2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2016, 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 * coastal.c: Routines to calculate the coastal flag
29 * Known contributors to this file:
30 * Ron Koenderink, 2005
36 #include "prototypes.h"
41 update_coastal_flag(coord x, coord y, coord ign_x, coord ign_y)
46 for (n = 1; n <= 6; n++) { /* Directions */
47 getsect(x + diroff[n][0], y + diroff[n][1], §);
48 if (sect.sct_x == ign_x && sect.sct_y == ign_y)
50 if (sect.sct_type == SCT_WATER || sect.sct_type == SCT_BTOWER ||
51 sect.sct_type == SCT_BSPAN)
59 coastal_sea_to_land(coord x, coord y)
64 for (n = 1; n <= 6; n++) { /* Directions */
65 getsect(x + diroff[n][0], y + diroff[n][1], §);
66 c = update_coastal_flag(sect.sct_x, sect.sct_y, x, y);
67 if (!sect.sct_coastal != !c) {
73 return update_coastal_flag(x, y, x, y);
77 coastal_land_to_sea(coord x, coord y)
82 for (n = 1; n <= 6; ++n) { /* Directions */
83 getsect(x + diroff[n][0], y + diroff[n][1], §);
84 if (!sect.sct_coastal) {
94 * Compute coastal flags for a change of @sp from @olddes to @newdes.
95 * Update adjacent sectors, but don't touch @sp.
98 set_coastal(struct sctstr *sp, int olddes, int newdes)
100 int old_water = olddes == SCT_WATER
101 || olddes == SCT_BTOWER || olddes == SCT_BSPAN;
102 int new_water = newdes == SCT_WATER
103 || newdes == SCT_BTOWER || newdes == SCT_BSPAN;
105 if (new_water != old_water)
106 sp->sct_coastal = new_water
107 ? coastal_land_to_sea(sp->sct_x, sp->sct_y)
108 : coastal_sea_to_land(sp->sct_x, sp->sct_y);