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         if (sigsetjmp(game_over, 1)) {
 116                 timer_setup(0);
 117                 move_ph (g.h/2+LINE_OFFSET, g.w);
 118                 printf ("snek ded :(");
 119                 fflush(stdout);
 120                 sleep(2);
 121                 exit(0);
 122         }
 123
 124         //TODO: call viiper() in a game loop
 125         viiper();
 126 quit:
 127         return 0;
 128 }
 129
 130 int viiper(void) {
 131         init_snake();
 132         show_playfield ();
 133         g.d = EAST;
 134         g.v = op.s;
 135
 136         timer_setup(1);
 137         g.t = time(NULL);
 138
 139         spawn_item(FOOD, rand() % NUM_FOODS, NULL); //TODO: shape distribution, so bigger values get selected less
 140
 141         for(;;) {
 142                 switch (getctrlseq()) {
 143                 case CTRSEQ_CURSOR_LEFT: case 'h':append_movement(WEST);  break;
 144                 case CTRSEQ_CURSOR_DOWN: case 'j':append_movement(SOUTH); break;
 145                 case CTRSEQ_CURSOR_UP:   case 'k':append_movement(NORTH); break;
 146                 case CTRSEQ_CURSOR_RIGHT:case 'l':append_movement(EAST);  break;
 147                 case 'p':
 148                         timer_setup(0);
 149                         move_ph (g.h/2+LINE_OFFSET, g.w*CW/2);
 150                         printf ("\033[5mPAUSE\033[0m"); /* blinking text */
 151                         if (getchar() == 'q') exit(0);
 152                         show_playfield();
 153                         timer_setup(1);
 154                         break;
 155                 case 'r': /*TODO:restart*/ return 0;
 156                 case 'q': return 0;
 157                 case CTRL_'L':
 158                         screen_setup(1);
 159                         show_playfield();
 160                         break;
 161                 case 0x02: /* STX; gets sent when returning from SIGALRM */
 162                         continue;
 163                 }
 164         }
 165
 166 }
 167
 168 #define pop_dir() (g.k.n? g.k.c[(16+g.k.h-g.k.n--)%16] : NONE)
 169 void snake_advance (void) {
 170         int new_dir = pop_dir();
 171         /* switch direction if new one is in the buffer and it won't kill us: */
 172         if (new_dir && g.d != OPPOSITE(new_dir)) g.d = new_dir;
 173
 174         int new_row = g.s->r +(g.d==SOUTH) -(g.d==NORTH);
 175         int new_col = g.s->c +(g.d==EAST)  -(g.d==WEST);
 176
 177         /* detect food hit and spawn a new food */
 178         for (struct item* i = g.i; i; i = i->next) {
 179                 if (i->r == new_row && i->c == new_col) {
 180                         consume_item (i);
 181                         spawn_item(FOOD, rand() % NUM_FOODS, i);
 182                 }
 183         }
 184
 185         /* NOTE: we are drawing the snake 1 column too far to the left, so it
 186         can directly touch the vertical walls. this also means that we essen-
 187         tially extend the width by 1 cell, so we need to check against g.w+1. */
 188         if (new_row >= g.h || new_col >= g.w+1 || new_row < 0 || new_col < 0)
 189                 siglongjmp(game_over, 1/*<-will be the retval of setjmp*/);
 190
 191         struct snake* new_head;
 192         struct snake* new_tail; /* former second-to-last element */
 193         for (new_tail = g.s; new_tail->next->next; new_tail = new_tail->next)
 194                 /* use the opportunity of looping to check if we eat ourselves*/
 195                 if(new_tail->next->r == new_row && new_tail->next->c == new_col)
 196                         siglongjmp(game_over, 1/*<-will be the retval of setjmp*/);
 197         int old_tail[2] = {new_tail->next->r, new_tail->next->c}; /* save it for erasing */
 198         new_head = new_tail->next; /* reuse element instead of malloc() */
 199         new_tail->next = NULL;
 200
 201         new_head->r = new_row;
 202         new_head->c = new_col;
 203         new_head->next = g.s;
 204
 205         g.s = new_head;
 206
 207         draw_sprites (old_tail[0], old_tail[1]);
 208 }
 209
 210 void spawn_item (int type, int value, struct item* p_item) {
 211         int row, col;
 212 try_again:
 213         row = rand() % g.h;
 214         col = rand() % g.w;
 215         /* loop through snake to check if we aren't on it */
 216         //WARN: inefficient as snake gets longer; near impossible in the end
 217         for (struct snake* s = g.s; s; s = s->next)
 218                 if (s->r == row && s->c == col) goto try_again; //TODO: appears to not work all the time
 219
 220         /* if we got a item buffer reuse it, otherwise create a new one: */
 221         struct item* new_item;
 222         if (p_item) new_item = p_item;
 223         else new_item = malloc (sizeof(struct item));
 224
 225         new_item->r = row;
 226         new_item->c = col;
 227         new_item->t = type;
 228         new_item->v = value;
 229         new_item->s = time(0);
 230         if (g.i) g.i->prev = new_item;
 231         new_item->next = g.i;
 232         new_item->prev = NULL;
 233
 234         g.i = new_item;
 235 }
 236
 237 void consume_item (struct item* i) {
 238         switch (i->t) {
 239         case FOOD:
 240                 switch (i->v) {
 241                 case FOOD_5:  g.p +=  5; break;
 242                 case FOOD_10: g.p += 10; break;
 243                 case FOOD_20: g.p += 20; break;
 244                 }
 245                 snake_append(&g.s, 0,0);  /* position doesn't matter, as item */
 246                 break;       /* will be reused as the head before it is drawn */
 247         case BONUS:
 248                 //TODO: handle bonus
 249                 break;
 250         }
 251
 252         if (i->next) i->next->prev = i->prev;
 253         if (i->prev) i->prev->next = i->next;
 254         else g.i = i->next;
 255 }
 256
 257 void show_playfield (void) {
 258         move_ph (0,0);
 259
 260         /* top border */
 261         print(BORDER(T,L));
 262         printm (g.w, BORDER(T,C));
 263         printf ("%s\n", BORDER(T,R));
 264
 265         /* main area */
 266         for (int row = 0; row < g.h; row++)
 267                 printf ("%s%*s%s\n", BORDER(C,L), CW*g.w, "", BORDER(C,R));
 268
 269         /* bottom border */
 270         print(BORDER(B,L));
 271         printm (g.w, BORDER(B,C));
 272         print (BORDER(B,R));
 273
 274         draw_sprites (0,0);
 275 }
 276
 277 void draw_sprites (int erase_r, int erase_c) {
 278         /* erase old tail */
 279         move_ph (erase_r+LINE_OFFSET, erase_c*CW+COL_OFFSET);
 280         printm (CW, " ");
 281
 282         /* print snake */
 283         struct snake* last = NULL;
 284         int color = 2;
 285         for (struct snake* s = g.s; s; s = s->next) {
 286                 move_ph (s->r+LINE_OFFSET, s->c*CW+COL_OFFSET); /*NOTE: all those are actually wrong; draws snake 1 col too far left*/
 287
 288                 int predecessor = (last==NULL)?NONE:
 289                         (last->r < s->r) ? NORTH:
 290                         (last->r > s->r) ? SOUTH:
 291                         (last->c > s->c) ? EAST:
 292                         (last->c < s->c) ? WEST:NONE;
 293                 int successor = (s->next == NULL)?NONE:
 294                         (s->next->r < s->r) ? NORTH:
 295                         (s->next->r > s->r) ? SOUTH:
 296                         (s->next->c > s->c) ? EAST:
 297                         (s->next->c < s->c) ? WEST:NONE;
 298
 299                 printf ("\033[%sm", op.scheme->color[color]);
 300                 print (op.scheme->snake[predecessor][successor]);
 301                 printf ("\033[0m");
 302                 last = s;
 303                 color = !color;
 304         }
 305
 306         /* print item queue */
 307         for (struct item* i = g.i; i; i = i->next) {
 308                 move_ph (i->r+LINE_OFFSET, i->c*CW+COL_OFFSET);
 309                 if (i->t == FOOD) print (op.scheme->item[i->v]);
 310                 else if (i->t==BONUS) /* TODO: print bonus */;
 311         }
 312
 313         /* print score */
 314         int score_width = g.p > 9999?6:4;
 315         move_ph (0, (g.w*CW-score_width)/2);
 316         printf ("%s %0*d %s", BORDER(S,L), score_width, g.p, BORDER(S,R));
 317 }
 318
 319 void snake_append (struct snake** s, int row, int col) {
 320         struct snake* new = malloc (sizeof(struct snake));
 321         new->r = row;
 322         new->c = col;
 323         new->next = NULL;
 324
 325         if (*s) {
 326                 struct snake* p = *s;
 327                 while (p->next) p = p->next;
 328                 p->next = new;
 329         } else {
 330                 *s = new;
 331         }
 332 }
 333
 334 void init_snake() {
 335         for (int i = 0; i < op.l; i++) {
 336                 if (g.w/2-i < 0) /* go upwards if we hit left wall */
 337                         snake_append(&g.s, g.h/2-(i-g.w/2), 0);
 338                 else /* normally just keep goint left */
 339                         snake_append(&g.s, g.h/2, g.w/2-i);
 340         }
 341 }
 342
 343 #define free_ll(head) do{ \
 344         while (head) { \
 345                 void* tmp = head; \
 346                 head = head->next; \
 347                 free(tmp); \
 348         } \
 349 }while(0)
 350
 351 void quit (void) {
 352         screen_setup(0);
 353         free_ll(g.s);
 354         free_ll(g.i);
 355 }
 356
 357 enum esc_states {
 358         START,
 359         ESC_SENT,
 360         CSI_SENT,
 361         MOUSE_EVENT,
 362 };
 363 int getctrlseq (void) {
 364         int c;
 365         int state = START;
 366         while ((c = getchar()) != EOF) {
 367                 switch (state) {
 368                 case START:
 369                         switch (c) {
 370                         case '\033': state=ESC_SENT; break;
 371                         default: return c;
 372                         }
 373                         break;
 374                 case ESC_SENT:
 375                         switch (c) {
 376                         case '[': state=CSI_SENT; break;
 377                         default: return CTRSEQ_INVALID;
 378                         }
 379                         break;
 380                 case CSI_SENT:
 381                         switch (c) {
 382                         case 'A': return CTRSEQ_CURSOR_UP;
 383                         case 'B': return CTRSEQ_CURSOR_DOWN;
 384                         case 'C': return CTRSEQ_CURSOR_RIGHT;
 385                         case 'D': return CTRSEQ_CURSOR_LEFT;
 386                         default: return CTRSEQ_INVALID;
 387                         }
 388                         break;
 389                 default:
 390                         return CTRSEQ_INVALID;
 391                 }
 392         }
 393         return 2;
 394 }
 395
 396 void append_movement (int dir) {
 397         if (g.k.n > 15) return; /* no space in buffer */
 398         if (g.k.n && g.k.c[(16+g.k.h-1)%16] == dir)
 399                 return; /* don't add the same direction twice */
 400
 401         g.k.c[g.k.h] = dir;
 402         g.k.n++;
 403         g.k.h = ++g.k.h % 16;
 404 }
 405
 406 void move_ph (int line, int col) {
 407         /* move printhead to zero-indexed position */
 408         printf ("\033[%d;%dH", line+1, col+1);
 409 }
 410
 411 void clamp_fieldsize (void) {
 412         /* clamp field size to terminal size and mouse maximum: */
 413         struct winsize w;
 414         ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
 415
 416         if (g.w < 10) g.w = 10;
 417         if (g.h < 10) g.h = 10;
 418
 419         if (COL_OFFSET + g.w*CW + COL_OFFSET > w.ws_col)
 420                 g.w = (w.ws_col - COL_OFFSET - COL_OFFSET)/CW-1; //TODO: does not work in `-d' (in xterm)
 421         if (LINE_OFFSET + g.h + LINES_AFTER > w.ws_row)
 422                 g.h = w.ws_row - (LINE_OFFSET+LINES_AFTER);
 423 }
 424
 425 void timer_setup (int enable) {
 426         static struct itimerval tbuf;
 427         tbuf.it_interval.tv_sec  = 0;//TODO: make it speed up automatically
 428         tbuf.it_interval.tv_usec = (1000000/g.v)-1; /*WARN: 1 <= g.v <= 999999*/
 429
 430         if (enable) {
 431                 tbuf.it_value.tv_sec  = tbuf.it_interval.tv_sec;
 432                 tbuf.it_value.tv_usec = tbuf.it_interval.tv_usec;
 433         } else {
 434                 tbuf.it_value.tv_sec  = 0;
 435                 tbuf.it_value.tv_usec = 0;
 436         }
 437
 438         if ( setitimer(ITIMER_REAL, &tbuf, NULL) == -1 ) {
 439                 perror("setitimer");
 440                 exit(1);
 441         }
 442
 443 }
 444
 445 void signal_setup (void) {
 446         struct sigaction saction;
 447
 448         saction.sa_handler = signal_handler;
 449         sigemptyset(&saction.sa_mask);
 450         saction.sa_flags = 0;
 451         if (sigaction(SIGALRM, &saction, NULL) < 0 ) {
 452                 perror("SIGALRM");
 453                 exit(1);
 454         }
 455
 456         if (sigaction(SIGINT, &saction, NULL) < 0 ) {
 457                 perror ("SIGINT");
 458                 exit (1);
 459         }
 460 }
 461
 462 void signal_handler (int signum) {
 463         switch (signum) {
 464         case SIGALRM:
 465                 snake_advance();
 466                 break;
 467         case SIGINT:
 468                 exit(128+SIGINT);
 469         }
 470 }
 471
 472 void screen_setup (int enable) {
 473         if (enable) {
 474                 raw_mode(1);
 475                 printf ("\033[s\033[?47h"); /* save cursor, alternate screen */
 476                 printf ("\033[H\033[J"); /* reset cursor, clear screen */
 477                 printf ("\033[?25l"); /* hide cursor */
 478                 print (op.scheme->init_seq); /* swich charset, if necessary */
 479         } else {
 480                 print (op.scheme->reset_seq); /* reset charset, if necessary */
 481                 printf ("\033[?25h"); /* show cursor */
 482                 printf ("\033[?47l\033[u"); /* primary screen, restore cursor */
 483                 raw_mode(0);
 484         }
 485 }
 486
 487 /* http://users.csc.calpoly.edu/~phatalsk/357/lectures/code/sigalrm.c */
 488 void raw_mode(int enable) {
 489         static struct termios saved_term_mode;
 490         struct termios raw_term_mode;
 491
 492         if (enable) {
 493                 tcgetattr(STDIN_FILENO, &saved_term_mode);
 494                 raw_term_mode = saved_term_mode;
 495                 raw_term_mode.c_lflag &= ~(ICANON | ECHO);
 496                 raw_term_mode.c_cc[VMIN] = 1 ;
 497                 raw_term_mode.c_cc[VTIME] = 0;
 498                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw_term_mode);
 499         } else {
 500                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_term_mode);
 501         }
 502 }