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