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 2 /* 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; //TODO: expose to getopt() once more sets are available
  73
  74         int optget;
  75         opterr = 0; /* don't print message on unrecognized option */
  76         while ((optget = getopt (argc, argv, "+h")) != -1) {
  77                 switch (optget) {
  78                 case 'h':
  79                 default:
  80                         fprintf (stderr, SHORTHELP LONGHELP, argv[0]);
  81                         return !(optget=='h');
  82                 }
  83         } if (optind < argc) { /* parse Fieldspec */
  84         }
  85
  86         srand(time(0));
  87         signal_setup();
  88         screen_setup(1);
  89         atexit (*quit);
  90
  91         if (sigsetjmp(game_over, 1)) {
  92                 timer_setup(0);
  93                 move_ph (g.h/2+LINE_OFFSET, g.w);
  94                 printf ("you died :(");
  95                 fflush(stdout);
  96                 sleep(5);
  97         }
  98
  99         //TODO: call viiper() in a game loop
 100         viiper();
 101 quit:
 102         return 0;
 103 }
 104
 105 int viiper(void) {
 106         init_snake();
 107         show_playfield ();
 108         g.d = EAST;
 109         g.v = op.s;
 110
 111         timer_setup(1);
 112
 113         spawn_item(FOOD, rand() % NUM_FOODS); //TODO: shape distribution, so bigger values get selected less
 114
 115         for(;;) {
 116                 switch (getctrlseq()) {
 117                 case '+': g.v++;timer_setup(1);break; //TODO: temporary, to set speed
 118                 case '#': if (g.v > 1) g.v--;timer_setup(1); break; //TODO: temporary, to set speed
 119                 case '\n': spawn_item(FOOD, rand() % NUM_FOODS); break; //TODO: for debugging segfault
 120
 121                 case CTRSEQ_CURSOR_LEFT:
 122                 case 'h': append_movement(WEST);  break;
 123                 case CTRSEQ_CURSOR_DOWN:
 124                 case 'j': append_movement(SOUTH); break;
 125                 case CTRSEQ_CURSOR_UP:
 126                 case 'k': append_movement(NORTH); break;
 127                 case CTRSEQ_CURSOR_RIGHT:
 128                 case 'l': append_movement(EAST);  break;
 129                 case 'p': /*TODO: pause*/ break;
 130                 case 'r': /*TODO:restart*/ return 0;
 131                 case 'q': return 0;
 132                 case CTRL_'L':
 133                         screen_setup(1);
 134                         show_playfield();
 135                         break;
 136                 }
 137
 138                 print ("\033[H\033[J");
 139                 show_playfield ();//TODO: only redraw diff
 140         }
 141
 142 }
 143
 144 void snake_advance (void) {
 145         if (g.n) {/* new direction in the buffer */
 146                 int possible_new_dir = get_movement();
 147                 if (g.d == EAST && possible_new_dir == WEST) goto ignore_new;
 148                 if (g.d == WEST && possible_new_dir == EAST) goto ignore_new;
 149                 if (g.d == NORTH && possible_new_dir == SOUTH) goto ignore_new;
 150                 if (g.d == SOUTH && possible_new_dir == NORTH) goto ignore_new;
 151                 g.d = possible_new_dir; /*pop off a new direction if available*/
 152 ignore_new:
 153                 1;
 154         }
 155
 156         int new_row = g.s->r +(g.d==SOUTH) -(g.d==NORTH);
 157         int new_col = g.s->c +(g.d==EAST)  -(g.d==WEST);
 158
 159         /* detect food hit and spawn a new food */
 160         for (struct item* i = g.i; i; i = i->next) {
 161                 if (i->r == new_row && i->c == new_col) {
 162                         consume_item (i);
 163                         spawn_item(FOOD, rand() % NUM_FOODS);
 164                 }
 165         }
 166
 167         /*NOTE:no idea why I have to use g.w+1, but otherwise we die too early*/
 168         if (new_row >= g.h || new_col >= g.w+1 || new_row < 0 || new_col < 0)
 169                 siglongjmp(game_over, 1/*<-will be the retval of setjmp*/);
 170
 171         struct snake* new_head;
 172         struct snake* new_tail; /* former second-to-last element */
 173         for (new_tail = g.s; new_tail->next->next; new_tail = new_tail->next)
 174                 /* use the opportunity of looping to check if we eat ourselves*/
 175                 if(new_tail->next->r == new_row && new_tail->next->c == new_col)
 176                         siglongjmp(game_over, 1/*<-will be the retval of setjmp*/);
 177         new_head = new_tail->next; /* reuse element instead of malloc() */
 178         new_tail->next = NULL;
 179
 180         new_head->r = new_row;
 181         new_head->c = new_col;
 182         new_head->next = g.s;
 183
 184         g.s = new_head;
 185 }
 186
 187 void spawn_item (int type, int value) {
 188         int row, col;
 189 try_again:
 190         row = rand() % g.h;
 191         col = rand() % g.w;
 192         /* loop through snake to check if we aren't on it */
 193         //TODO: inefficient as snake gets longer; near impossible in the end
 194         for (struct snake* s = g.s; s; s = s->next)
 195                 if (s->r == row && s->c == col) goto try_again;
 196
 197         //3. get item from category TODO
 198         struct item* new_item = malloc (sizeof(struct item));
 199         new_item->r = row;
 200         new_item->c = col;
 201         new_item->t = type;
 202         new_item->v = value;
 203         new_item->s = time(0);
 204         if (g.i) g.i->prev = new_item;
 205         new_item->next = g.i;
 206         new_item->prev = NULL;
 207
 208         g.i = new_item;
 209 }
 210
 211 void consume_item (struct item* i) {
 212         switch (i->t) {
 213         case FOOD:
 214                 switch (i->v) {
 215                 case FOOD_5:  g.p +=  5; break;
 216                 case FOOD_10: g.p += 10; break;
 217                 case FOOD_20: g.p += 20; break;
 218                 }
 219                 snake_append(&g.s, 0,0);  /* position doesn't matter, as item */
 220                 break;       /* will be reused as the head before it is drawn */
 221         case BONUS:
 222                 //TODO: handle bonus
 223                 break;
 224         }
 225
 226         if (i->next) i->next->prev = i->prev;
 227         if (i->prev) i->prev->next = i->next;
 228         else g.i = i->next;
 229
 230         free (i);
 231 }
 232
 233 void show_playfield (void) {
 234         //int score_width = g.p > 9999?6:4;
 235         int score_width = 4;             //        v- = the -| spacer |-
 236         float half_width = (g.w - score_width/CW - 2)/2.0; //TODO: this whole endavour is ugly
 237         /* top border */
 238         print(BORDER(T,L));
 239         printm (half_width, BORDER(T,C)); //TODO: i bet this breaks in dec mode
 240         printf ("%s %0*d %s", BORDER(S,L), score_width, g.p, BORDER(S,R));
 241         printm ((int)(half_width+.5), BORDER(T,C));
 242         printf ("%s\n", BORDER(T,R));
 243
 244         /* main area */
 245         for (int row = 0; row < g.h; row++)
 246                 printf ("%s%*s%s\n", BORDER(C,L), CW*g.w, "", BORDER(C,R));
 247
 248         /* bottom border */
 249         print(BORDER(B,L));
 250         printm (g.w, BORDER(B,C));
 251         print (BORDER(B,R));
 252
 253         /* print snake */
 254         struct snake* last = NULL;
 255         int color = -1; //TODO: that's a hack
 256         for (struct snake* s = g.s; s; s = s->next) {
 257                 move_ph (s->r+COL_OFFSET, s->c*CW+LINE_OFFSET);
 258
 259                 int predecessor = (last==NULL)?NONE:
 260                         (last->r < s->r) ? NORTH:
 261                         (last->r > s->r) ? SOUTH:
 262                         (last->c > s->c) ? EAST:
 263                         (last->c < s->c) ? WEST:NONE;
 264                 int successor = (s->next == NULL)?NONE:
 265                         (s->next->r < s->r) ? NORTH:
 266                         (s->next->r > s->r) ? SOUTH:
 267                         (s->next->c > s->c) ? EAST:
 268                         (s->next->c < s->c) ? WEST:NONE;
 269
 270                 printf ("\033[%sm", color==-1?"1m\033[92":color?"92":"32"); //TODO: clean this up
 271                 print (op.scheme->snake[predecessor][successor]);
 272                 printf ("\033[0m");
 273                 last = s;
 274                 color = (color+1) % 2;
 275         }
 276
 277         /* print item queue */
 278         for (struct item* i = g.i; i; i = i->next) {
 279                 move_ph (i->r+LINE_OFFSET, i->c*CW+COL_OFFSET);
 280                 if (i->t == FOOD) print (op.scheme->item[i->v]);
 281                 else if (i->t==BONUS) /* TODO: print bonus */;
 282         }
 283
 284         //TODO: temporarily print speed
 285         move_ph (g.h+LINE_OFFSET, g.w);
 286         printf ("%f", g.v);
 287 }
 288
 289 void snake_append (struct snake** s, int row, int col) {
 290         struct snake* new = malloc (sizeof(struct snake));
 291         new->r = row;
 292         new->c = col;
 293         new->next = NULL;
 294
 295         if (*s) {
 296                 struct snake* p = *s;
 297                 while (p->next) p = p->next;
 298                 p->next = new;
 299         } else {
 300                 *s = new;
 301         }
 302 }
 303
 304 void init_snake() {
 305         for (int i = 0; i < op.l; i++)
 306                 snake_append(&g.s, g.h/2, g.w/2-i);
 307 }
 308
 309 #define free_ll(head) do{ \
 310         while (head) { \
 311                 void* tmp = head; \
 312                 head = head->next; \
 313                 free(tmp); \
 314         } \
 315 }while(0)
 316
 317 void quit (void) {
 318         screen_setup(0);
 319         free_ll(g.s);
 320         free_ll(g.i);
 321         free_ll(g.n); //TODO: doesn't get free'd correctly
 322 }
 323
 324 enum esc_states {
 325         START,
 326         ESC_SENT,
 327         CSI_SENT,
 328         MOUSE_EVENT,
 329 };
 330 int getctrlseq (void) {
 331         int c;
 332         int state = START;
 333         int offset = 0x20; /* never sends control chars as data */
 334         while ((c = getchar()) != EOF) {
 335                 switch (state) {
 336                 case START:
 337                         switch (c) {
 338                         case '\033': state=ESC_SENT; break;
 339                         default: return c;
 340                         }
 341                         break;
 342                 case ESC_SENT:
 343                         switch (c) {
 344                         case '[': state=CSI_SENT; break;
 345                         default: return CTRSEQ_INVALID;
 346                         }
 347                         break;
 348                 case CSI_SENT:
 349                         switch (c) {
 350                         case 'A': return CTRSEQ_CURSOR_UP;
 351                         case 'B': return CTRSEQ_CURSOR_DOWN;
 352                         case 'C': return CTRSEQ_CURSOR_RIGHT;
 353                         case 'D': return CTRSEQ_CURSOR_LEFT;
 354                         default: return CTRSEQ_INVALID;
 355                         }
 356                         break;
 357                 default:
 358                         return CTRSEQ_INVALID;
 359                 }
 360         }
 361         return 2;
 362 }
 363
 364 void append_movement (int dir) {
 365         struct directions* n;
 366         for (n = g.n; n && n->next; n = n->next); /* advance to the end */
 367         if (n && n->d == dir) return; /* don't add the same direction twice */
 368
 369         struct directions* new_event = malloc (sizeof(struct directions));
 370         new_event->d = dir;
 371         new_event->next = NULL;
 372
 373         if (g.n == NULL)
 374                 g.n = new_event;
 375         else
 376                 n->next = new_event;
 377 }
 378
 379 int get_movement (void) {
 380         if (g.n == NULL) return -1;
 381
 382         int retval = g.n->d;
 383         struct directions* delet_this = g.n;
 384         g.n = g.n->next;
 385         free(delet_this);
 386         return retval;
 387 }
 388
 389 void move_ph (int line, int col) {
 390         /* move printhead to zero-indexed position */
 391         printf ("\033[%d;%dH", line+1, col+1);
 392 }
 393
 394 void clamp_fieldsize (void) { //TODO: use
 395         /* clamp field size to terminal size and mouse maximum: */
 396         struct winsize w;
 397         ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
 398
 399         if (g.w < 1) g.w = 1;
 400         if (g.h < 1) g.h = 1;
 401
 402         if (COL_OFFSET + g.w*CW + COL_OFFSET > w.ws_col)
 403                 g.w = (w.ws_col - COL_OFFSET - COL_OFFSET)/CW; //TODO: does not work in `-d' (in xterm)
 404         if (LINE_OFFSET + g.h + LINES_AFTER > w.ws_row)
 405                 g.h = w.ws_row - (LINE_OFFSET+LINES_AFTER);
 406 }
 407
 408 void timer_setup (int enable) {
 409         static struct itimerval tbuf;
 410         tbuf.it_interval.tv_sec  = 0;//TODO: make it speed up automatically
 411         tbuf.it_interval.tv_usec = (1000000/g.v)-1; /*WARN: 1 <= g.v <= 999999*/
 412
 413         if (enable) {
 414                 g.t = time(NULL);//TODO: interferes with 'pause'
 415                 tbuf.it_value.tv_sec  = tbuf.it_interval.tv_sec;
 416                 tbuf.it_value.tv_usec = tbuf.it_interval.tv_usec;
 417         } else {
 418                 tbuf.it_value.tv_sec  = 0;
 419                 tbuf.it_value.tv_usec = 0;
 420         }
 421
 422         if ( setitimer(ITIMER_REAL, &tbuf, NULL) == -1 ) {
 423                 perror("setitimer");
 424                 exit(1);
 425         }
 426
 427 }
 428
 429 void signal_setup (void) {
 430         struct sigaction saction;
 431
 432         saction.sa_handler = signal_handler;
 433         sigemptyset(&saction.sa_mask);
 434         saction.sa_flags = 0;
 435         if (sigaction(SIGALRM, &saction, NULL) < 0 ) {
 436                 perror("SIGALRM");
 437                 exit(1);
 438         }
 439
 440         if (sigaction(SIGINT, &saction, NULL) < 0 ) {
 441                 perror ("SIGINT");
 442                 exit (1);
 443         }
 444 }
 445
 446 void signal_handler (int signum) {
 447         //int dtime;
 448         switch (signum) {
 449         case SIGALRM:
 450                 //dtime = difftime (time(NULL), g.t);
 451                 //move_ph (1, g.w*CW-(CW%2)-3-(dtime>999));
 452                 //printf ("[%03d]", g.t?dtime:0);
 453                 snake_advance();
 454                 break;
 455         case SIGINT:
 456                 exit(128+SIGINT);
 457         }
 458 }
 459
 460 void screen_setup (int enable) {
 461         if (enable) {
 462                 raw_mode(1);
 463                 printf ("\033[s\033[?47h"); /* save cursor, alternate screen */
 464                 printf ("\033[H\033[J"); /* reset cursor, clear screen */
 465                 printf ("\033[?25l"); /* hide cursor */
 466                 print (op.scheme->init_seq); /* swich charset, if necessary */
 467         } else {
 468                 print (op.scheme->reset_seq); /* reset charset, if necessary */
 469                 printf ("\033[?25h"); /* show cursor */
 470                 printf ("\033[?47l\033[u"); /* primary screen, restore cursor */
 471                 raw_mode(0);
 472         }
 473 }
 474
 475 /* http://users.csc.calpoly.edu/~phatalsk/357/lectures/code/sigalrm.c */
 476 void raw_mode(int enable) {
 477         static struct termios saved_term_mode;
 478         struct termios raw_term_mode;
 479
 480         if (enable) {
 481                 tcgetattr(STDIN_FILENO, &saved_term_mode);
 482                 raw_term_mode = saved_term_mode;
 483                 raw_term_mode.c_lflag &= ~(ICANON | ECHO);
 484                 raw_term_mode.c_cc[VMIN] = 1 ;
 485                 raw_term_mode.c_cc[VTIME] = 0;
 486                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw_term_mode);
 487         } else {
 488                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_term_mode);
 489         }
 490 }