110 lines
2.3 KiB
C
110 lines
2.3 KiB
C
/*
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* Empire - A multi-player, client/server Internet based war game.
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* Copyright (C) 1986-2006, Dave Pare, Jeff Bailey, Thomas Ruschak,
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* Ken Stevens, Steve McClure
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* ---
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*
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* See the "LEGAL", "LICENSE", "CREDITS" and "README" files for all the
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* related information and legal notices. It is expected that any future
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* projects/authors will amend these files as needed.
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*
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* ---
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*
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* mapdist.c: Return the distance between two sectors
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*
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* Known contributors to this file:
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*
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*/
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/*
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* mapdist returns (integer) distance between two sectors.
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*/
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#include <config.h>
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#include "misc.h"
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#include "gen.h"
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#include "optlist.h"
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int
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diffx(int x1, int x2)
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{
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int dx;
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dx = x1 - x2;
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dx = dx % WORLD_X;
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if (dx > WORLD_X / 2)
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dx = dx - WORLD_X;
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if (dx < -WORLD_X / 2)
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dx = dx + WORLD_X;
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return dx;
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}
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int
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diffy(int y1, int y2)
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{
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int dy;
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dy = y1 - y2;
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dy = dy % WORLD_Y;
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if (dy > WORLD_Y / 2)
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dy = dy - WORLD_Y;
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if (dy < -WORLD_Y / 2)
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dy = dy + WORLD_Y;
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return dy;
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}
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int
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deltax(int x1, int x2)
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{
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int dx;
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dx = abs(x1 - x2);
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dx = dx % WORLD_X;
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if (dx > WORLD_X / 2)
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dx = WORLD_X - dx;
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return dx;
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}
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int
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deltay(int y1, int y2)
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{
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int dy;
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dy = abs(y1 - y2);
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dy = dy % WORLD_Y;
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if (dy > WORLD_Y / 2)
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dy = WORLD_Y - dy;
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return dy;
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}
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int
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mapdist(int x1, int y1, int x2, int y2)
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{
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int dx, dy;
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x1 = x1 % WORLD_X;
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y1 = y1 % WORLD_Y;
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x2 = x2 % WORLD_X;
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y2 = y2 % WORLD_Y;
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dx = deltax(x1, x2);
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dy = deltay(y1, y2);
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if (dx > dy)
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return (dx - dy) / 2 + dy;
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return dy;
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}
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