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 * landgun.c: Fire weapons
30 * Known contributors to this file:
31 * Markus Armbruster, 2006-2008
41 #include "prototypes.h"
46 fortgun(int effic, int guns)
49 double g = MIN(guns, 7);
51 d = (random() % 30 + 20.0) * (g / 7.0);
57 seagun(int effic, int guns)
63 d += 10.0 + random() % 6;
69 landunitgun(int effic, int guns)
75 d += 5.0 + random() % 6;
81 * Fire from fortress SP.
82 * Use ammo, resupply if necessary.
83 * Return damage if the fortress fires, else -1.
86 fort_fire(struct sctstr *sp)
88 int guns = sp->sct_item[I_GUN];
91 if (sp->sct_type != SCT_FORTR || sp->sct_effic < FORTEFF)
93 if (sp->sct_item[I_MILIT] < 5 || guns == 0)
95 shells = sp->sct_item[I_SHELL];
96 shells += supply_commod(sp->sct_own, sp->sct_x, sp->sct_y,
100 sp->sct_item[I_SHELL] = shells - 1;
101 return (int)fortgun(sp->sct_effic, guns);
106 * Use ammo, resupply if necessary.
107 * Return damage if the ship fires, else -1.
110 shp_fire(struct shpstr *sp)
114 if (sp->shp_effic < 60)
116 guns = shp_usable_guns(sp);
117 guns = MIN(guns, (sp->shp_item[I_MILIT] + 1) / 2);
120 shells = sp->shp_item[I_SHELL];
121 shells += supply_commod(sp->shp_own, sp->shp_x, sp->shp_y,
122 I_SHELL, (guns + 1) / 2 - shells);
123 guns = MIN(guns, shells * 2);
126 sp->shp_item[I_SHELL] = shells - (guns + 1) / 2;
127 return (int)seagun(sp->shp_effic, guns);
131 * Drop depth-charges from ship SP.
132 * Use ammo, resupply if necessary.
133 * Return damage if the ship drops depth-charges, else -1.
136 shp_dchrg(struct shpstr *sp)
140 if (sp->shp_effic < 60 || (mchr[sp->shp_type].m_flags & M_DCH) == 0)
142 if (sp->shp_item[I_MILIT] == 0)
144 shells = sp->shp_item[I_SHELL];
145 shells += supply_commod(sp->shp_own, sp->shp_x, sp->shp_y,
146 I_SHELL, 2 - shells);
149 dchrgs = MIN(2, shells);
150 sp->shp_item[I_SHELL] = shells - dchrgs;
151 return (int)seagun(sp->shp_effic, 2 * dchrgs - 1);
155 * Fire torpedo from ship SP.
156 * Use ammo and mobility, resupply if necessary.
157 * Return damage if the ship fires, else -1.
160 shp_torp(struct shpstr *sp, int usemob)
164 if (sp->shp_effic < 60 || (mchr[sp->shp_type].m_flags & M_TORP) == 0)
166 if (sp->shp_item[I_MILIT] == 0 || sp->shp_item[I_GUN] == 0)
168 if (usemob && sp->shp_mobil <= 0)
170 shells = sp->shp_item[I_SHELL];
171 shells += supply_commod(sp->shp_own, sp->shp_x, sp->shp_y,
172 I_SHELL, SHP_TORP_SHELLS - shells);
173 if (shells < SHP_TORP_SHELLS)
175 sp->shp_item[I_SHELL] = shells - SHP_TORP_SHELLS;
177 sp->shp_mobil -= (int)shp_mobcost(sp) / 2.0;
178 return TORP_DAMAGE();
182 * Fire from land unit LP.
183 * Use ammo, resupply if necessary.
184 * Return damage if the land unit fires, else -1.
187 lnd_fire(struct lndstr *lp)
189 int guns, ammo, shells;
192 if (lp->lnd_effic < LAND_MINFIREEFF)
194 if (lp->lnd_ship >= 0 || lp->lnd_land >= 0)
196 if (lp->lnd_item[I_MILIT] == 0)
199 guns = MIN(guns, lp->lnd_item[I_GUN]);
202 ammo = lchr[lp->lnd_type].l_ammo;
203 if (CANT_HAPPEN(ammo == 0))
205 shells = lp->lnd_item[I_SHELL];
206 shells += supply_commod(lp->lnd_own, lp->lnd_x, lp->lnd_y,
207 I_SHELL, ammo - shells);
210 d = landunitgun(lp->lnd_effic, guns);
212 d *= (double)shells / (double)ammo;
215 lp->lnd_item[I_SHELL] = shells - ammo;
220 * Return number of guns ship SP can fire.
223 shp_usable_guns(struct shpstr *sp)
225 return MIN(shp_glim(sp), sp->shp_item[I_GUN]);
229 * Return effective firing range for range factor RNG at tech TLEV.
232 effrange(int rng, double tlev)
234 /* FIXME don't truncate TLEV */
235 return techfact((int)tlev, rng / 2.0);
239 * Return firing range for sector SP.
242 fortrange(struct sctstr *sp)
244 struct natstr *np = getnatp(sp->sct_own);
247 if (sp->sct_type != SCT_FORTR || sp->sct_effic < FORTEFF)
250 rng = effrange(14.0 * fire_range_factor, np->nat_level[NAT_TLEV]);
251 if (sp->sct_effic > 59)
257 * Return firing range for ship SP.
260 shp_fire_range(struct shpstr *sp)
262 return effrange(shp_frnge(sp), sp->shp_tech);
266 * Return torpedo range for ship SP.
269 torprange(struct shpstr *sp)
271 return effrange(shp_frnge(sp) * 2, sp->shp_tech)
272 * sp->shp_effic / 100.0;
276 * Return hit chance for torpedo from ship SP at range RANGE.
279 shp_torp_hitchance(struct shpstr *sp, int range)
281 return DTORP_HITCHANCE(range, shp_visib(sp));
285 * Return firing range for land unit SP.
288 lnd_fire_range(struct lndstr *lp)
290 return effrange(lnd_frg(lp), lp->lnd_tech);