1 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */ 2 /* hack.track.c - version 1.0.2 */ 3 4 #include "hack.h" 5 6 #define UTSZ 50 7 8 coord utrack[UTSZ]; 9 int utcnt = 0; 10 int utpnt = 0; 11 12 initrack(){ 13 utcnt = utpnt = 0; 14 } 15 16 /* add to track */ 17 settrack(){ 18 if(utcnt < UTSZ) utcnt++; 19 if(utpnt == UTSZ) utpnt = 0; 20 utrack[utpnt].x = u.ux; 21 utrack[utpnt].y = u.uy; 22 utpnt++; 23 } 24 25 coord * 26 gettrack(x,y) register x,y; { 27 register int i,cnt,dist; 28 coord tc; 29 cnt = utcnt; 30 for(i = utpnt-1; cnt--; i--){ 31 if(i == -1) i = UTSZ-1; 32 tc = utrack[i]; 33 dist = (x-tc.x)*(x-tc.x) + (y-tc.y)*(y-tc.y); 34 if(dist < 3) 35 return(dist ? &(utrack[i]) : 0); 36 } 37 return(0); 38 } 39