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 <ctype.h>
  20 #include <poll.h>
  21 #include <setjmp.h>
  22 #include <signal.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <sys/ioctl.h>
  26 #include <sys/time.h>
  27 #include <termios.h>
  28 #include <time.h>
  29 #include <unistd.h>
  30
  31 #include "viiper.h"
  32 #include "schemes.h"
  33
  34 #define MIN(a,b) (a>b?b:a)
  35 #define MAX(a,b) (a>b?a:b)
  36 #define CLAMP(a,m,M) (a<m?m:(a>M?M:a))
  37 #define printm(n, s) for (int _loop = 0; _loop < n; _loop++) fputs (s, stdout)
  38 #define print(str) fputs (str?str:"", stdout)
  39 #define CTRL_ 0x1F &
  40
  41 #define COL_OFFSET 1
  42 #define LINE_OFFSET 1
  43 #define LINES_AFTER 1
  44 #define CW op.scheme->cell_width
  45
  46 struct game {
  47         int w; /* field width */
  48         int h; /* field height */
  49         int d; /* direction the snake is looking */
  50         int t; /* time of game start */
  51         int p; /* score */
  52         float v; /* velocity in moves per second */
  53         struct snake* s; /* snek */
  54         struct item* i; /* items (food, boni) */
  55         struct directions* n;/* next direction events to process */
  56 } g;
  57
  58 struct opt {
  59         int l; /* initial snake length */
  60         int s; /* initial snake speed */
  61         struct scheme* scheme;
  62 } op;
  63
  64 jmp_buf game_over;
  65
  66 int main (int argc, char** argv) {
  67         /* defaults: */
  68         g.w = 30; //two-char-width
  69         g.h = 20;
  70         op.l = 10;
  71         op.s = 8;
  72         op.scheme = &unic0de;
  73
  74         int optget;
  75         opterr = 0; /* don't print message on unrecognized option */
  76         while ((optget = getopt (argc, argv, "+s:dh")) != -1) {
  77                 switch (optget) {
  78                 case 's':
  79                         op.s = atof(optarg);
  80                         if (op.s < 1) {
  81                                 fprintf (stderr, SHORTHELP "speed must be >= 1\n", argv[0]);
  82                                 return 1;
  83                         }
  84                         break;
  85                 case 'd': op.scheme = &vt220_charset; break;
  86                 case 'h':
  87                 default:
  88                         fprintf (stderr, SHORTHELP LONGHELP, argv[0]);
  89                         return !(optget=='h');
  90                 }
  91         } if (optind < argc) { /* parse Fieldspec */
  92                 int n = sscanf (argv[optind], "%dx%d", &g.w, &g.h);
  93
  94                 if (n < 2) {
  95                         fprintf (stderr, SHORTHELP "FIELDSIZE is WxH (width 'x' height)\n", argv[0]);
  96                         return 1;
  97                 }
  98         }
  99
 100         clamp_fieldsize();
 101
 102         srand(time(0));
 103         signal_setup();
 104         screen_setup(1);
 105         atexit (*quit);
 106
 107         if (sigsetjmp(game_over, 1)) {
 108                 timer_setup(0);
 109                 move_ph (g.h/2+LINE_OFFSET, g.w);
 110                 printf ("you died :(");
 111                 fflush(stdout);
 112                 sleep(5);
 113                 exit(0);
 114         }
 115
 116         //TODO: call viiper() in a game loop
 117         viiper();
 118 quit:
 119         return 0;
 120 }
 121
 122 int viiper(void) {
 123         init_snake();
 124         show_playfield ();
 125         g.d = EAST;
 126         g.v = op.s;
 127
 128         timer_setup(1);
 129
 130         spawn_item(FOOD, rand() % NUM_FOODS); //TODO: shape distribution, so bigger values get selected less
 131
 132         for(;;) {
 133                 switch (getctrlseq()) {
 134                 case CTRSEQ_CURSOR_LEFT: case 'h':append_movement(WEST);  break;
 135                 case CTRSEQ_CURSOR_DOWN: case 'j':append_movement(SOUTH); break;
 136                 case CTRSEQ_CURSOR_UP:   case 'k':append_movement(NORTH); break;
 137                 case CTRSEQ_CURSOR_RIGHT:case 'l':append_movement(EAST);  break;
 138                 case 'p': /*TODO: pause*/ break;
 139                 case 'r': /*TODO:restart*/ return 0;
 140                 case 'q': return 0;
 141                 case CTRL_'L':
 142                         screen_setup(1);
 143                         show_playfield();
 144                         break;
 145                 }
 146
 147                 print ("\033[H\033[J");
 148                 show_playfield ();//TODO: only redraw diff
 149         }
 150
 151 }
 152
 153 void snake_advance (void) {
 154         if (g.n) {/* new direction in the buffer */
 155                 int possible_new_dir = get_movement();
 156                 if (g.d == EAST && possible_new_dir == WEST) goto ignore_new;
 157                 if (g.d == WEST && possible_new_dir == EAST) goto ignore_new;
 158                 if (g.d == NORTH && possible_new_dir == SOUTH) goto ignore_new;
 159                 if (g.d == SOUTH && possible_new_dir == NORTH) goto ignore_new;
 160                 g.d = possible_new_dir; /*pop off a new direction if available*/
 161 ignore_new:
 162                 1;
 163         }
 164
 165         int new_row = g.s->r +(g.d==SOUTH) -(g.d==NORTH);
 166         int new_col = g.s->c +(g.d==EAST)  -(g.d==WEST);
 167
 168         /* detect food hit and spawn a new food */
 169         for (struct item* i = g.i; i; i = i->next) {
 170                 if (i->r == new_row && i->c == new_col) {
 171                         consume_item (i);
 172                         spawn_item(FOOD, rand() % NUM_FOODS);
 173                 }
 174         }
 175
 176         /*NOTE:no idea why I have to use g.w+1, but otherwise we die too early*/
 177         if (new_row >= g.h || new_col >= g.w+1 || new_row < 0 || new_col < 0)
 178                 siglongjmp(game_over, 1/*<-will be the retval of setjmp*/);
 179
 180         struct snake* new_head;
 181         struct snake* new_tail; /* former second-to-last element */
 182         for (new_tail = g.s; new_tail->next->next; new_tail = new_tail->next)
 183                 /* use the opportunity of looping to check if we eat ourselves*/
 184                 if(new_tail->next->r == new_row && new_tail->next->c == new_col)
 185                         siglongjmp(game_over, 1/*<-will be the retval of setjmp*/);
 186         new_head = new_tail->next; /* reuse element instead of malloc() */
 187         new_tail->next = NULL;
 188
 189         new_head->r = new_row;
 190         new_head->c = new_col;
 191         new_head->next = g.s;
 192
 193         g.s = new_head;
 194 }
 195
 196 void spawn_item (int type, int value) {
 197         int row, col;
 198 try_again:
 199         row = rand() % g.h;
 200         col = rand() % g.w;
 201         /* loop through snake to check if we aren't on it */
 202         //WARN: inefficient as snake gets longer; near impossible in the end
 203         for (struct snake* s = g.s; s; s = s->next)
 204                 if (s->r == row && s->c == col) goto try_again;
 205
 206         struct item* new_item = malloc (sizeof(struct item));
 207         new_item->r = row;
 208         new_item->c = col;
 209         new_item->t = type;
 210         new_item->v = value;
 211         new_item->s = time(0);
 212         if (g.i) g.i->prev = new_item;
 213         new_item->next = g.i;
 214         new_item->prev = NULL;
 215
 216         g.i = new_item;
 217 }
 218
 219 void consume_item (struct item* i) {
 220         switch (i->t) {
 221         case FOOD:
 222                 switch (i->v) {
 223                 case FOOD_5:  g.p +=  5; break;
 224                 case FOOD_10: g.p += 10; break;
 225                 case FOOD_20: g.p += 20; break;
 226                 }
 227                 snake_append(&g.s, 0,0);  /* position doesn't matter, as item */
 228                 break;       /* will be reused as the head before it is drawn */
 229         case BONUS:
 230                 //TODO: handle bonus
 231                 break;
 232         }
 233
 234         if (i->next) i->next->prev = i->prev;
 235         if (i->prev) i->prev->next = i->next;
 236         else g.i = i->next;
 237
 238         free (i);
 239 }
 240
 241 void show_playfield (void) {
 242         /* top border */
 243         print(BORDER(T,L));
 244         printm (g.w, BORDER(T,C));
 245         printf ("%s\n", BORDER(T,R));
 246
 247         /* main area */
 248         for (int row = 0; row < g.h; row++)
 249                 printf ("%s%*s%s\n", BORDER(C,L), CW*g.w, "", BORDER(C,R));
 250
 251         /* bottom border */
 252         print(BORDER(B,L));
 253         printm (g.w, BORDER(B,C));
 254         print (BORDER(B,R));
 255
 256         /* print score */
 257         int score_width = g.p > 9999?6:4;
 258         move_ph (0, (g.w*CW-score_width)/2);
 259         printf ("%s %0*d %s", BORDER(S,L), score_width, g.p, BORDER(S,R));
 260
 261         /* print snake */
 262         struct snake* last = NULL;
 263         int color = -1; //TODO: that's a hack
 264         for (struct snake* s = g.s; s; s = s->next) {
 265                 move_ph (s->r+COL_OFFSET, s->c*CW+LINE_OFFSET);
 266
 267                 int predecessor = (last==NULL)?NONE:
 268                         (last->r < s->r) ? NORTH:
 269                         (last->r > s->r) ? SOUTH:
 270                         (last->c > s->c) ? EAST:
 271                         (last->c < s->c) ? WEST:NONE;
 272                 int successor = (s->next == NULL)?NONE:
 273                         (s->next->r < s->r) ? NORTH:
 274                         (s->next->r > s->r) ? SOUTH:
 275                         (s->next->c > s->c) ? EAST:
 276                         (s->next->c < s->c) ? WEST:NONE;
 277
 278                 printf ("\033[%sm", color==-1?"92;1":color?"92":"32"); //TODO: clean this up
 279                 print (op.scheme->snake[predecessor][successor]);
 280                 printf ("\033[0m");
 281                 last = s;
 282                 color = (color+1) % 2;
 283         }
 284
 285         /* print item queue */
 286         for (struct item* i = g.i; i; i = i->next) {
 287                 move_ph (i->r+LINE_OFFSET, i->c*CW+COL_OFFSET);
 288                 if (i->t == FOOD) print (op.scheme->item[i->v]);
 289                 else if (i->t==BONUS) /* TODO: print bonus */;
 290         }
 291 }
 292
 293 void snake_append (struct snake** s, int row, int col) {
 294         struct snake* new = malloc (sizeof(struct snake));
 295         new->r = row;
 296         new->c = col;
 297         new->next = NULL;
 298
 299         if (*s) {
 300                 struct snake* p = *s;
 301                 while (p->next) p = p->next;
 302                 p->next = new;
 303         } else {
 304                 *s = new;
 305         }
 306 }
 307
 308 void init_snake() {
 309         for (int i = 0; i < op.l; i++)
 310                 snake_append(&g.s, g.h/2, g.w/2-i);
 311 }
 312
 313 #define free_ll(head) do{ \
 314         while (head) { \
 315                 void* tmp = head; \
 316                 head = head->next; \
 317                 free(tmp); \
 318         } \
 319 }while(0)
 320
 321 void quit (void) {
 322         screen_setup(0);
 323         free_ll(g.s);
 324         free_ll(g.i);
 325         free_ll(g.n);
 326 }
 327
 328 enum esc_states {
 329         START,
 330         ESC_SENT,
 331         CSI_SENT,
 332         MOUSE_EVENT,
 333 };
 334 int getctrlseq (void) {
 335         int c;
 336         int state = START;
 337         int offset = 0x20; /* never sends control chars as data */
 338         while ((c = getchar()) != EOF) {
 339                 switch (state) {
 340                 case START:
 341                         switch (c) {
 342                         case '\033': state=ESC_SENT; break;
 343                         default: return c;
 344                         }
 345                         break;
 346                 case ESC_SENT:
 347                         switch (c) {
 348                         case '[': state=CSI_SENT; break;
 349                         default: return CTRSEQ_INVALID;
 350                         }
 351                         break;
 352                 case CSI_SENT:
 353                         switch (c) {
 354                         case 'A': return CTRSEQ_CURSOR_UP;
 355                         case 'B': return CTRSEQ_CURSOR_DOWN;
 356                         case 'C': return CTRSEQ_CURSOR_RIGHT;
 357                         case 'D': return CTRSEQ_CURSOR_LEFT;
 358                         default: return CTRSEQ_INVALID;
 359                         }
 360                         break;
 361                 default:
 362                         return CTRSEQ_INVALID;
 363                 }
 364         }
 365         return 2;
 366 }
 367
 368 void append_movement (int dir) {
 369         struct directions* n;
 370         for (n = g.n; n && n->next; n = n->next); /* advance to the end */
 371         if (n && n->d == dir) return; /* don't add the same direction twice */
 372
 373         struct directions* new_event = malloc (sizeof(struct directions));
 374         new_event->d = dir;
 375         new_event->next = NULL;
 376
 377         if (g.n == NULL)
 378                 g.n = new_event;
 379         else
 380                 n->next = new_event;
 381 }
 382
 383 int get_movement (void) {
 384         if (g.n == NULL) return -1;
 385
 386         int retval = g.n->d;
 387         struct directions* delet_this = g.n;
 388         g.n = g.n->next;
 389         free(delet_this);
 390         return retval;
 391 }
 392
 393 void move_ph (int line, int col) {
 394         /* move printhead to zero-indexed position */
 395         printf ("\033[%d;%dH", line+1, col+1);
 396 }
 397
 398 void clamp_fieldsize (void) { //TODO: use
 399         /* clamp field size to terminal size and mouse maximum: */
 400         struct winsize w;
 401         ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
 402
 403         if (g.w < 1) g.w = 1; //TODO. sensible minimum
 404         if (g.h < 1) g.h = 1;
 405
 406         if (COL_OFFSET + g.w*CW + COL_OFFSET > w.ws_col)
 407                 g.w = (w.ws_col - COL_OFFSET - COL_OFFSET)/CW-1; //TODO: does not work in `-d' (in xterm)
 408         if (LINE_OFFSET + g.h + LINES_AFTER > w.ws_row)
 409                 g.h = w.ws_row - (LINE_OFFSET+LINES_AFTER);
 410 }
 411
 412 void timer_setup (int enable) {
 413         static struct itimerval tbuf;
 414         tbuf.it_interval.tv_sec  = 0;//TODO: make it speed up automatically
 415         tbuf.it_interval.tv_usec = (1000000/g.v)-1; /*WARN: 1 <= g.v <= 999999*/
 416
 417         if (enable) {
 418                 g.t = time(NULL);//TODO: interferes with 'pause'
 419                 tbuf.it_value.tv_sec  = tbuf.it_interval.tv_sec;
 420                 tbuf.it_value.tv_usec = tbuf.it_interval.tv_usec;
 421         } else {
 422                 tbuf.it_value.tv_sec  = 0;
 423                 tbuf.it_value.tv_usec = 0;
 424         }
 425
 426         if ( setitimer(ITIMER_REAL, &tbuf, NULL) == -1 ) {
 427                 perror("setitimer");
 428                 exit(1);
 429         }
 430
 431 }
 432
 433 void signal_setup (void) {
 434         struct sigaction saction;
 435
 436         saction.sa_handler = signal_handler;
 437         sigemptyset(&saction.sa_mask);
 438         saction.sa_flags = 0;
 439         if (sigaction(SIGALRM, &saction, NULL) < 0 ) {
 440                 perror("SIGALRM");
 441                 exit(1);
 442         }
 443
 444         if (sigaction(SIGINT, &saction, NULL) < 0 ) {
 445                 perror ("SIGINT");
 446                 exit (1);
 447         }
 448 }
 449
 450 void signal_handler (int signum) {
 451         //int dtime;
 452         switch (signum) {
 453         case SIGALRM:
 454                 //dtime = difftime (time(NULL), g.t);
 455                 //move_ph (1, g.w*CW-(CW%2)-3-(dtime>999));
 456                 //printf ("[%03d]", g.t?dtime:0);
 457                 snake_advance();
 458                 break;
 459         case SIGINT:
 460                 exit(128+SIGINT);
 461         }
 462 }
 463
 464 void screen_setup (int enable) {
 465         if (enable) {
 466                 raw_mode(1);
 467                 printf ("\033[s\033[?47h"); /* save cursor, alternate screen */
 468                 printf ("\033[H\033[J"); /* reset cursor, clear screen */
 469                 printf ("\033[?25l"); /* hide cursor */
 470                 print (op.scheme->init_seq); /* swich charset, if necessary */
 471         } else {
 472                 print (op.scheme->reset_seq); /* reset charset, if necessary */
 473                 printf ("\033[?25h"); /* show cursor */
 474                 printf ("\033[?47l\033[u"); /* primary screen, restore cursor */
 475                 raw_mode(0);
 476         }
 477 }
 478
 479 /* http://users.csc.calpoly.edu/~phatalsk/357/lectures/code/sigalrm.c */
 480 void raw_mode(int enable) {
 481         static struct termios saved_term_mode;
 482         struct termios raw_term_mode;
 483
 484         if (enable) {
 485                 tcgetattr(STDIN_FILENO, &saved_term_mode);
 486                 raw_term_mode = saved_term_mode;
 487                 raw_term_mode.c_lflag &= ~(ICANON | ECHO);
 488                 raw_term_mode.c_cc[VMIN] = 1 ;
 489                 raw_term_mode.c_cc[VTIME] = 0;
 490                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw_term_mode);
 491         } else {
 492                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_term_mode);
 493         }
 494 }