63 lines
1.5 KiB
C
63 lines
1.5 KiB
C
/* NetHack 3.7 track.c $NHDT-Date: 1596498219 2020/08/03 23:43:39 $ $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.12 $ */
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/* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
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/*-Copyright (c) Kenneth Lorber, Kensington, Maryland, 2015. */
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/* NetHack may be freely redistributed. See license for details. */
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/* track.c - version 1.0.2 */
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#include "hack.h"
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#define UTSZ 50
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static NEARDATA int utcnt, utpnt;
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static NEARDATA coord utrack[UTSZ];
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void
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initrack(void)
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{
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utcnt = utpnt = 0;
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}
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/* add to track */
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void
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settrack(void)
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{
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if (utcnt < UTSZ)
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utcnt++;
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if (utpnt == UTSZ)
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utpnt = 0;
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utrack[utpnt].x = u.ux;
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utrack[utpnt].y = u.uy;
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utpnt++;
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}
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coord *
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gettrack(register int x, register int y)
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{
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register int cnt, ndist;
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register coord *tc;
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cnt = utcnt;
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for (tc = &utrack[utpnt]; cnt--;) {
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if (tc == utrack)
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tc = &utrack[UTSZ - 1];
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else
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tc--;
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ndist = distmin(x, y, tc->x, tc->y);
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/* if far away, skip track entries til we're closer */
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if (ndist > 2) {
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ndist -= 2; /* be careful due to extra decrement at top of loop */
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cnt -= ndist;
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if (cnt <= 0)
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return (coord *) 0; /* too far away, no matches possible */
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if (tc < &utrack[ndist])
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tc += (UTSZ - ndist);
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else
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tc -= ndist;
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} else if (ndist <= 1)
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return (ndist ? tc : 0);
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}
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return (coord *) 0;
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}
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/*track.c*/
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