| 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 | } |