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