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