2 * Copyright (c) 1980, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * @(#) Copyright (c) 1980, 1993 The Regents of the University of California. All rights reserved.
34 * @(#)snake.c 8.2 (Berkeley) 1/7/94
35 * $FreeBSD: src/games/snake/snake/snake.c,v 1.11.2.1 2000/08/17 06:21:44 jhb Exp $
36 * $DragonFly: src/games/snake/snake/snake.c,v 1.4 2006/09/03 23:47:56 pavalos Exp $
40 * snake - crt hack game.
42 * You move around the screen with arrow keys trying to pick up money
43 * without getting eaten by the snake. hjkl work as in vi in place of
44 * arrow keys. You can leave at the exit any time.
47 * cc -O snake.c move.c -o snake -lm -ltermlib
50 #include <sys/param.h>
58 #include <sys/types.h>
67 #include "pathnames.h"
69 #define cashvalue chunk*(loot-penalty)/25
75 #define same(s1, s2) ((s1)->line == (s2)->line && (s1)->col == (s2)->col)
77 #define PENALTY 10 /* % penalty for invoking spacewarp */
90 #define MIN(a, b) ((a) < (b) ? (a) : (b))
93 #define pchar(point, c) mvaddch((point)->line + 1, (point)->col + 1, (c))
94 #define delay(t) usleep(t * 50000);
99 struct point snake[6];
108 int lcnt, ccnt; /* user's idea of screen size */
109 int chunk; /* amount of money given at a time */
111 void chase(struct point *, struct point *);
112 int chk(const struct point *);
117 void logit(const char *);
118 int main(int, char **);
119 void mainloop(void) __attribute__((__noreturn__));
120 struct point *point(struct point *, int, int);
123 void right(const struct point *);
126 void snrand(struct point *);
128 void stop(int) __attribute__((__noreturn__));
129 int stretch(const struct point *);
130 void surround(struct point *);
132 void win(const struct point *);
136 main(int argc, char **argv)
141 /* Open score files then revoke setgid privileges */
142 rawscores = open(_PATH_RAWSCORES, O_RDWR|O_CREAT, 0664);
144 warn("open %s", _PATH_RAWSCORES);
146 } else if (rawscores < 3)
148 logfile = fopen(_PATH_LOGFILE, "a");
149 if (logfile == NULL) {
150 warn("fopen %s", _PATH_LOGFILE);
157 while ((ch = getopt(argc, argv, "l:w:t")) != -1)
164 case 'w': /* width */
167 case 'l': /* length */
176 fputs("usage: snake [-d seed] [-w width] [-l length] [-t]\n", stderr);
178 fputs("usage: snake [-w width] [-l length] [-t]\n", stderr);
190 keypad(stdscr, TRUE);
192 if (!lcnt || lcnt > LINES - 2)
194 if (!ccnt || ccnt > COLS - 2)
200 errx(1, "screen too small for a fair game.");
204 * chunk is the amount of money the user gets for each $.
205 * The formula below tries to be fair for various screen sizes.
206 * We only pay attention to the smaller of the 2 edges, since
207 * that seems to be the bottleneck.
208 * This formula is a hyperbola which includes the following points:
209 * (24, $25) (original scoring algorithm)
210 * (12, $40) (experimentally derived by the "feel")
211 * (48, $15) (a guess)
212 * This will give a 4x4 screen $99/shot. We don't allow anything
213 * smaller than 4x4 because there is a 3x3 game where you can win
214 * an infinite amount of money.
216 if (i < 12) i = 12; /* otherwise it isn't fair */
218 * Compensate for border. This really changes the game since
219 * the screen is two squares smaller but we want the default
220 * to be $25, and the high scores on small screens were a bit
224 chunk = (675.0 / (i+6)) + 2.5; /* min screen edge */
226 signal (SIGINT, stop);
234 chase (&snake[i], &snake[i-1]);
242 point(struct point *ps, int x, int y)
249 /* Main command loop */
260 /* Highlight you, not left & above */
261 move(you.line + 1, you.col + 1);
263 if (((c = getch()) <= '9') && (c >= '0')) {
265 while (((c = getch()) <= '9') && (c >= '0'))
266 repeat = 10 * repeat + (c - '0');
268 if (c != '.') repeat = 1;
281 case 0177: /* del or end of file */
303 repeat = you.col - money.col;
312 repeat = you.line - money.line;
316 repeat = ccnt - 1 - you.col;
321 repeat = money.col - you.col;
325 repeat = lcnt - 1 - you.line;
330 repeat = money.line - you.line;
334 for(k=1;k<=repeat;k++){
347 if((fast) || (k == repeat) ||
358 if (you.col < ccnt-1) {
362 if((fast) || (k == repeat) ||
378 if((fast) || (k == repeat) ||
391 if (you.line+1 < lcnt) {
395 if((fast) || (k == repeat) ||
396 (you.line == lcnt-1))
402 if (same(&you,&money))
409 } while ((money.col == finish.col && money.line == finish.line) ||
410 (money.col < 5 && money.line == 0) ||
411 (money.col == you.col && money.line == you.line));
412 pchar(&money,TREASURE);
416 if (same(&you,&finish))
421 printf("You have won with $%d.\n", cashvalue);
428 if (pushsnake())break;
443 pchar(&money,TREASURE);
445 pchar(&snake[i],SNAKETAIL);
447 pchar(&snake[0], SNAKEHEAD);
457 for (i = 1; i <= ccnt; i++) {
459 mvaddch(lcnt + 1, i, '-');
461 for (i = 0; i <= lcnt + 1; i++) {
463 mvaddch(i, ccnt + 1, '|');
468 snrand(struct point *sp)
474 p.col = random() % ccnt;
475 p.line = random() % lcnt;
477 /* make sure it's not on top of something else */
478 if (p.line == 0 && p.col < 5)
482 if (same(&p, &money))
484 if (same(&p, &finish))
486 for (i = 0; i < 6; i++)
487 if (same(&p, &snake[i]))
497 post(int iscore, int flag)
499 short score = iscore;
502 short allbwho=0, allbscore=0;
505 /* I want to printf() the scores for terms that clear on cook(),
506 * but this routine also gets called with flag == 0 to see if
507 * the snake should wink. If (flag) then we're at game end and
511 * Neg uid, 0, and 1 cannot have scores recorded.
513 if ((uid = getuid()) <= 1) {
515 printf("No saved scores for uid %d.\n", uid);
519 /* Error reported earlier */
522 /* Figure out what happened in the past */
523 read(rawscores, &allbscore, sizeof(short));
524 read(rawscores, &allbwho, sizeof(short));
525 lseek(rawscores, ((off_t)uid)*sizeof(short), 0);
526 read(rawscores, &oldbest, sizeof(short));
528 lseek(rawscores, 0, SEEK_SET);
529 return (score > oldbest ? 1 : 0);
532 /* Update this jokers best */
533 if (score > oldbest) {
534 lseek(rawscores, ((off_t)uid)*sizeof(short), 0);
535 write(rawscores, &score, sizeof(short));
536 printf("You bettered your previous best of $%d\n", oldbest);
538 printf("Your best to date is $%d\n", oldbest);
540 /* See if we have a new champ */
541 p = getpwuid(allbwho);
542 if (score > allbscore) {
543 lseek(rawscores, 0, SEEK_SET);
544 write(rawscores, &score, sizeof(short));
545 write(rawscores, &uid, sizeof(short));
548 printf("You beat %s's old record of $%d!\n",
549 p->pw_name, allbscore);
551 printf("You beat (%d)'s old record of $%d!\n",
552 (int)allbwho, allbscore);
555 printf("You set a new record!\n");
557 printf("The highest is %s with $%d\n", p->pw_name, allbscore);
559 printf("The highest is (%d) with $%d\n", (int)allbwho,
561 lseek(rawscores, 0, SEEK_SET);
566 * Flush typeahead to keep from buffering a bunch of chars and then
567 * overshooting. This loses horribly at 9600 baud, but works nicely
568 * if the terminal gets behind.
573 tcflush(0, TCIFLUSH);
576 0, 1, 1, 1, 0,-1,-1,-1};
578 -1,-1, 0, 1, 1, 1, 0,-1};
580 1, 1.4, 1, 1.4, 1, 1.4, 1, 1.4
585 chase(struct point *np, struct point *sp)
587 /* this algorithm has bugs; otherwise the
588 snake would get too good */
591 double v1, v2, vp, max;
592 point(&d,you.col-sp->col,you.line-sp->line);
593 v1 = sqrt( (double) (d.col*d.col + d.line*d.line) );
598 vp = d.col*mx[i] + d.line*my[i];
601 vp = ((double)vp)/(v1*v2);
611 point(&d,sp->col+mx[i],sp->line+my[i]);
613 if (d.col<0 || d.col>=ccnt || d.line<0 || d.line>=lcnt)
616 * Change to allow snake to eat you if you're on the money,
617 * otherwise, you can just crouch there until the snake goes
618 * away. Not positive it's right.
620 * if (d.line == 0 && d.col < 5) continue;
622 if (same(&d,&money)) continue;
623 if (same(&d,&finish)) continue;
624 wt[i]= i==w ? loot/10 : 1;
625 if (i==oldw) wt [i] += loot/20;
629 vp = ((random() >> 6) & 01777) % w;
638 while (wt[i]==0) i++;
641 point(np,sp->col+mx[w],sp->line+my[w]);
652 point(&p, COLS / 2 - 8, LINES / 2 - 1);
659 loot = loot - penalty;
662 str = "SPACE WARP!!!";
663 penalty += loot/PENALTY;
669 mvaddstr(p.line + 1, p.col + 1, str);
680 if (!stretch(&money))
681 if (!stretch(&finish)) {
691 stretch(const struct point *ps)
695 point(&p,you.col,you.line);
696 if ((abs(ps->col - you.col) < (ccnt / 12)) && (you.line != ps->line)) {
697 if(you.line < ps->line){
698 for (p.line = you.line+1;p.line <= ps->line;p.line++)
702 for (;p.line > you.line;p.line--)
705 for (p.line = you.line-1;p.line >= ps->line;p.line--)
709 for (;p.line < you.line;p.line++)
714 if ((abs(ps->line - you.line) < (lcnt/7))
715 && (you.col != ps->col)) {
717 if(you.col < ps->col){
718 for (p.col = you.col+1;p.col <= ps->col;p.col++)
722 for (;p.col > you.col;p.col--)
725 for (p.col = you.col-1;p.col >= ps->col;p.col--)
729 for (;p.col < you.col;p.col++)
738 surround(struct point *ps)
742 if(ps->col == 0)ps->col++;
743 if(ps->line == 0)ps->line++;
744 if(ps->line == LINES -1)ps->line--;
745 if(ps->col == COLS -1)ps->col--;
746 mvaddstr(ps->line, ps->col, "/*\\");
747 mvaddstr(ps->line + 1, ps->col, "* *");
748 mvaddstr(ps->line + 2, ps->col, "\\*/");
757 if (post(cashvalue,0)) {
758 mvaddstr(ps->line, ps->col, " ");
759 mvaddstr(ps->line + 1, ps->col, "o.o");
760 mvaddstr(ps->line + 2, ps->col, "\\_/");
763 mvaddstr(ps->line, ps->col, " ");
764 mvaddstr(ps->line + 1, ps->col, "o.-");
765 mvaddstr(ps->line + 2, ps->col, "\\_/");
769 mvaddstr(ps->line, ps->col, " ");
770 mvaddstr(ps->line + 1, ps->col, "o.o");
771 mvaddstr(ps->line + 2, ps->col, "\\_/");
777 win(const struct point *ps)
781 int boxsize; /* actually diameter of box, not radius */
783 boxsize = fast ? 10 : 4;
784 point(&x,ps->col,ps->line);
785 for(j=1;j<boxsize;j++){
816 * My manual says times doesn't return a value. Furthermore, the
817 * snake should get his turn every time no matter if the user is
818 * on a fast terminal with typematic keys or not.
819 * So I have taken the call to times out.
822 if (same(&snake[i], &snake[5]))
825 pchar(&snake[5],' ');
826 /* Need the following to catch you if you step on the snake's tail */
827 tmp.col = snake[5].col;
828 tmp.line = snake[5].line;
830 snake[i+1]= snake[i];
831 chase(&snake[0], &snake[1]);
832 pchar(&snake[1],SNAKETAIL);
833 pchar(&snake[0],SNAKEHEAD);
836 if (same(&snake[i],&you) || same(&tmp, &you))
839 i = (cashvalue) % 10;
840 bonus = ((random() >> 8) & 0377) % 10;
841 mvprintw(lcnt + 1, 0, "%d\n", bonus);
852 if ( loot >= penalty ){
853 printf("\nYou and your $%d have been eaten\n",
856 printf("\nThe snake ate you. You owe $%d.\n",
868 chk(const struct point *sp)
872 if (same(sp,&money)) {
876 if (same(sp,&finish)) {
880 if (same(sp,&snake[0])) {
885 if(same(sp,&snake[j])){
890 if ((sp->col < 4) && (sp->line == 0)){
892 if((you.line == 0) && (you.col < 4)) pchar(&you,ME);
907 mvprintw(1, 1, "$%d", won);
912 stop(__unused int dummy)
914 signal(SIGINT,SIG_IGN);
924 kill(getpid(), SIGTSTP);
932 printf("You made %d moves.\n", num);
936 logit(const char *msg)
940 if (logfile != NULL) {
942 fprintf(logfile, "%s $%d %dx%d %s %s",
943 getlogin(), cashvalue, lcnt, ccnt, msg, ctime(&t));