2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2010, 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, 2006-2009
51 #include "prototypes.h"
56 #define FLAK_GUN_MAX 14
58 static void sam_intercept(struct emp_qelem *, struct emp_qelem *,
59 natid, natid, coord, coord, int);
60 static void ac_intercept(struct emp_qelem *, struct emp_qelem *,
61 struct emp_qelem *, natid, coord, coord, int);
62 static void ac_combat_headers(natid, natid);
63 static void ac_airtoair(struct emp_qelem *, struct emp_qelem *);
64 static void ac_dog(struct plist *, struct plist *);
65 static void ac_planedamage(struct plist *, natid, int, natid, int,
67 static void ac_doflak(struct emp_qelem *, struct sctstr *);
68 static void ac_landflak(struct emp_qelem *, coord, coord);
69 static void ac_shipflak(struct emp_qelem *, coord, coord);
70 static void ac_fireflak(struct emp_qelem *, natid, int);
71 static void getilists(struct emp_qelem *, unsigned char *, natid);
72 static int do_evade(struct emp_qelem *, struct emp_qelem *);
75 ac_encounter(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
76 coord x, coord y, char *path, int mission_flags)
80 unsigned char gotships[MAXNOC];
81 unsigned char gotlands[MAXNOC];
82 unsigned char rel[MAXNOC];
85 struct emp_qelem ilist[MAXNOC];
94 struct shiplist *head = NULL;
96 /* We want to only intercept once per sector per owner. So, if we overfly
97 a sector, and then overfly some land units or ships, we don't want to
98 potentially intercept 3 times. */
100 plp = (struct plist *)bomb_list->q_forw;
101 plane_owner = plp->plane.pln_own;
103 memset(overfly, 0, sizeof(overfly));
104 getilists(ilist, rel, plane_owner);
106 if (CANT_HAPPEN(mission_flags && plane_owner != player->cnum))
109 if (mission_flags & PM_R) {
110 flags = pln_caps(bomb_list);
112 pr("\nSPY Plane report\n");
115 } else if (flags & P_A) {
116 pr("\nAnti-Sub Patrol report\n");
118 pr("\nReconnaissance report\n");
124 getsect(x, y, §);
125 memset(gotships, 0, sizeof(gotships));
126 snxtitem_xy(&ni, EF_SHIP, x, y);
127 while (nxtitem(&ni, &ship)) {
128 if (mchr[(int)ship.shp_type].m_flags & M_SUB)
130 gotships[ship.shp_own] = 1;
132 memset(gotlands, 0, sizeof(gotlands));
133 snxtitem_xy(&ni, EF_LAND, x, y);
134 while (nxtitem(&ni, &land)) {
135 if (land.lnd_ship >= 0 || land.lnd_land >= 0)
137 gotlands[land.lnd_own] = 1;
140 if (mission_flags & PM_R) {
141 flags = pln_caps(bomb_list);
143 setcont(player->cnum, sect.sct_own, FOUND_FLY);
144 if (sect.sct_type == SCT_WATER) {
145 pr("flying over %s at %s\n",
146 dchr[sect.sct_type].d_name, xyas(x, y, player->cnum));
147 if (mission_flags & PM_S)
148 plane_sweep(bomb_list, x, y);
150 plane_sona(bomb_list, x, y, &head);
151 } else if (flags & P_S)
152 satdisp_sect(§, flags & P_I ? 10 : 50);
154 look_at_sect(§, 25);
155 changed += map_set(player->cnum, sect.sct_x, sect.sct_y,
156 dchr[sect.sct_type].d_mnem, 0);
158 satdisp_units(sect.sct_x, sect.sct_y);
160 for (cn = 1; cn < MAXNOC; cn++) {
161 if (cn == player->cnum)
164 pr("Flying over %s ships in %s\n",
165 cname(cn), xyas(x, y, player->cnum));
167 pr("Flying over %s land units in %s\n",
168 cname(cn), xyas(x, y, player->cnum));
172 PR(plane_owner, "flying over %s at %s\n",
173 dchr[sect.sct_type].d_name, xyas(x, y, plane_owner));
174 changed += map_set(plane_owner, sect.sct_x, sect.sct_y,
175 dchr[sect.sct_type].d_mnem, 0);
178 evaded = do_evade(bomb_list, esc_list);
180 overfly[sect.sct_own]++;
181 for (cn = 1; cn < MAXNOC; cn++) {
182 if (cn == plane_owner || rel[cn] == ALLIED)
184 if (cn != sect.sct_own && !gotships[cn] && !gotlands[cn])
186 PR(cn, "%s planes spotted over %s\n",
187 cname(plane_owner), xyas(x, y, cn));
189 setcont(cn, plane_owner, FOUND_FLY);
193 if (rel[sect.sct_own] <= HOSTILE)
194 ac_doflak(bomb_list, §);
195 /* If bombers left, fire flak from units and ships */
196 if (!QEMPTY(bomb_list))
197 ac_landflak(bomb_list, x, y);
198 if (!QEMPTY(bomb_list))
199 ac_shipflak(bomb_list, x, y);
200 /* mission planes aborted due to flak -- don't send escorts */
201 if (QEMPTY(bomb_list))
204 for (cn = 1; cn < MAXNOC && !QEMPTY(bomb_list); cn++) {
205 if (rel[cn] > HOSTILE)
207 ac_intercept(bomb_list, esc_list, &ilist[cn], cn, x, y,
209 || gotships[cn] || gotlands[cn]));
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 (plane_owner == cn)
224 if (overfly[cn] > 0 && rel[cn] != ALLIED)
225 nreport(plane_owner, N_OVFLY_SECT, cn, overfly[cn]);
227 /* If the map changed, update it */
229 writemap(player->cnum);
231 free_shiplist(&head);
232 for (cn = 1; cn < MAXNOC; cn++)
237 sam_intercept(struct emp_qelem *att_list, struct emp_qelem *def_list,
238 natid def_own, natid plane_owner, coord x, coord y,
241 struct emp_qelem *aqp;
242 struct emp_qelem *anext;
243 struct emp_qelem *dqp;
244 struct emp_qelem *dnext;
250 for (aqp = att_list->q_forw,
251 dqp = def_list->q_forw;
252 aqp != att_list && dqp != def_list; aqp = anext) {
254 aplp = (struct plist *)aqp;
255 if (aplp->pcp->pl_cost < 1000)
257 for (; dqp != def_list; dqp = dnext) {
259 dplp = (struct plist *)dqp;
261 if (!(dplp->pcp->pl_flags & P_M))
263 if (only_mission && !pp->pln_mission)
265 if (pp->pln_range < mapdist(x, y, pp->pln_x, pp->pln_y))
268 && pp->pln_radius < mapdist(x, y, pp->pln_opx, pp->pln_opy))
270 if (CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED)
271 || mission_pln_equip(dplp, NULL, 0) < 0) {
276 pp->pln_flags |= PLN_LAUNCHED;
277 putplane(pp->pln_uid, pp);
280 PR(plane_owner, "%s launches SAMs!\n", cname(def_own));
281 PR(def_own, "Launching SAMs at %s planes over %s!\n",
282 cname(plane_owner), xyas(x, y, def_own));
283 ac_combat_headers(plane_owner, def_own);
291 PR(plane_owner, "\n");
297 ac_intercept(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
298 struct emp_qelem *def_list, natid def_own, coord x, coord y,
304 struct emp_qelem *next;
305 struct emp_qelem *qp;
306 struct emp_qelem int_list;
311 plp = (struct plist *)bomb_list->q_forw;
312 plane_owner = plp->plane.pln_own;
314 sam_intercept(bomb_list, def_list, def_own, plane_owner, x, y,
316 sam_intercept(esc_list, def_list, def_own, plane_owner, x, y,
320 for (qp = bomb_list->q_forw; qp != bomb_list; qp = qp->q_forw)
322 for (qp = esc_list->q_forw; qp != esc_list; qp = qp->q_forw)
327 emp_initque(&int_list);
329 for (qp = def_list->q_forw; qp != def_list; qp = next) {
331 plp = (struct plist *)qp;
333 /* SAMs interdict separately */
334 if (plp->pcp->pl_flags & P_M)
336 if (only_mission && !pp->pln_mission)
338 dist = mapdist(x, y, pp->pln_x, pp->pln_y) * 2;
339 if (pp->pln_range < dist)
342 && pp->pln_radius < mapdist(x, y, pp->pln_opx, pp->pln_opy))
344 if (CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED)
345 || mission_pln_equip(plp, NULL, 0) < 0) {
350 /* got one; delete from def_list, add to int_list */
352 emp_insque(qp, &int_list);
353 pp->pln_flags |= PLN_LAUNCHED;
354 pp->pln_mobil -= pln_mobcost(dist, pp, 0);
355 putplane(pp->pln_uid, pp);
357 if (icount > att_count)
362 PR(plane_owner, "%d %s fighter%s rising to intercept!\n",
363 icount, cname(def_own), icount == 1 ? " is" : "s are");
364 PR(def_own, "%d fighter%s intercepting %s planes over %s!\n",
365 icount, icount == 1 ? " is" : "s are", cname(plane_owner),
366 xyas(x, y, def_own));
367 ac_combat_headers(plane_owner, def_own);
368 ac_airtoair(esc_list, &int_list);
369 ac_airtoair(bomb_list, &int_list);
370 PR(plane_owner, "\n");
376 ac_combat_headers(natid plane_owner, natid def_own)
379 " %-10.10s %-10.10s strength int odds damage results\n",
380 cname(plane_owner), cname(def_own));
382 " %-10.10s %-10.10s strength int odds damage results\n",
383 cname(def_own), cname(plane_owner));
390 ac_airtoair(struct emp_qelem *att_list, struct emp_qelem *int_list)
392 struct plist *attacker;
393 struct plist *interceptor;
394 struct emp_qelem *att;
395 struct emp_qelem *in;
398 struct emp_qelem *att_next;
399 struct emp_qelem *in_next;
401 att = att_list->q_forw;
402 in = int_list->q_forw;
405 if (QEMPTY(att_list) || QEMPTY(int_list)) {
409 while (more_att || more_int) {
410 in_next = in->q_forw;
411 att_next = att->q_forw;
412 attacker = (struct plist *)att;
413 interceptor = (struct plist *)in;
414 ac_dog(attacker, interceptor);
417 if (att == att_list) {
419 if (QEMPTY(att_list))
424 if (in == int_list) {
426 if (QEMPTY(int_list))
435 ac_dog(struct plist *ap, struct plist *dp)
440 natid att_own, def_own;
445 att_own = ap->plane.pln_own;
446 def_own = dp->plane.pln_own;
448 PR(att_own, " %3.3s #%-4d %3.3s #%-4d",
450 ap->plane.pln_uid, dp->pcp->pl_name, dp->plane.pln_uid);
452 PR(def_own, " %3.3s #%-4d %3.3s #%-4d",
454 dp->plane.pln_uid, ap->pcp->pl_name, ap->plane.pln_uid);
455 att = pln_att(&ap->plane);
457 att = pln_def(&ap->plane);
458 att = att * ap->plane.pln_effic / 100;
459 att = MAX(att, ap->pcp->pl_def / 2);
461 def = pln_def(&dp->plane) * dp->plane.pln_effic / 100;
462 def = MAX(def, dp->pcp->pl_def / 2);
464 if ((ap->pcp->pl_flags & P_F) && ap->load != 0)
466 if ((dp->pcp->pl_flags & P_F) && dp->load != 0)
468 att += ap->pcp->pl_stealth / 25.0;
469 def += dp->pcp->pl_stealth / 25.0;
478 odds = ((double)att / ((double)def + (double)att));
481 intensity = roll(20) + roll(20) + roll(20) + roll(20) + 1;
483 PR(att_own, " %3d/%-3d %3d %3.2f ", att, def, intensity, odds);
484 PR(def_own, " %3d/%-3d %3d %3.2f ", def, att, intensity, odds);
488 while ((intensity--) > 0) {
492 if ((dp->plane.pln_effic - ddam) < PLANE_MINEFF)
496 if ((ap->plane.pln_effic - adam) < PLANE_MINEFF)
501 if (dp->pcp->pl_flags & P_M)
504 PR(att_own, "%3d/%-3d", adam, ddam);
505 PR(def_own, "%3d/%-3d", ddam, adam);
506 ac_planedamage(ap, def_own, adam, def_own, 1, 0, mesg);
507 strncpy(temp, mesg, 14);
508 ac_planedamage(dp, att_own, ddam, att_own, 1, 0, mesg);
509 PR(att_own, "%-13.13s %-13.13s\n", temp, mesg);
510 PR(def_own, "%-13.13s %-13.13s\n", mesg, temp);
513 setcont(att_own, def_own, FOUND_FLY);
514 setcont(def_own, att_own, FOUND_FLY);
519 * zap plane associated with plp.
520 * Damaging country is "from", damage is "dam".
521 * def_own is the country on the other side of the conflict from the plane
522 * owner. The only time def_own != from is when the interceptor is getting
525 * NOTE: This routine removes the appropriate plane element from the
526 * queue if it gets destroyed. That means that the caller must assume
527 * that the current queue pointer is invalid on return from the ac_planedamage
528 * call. (this has caused bugs in the past)
531 ac_planedamage(struct plist *plp, natid from, int dam, natid other,
532 int checkabort, int show, char *mesg)
542 plane_owner = pp->pln_own;
544 sprintf(dmess, " no damage");
549 memset(dmess, 0, sizeof(dmess));
553 if (eff < PLANE_MINEFF) {
554 sprintf(dmess, " shot down");
556 } else if (eff < 80 && chance((80 - eff) / 100.0) && checkabort) {
557 sprintf(dmess, " aborted @%2d%%", eff);
559 } else if (show == 0) {
560 sprintf(dmess, " cleared");
563 if ((plp->pcp->pl_flags & P_M) == 0) {
565 PR(plane_owner, " %s %s takes %d%s.\n",
566 cname(pp->pln_own), prplane(pp), dam, dmess);
568 PR(other, " %s %s takes %d%s.\n",
569 cname(pp->pln_own), prplane(pp), dam, dmess);
572 if (show && checkabort == 1) {
573 PR(plane_owner, "\n");
579 pp->pln_mobil -= MIN(32 + pp->pln_mobil, dam / 2);
581 if (disp == 1 && from != 0 && (plp->pcp->pl_flags & P_M) == 0)
582 nreport(from, N_DOWN_PLANE, pp->pln_own, 1);
585 putplane(pp->pln_uid, pp);
590 ac_doflak(struct emp_qelem *list, struct sctstr *from)
596 plp = (struct plist *)list->q_forw;
597 plane_owner = plp->plane.pln_own;
599 gun = MIN(FLAK_GUN_MAX, from->sct_item[I_GUN]);
600 gun = roundavg(tfact(from->sct_own, 2.0 * gun));
602 PR(plane_owner, "firing %d flak guns in %s...\n",
603 gun, xyas(from->sct_x, from->sct_y, plane_owner));
604 if (from->sct_own != 0)
605 PR(from->sct_own, "firing %d flak guns in %s...\n",
606 gun, xyas(from->sct_x, from->sct_y, from->sct_own));
607 ac_fireflak(list, from->sct_own, gun);
612 ac_shipflak(struct emp_qelem *list, coord x, coord y)
617 double flak, total, ngun;
624 plp = (struct plist *)list->q_forw;
625 plane_owner = plp->plane.pln_own;
628 snxtitem_xy(&ni, EF_SHIP, x, y);
629 while (!QEMPTY(list) && nxtitem(&ni, &ship)) {
630 if (ship.shp_own == 0 || ship.shp_own == plane_owner)
632 mcp = &mchr[(int)ship.shp_type];
633 if (mcp->m_flags & M_SUB)
635 rel = getrel(getnatp(ship.shp_own), plane_owner);
638 gun = shp_usable_guns(&ship);
641 flak = gun * (ship.shp_effic / 100.0);
643 total += techfact(ship.shp_tech, flak * 2.0);
645 PR(ship.shp_own, "firing %.0f flak guns from %s...\n",
646 flak, prship(&ship));
650 /* Limit to FLAK_GUN_MAX guns of average tech factor */
651 if (ngun > FLAK_GUN_MAX)
652 total *= FLAK_GUN_MAX / ngun;
654 gun = roundavg(total);
656 PR(plane_owner, "Flak! Ships firing %d flak guns...\n", gun);
657 ac_fireflak(list, from, gun);
662 ac_landflak(struct emp_qelem *list, coord x, coord y)
667 double flak, total, ngun;
674 plp = (struct plist *)list->q_forw;
675 plane_owner = plp->plane.pln_own;
678 snxtitem_xy(&ni, EF_LAND, x, y);
679 while (!QEMPTY(list) && nxtitem(&ni, &land)) {
680 if (land.lnd_own == 0 || land.lnd_own == plane_owner)
682 lcp = &lchr[(int)land.lnd_type];
683 aaf = lnd_aaf(&land);
684 if ((lcp->l_flags & L_FLAK) == 0 || aaf == 0)
686 if (land.lnd_ship >= 0 || land.lnd_land >= 0)
688 rel = getrel(getnatp(land.lnd_own), plane_owner);
691 flak = aaf * 1.5 * land.lnd_effic / 100.0;
693 total += techfact(land.lnd_tech, flak * 2.0);
695 PR(land.lnd_own, "firing flak guns from unit %s (aa rating %d)\n",
700 /* Limit to FLAK_GUN_MAX guns of average tech factor */
701 if (ngun > FLAK_GUN_MAX)
702 total *= FLAK_GUN_MAX / ngun;
704 gun = roundavg(total);
706 PR(plane_owner, "Flak! Land units firing %d flak guns...\n", gun);
707 ac_fireflak(list, from, gun);
712 * Called from shipflak, landflak, and doflak.
715 ac_fireflak(struct emp_qelem *list, natid from, int guns)
719 struct emp_qelem *qp;
720 struct emp_qelem *next;
723 for (qp = list->q_forw; qp != list; qp = next) {
725 plp = (struct plist *)qp;
726 n = ac_flak_dam(guns, pln_def(&plp->plane), plp->pcp->pl_flags);
727 ac_planedamage(plp, from, n, 0, 2, 1, msg);
732 * Calculate flak damage
735 ac_flak_dam(int guns, int def, int pl_flags)
739 /* <-7 -7 -6 -5 -4 */
740 static float flaktable[18] = { 0.132f, 0.20f, 0.20f, 0.25f, 0.30f,
741 /* -3 -2 -1 0 +1 +2 +3 +4 */
742 0.35f, 0.40f, 0.45f, 0.50f, 0.50f, 0.55f, 0.60f, 0.65f,
743 /* +5 +6 +7 +8 >+8 */
744 0.70f,0.75f, 0.80f, 0.85f, 1.1305f };
745 enum { FLAK_MAX = sizeof(flaktable)/sizeof(flaktable[0]) - 1 };
748 if ((pl_flags & P_T) == 0)
752 mult = flaktable[FLAK_MAX];
757 mult = flaktable[flak];
760 dam = (int)((roll(8) + 2) * mult);
767 * Get planes available for interception duties.
770 getilists(struct emp_qelem *list, unsigned char *rel, natid intruder)
773 struct plchrstr *pcp;
779 for (cn = 1; cn < MAXNOC; cn++) {
780 rel[cn] = getrel(getnatp(cn), intruder);
781 emp_initque(&list[cn]);
784 snxtitem_all(&ni, EF_PLANE);
785 while (nxtitem(&ni, &plane)) {
786 if (rel[plane.pln_own] > HOSTILE)
788 pcp = &plchr[(int)plane.pln_type];
789 if ((pcp->pl_flags & P_F) == 0)
791 if (plane.pln_flags & PLN_LAUNCHED)
793 if (plane.pln_mission && plane.pln_mission != MI_AIR_DEFENSE)
795 if (plane.pln_mobil <= 0)
797 if (plane.pln_effic < 40)
799 if (!pln_airbase_ok(&plane, 0, 0))
802 ip = malloc(sizeof(*ip));
804 ip->pcp = &plchr[(int)plane.pln_type];
806 emp_insque(&ip->queue, &list[plane.pln_own]);
811 do_evade(struct emp_qelem *bomb_list, struct emp_qelem *esc_list)
813 struct emp_qelem *qp;
818 for (qp = bomb_list->q_forw; qp != bomb_list; qp = qp->q_forw) {
819 plp = (struct plist *)qp;
820 if (evade > plp->pcp->pl_stealth / 100.0)
821 evade = plp->pcp->pl_stealth / 100.0;
823 for (qp = esc_list->q_forw; qp != esc_list; qp = qp->q_forw) {
824 plp = (struct plist *)qp;
825 if (evade > plp->pcp->pl_stealth / 100.0)
826 evade = plp->pcp->pl_stealth / 100.0;