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torpedo: Fix mobility cost of retreat after hit
[empserver] / src / lib / commands / torp.c
1 /*
2  *  Empire - A multi-player, client/server Internet based war game.
3  *  Copyright (C) 1986-2015, Dave Pare, Jeff Bailey, Thomas Ruschak,
4  *                Ken Stevens, Steve McClure, Markus Armbruster
5  *
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.
10  *
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.
15  *
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/>.
18  *
19  *  ---
20  *
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.
24  *
25  *  ---
26  *
27  *  torp.c: Fire torpedoes at enemy ships
28  *
29  *  Known contributors to this file:
30  *     Dave Pare
31  *     Thomas Ruschak, 1992
32  *     Ken Stevens, 1995
33  *     Steve McClure, 2000
34  *     Markus Armbruster, 2004-2015
35  */
36
37 #include <config.h>
38
39 #include "chance.h"
40 #include "commands.h"
41 #include "news.h"
42 #include "retreat.h"
43 #include "ship.h"
44
45 static void anti_torp(int f, int ntorping, int vshipown);
46 static void fire_dchrg(struct shpstr *, struct shpstr *, int);
47 static int fire_torp(struct shpstr *, struct shpstr *, int);
48
49 int
50 torp(void)
51 {
52     natid vshipown;
53     int range;
54     int dam;
55     int subno;
56     int victno;
57     int erange;
58     double hitchance;
59     struct shpstr vship;
60     struct shpstr sub;
61     char *ptr;
62     struct nstr_item nbst;
63     char buf[1024];
64     int ntorping = 0;
65     char prompt[128];
66
67     if (!snxtitem(&nbst, EF_SHIP, player->argp[1], "From ship(s)? "))
68         return RET_SYN;
69     while (nxtitem(&nbst, &sub)) {
70         if (sub.shp_own != player->cnum)
71             continue;
72         if ((mchr[(int)sub.shp_type].m_flags & M_TORP) == 0)
73             continue;
74         if (sub.shp_item[I_GUN] == 0
75             || sub.shp_item[I_SHELL] < SHP_TORP_SHELLS)
76             continue;
77         if (sub.shp_item[I_MILIT] < 1)
78             continue;
79         if (sub.shp_effic < 60)
80             continue;
81         if (sub.shp_mobil <= 0)
82             continue;
83         ntorping++;
84     }
85     pr("%d ships are eligible to torp\n", ntorping);
86     snxtitem_rewind(&nbst);
87     while (nxtitem(&nbst, &sub)) {
88         if (!sub.shp_own)
89             continue;
90         if (sub.shp_own != player->cnum) {
91             continue;
92         }
93         if ((mchr[(int)sub.shp_type].m_flags & M_TORP) == 0) {
94             pr("Ship # %d: A %s can't fire torpedoes!\n",
95                sub.shp_uid, mchr[(int)sub.shp_type].m_name);
96             continue;
97         }
98         if (sub.shp_item[I_GUN] == 0
99             || sub.shp_item[I_SHELL] < SHP_TORP_SHELLS) {
100             pr("Ship #%d has insufficient armament\n", sub.shp_uid);
101             continue;
102         }
103         if (sub.shp_item[I_MILIT] < 1) {
104             pr("Ship #%d has insufficient crew\n", sub.shp_uid);
105             continue;
106         }
107         if (sub.shp_effic < 60) {
108             pr("Ship #%d torpedo tubes inoperative.\n", sub.shp_uid);
109             continue;
110         }
111         if (sub.shp_mobil <= 0) {
112             pr("Ship #%d has insufficient mobility\n", sub.shp_uid);
113             continue;
114         }
115         subno = sub.shp_uid;
116         sprintf(prompt, "Ship %d, target? ", sub.shp_uid);
117         if (!(ptr = getstarg(player->argp[2], prompt, buf)))
118             return RET_SYN;
119         if (!check_ship_ok(&sub))
120             return RET_FAIL;
121         if ((victno = atoi(ptr)) < 0)
122             return RET_SYN;
123         if (!getship(victno, &vship))
124             return RET_FAIL;
125         if (!vship.shp_own)
126             return RET_FAIL;
127         vshipown = vship.shp_own;
128         if (victno == subno) {
129             pr("Shooting yourself, eh?  How strange...\n");
130             continue;
131         }
132         if (mchr[(int)vship.shp_type].m_flags & M_SUB) {
133             if (!(mchr[(int)sub.shp_type].m_flags & M_SUBT)) {
134                 pr("You can't torpedo a submarine!\n");
135                 continue;
136             }
137         }
138         dam = shp_torp(&sub, 1);
139         sub.shp_mission = 0;
140         putship(sub.shp_uid, &sub);
141         if (CANT_HAPPEN(dam < 0)) {
142             pr("Ship #%d has insufficient armament\n", sub.shp_uid);
143             continue;
144         }
145
146         if ((mchr[(int)sub.shp_type].m_flags & M_SUB) == 0)
147             anti_torp(sub.shp_uid, ntorping, vshipown);
148         getship(sub.shp_uid, &sub);
149         if (sub.shp_own == 0)
150             continue;
151
152         erange = roundrange(torprange(&sub));
153         pr("Effective torpedo range is %d.0\n", erange);
154         pr("Whooosh... ");
155         getship(victno, &vship);
156         vshipown = vship.shp_own;
157         range = mapdist(sub.shp_x, sub.shp_y, vship.shp_x, vship.shp_y);
158         hitchance = shp_torp_hitchance(&sub, range);
159         if (range <= erange) {
160             pr("Hitchance = %d%%\n", (int)(hitchance * 100));
161         }
162         /* Now, can the torpedo even get there? */
163         if (!line_of_sight(NULL, sub.shp_x, sub.shp_y,
164                            vship.shp_x, vship.shp_y)) {
165             pr("BOOM!... Torpedo slams into land before reaching target.\n");
166             /* We only tell the victim if we were within range. */
167             if (range <= erange) {
168                 if (vshipown != 0)
169                     wu(0, vshipown, "Torpedo sighted @ %s by %s\n",
170                        xyas(sub.shp_x, sub.shp_y, vshipown),
171                        prship(&vship));
172             }
173         } else if (range > erange) {
174             pr("Out of range\n");
175         } else if (chance(hitchance)) {
176             pr("BOOM!...\n");
177             if (vshipown != 0)
178                 wu(0, vshipown, "%s in %s torpedoed %s for %d damage.\n",
179                    prsub(&sub), xyas(sub.shp_x, sub.shp_y, vshipown),
180                    prship(&vship), dam);
181             shipdamage(&vship, dam);
182             if (vship.shp_rflags & RET_TORPED)
183                 retreat_ship(&vship, 't');
184             pr("Torpedo hit %s for %d damage.\n", prship(&vship), dam);
185
186             if (vship.shp_effic < SHIP_MINEFF)
187                 pr("%s sunk!\n", prship(&vship));
188             putship(vship.shp_uid, &vship);
189             if (mchr[(int)sub.shp_type].m_flags & M_SUB)
190                 nreport(vshipown, N_TORP_SHIP, 0, 1);
191             else
192                 nreport(vshipown, N_SHIP_TORP, player->cnum, 1);
193         } else {
194             pr("Missed\n");
195             if (vshipown != 0)
196                 wu(0, vshipown, "Torpedo sighted @ %s by %s\n",
197                    xyas(sub.shp_x, sub.shp_y, vshipown), prship(&vship));
198         }
199
200         if (mchr[(int)sub.shp_type].m_flags & M_SUB)
201             anti_torp(sub.shp_uid, ntorping, vshipown);
202     }
203     return RET_OK;
204 }
205
206 static void
207 anti_torp(int f, int ntorping, int vshipown)
208 {
209     struct shpstr sub;
210     struct shpstr dd;
211     int x;
212
213     getship(f, &sub);
214
215     if (sub.shp_own == vshipown)
216         return;
217
218     if ((mchr[(int)sub.shp_type].m_flags & M_SUB) == 0)
219         pr("Starting our attack run...\n");
220
221     x = 0;
222     while (getship(x++, &dd) && sub.shp_effic >= SHIP_MINEFF) {
223         if (dd.shp_own == 0)
224             continue;
225         if (dd.shp_own != vshipown)
226             continue;
227
228         if (!fire_torp(&dd, &sub, ntorping))
229             fire_dchrg(&dd, &sub, ntorping);
230     }
231 }
232
233 static void
234 fire_dchrg(struct shpstr *sp, struct shpstr *targ, int ntargets)
235 {
236     int range, erange, dam;
237
238     erange = roundrange(shp_fire_range(sp));
239     range = mapdist(sp->shp_x, sp->shp_y, targ->shp_x, targ->shp_y);
240     if (range > erange)
241         return;
242
243     if ((mchr[(int)targ->shp_type].m_flags & M_SUB) == 0) {
244         /* Return fire to a torpedo boat */
245         if (mchr[sp->shp_type].m_flags & M_SUB)
246             return;             /* sub deck gun can't return fire */
247         dam = shp_fire(sp);
248         putship(sp->shp_uid, sp);
249         if (dam < 0)
250             return;
251         if (ntargets > 2)
252             dam /= ntargets / 2;
253
254         pr_beep();
255         pr("Kaboom!!! Incoming shells!\n");
256         if (sp->shp_own != 0)
257             wu(0, sp->shp_own,
258                "%s fired at %s\n", prship(sp), prship(targ));
259         pr_beep();
260         pr("BLAM! %d damage!\n", dam);
261     } else {
262         /* Return fire to a submarine */
263         dam = shp_dchrg(sp);
264         putship(sp->shp_uid, sp);
265         if (dam < 0)
266             return;
267         if (ntargets > 2)
268             dam /= ntargets / 2;
269
270         pr("\nCAPTAIN!  !!Depth charges!!...\n");
271         if (sp->shp_own != 0)
272             wu(0, sp->shp_own,
273                "%s depth charged %s\n", prship(sp), prsub(targ));
274         pr("click...WHAM!  %d damage!\n", dam);
275     }
276     shipdamage(targ, dam);
277     putship(targ->shp_uid, targ);
278 }
279
280 static int
281 fire_torp(struct shpstr *sp, struct shpstr *targ, int ntargets)
282 {
283     int range, erange, dam;
284
285     if ((mchr[targ->shp_type].m_flags & M_SUB)
286         && (mchr[sp->shp_type].m_flags & M_SUBT) == 0)
287         return 0;               /* need sub-torp to torpedo a sub */
288
289     erange = roundrange(torprange(sp));
290     range = mapdist(sp->shp_x, sp->shp_y, targ->shp_x, targ->shp_y);
291     if (range > erange)
292         return 0;
293
294     if (!line_of_sight(NULL, sp->shp_x, sp->shp_y,
295                        targ->shp_x, targ->shp_y))
296         return 0;
297     dam = shp_torp(sp, 1);
298     putship(sp->shp_uid, sp);
299     if (dam < 0)
300         return 0;
301
302     pr("Captain! Torpedoes sighted!\n");
303
304     if (chance(shp_torp_hitchance(sp, range))) {
305         pr("BOOM!...\n");
306         if (sp->shp_own != 0)
307             wu(0, sp->shp_own, "%s @ %s torpedoed %s\n",
308                prship(sp),
309                xyas(sp->shp_x, sp->shp_y, sp->shp_own), prsub(targ));
310         if (ntargets > 2)
311             dam /= ntargets / 2;
312
313         shipdamage(targ, dam);
314         putship(targ->shp_uid, targ);
315
316         if (mchr[(int)sp->shp_type].m_flags & M_SUB)
317             nreport(targ->shp_own, N_TORP_SHIP, 0, 1);
318         else
319             nreport(targ->shp_own, N_SHIP_TORP, sp->shp_own, 1);
320     } else {
321         pr("Missed!\n");
322         if (sp->shp_own != 0)
323             wu(0, sp->shp_own,
324                "%s missed %s with a torp at %s\n",
325                prship(sp), prsub(targ),
326                xyas(sp->shp_x, sp->shp_y, sp->shp_own));
327     }
328
329     return 1;
330 }
331
332 char *
333 prsub(struct shpstr *sp)
334 {
335     if (mchr[(int)sp->shp_type].m_flags & M_SUB)
336         return "sub";
337     else
338         return prship(sp);
339 }