, plane_owner, x, y,
360 sam_intercept(esc_list, def_list, def_own, plane_owner, x, y,
364 for (qp = bomb_list->q_forw; qp != bomb_list; qp = qp->q_forw)
366 for (qp = esc_list->q_forw; qp != esc_list; qp = qp->q_forw)
371 emp_initque(&int_list);
373 for (qp = def_list->q_forw; qp != def_list; qp = next) {
375 plp = (struct plist *)qp;
377 /* SAMs interdict separately */
378 if (plp->pcp->pl_flags & P_M)
380 if (only_mission && !pp->pln_mission)
382 dist = mapdist(x, y, pp->pln_x, pp->pln_y) * 2;
383 if (pp->pln_range < dist)
386 && pp->pln_radius < mapdist(x, y, pp->pln_opx, pp->pln_opy))
388 if (CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED)
389 || mission_pln_equip(plp, 0, P_F, 0) < 0) {
394 /* got one; delete from def_list, add to int_list */
396 emp_insque(qp, &int_list);
397 pp->pln_flags |= PLN_LAUNCHED;
398 pp->pln_mobil -= pln_mobcost(dist, pp, P_F);
399 putplane(pp->pln_uid, pp);
401 if (icount > att_count)
406 PR(plane_owner, "%d %s fighter%s rising to intercept!\n",
407 icount, cname(def_own), icount == 1 ? " is" : "s are");
408 PR(def_own, "%d fighter%s intercepting %s planes over %s!\n",
409 icount, icount == 1 ? " is" : "s are", cname(plane_owner),
410 xyas(x, y, def_own));
411 ac_combat_headers(plane_owner, def_own);
412 ac_airtoair(esc_list, &int_list);
413 ac_airtoair(bomb_list, &int_list);
414 PR(plane_owner, "\n");
420 ac_combat_headers(natid plane_owner, natid def_own)
423 " %-10.10s %-10.10s strength int odds damage results\n",
424 cname(plane_owner), cname(def_own));
426 " %-10.10s %-10.10s strength int odds damage results\n",
427 cname(def_own), cname(plane_owner));
434 ac_airtoair(struct emp_qelem *att_list, struct emp_qelem *int_list)
436 struct plist *attacker;
437 struct plist *interceptor;
438 struct emp_qelem *att;
439 struct emp_qelem *in;
443 struct emp_qelem *att_next;
444 struct emp_qelem *in_next;
446 att = att_list->q_forw;
447 in = int_list->q_forw;
450 if (QEMPTY(att_list) || QEMPTY(int_list)) {
454 while (more_att || more_int) {
455 in_next = in->q_forw;
456 att_next = att->q_forw;
457 attacker = (struct plist *)att;
458 interceptor = (struct plist *)in;
459 nplanes = attacker->plane.pln_effic;
460 if (nplanes > interceptor->plane.pln_effic)
461 nplanes = interceptor->plane.pln_effic;
462 ac_dog(attacker, interceptor);
465 if (att == att_list) {
467 if (QEMPTY(att_list))
472 if (in == int_list) {
474 if (QEMPTY(int_list))
483 ac_dog(struct plist *ap, struct plist *dp)
488 natid att_own, def_own;
493 att_own = ap->plane.pln_own;
494 def_own = dp->plane.pln_own;
496 PR(att_own, " %3.3s #%-4d %3.3s #%-4d",
498 ap->plane.pln_uid, dp->pcp->pl_name, dp->plane.pln_uid);
500 PR(def_own, " %3.3s #%-4d %3.3s #%-4d",
502 dp->plane.pln_uid, ap->pcp->pl_name, ap->plane.pln_uid);
503 att = pln_att(&ap->plane);
505 att = pln_def(&ap->plane);
506 att = att * ap->plane.pln_effic / 100;
507 att = MAX(att, ap->pcp->pl_def / 2);
509 def = pln_def(&dp->plane) * dp->plane.pln_effic / 100;
510 def = MAX(def, dp->pcp->pl_def / 2);
512 if ((ap->pcp->pl_flags & P_F) && ap->bombs != 0)
514 if ((dp->pcp->pl_flags & P_F) && dp->bombs != 0)
516 att += ap->pcp->pl_stealth / 25.0;
517 def += dp->pcp->pl_stealth / 25.0;
526 odds = ((double)att / ((double)def + (double)att));
529 intensity = roll(20) + roll(20) + roll(20) + roll(20) + 1;
531 PR(att_own, " %3d/%-3d %3d %3.2f ", att, def, intensity, odds);
532 PR(def_own, " %3d/%-3d %3d %3.2f ", def, att, intensity, odds);
536 while ((intensity--) > 0) {
540 if ((dp->plane.pln_effic - ddam) < PLANE_MINEFF)
544 if ((ap->plane.pln_effic - adam) < PLANE_MINEFF)
549 if (dp->pcp->pl_flags & P_M)
552 PR(att_own, "%3d/%-3d", adam, ddam);
553 PR(def_own, "%3d/%-3d", ddam, adam);
554 ac_planedamage(ap, def_own, adam, def_own, 1, 0, mesg);
555 strncpy(temp, mesg, 14);
556 ac_planedamage(dp, att_own, ddam, att_own, 1, 0, mesg);
557 PR(att_own, "%-13.13s %-13.13s\n", temp, mesg);
558 PR(def_own, "%-13.13s %-13.13s\n", mesg, temp);
561 setcont(att_own, def_own, FOUND_FLY);
562 setcont(def_own, att_own, FOUND_FLY);
567 * zap plane associated with plp.
568 * Damaging country is "from", damage is "dam".
569 * def_own is the country on the other side of the conflict from the plane
570 * owner. The only time def_own != from is when the interceptor is getting
573 * NOTE: This routine removes the appropriate plane element from the
574 * queue if it gets destroyed. That means that the caller must assume
575 * that the current queue pointer is invalid on return from the ac_planedamage
576 * call. (this has caused bugs in the past)
579 ac_planedamage(struct plist *plp, natid from, int dam, natid other,
580 int checkabort, int show, char *mesg)
590 plane_owner = pp->pln_own;
592 sprintf(dmess, " no damage");
597 memset(dmess, 0, sizeof(dmess));
601 if (eff < PLANE_MINEFF) {
602 sprintf(dmess, " shot down");
604 } else if (eff < 80 && chance((80 - eff) / 100.0) && checkabort) {
605 sprintf(dmess, " aborted @%2d%%", eff);
607 } else if (show == 0) {
608 sprintf(dmess, " cleared");
611 if ((plp->pcp->pl_flags & P_M) == 0) {
613 PR(plane_owner, " %s %s takes %d%s.\n",
614 cname(pp->pln_own), prplane(pp), dam, dmess);
616 PR(other, " %s %s takes %d%s.\n",
617 cname(pp->pln_own), prplane(pp), dam, dmess);
620 if (show && checkabort == 1) {
621 PR(plane_owner, "\n");
627 pp->pln_mobil -= MIN(32 + pp->pln_mobil, dam / 2);
629 if (disp == 1 && from != 0 && (plp->pcp->pl_flags & P_M) == 0)
630 nreport(from, N_DOWN_PLANE, pp->pln_own, 1);
633 putplane(pp->pln_uid, pp);
638 ac_doflak(struct emp_qelem *list, struct sctstr *from)
645 plp = (struct plist *)list->q_forw;
646 plane_owner = plp->plane.pln_own;
648 gun = MIN(FLAK_GUN_MAX, from->sct_item[I_GUN]);
649 shell = from->sct_item[I_SHELL];
650 if (gun > shell * 2) {
651 shell += supply_commod(from->sct_own, from->sct_x, from->sct_y,
652 I_SHELL, (gun + 1) / 2 - shell);
653 from->sct_item[I_SHELL] = shell;
659 gun = roundavg(tfact(from->sct_own, 2.0 * gun));
661 PR(plane_owner, "firing %d flak guns in %s...\n",
662 gun, xyas(from->sct_x, from->sct_y, plane_owner));
663 if (from->sct_own != 0)
664 PR(from->sct_own, "firing %d flak guns in %s...\n",
665 gun, xyas(from->sct_x, from->sct_y, from->sct_own));
666 ac_fireflak(list, from->sct_own, gun);
671 ac_shipflak(struct emp_qelem *list, coord x, coord y)
676 double flak, total, ngun;
683 plp = (struct plist *)list->q_forw;
684 plane_owner = plp->plane.pln_own;
687 snxtitem_xy(&ni, EF_SHIP, x, y);
688 while (!QEMPTY(list) && nxtitem(&ni, &ship)) {
689 if (ship.shp_own == 0 || ship.shp_own == plane_owner)
691 mcp = &mchr[(int)ship.shp_type];
692 if (mcp->m_flags & M_SUB)
694 rel = getrel(getnatp(ship.shp_own), plane_owner);
698 gun = shp_usable_guns(&ship);
700 shell = ship.shp_item[I_SHELL];
702 shell = supply_commod(ship.shp_own, ship.shp_x, ship.shp_y,
704 ship.shp_item[I_SHELL] = shell;
705 putship(ship.shp_uid, &ship);
708 if (gun == 0 || shell == 0)
710 flak = gun * (ship.shp_effic / 100.0);
712 total += techfact(ship.shp_tech, flak * 2.0);
714 PR(ship.shp_own, "firing %.0f flak guns from %s...\n",
715 flak, prship(&ship));
719 /* Limit to FLAK_GUN_MAX guns of average tech factor */
720 if (ngun > FLAK_GUN_MAX)
721 total *= FLAK_GUN_MAX / ngun;
723 gun = roundavg(total);
725 PR(plane_owner, "Flak! Ships firing %d flak guns...\n", gun);
726 ac_fireflak(list, from, gun);
731 ac_landflak(struct emp_qelem *list, coord x, coord y)
736 double flak, total, ngun;
743 plp = (struct plist *)list->q_forw;
744 plane_owner = plp->plane.pln_own;
747 snxtitem_xy(&ni, EF_LAND, x, y);
748 while (!QEMPTY(list) && nxtitem(&ni, &land)) {
749 if (land.lnd_own == 0 || land.lnd_own == plane_owner)
751 lcp = &lchr[(int)land.lnd_type];
752 aaf = lnd_aaf(&land);
753 if ((lcp->l_flags & L_FLAK) == 0 || aaf == 0)
755 if (land.lnd_ship >= 0 || land.lnd_land >= 0)
757 rel = getrel(getnatp(land.lnd_own), plane_owner);
760 flak = aaf * 1.5 * land.lnd_effic / 100.0;
762 total += techfact(land.lnd_tech, flak * 2.0);
764 PR(land.lnd_own, "firing flak guns from unit %s (aa rating %d)\n",
769 /* Limit to FLAK_GUN_MAX guns of average tech factor */
770 if (ngun > FLAK_GUN_MAX)
771 total *= FLAK_GUN_MAX / ngun;
773 gun = roundavg(total);
775 PR(plane_owner, "Flak! Land units firing %d flak guns...\n", gun);
776 ac_fireflak(list, from, gun);
781 * Called from shipflak, landflak, and doflak.
784 ac_fireflak(struct emp_qelem *list, natid from, int guns)
788 struct emp_qelem *qp;
789 struct emp_qelem *next;
792 plp = (struct plist *)list->q_forw;
794 for (qp = list->q_forw; qp != list; qp = next) {
796 plp = (struct plist *)qp;
797 n = ac_flak_dam(guns, pln_def(&plp->plane), plp->pcp->pl_flags);
798 ac_planedamage(plp, from, n, 0, 2, 1, msg);
803 * Calculate flak damage
806 ac_flak_dam(int guns, int def, int pl_flags)
810 /* <-7 -7 -6 -5 -4 */
811 static float flaktable[18] = { 0.132f, 0.20f, 0.20f, 0.25f, 0.30f,
812 /* -3 -2 -1 0 +1 +2 +3 +4 */
813 0.35f, 0.40f, 0.45f, 0.50f, 0.50f, 0.55f, 0.60f, 0.65f,
814 /* +5 +6 +7 +8 >+8 */
815 0.70f,0.75f, 0.80f, 0.85f, 1.1305f };
816 enum { FLAK_MAX = sizeof(flaktable)/sizeof(flaktable[0]) - 1 };
819 if ((pl_flags & P_T) == 0)
827 mult = flaktable[FLAK_MAX];
832 mult = flaktable[flak];
835 dam = (int)((roll(8) + 2) * mult);
842 * Get planes available for interception duties.
845 getilists(struct emp_qelem *list, unsigned char *rel, natid intruder)
848 struct plchrstr *pcp;
854 for (cn = 1; cn < MAXNOC; cn++) {
855 rel[cn] = getrel(getnatp(cn), intruder);
856 emp_initque(&list[cn]);
859 snxtitem_all(&ni, EF_PLANE);
860 while (nxtitem(&ni, &plane)) {
861 if (rel[plane.pln_own] > HOSTILE)
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 && plane.pln_mission != MI_AIR_DEFENSE)
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[plane.pln_own]);
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;