2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2012, Dave Pare, Jeff Bailey, Thomas Ruschak,
4 * Ken Stevens, Steve McClure, Markus Armbruster
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.
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, see <http://www.gnu.org/licenses/>.
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.
27 * game.c: Game file access
29 * Known contributors to this file:
30 * Markus Armbruster, 2007-2009
36 * An Empire turn is terminated by an update. The Empire clock counts
37 * turns and ETUs, i.e. it ticks etu_per_update times per turn. When
38 * updates move around in real time (schedule change, downtime, etc.),
39 * the Empire clock automatically adapts the duration of an ETU
52 * Enable / disable updates
55 game_ctrl_update(int enable)
57 struct gamestr *game = getgamep();
59 game->game_upd_disable = !enable;
64 * Are updates disabled?
67 updates_disabled(void)
69 return getgamep()->game_upd_disable;
73 * Enable / disable play
76 game_ctrl_play(int enable)
78 struct gamestr *game = getgamep();
80 game->game_down = !enable;
88 game_play_disabled(void)
90 return getgamep()->game_down;
94 * Notice that a player broke sanctuary.
95 * This starts the Empire clock if it hasn't been started yet.
98 game_note_bsanct(void)
100 struct gamestr *game = getgamep();
102 if (game->game_rt == 0) {
103 game->game_rt = time(NULL);
109 * Record an update in the game file, the current time is NOW.
110 * This starts the Empire clock if it hasn't been started yet.
113 game_record_update(time_t now)
115 struct gamestr *game = getgamep();
124 * Return current duration of an ETU in seconds.
125 * Note: may return HUGE_VAL when the Empire clock is not ticking.
128 secs_per_etu(struct gamestr *game)
132 if (!game->game_rt || !update_time[0])
133 return HUGE_VAL; /* not started or no update scheduled */
135 secs = update_time[0] - game->game_rt;
137 return HUGE_VAL; /* update seems to be late */
138 return secs / (etu_per_update - game->game_tick);
142 * Update the Empire clock according to the current real time.
143 * Return the game struct.
148 struct gamestr *game = getgamep();
149 double dsecs, s_p_etu;
152 dsecs = time(NULL) - game->game_rt;
153 if (CANT_HAPPEN(dsecs < 0))
155 s_p_etu = secs_per_etu(game);
156 detu = (int)(dsecs / s_p_etu);
158 if (CANT_HAPPEN(game->game_tick + detu > etu_per_update))
159 detu = etu_per_update - game->game_tick;
160 game->game_tick += detu;
161 game->game_rt += detu * s_p_etu;
169 * Set ETU timestamp *TICK to the current ETU time.
170 * Return by how many ETUs it was increased.
173 game_tick_to_now(short *tick)
175 return game_step_a_tick(game_tick_tick(), tick);
179 * Set ETU timestamp *TICK to the ETU time recorded in the game struct.
180 * The Empire clock is not updated.
181 * Return by how many ETUs it was increased.
184 game_step_a_tick(struct gamestr *game, short *tick)
188 etu = game->game_tick - *tick;
189 if (CANT_HAPPEN(etu < 0))
191 *tick = game->game_tick;
196 * Reset ETU timestamp *TICK to zero.
197 * Return how many ETUs it had left until etu_per_update.
200 game_reset_tick(short *tick)
204 etu = etu_per_update - *tick;
205 if (CANT_HAPPEN(etu < 0))