viiper.c

   1 /*******************************************************************************
   2  viiper 0.1
   3  By Tobias Girstmair, 2018
   4
   5  ./viiper 40x25
   6  (see ./viiper -h for full list of options)
   7
   8  KEYBINDINGS:  - hjkl to move
   9                - p to pause and resume
  10                - r to restart
  11                - q to quit
  12                - (see `./minesviiper -h' for all keybindings)
  13
  14  GNU GPL v3, see LICENSE or https://www.gnu.org/licenses/gpl-3.0.txt
  15 *******************************************************************************/
  16
  17
  18 #define _POSIX_C_SOURCE 2 /*for getopt and sigaction in c99, sigsetjmp*/
  19 #include <setjmp.h>
  20 #include <signal.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/ioctl.h>
  25 #include <sys/time.h>
  26 #include <termios.h>
  27 #include <time.h>
  28 #include <unistd.h>
  29
  30 #include "viiper.h"
  31 #include "schemes.h"
  32
  33 #define MIN(a,b) (a>b?b:a)
  34 #define MAX(a,b) (a>b?a:b)
  35 #define CLAMP(a,m,M) (a<m?m:(a>M?M:a))
  36 #define printm(n, s) for (int _loop = 0; _loop < n; _loop++) fputs (s, stdout)
  37 #define print(str) fputs (str?str:"", stdout)
  38 #define CTRL_ 0x1F &
  39
  40 #define OPPOSITE(dir) ( \
  41         dir == EAST  ? WEST  :   \
  42         dir == WEST  ? EAST  :   \
  43         dir == NORTH ? SOUTH :   \
  44         dir == SOUTH ? NORTH : -1)
  45
  46 #define COL_OFFSET 1
  47 #define LINE_OFFSET 1
  48 #define LINES_AFTER 1
  49 #define CW op.sch->cell_width
  50
  51 #define SPEEDUP_AFTER 100 /* increment speed every n points */
  52 #define BONUS_INTERVAL 90 /* how often a bonus item is spawned */
  53
  54 struct game {
  55         int w; /* field width */
  56         int h; /* field height */
  57         int d; /* direction the snake is looking */
  58         int t; /* time of game start */
  59         int p; /* score */
  60         int b; /* time of last bonus item spawned */
  61         float v; /* velocity in moves per second */
  62         struct snake* s; /* snek */
  63         struct item* i; /* items (food, boni) */
  64         struct directions {
  65                 int h; /* write head */
  66                 int n; /* number of elements */
  67                 int c[16];
  68         } k; /* ring buffer for direction events */
  69 } g;
  70
  71 struct opt {
  72         int l; /* initial snake length */
  73         int s; /* initial snake speed */
  74         struct scheme* sch;
  75 } op;
  76
  77 jmp_buf game_over;
  78
  79 int main (int argc, char** argv) {
  80         /* defaults: */
  81         g.w = 30; //two-char-width
  82         g.h = 20;
  83         op.l = 10;
  84         op.s = 8;
  85         op.sch = &unic0de;
  86
  87         int optget;
  88         opterr = 0; /* don't print message on unrecognized option */
  89         while ((optget = getopt (argc, argv, "+s:l:dh")) != -1) {
  90                 switch (optget) {
  91                 case 's':
  92                         op.s = atof(optarg);
  93                         if (op.s < 1) {
  94                                 fprintf (stderr, "speed must be >= 1\n");
  95                                 return 1;
  96                         }
  97                         break;
  98                 case 'l':
  99                         op.l = atoi(optarg);
 100                         if (op.s < 2 || op.s > g.w*g.h-1) {
 101                                 fprintf (stderr, "length must be >= 2 and < W*H\n");
 102                                 return 1;
 103                         }
 104                         break;
 105                 case 'd': op.sch = &vt220_charset; break;
 106                 case 'h':
 107                 default:
 108                         fprintf (stderr, SHORTHELP LONGHELP, argv[0]);
 109                         return !(optget=='h');
 110                 }
 111         } if (optind < argc) { /* parse Fieldspec */
 112                 int n = sscanf (argv[optind], "%dx%d", &g.w, &g.h);
 113
 114                 if (n < 2) {
 115                         fprintf(stderr,"FIELDSIZE is WxH (width 'x' height)\n");
 116                         return 1;
 117                 }
 118         }
 119
 120         clamp_fieldsize();
 121
 122         srand(time(0));
 123         signal_setup();
 124         screen_setup(1);
 125         atexit (*quit);
 126
 127         char* end_screen_msg = "";
 128 restart:
 129         switch (sigsetjmp(game_over, 1)) {
 130         case GAME_INIT:
 131         case GAME_START:
 132                 viiper();
 133                 break; /* function doesn't return, but `-Wextra' complains */
 134         case GAME_OVER:
 135                 end_screen_msg = " GAME  OVER ";
 136                 goto end_screen;
 137         case GAME_WON:
 138                 end_screen_msg = "CONGRATULATIONS!";
 139                 goto end_screen;
 140 end_screen:
 141                 timer_setup(0);
 142                 show_playfield();
 143                 for (;;) switch (end_screen(end_screen_msg)) {
 144                 case 'r': goto restart;
 145                 case 'q': goto quit;
 146                 case CTRL_'L':
 147                         screen_setup(1);
 148                         show_playfield();
 149                         break;
 150                 default: continue;
 151                 }
 152         case GAME_EXIT:
 153                 goto quit;
 154         }
 155
 156 quit:
 157         return 0;
 158 }
 159
 160 int viiper(void) {
 161         init_snake();
 162         show_playfield ();
 163         g.d = EAST;
 164         g.v = op.s;
 165
 166         timer_setup(1);
 167         g.t = time(NULL);
 168         g.p = 0;
 169         g.k.n = 0;
 170         g.b = time(NULL) + BONUS_INTERVAL;
 171
 172         spawn_item(FOOD, rand() % NUM_FOODS, NULL); //TODO: shape distribution, so bigger values get selected less
 173
 174         for(;;) {
 175                 switch (getctrlseq()) {
 176                 case CTRSEQ_CURSOR_LEFT: case 'h':append_movement(WEST);  break;
 177                 case CTRSEQ_CURSOR_DOWN: case 'j':append_movement(SOUTH); break;
 178                 case CTRSEQ_CURSOR_UP:   case 'k':append_movement(NORTH); break;
 179                 case CTRSEQ_CURSOR_RIGHT:case 'l':append_movement(EAST);  break;
 180                 case 'p':
 181                         timer_setup(0);
 182                         move_ph (g.h/2+LINE_OFFSET, g.w*CW/2);
 183                         printf ("\033[5mPAUSE\033[0m"); /* blinking text */
 184                         if (getchar() == 'q') exit(0);
 185                         show_playfield();
 186                         timer_setup(1);
 187                         break;
 188                 case 'r': siglongjmp(game_over, GAME_START);
 189                 case 'q': siglongjmp(game_over, GAME_EXIT);
 190                 case CTRL_'L':
 191                         screen_setup(1);
 192                         show_playfield();
 193                         break;
 194                 case 0x02: /* STX; gets sent when returning from SIGALRM */
 195                         continue;
 196                 }
 197         }
 198
 199 }
 200
 201 #define pop_dir() (g.k.n? g.k.c[(16+g.k.h-g.k.n--)%16] : NONE)
 202 void snake_advance (void) {
 203         int respawn = 0;
 204         struct item* i; /*temporary item (defined here to respawn at the end) */
 205         int new_dir = pop_dir();
 206         /* switch direction if new one is in the buffer and it won't kill us: */
 207         if (new_dir && g.d != OPPOSITE(new_dir)) g.d = new_dir;
 208
 209         int new_row = g.s->r +(g.d==SOUTH) -(g.d==NORTH);
 210         int new_col = g.s->c +(g.d==EAST)  -(g.d==WEST);
 211
 212         /* detect food hit and spawn a new food */
 213         for (i = g.i; i; i = i->next) {
 214                 if (i->r == new_row && i->c == new_col) {
 215                         consume_item (i);
 216
 217                         switch (i->t) {
 218                         case FOOD: respawn = 1; break;
 219                         case BONUS: free(i); break; //TODO: reuse item buffer
 220                         }
 221                         break;
 222                 }
 223         }
 224
 225         if (new_row >= g.h || new_col >= g.w || new_row < 0 || new_col < 0)
 226                 siglongjmp(game_over, GAME_OVER);
 227
 228         struct snake* new_head;
 229         struct snake* new_tail; /* former second-to-last element */
 230         for (new_tail = g.s; new_tail->next->next; new_tail = new_tail->next)
 231                 /*use the opportunity of looping to check if we eat ourselves:*/
 232                 if(new_tail->next->r == new_row && new_tail->next->c == new_col)
 233                         siglongjmp(game_over, GAME_OVER);
 234         int old_tail[2] = {new_tail->next->r, new_tail->next->c};/*gets erased*/
 235         new_head = new_tail->next; /* reuse element instead of malloc() */
 236         new_tail->next = NULL;
 237
 238         new_head->r = new_row;
 239         new_head->c = new_col;
 240         new_head->next = g.s;
 241
 242         g.s = new_head;
 243
 244         if (respawn) spawn_item(FOOD, rand() % NUM_FOODS, i);
 245         draw_sprites (old_tail[0], old_tail[1]);
 246 }
 247
 248 void spawn_item (int type, int value, struct item* p_item) {
 249         int row, col;
 250         char occupied[g.w][g.h]; int snake_len = 0;
 251         memset(*occupied, 0, g.w*g.h);
 252 try_again:
 253         row = rand() % g.h;
 254         col = rand() % g.w;
 255         if (snake_len >= g.w*g.h-1) siglongjmp(game_over, GAME_WON);
 256         /* loop through snake to check if we aren't on it */
 257         if (occupied[row][col]) goto try_again; /* shortcut */
 258         for (struct snake* s = g.s; s; s = s->next)
 259                 if (s->r == row && s->c == col) {
 260                         occupied[s->r][s->c] = 1; snake_len++;
 261                         goto try_again;
 262                 }
 263
 264         /* if we got a item buffer reuse it, otherwise create a new one: */
 265         struct item* new_item;
 266         if (p_item) new_item = p_item;
 267         else new_item = malloc (sizeof(struct item));
 268
 269         new_item->r = row;
 270         new_item->c = col;
 271         new_item->t = type;
 272         new_item->v = value;
 273         new_item->s = time(0);
 274         if (g.i) g.i->prev = new_item;
 275         new_item->next = g.i;
 276         new_item->prev = NULL;
 277
 278         g.i = new_item;
 279 }
 280
 281 void consume_item (struct item* i) {
 282         int old_score = g.p;
 283
 284         switch (i->t) {
 285         case FOOD:
 286                 switch (i->v) {
 287                 case FOOD_5:  g.p +=  5; break;
 288                 case FOOD_10: g.p += 10; break;
 289                 case FOOD_20: g.p += 20; break;
 290                 }
 291                 snake_append(&g.s, -1, -1);
 292                 break;       /* will be reused as the head before it is drawn */
 293         case BONUS:
 294                 switch (i->v) {
 295                 case BONUS_SNIP:
 296                         for (int i = 5; i && g.s->next->next; i--) {
 297                                 struct snake* p = g.s;
 298                                 while (p->next->next) p = p->next;
 299                                 free (p->next);
 300                                 p->next = NULL;
 301                         }
 302                         show_playfield();
 303                         break;
 304                 case BONUS_GROW:
 305                         for (int i = 5; i; i--) snake_append(&g.s, -1, -1);
 306                         break;
 307                 case BONUS_SLOW:
 308                         if (g.v > 1) g.v--;
 309                         timer_setup(1);
 310                         break;
 311                 case BONUS_FAST:
 312                         g.v++;
 313                         timer_setup(1);
 314                         break;
 315                 }
 316                 break;
 317         }
 318
 319         if (i->next) i->next->prev = i->prev;
 320         if (i->prev) i->prev->next = i->next;
 321         else g.i = i->next;
 322
 323         /* snake speedup every 100 points: */
 324         if (g.p/SPEEDUP_AFTER - old_score/SPEEDUP_AFTER) g.v++;
 325 }
 326
 327 void spawn_bonus(void) { //TODO: items should be removed after a timeout (and blink x seconds before timeout) if not eaten
 328         if (g.b > time(NULL)) return;
 329         for (struct item* i = g.i; i; i = i->next) /*don't spawn bonus*/
 330                 if (i->t == BONUS) return; /* if one is already there */
 331
 332         spawn_item(BONUS, rand() % NUM_BONI, NULL);
 333         g.b = time(NULL) + BONUS_INTERVAL;
 334 }
 335
 336 void show_playfield (void) {
 337         move_ph (0,0);
 338
 339         /* top border */
 340         print(BORDER(T,L));
 341         printm (g.w, BORDER(T,C));
 342         printf ("%s\n", BORDER(T,R));
 343
 344         /* main area */
 345         for (int row = 0; row < g.h; row++)
 346                 printf ("%s%*s%s\n", BORDER(C,L), CW*g.w, "", BORDER(C,R));
 347
 348         /* bottom border */
 349         print(BORDER(B,L));
 350         printm (g.w, BORDER(B,C));
 351         print (BORDER(B,R));
 352
 353         draw_sprites (0,0);
 354 }
 355
 356 void draw_sprites (int erase_r, int erase_c) {
 357         /* erase old tail, if any */
 358         if (erase_r >= 0 && erase_c >= 0) {
 359                 move_ph (erase_r+LINE_OFFSET, erase_c*CW+COL_OFFSET);
 360                 printm (CW, " ");
 361         }
 362
 363         /* print snake */
 364         struct snake* last = NULL;
 365         int color = 2;
 366         for (struct snake* s = g.s; s; s = s->next) {
 367                 if (s->r < 0 || s->c < 0) continue; /*can't draw outside term.*/
 368                 move_ph (s->r+LINE_OFFSET, s->c*CW+COL_OFFSET);
 369
 370                 int predecessor = (last==NULL)?NONE:
 371                         (last->r < s->r) ? NORTH:
 372                         (last->r > s->r) ? SOUTH:
 373                         (last->c > s->c) ? EAST:
 374                         (last->c < s->c) ? WEST:NONE;
 375                 int successor = (s->next == NULL)?NONE:
 376                         (s->next->r < s->r) ? NORTH:
 377                         (s->next->r > s->r) ? SOUTH:
 378                         (s->next->c > s->c) ? EAST:
 379                         (s->next->c < s->c) ? WEST:NONE;
 380
 381                 printf ("\033[%sm", op.sch->color[color]);
 382                 print (op.sch->snake[predecessor][successor]);
 383                 printf ("\033[0m");
 384                 last = s;
 385                 color = !color;
 386         }
 387
 388         /* print item queue */
 389         for (struct item* i = g.i; i; i = i->next) {
 390                 move_ph (i->r+LINE_OFFSET, i->c*CW+COL_OFFSET);
 391                 if      (i->t == FOOD)  print(op.sch->food[i->v]);
 392                 else if (i->t == BONUS) print(op.sch->boni[i->v]);
 393         }
 394
 395         /* print score */
 396         int score_width = g.p > 9999?6:4;
 397         move_ph (0, (g.w*CW-score_width)/2-COL_OFFSET);
 398         printf ("%s %0*d %s", BORDER(S,L), score_width, g.p, BORDER(S,R));
 399 }
 400
 401 #define MOVE_POPUP(WIDTH, LINE) \
 402         move_ph(g.h/2+LINE_OFFSET-1+LINE,(g.w*op.sch->display_width-WIDTH)/2)
 403 int end_screen(char* message) {
 404         int msg_w = strlen(message);
 405         MOVE_POPUP(msg_w, -1);
 406         print(BORDER(T,L));
 407         printm ((msg_w+2)/op.sch->display_width, BORDER(T,C));
 408         print (BORDER(T,R));
 409
 410         MOVE_POPUP(msg_w, 0);
 411         printf("%s %s %s", BORDER(C,L), message, BORDER(C,R));
 412         MOVE_POPUP(msg_w, 1);
 413         printf("%s `r' restart%*s%s", BORDER(C,L), msg_w-10, "", BORDER(C,R));
 414         MOVE_POPUP(msg_w, 2);
 415         printf("%s `q' quit%*s%s", BORDER(C,L), msg_w-7, "", BORDER(C,R));
 416
 417         MOVE_POPUP(msg_w, 3);
 418         print(BORDER(B,L));
 419         printm ((msg_w+2)/op.sch->display_width, BORDER(B,C));
 420         print (BORDER(B,R));
 421         fflush(stdout);
 422
 423         return getctrlseq();
 424 }
 425
 426 void snake_append (struct snake** s, int row, int col) {
 427         struct snake* new = malloc (sizeof(struct snake));
 428         new->r = row;
 429         new->c = col;
 430         new->next = NULL;
 431
 432         if (*s) {
 433                 struct snake* p = *s;
 434                 while (p->next) p = p->next;
 435                 p->next = new;
 436         } else {
 437                 *s = new;
 438         }
 439 }
 440
 441 #define free_ll(head) do{ \
 442         while (head) { \
 443                 void* tmp = head; \
 444                 head = head->next; \
 445                 free(tmp); \
 446         } \
 447         head = NULL; \
 448 }while(0)
 449
 450 void init_snake() {
 451         free_ll(g.s);
 452         free_ll(g.i);
 453
 454         int direction = WEST;
 455         int r = g.h/2;
 456         int c = g.w/2;
 457         int min_r = 0;
 458         int max_r = g.h-1;
 459         int min_c = 0;
 460         int max_c = g.w-1;
 461         for (int i = 0; i < op.l; i++) {
 462                 switch (direction) {
 463                 case NORTH: r--; if(r <= min_r){direction=EAST; min_r++;}break;
 464                 case EAST:  c++; if(c >= max_c){direction=SOUTH;max_c--;}break;
 465                 case SOUTH: r++; if(r >= max_r){direction=WEST; max_r--;}break;
 466                 case WEST:  c--; if(c <= min_c){direction=NORTH;min_c++;}break;
 467                 }
 468
 469                 snake_append(&g.s, r, c);
 470         }
 471 }
 472
 473 void quit (void) {
 474         screen_setup(0);
 475         free_ll(g.s);
 476         free_ll(g.i);
 477 }
 478
 479 enum esc_states {
 480         START,
 481         ESC_SENT,
 482         CSI_SENT,
 483         MOUSE_EVENT,
 484 };
 485 int getctrlseq (void) {
 486         int c;
 487         int state = START;
 488         while ((c = getchar()) != EOF) {
 489                 switch (state) {
 490                 case START:
 491                         switch (c) {
 492                         case '\033': state=ESC_SENT; break;
 493                         default: return c;
 494                         }
 495                         break;
 496                 case ESC_SENT:
 497                         switch (c) {
 498                         case '[': state=CSI_SENT; break;
 499                         default: return CTRSEQ_INVALID;
 500                         }
 501                         break;
 502                 case CSI_SENT:
 503                         switch (c) {
 504                         case 'A': return CTRSEQ_CURSOR_UP;
 505                         case 'B': return CTRSEQ_CURSOR_DOWN;
 506                         case 'C': return CTRSEQ_CURSOR_RIGHT;
 507                         case 'D': return CTRSEQ_CURSOR_LEFT;
 508                         default: return CTRSEQ_INVALID;
 509                         }
 510                         break;
 511                 default:
 512                         return CTRSEQ_INVALID;
 513                 }
 514         }
 515         return 2;
 516 }
 517
 518 void append_movement (int dir) {
 519         if (g.k.n > 15) return; /* no space in buffer */
 520         if (g.k.n && g.k.c[(16+g.k.h-1)%16] == dir)
 521                 return; /* don't add the same direction twice */
 522
 523         g.k.c[g.k.h] = dir;
 524         g.k.n++;
 525         g.k.h = (g.k.h+1) % 16;
 526 }
 527
 528 void move_ph (int line, int col) {
 529         /* move printhead to zero-indexed position */
 530         printf ("\033[%d;%dH", line+1, col+1);
 531 }
 532
 533 void clamp_fieldsize (void) {
 534         /* clamp field size to terminal size and mouse maximum: */
 535         struct winsize w;
 536         ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
 537
 538         if (g.w < 10) g.w = 10;
 539         if (g.h < 10) g.h = 10;
 540
 541         if (COL_OFFSET + g.w*CW + COL_OFFSET > w.ws_col)
 542                 g.w = (w.ws_col - 2*COL_OFFSET) / op.sch->display_width;
 543         if (LINE_OFFSET + g.h + LINES_AFTER > w.ws_row)
 544                 g.h = w.ws_row - (LINE_OFFSET+LINES_AFTER);
 545 }
 546
 547 void timer_setup (int enable) {
 548         static struct itimerval tbuf;
 549         tbuf.it_interval.tv_sec  = 0;
 550         tbuf.it_interval.tv_usec = (1000000/g.v)-1; /*WARN: 1 <= g.v <= 999999*/
 551
 552         if (enable) {
 553                 tbuf.it_value.tv_sec  = tbuf.it_interval.tv_sec;
 554                 tbuf.it_value.tv_usec = tbuf.it_interval.tv_usec;
 555         } else {
 556                 tbuf.it_value.tv_sec  = 0;
 557                 tbuf.it_value.tv_usec = 0;
 558         }
 559
 560         if ( setitimer(ITIMER_REAL, &tbuf, NULL) == -1 ) {
 561                 perror("setitimer");
 562                 exit(1);
 563         }
 564
 565 }
 566
 567 void signal_setup (void) {
 568         struct sigaction saction;
 569
 570         saction.sa_handler = signal_handler;
 571         sigemptyset(&saction.sa_mask);
 572         saction.sa_flags = 0;
 573         if (sigaction(SIGALRM, &saction, NULL) < 0 ) {
 574                 perror("SIGALRM");
 575                 exit(1);
 576         }
 577
 578         if (sigaction(SIGINT, &saction, NULL) < 0 ) {
 579                 perror ("SIGINT");
 580                 exit (1);
 581         }
 582
 583         if (sigaction(SIGCONT, &saction, NULL) < 0 ) {
 584                 perror ("SIGCONT");
 585                 exit (1);
 586         }
 587 }
 588
 589 void signal_handler (int signum) {
 590         switch (signum) {
 591         case SIGALRM:
 592                 snake_advance();
 593                 spawn_bonus();
 594                 break;
 595         case SIGINT:
 596                 exit(128+SIGINT);
 597         case SIGCONT:
 598                 screen_setup(1);
 599                 show_playfield();
 600         }
 601 }
 602
 603 void screen_setup (int enable) {
 604         if (enable) {
 605                 raw_mode(1);
 606                 printf ("\033[s\033[?47h"); /* save cursor, alternate screen */
 607                 printf ("\033[H\033[J"); /* reset cursor, clear screen */
 608                 printf ("\033[?25l"); /* hide cursor */
 609                 print (op.sch->init_seq); /* swich charset, if necessary */
 610         } else {
 611                 print (op.sch->reset_seq); /* reset charset, if necessary */
 612                 printf ("\033[?25h"); /* show cursor */
 613                 printf ("\033[?47l\033[u"); /* primary screen, restore cursor */
 614                 raw_mode(0);
 615         }
 616 }
 617
 618 /* http://users.csc.calpoly.edu/~phatalsk/357/lectures/code/sigalrm.c */
 619 void raw_mode(int enable) {
 620         static struct termios saved_term_mode;
 621         struct termios raw_term_mode;
 622
 623         if (enable) {
 624                 tcgetattr(STDIN_FILENO, &saved_term_mode);
 625                 raw_term_mode = saved_term_mode;
 626                 raw_term_mode.c_lflag &= ~(ICANON | ECHO);
 627                 raw_term_mode.c_cc[VMIN] = 1 ;
 628                 raw_term_mode.c_cc[VTIME] = 0;
 629                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw_term_mode);
 630         } else {
 631                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_term_mode);
 632         }
 633 }