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 * coastal.c: Routines to calculate the coastal flag
30 * Known contributors to this file:
31 * Ron Koenderink, 2005
38 #include "prototypes.h"
42 update_coastal_flag(coord x, coord y, coord ign_x, coord ign_y)
47 for (n = 1; n <= 6; n++) { /* Directions */
48 getsect(x + diroff[n][0], y + diroff[n][1], §);
49 if (sect.sct_x == ign_x && sect.sct_y == ign_y)
51 if (sect.sct_type == SCT_WATER || sect.sct_type == SCT_BTOWER ||
52 sect.sct_type == SCT_BSPAN)
60 coastal_sea_to_land(coord x, coord y)
65 for (n = 1; n <= 6; n++) { /* Directions */
66 getsect(x + diroff[n][0], y + diroff[n][1], §);
67 c = update_coastal_flag(sect.sct_x, sect.sct_y, x, y);
68 if (!sect.sct_coastal != !c) {
74 return update_coastal_flag(x, y, x, y);
78 coastal_land_to_sea(coord x, coord y)
83 for (n = 1; n <= 6; ++n) { /* Directions */
84 getsect(x + diroff[n][0], y + diroff[n][1], §);
85 if (!sect.sct_coastal) {
95 * Compute coastal flags for a change of SP from OLDDES to NEWDES.
96 * Update adjacent sectors, but don't touch SP.
97 * Return new coastal flag for SP.
100 set_coastal(struct sctstr *sp, int olddes, int newdes)
102 int old_water = olddes == SCT_WATER
103 || olddes == SCT_BTOWER || olddes == SCT_BSPAN;
104 int new_water = newdes == SCT_WATER
105 || newdes == SCT_BTOWER || newdes == SCT_BSPAN;
107 if (new_water != old_water)
108 sp->sct_coastal = new_water
109 ? coastal_land_to_sea(sp->sct_x, sp->sct_y)
110 : coastal_sea_to_land(sp->sct_x, sp->sct_y);