1 /*
2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2021, 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 * btu.c: Dealing with BTUs
28 *
29 * Known contributors to this file:
30 * Markus Armbruster, 2007
31 */
32
33 #include <config.h>
34
35 #include "chance.h"
36 #include "nat.h"
37 #include "optlist.h"
38 #include "sect.h"
39
40 /*
41 * Return BTUs produced by @cap in @etu ETUs.
42 */
43 static int
accrued_btus(struct sctstr * cap,int etu)44 accrued_btus(struct sctstr *cap, int etu)
45 {
46 double eff, civ;
47
48 switch (cap->sct_type) {
49 case SCT_CAPIT:
50 case SCT_SANCT:
51 eff = cap->sct_effic;
52 break;
53 case SCT_MOUNT:
54 eff = 0;
55 break;
56 default:
57 return 0;
58 }
59
60 eff *= cap->sct_work / 100.0;
61 if (eff < 0.5)
62 eff = 0.5;
63
64 civ = cap->sct_item[I_CIVIL];
65 if (civ > 1000)
66 civ = 1000;
67
68 return roundavg(etu * civ * eff * btu_build_rate);
69 }
70
71 /*
72 * Grant nation @np the BTUs produced by its capital in @etu ETUs.
73 * Return whether it has a capital.
74 */
75 int
grant_btus(struct natstr * np,int etu)76 grant_btus(struct natstr *np, int etu)
77 {
78 int has_cap, delta;
79 struct sctstr sect;
80
81 getsect(np->nat_xcap, np->nat_ycap, §);
82 has_cap = np->nat_stat >= STAT_ACTIVE && !influx(np);
83
84 if (has_cap) {
85 delta = accrued_btus(§, etu);
86 if (delta + np->nat_btu > max_btus)
87 np->nat_btu = max_btus;
88 else
89 np->nat_btu += delta;
90 }
91 if (np->nat_stat == STAT_VIS || np->nat_stat == STAT_GOD)
92 np->nat_btu = max_btus;
93
94 return has_cap;
95 }
96