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, sigaction in c99*/
  19 #include <ctype.h>
  20 #include <poll.h>
  21 #include <signal.h>
  22 #include <stdio.h>
  23 #include <stdlib.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 COL_OFFSET 1
  41 #define LINE_OFFSET 1
  42 #define LINES_AFTER 1
  43 #define CW 2 /* cell width */
  44
  45 struct game {
  46         int w; /* field width */
  47         int h; /* field height */
  48         int d; /* direction the snake is looking */
  49         int t; /* time of game start */
  50         int p; /* score */ //TODO: rename?
  51         float f; /* speed in moves per second */ //TODO: rename :XXX
  52         struct snake* s; /* snek */ //TODO: rename to S
  53         struct item* i; /* items (food, boni) */
  54         struct directions* n;/* next direction events to process */
  55 } g;
  56
  57 struct opt {
  58         int l; /* initial snake length */
  59         int s; /* initial snake speed */
  60         struct scheme* scheme;
  61 } op;
  62
  63 int main (int argc, char** argv) {
  64         /* defaults: */
  65         g.w = 30; //two-char-width
  66         g.h = 20;
  67         op.l = 10;
  68         op.s = 8;
  69         op.scheme = &unic0de; //TODO: expose to getopt() once more sets are available
  70
  71         int optget;
  72         opterr = 0; /* don't print message on unrecognized option */
  73         while ((optget = getopt (argc, argv, "+h")) != -1) {
  74                 switch (optget) {
  75                 case 'h':
  76                 default:
  77                         fprintf (stderr, SHORTHELP LONGHELP, argv[0]);
  78                         return !(optget=='h');
  79                 }
  80         } if (optind < argc) { /* parse Fieldspec */
  81         }
  82
  83         srand(time(0));
  84         signal_setup();
  85         screen_setup(1);
  86         atexit (*quit);
  87
  88         //TODO: call viiper() in a game loop
  89         viiper();
  90 quit:
  91         return 0;
  92 }
  93
  94 int viiper(void) {
  95         init_snake();
  96         show_playfield ();
  97         g.d = EAST;
  98         g.f = op.s;
  99
 100         timer_setup(1);
 101
 102         spawn_item(FOOD, rand() % NUM_FOODS); //TODO: shape distribution, so bigger values get selected less
 103
 104         for(;;) {
 105                 switch (getctrlseq()) {
 106                 case '+': g.f++;timer_setup(1);break; //TODO: temporary, to set speed
 107                 case '#': if (g.f > 1) g.f--;timer_setup(1); break; //TODO: temporary, to set speed
 108
 109                 case CTRSEQ_CURSOR_LEFT:
 110                 case 'h': append_movement(WEST);  break;
 111                 case CTRSEQ_CURSOR_DOWN:
 112                 case 'j': append_movement(SOUTH); break;
 113                 case CTRSEQ_CURSOR_UP:
 114                 case 'k': append_movement(NORTH); break;
 115                 case CTRSEQ_CURSOR_RIGHT:
 116                 case 'l': append_movement(EAST);  break;
 117                 case 'p': /*TODO: pause*/ break;
 118                 case 'r': /*TODO:restart*/ return 0;
 119                 case 'q': return 0;
 120                 case CTRL_'L':
 121                         screen_setup(1);
 122                         show_playfield();
 123                         break;
 124                 }
 125
 126                 print ("\033[H\033[J");
 127                 show_playfield ();//TODO: only redraw diff
 128         }
 129
 130 }
 131
 132 void snake_advance (void) {
 133         if (g.n) {/* new direction in the buffer */
 134                 int possible_new_dir = get_movement();
 135                 if (g.d == EAST && possible_new_dir == WEST) goto ignore_new;
 136                 if (g.d == WEST && possible_new_dir == EAST) goto ignore_new;
 137                 if (g.d == NORTH && possible_new_dir == SOUTH) goto ignore_new;
 138                 if (g.d == SOUTH && possible_new_dir == NORTH) goto ignore_new;
 139                 g.d = possible_new_dir; /* pop off a new direction if available*/
 140 ignore_new:
 141                 1;
 142         }
 143
 144         int new_row = g.s->r +(g.d==SOUTH) -(g.d==NORTH);
 145         int new_col = g.s->c +(g.d==EAST)  -(g.d==WEST);
 146
 147         /* detect food hit and spawn a new food */
 148         for (struct item* i = g.i; i; i = i->next) {
 149                 if (i->r == new_row && i->c == new_col) {
 150                         consume_item (i);
 151                         spawn_item(FOOD, rand() % NUM_FOODS);
 152                 }
 153         }
 154
 155         /*NOTE:no idea why I have to use g.w+1, but otherwise we die too early*/
 156         if (new_row >= g.h || new_col >= g.w+1 || new_row < 0 || new_col < 0)
 157                 exit(1); //TODO: longjump?
 158
 159         struct snake* new_head;
 160         struct snake* new_tail; /* former second-to-last element */
 161         for (new_tail = g.s; new_tail->next->next; new_tail = new_tail->next)
 162                 /* use the opportunity of looping to check if we eat ourselves*/
 163                 if(new_tail->next->r == new_row && new_tail->next->c == new_col)
 164                         exit(1);
 165         new_head = new_tail->next; /* reuse element instead of malloc() */
 166         new_tail->next = NULL;
 167
 168         new_head->r = new_row;
 169         new_head->c = new_col;
 170         new_head->next = g.s;
 171
 172         g.s = new_head;
 173 }
 174
 175 void spawn_item (int type, int value) {
 176         int row, col;
 177 try_again:
 178         row = rand() % g.h;
 179         col = rand() % g.w;
 180         /* loop through snake to check if we aren't on it */
 181         //TODO: inefficient as snake gets longer; near impossible in the end
 182         for (struct snake* s = g.s; s; s = s->next)
 183                 if (s->r == row && s->c == col) goto try_again;
 184
 185         //3. get item from category TODO
 186         struct item* new_item = malloc (sizeof(struct item));
 187         new_item->r = row;
 188         new_item->c = col;
 189         new_item->t = type;
 190         new_item->v = value;
 191         new_item->s = time(0);
 192         if (g.i) g.i->prev = new_item;
 193         new_item->next = g.i;
 194
 195         g.i = new_item;
 196 }
 197
 198 void consume_item (struct item* i) {
 199         struct item* predecessor = i->prev;
 200         struct item* successor = i->next;
 201
 202         switch (i->t) {
 203         case FOOD:
 204                 switch (i->v) {
 205                 case FOOD_5:  g.p +=  5; break;
 206                 case FOOD_10: g.p += 10; break;
 207                 case FOOD_20: g.p += 20; break;
 208                 }
 209                 snake_append(g.s, 0,0);   /* position doesn't matter, as item */
 210                 break;       /* will be reused as the head before it is drawn */
 211         case BONUS:
 212                 //TODO: handle bonus
 213                 break;
 214         }
 215
 216         if (predecessor == NULL) {
 217                 g.i = successor;
 218                 if (successor) successor->prev = NULL;
 219         } else {
 220                 predecessor->next = successor;
 221                 successor->prev = predecessor;
 222         }
 223
 224         free (i);
 225 }
 226
 227 void show_playfield (void) {
 228         //int score_width = g.p > 9999?6:4;
 229         int score_width = 4;             //        v- = the -| spacer |-
 230         float half_width = (g.w - score_width/CW - 2)/2.0; //TODO: this whole endavour is ugly
 231         /* top border */
 232         print(BORDER(T,L));
 233         printm (half_width, BORDER(T,C)); //TODO: i bet this breaks in dec mode
 234         printf ("%s %0*d %s", BORDER(S,L), score_width, g.p, BORDER(S,R));
 235         printm ((int)(half_width+.5), BORDER(T,C));
 236         printf ("%s\n", BORDER(T,R));
 237
 238         /* main area */
 239         for (int row = 0; row < g.h; row++)
 240                 printf ("%s%*s%s\n", BORDER(C,L), CW*g.w, "", BORDER(C,R));
 241
 242         /* bottom border */
 243         print(BORDER(B,L));
 244         printm (g.w, BORDER(B,C));
 245         print (BORDER(B,R));
 246
 247         /* print snake */
 248         struct snake* last = NULL;
 249         int color = -1; //TODO: that's a hack
 250         for (struct snake* s = g.s; s; s = s->next) {
 251                 move_ph (s->r+COL_OFFSET, s->c*CW+LINE_OFFSET);
 252
 253                 int predecessor = (last==NULL)?NONE:
 254                         (last->r < s->r) ? NORTH:
 255                         (last->r > s->r) ? SOUTH:
 256                         (last->c > s->c) ? EAST:
 257                         (last->c < s->c) ? WEST:NONE;
 258                 int successor = (s->next == NULL)?NONE:
 259                         (s->next->r < s->r) ? NORTH:
 260                         (s->next->r > s->r) ? SOUTH:
 261                         (s->next->c > s->c) ? EAST:
 262                         (s->next->c < s->c) ? WEST:NONE;
 263
 264                 printf ("\033[%sm", color==-1?"91":color?"92":"32");
 265                 print (op.scheme->snake[predecessor][successor]);
 266                 printf ("\033[0m");
 267                 last = s;
 268                 color = (color+1) % 2;
 269         }
 270
 271         /* print item queue */
 272         for (struct item* i = g.i; i; i = i->next) {
 273                 move_ph (i->r+LINE_OFFSET, i->c*CW+COL_OFFSET);
 274                 if (i->t == FOOD) print (op.scheme->item[i->v]);
 275                 else if (i->t==BONUS) /* TODO: print bonus */;
 276         }
 277
 278         //TODO: temporarily print speed
 279         move_ph (g.h+LINE_OFFSET, g.w);
 280         printf ("%f", g.f);
 281 }
 282
 283 void snake_append (struct snake* s, int row, int col) {
 284         struct snake* new = malloc (sizeof(struct snake));
 285         new->r = row;
 286         new->c = col;
 287         new->next = NULL;
 288
 289         struct snake* p = s;
 290         while (p->next) p = p->next;
 291         p->next = new;
 292 }
 293
 294 void init_snake() {
 295         g.s = malloc (sizeof(struct snake));
 296         g.s->r = g.h/2;
 297         g.s->c = g.w/2;
 298         g.s->next=NULL;
 299
 300         for (int i = 1; i < op.l; i++)
 301                 snake_append(g.s, g.h/2, g.w/2-i);
 302 }
 303
 304 void quit (void) {
 305         screen_setup(0);
 306         for (struct snake* s = g.s; s;) {
 307                 struct snake* tmp = s->next;
 308                 free (s);
 309                 s = tmp;
 310         }
 311         for (struct item* i = g.i; i;) {
 312                 struct item* tmp = i->next;
 313                 free (i);
 314                 i = tmp;
 315         }
 316 }
 317
 318 enum esc_states {
 319         START,
 320         ESC_SENT,
 321         CSI_SENT,
 322         MOUSE_EVENT,
 323 };
 324 int getctrlseq (void) {
 325         int c;
 326         int state = START;
 327         int offset = 0x20; /* never sends control chars as data */
 328         while ((c = getchar()) != EOF) {
 329                 switch (state) {
 330                 case START:
 331                         switch (c) {
 332                         case '\033': state=ESC_SENT; break;
 333                         default: return c;
 334                         }
 335                         break;
 336                 case ESC_SENT:
 337                         switch (c) {
 338                         case '[': state=CSI_SENT; break;
 339                         default: return CTRSEQ_INVALID;
 340                         }
 341                         break;
 342                 case CSI_SENT:
 343                         switch (c) {
 344                         case 'A': return CTRSEQ_CURSOR_UP;
 345                         case 'B': return CTRSEQ_CURSOR_DOWN;
 346                         case 'C': return CTRSEQ_CURSOR_RIGHT;
 347                         case 'D': return CTRSEQ_CURSOR_LEFT;
 348                         default: return CTRSEQ_INVALID;
 349                         }
 350                         break;
 351                 default:
 352                         return CTRSEQ_INVALID;
 353                 }
 354         }
 355         return 2;
 356 }
 357
 358 void append_movement (int dir) {
 359         struct directions* new_event = malloc (sizeof(struct directions));
 360         new_event->d = dir;
 361         new_event->next = NULL;
 362         if (g.n == NULL) {
 363                 g.n = new_event;
 364         } else {
 365                 struct directions* n;
 366                 for (n = g.n; n->next; n = n->next);
 367                 n->next = new_event;
 368         }
 369 }
 370
 371 int get_movement (void) {
 372         if (g.n == NULL) return -1;
 373
 374         int retval = g.n->d;
 375         struct directions* delet_this = g.n;
 376         g.n = g.n->next;
 377         free(delet_this);
 378         return retval;
 379 }
 380
 381 void move_ph (int line, int col) {
 382         /* move printhead to zero-indexed position */
 383         printf ("\033[%d;%dH", line+1, col+1);
 384 }
 385
 386 void clamp_fieldsize (void) { //TODO: use
 387         /* clamp field size to terminal size and mouse maximum: */
 388         struct winsize w;
 389         ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
 390
 391         if (g.w < 1) g.w = 1;
 392         if (g.h < 1) g.h = 1;
 393
 394         if (COL_OFFSET + g.w*CW + COL_OFFSET > w.ws_col)
 395                 g.w = (w.ws_col - COL_OFFSET - COL_OFFSET)/CW; //TODO: does not work in `-d' (in xterm)
 396         if (LINE_OFFSET + g.h + LINES_AFTER > w.ws_row)
 397                 g.h = w.ws_row - (LINE_OFFSET+LINES_AFTER);
 398 }
 399
 400 void timer_setup (int enable) {
 401         static struct itimerval tbuf;
 402         tbuf.it_interval.tv_sec  = 0;//TODO: make configurable, TODO: speed up
 403         tbuf.it_interval.tv_usec = (1000000/g.f)-1; /*WARN: 1 <= g.f <= 999999*/
 404
 405         if (enable) {
 406                 g.t = time(NULL);//TODO: interferes with 'pause'
 407                 tbuf.it_value.tv_sec  = tbuf.it_interval.tv_sec;
 408                 tbuf.it_value.tv_usec = tbuf.it_interval.tv_usec;
 409         } else {
 410                 tbuf.it_value.tv_sec  = 0;
 411                 tbuf.it_value.tv_usec = 0;
 412         }
 413
 414         if ( setitimer(ITIMER_REAL, &tbuf, NULL) == -1 ) {
 415                 perror("setitimer");
 416                 exit(1);
 417         }
 418
 419 }
 420
 421 void signal_setup (void) {
 422         struct sigaction saction;
 423
 424         saction.sa_handler = signal_handler;
 425         sigemptyset(&saction.sa_mask);
 426         saction.sa_flags = 0;
 427         if (sigaction(SIGALRM, &saction, NULL) < 0 ) {
 428                 perror("SIGALRM");
 429                 exit(1);
 430         }
 431
 432         if (sigaction(SIGINT, &saction, NULL) < 0 ) {
 433                 perror ("SIGINT");
 434                 exit (1);
 435         }
 436 }
 437
 438 void signal_handler (int signum) {
 439         //int dtime;
 440         switch (signum) {
 441         case SIGALRM:
 442                 //dtime = difftime (time(NULL), g.t);
 443                 //move_ph (1, g.w*CW-(CW%2)-3-(dtime>999));
 444                 //printf ("[%03d]", g.t?dtime:0);
 445                 snake_advance();
 446                 break;
 447         case SIGINT:
 448                 exit(128+SIGINT);
 449         }
 450 }
 451
 452 void screen_setup (int enable) {
 453         if (enable) {
 454                 raw_mode(1);
 455                 printf ("\033[s\033[?47h"); /* save cursor, alternate screen */
 456                 printf ("\033[H\033[J"); /* reset cursor, clear screen */
 457                 printf ("\033[?25l"); /* hide cursor */
 458                 print (op.scheme->init_seq); /* swich charset, if necessary */
 459         } else {
 460                 print (op.scheme->reset_seq); /* reset charset, if necessary */
 461                 printf ("\033[?25h"); /* show cursor */
 462                 printf ("\033[?47l\033[u"); /* primary screen, restore cursor */
 463                 raw_mode(0);
 464         }
 465 }
 466
 467 /* http://users.csc.calpoly.edu/~phatalsk/357/lectures/code/sigalrm.c */
 468 void raw_mode(int enable) {
 469         static struct termios saved_term_mode;
 470         struct termios raw_term_mode;
 471
 472         if (enable) {
 473                 tcgetattr(STDIN_FILENO, &saved_term_mode);
 474                 raw_term_mode = saved_term_mode;
 475                 raw_term_mode.c_lflag &= ~(ICANON | ECHO);
 476                 raw_term_mode.c_cc[VMIN] = 1 ;
 477                 raw_term_mode.c_cc[VTIME] = 0;
 478                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw_term_mode);
 479         } else {
 480                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_term_mode);
 481         }
 482 }