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         struct snake* s; /* snek */ //TODO: rename to S
  49         struct item* i; /* items (food, boni) */
  50         int d; /* direction the snake is looking */
  51         int n;/* direction to move on next tick */
  52         int t; /* time of game start */
  53         int p; /* score */ //TODO: rename?
  54         float f; /* speed in moves per second */ //TODO: rename
  55 } g;
  56
  57 struct opt {
  58         struct scheme* scheme;
  59         int l; /* initial snake length */
  60         int s; /* initial snake speed */
  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 = 2;
  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 = g.n = 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;
 107 case '#': if (g.f > 1) g.f--;timer_setup(1); break;
 108                 case 'h': if (g.d != EAST)  g.n = WEST;  break;
 109                 case 'j': if (g.d != NORTH) g.n = SOUTH; break;
 110                 case 'k': if (g.d != SOUTH) g.n = NORTH; break;
 111                 case 'l': if (g.d != WEST)  g.n = EAST;  break;
 112                 case 'p': /*TODO: pause*/ break;
 113                 case 'r': /*TODO:restart*/ return 0;
 114                 case 'q': return 0;
 115                 case CTRL_'L':
 116                         screen_setup(1);
 117                         show_playfield();
 118                         break;
 119                 }
 120
 121                 print ("\033[H\033[J");
 122                 show_playfield ();//TODO: only redraw diff
 123         }
 124
 125 }
 126
 127 void snake_advance (void) {
 128         g.d = g.n;
 129         int new_row = g.s->r +(g.d==SOUTH) -(g.d==NORTH);
 130         int new_col = g.s->c +(g.d==EAST)  -(g.d==WEST);
 131
 132         /* detect food hit and spawn a new food */
 133         for (struct item* i = g.i; i; i = i->next) {
 134                 if (i->r == new_row && i->c == new_col) {
 135                         consume_item (i);
 136                         spawn_item(FOOD, rand() % NUM_FOODS);
 137                 }
 138         }
 139
 140         if (new_row >= g.h || new_col >= g.w || new_row < 0 || new_col < 0)
 141                 exit(1); //TODO: longjump?
 142
 143         struct snake* new_head;
 144         struct snake* new_tail; /* former second-to-last element */
 145         for (new_tail = g.s; new_tail->next->next; new_tail = new_tail->next)
 146                 /* use the opportunity of looping to check if we eat ourselves*/
 147                 if(new_tail->next->r == new_row && new_tail->next->c == new_col)
 148                         exit(1);
 149         new_head = new_tail->next; /* reuse element instead of malloc() */
 150         new_tail->next = NULL;
 151
 152         new_head->r = new_row;
 153         new_head->c = new_col;
 154         new_head->next = g.s;
 155
 156         g.s = new_head;
 157 }
 158
 159 void spawn_item (int type, int value) {
 160         int row, col;
 161 try_again:
 162         row = rand() % g.h;
 163         col = rand() % g.w;
 164         /* loop through snake to check if we aren't on it */
 165         //TODO: inefficient as snake gets longer; near impossible in the end
 166         for (struct snake* s = g.s; s; s = s->next)
 167                 if (s->r == row && s->c == col) goto try_again;
 168
 169         //3. get item from category TODO
 170         struct item* new_item = malloc (sizeof(struct item));
 171         new_item->r = row;
 172         new_item->c = col;
 173         new_item->t = type;
 174         new_item->v = value;
 175         new_item->s = time(0);
 176         if (g.i) g.i->prev = new_item;
 177         new_item->next = g.i;
 178
 179         g.i = new_item;
 180 }
 181
 182 void consume_item (struct item* i) {
 183         struct item* predecessor = i->prev;
 184         struct item* successor = i->next;
 185
 186         switch (i->t) {
 187         case FOOD:
 188                 switch (i->v) {
 189                 case FOOD_5:  g.p +=  5; break;
 190                 case FOOD_10: g.p += 10; break;
 191                 case FOOD_20: g.p += 20; break;
 192                 }
 193                 snake_append(g.s, 0,0);   /* position doesn't matter, as item */
 194                 break;       /* will be reused as the head before it is drawn */
 195         case BONUS:
 196                 //handle bonus
 197                 break;
 198         }
 199
 200         if (predecessor == NULL) {
 201                 g.i = successor;
 202                 if (successor) successor->prev = NULL;
 203         } else {
 204                 predecessor->next = successor;
 205                 successor->prev = predecessor;
 206         }
 207
 208         free (i);
 209 }
 210
 211 void show_playfield (void) {
 212         //int score_width = g.p > 9999?6:4;
 213         int score_width = 4;             //        v- = the -| spacer |-
 214         float half_width = (g.w - score_width/CW - 2)/2.0; //TODO: this whole endavour is ugly
 215         /* top border */
 216         print(BORDER(T,L));
 217         printm (half_width, BORDER(T,C)); //TODO: i bet this breaks in dec mode
 218         printf ("%s %0*d %s", BORDER(S,L), score_width, g.p, BORDER(S,R));
 219         printm ((int)(half_width+.5), BORDER(T,C));
 220         printf ("%s\n", BORDER(T,R));
 221
 222         /* main area */
 223         for (int row = 0; row < g.h; row++)
 224                 printf ("%s%*s%s\n", BORDER(C,L), CW*g.w, "", BORDER(C,R));
 225
 226         /* bottom border */
 227         print(BORDER(B,L));
 228         printm (g.w, BORDER(B,C));
 229         print (BORDER(B,R));
 230
 231         /* print snake */
 232         struct snake* last = NULL;
 233         for (struct snake* s = g.s; s; s = s->next) {
 234                 move_ph (s->r+COL_OFFSET, s->c*CW+LINE_OFFSET);
 235
 236                 int predecessor = (last==NULL)?NONE:
 237                         (last->r < s->r) ? NORTH:
 238                         (last->r > s->r) ? SOUTH:
 239                         (last->c > s->c) ? EAST:
 240                         (last->c < s->c) ? WEST:NONE;
 241                 int successor = (s->next == NULL)?NONE:
 242                         (s->next->r < s->r) ? NORTH:
 243                         (s->next->r > s->r) ? SOUTH:
 244                         (s->next->c > s->c) ? EAST:
 245                         (s->next->c < s->c) ? WEST:NONE;
 246
 247                 print (op.scheme->snake[predecessor][successor]);
 248                 last = s;
 249         }
 250
 251         /* print item queue */
 252         for (struct item* i = g.i; i; i = i->next) {
 253                 move_ph (i->r+LINE_OFFSET, i->c*CW+COL_OFFSET);
 254                 if (i->t == FOOD) print (op.scheme->item[i->v]);
 255                 else if (i->t==BONUS) /* TODO: print bonus */;
 256         }
 257
 258         //TODO: temporarily print speed
 259         move_ph (g.h+LINE_OFFSET, g.w);
 260         printf ("%f", g.f);
 261 }
 262
 263 void snake_append (struct snake* s, int row, int col) {
 264         struct snake* new = malloc (sizeof(struct snake));
 265         new->r = row;
 266         new->c = col;
 267         new->next = NULL;
 268
 269         struct snake* p = s;
 270         while (p->next) p = p->next;
 271         p->next = new;
 272 }
 273
 274 void init_snake() {
 275         g.s = malloc (sizeof(struct snake));
 276         g.s->r = g.h/2;
 277         g.s->c = g.w/2;
 278         g.s->next=NULL;
 279
 280         for (int i = 1; i < op.l; i++)
 281                 snake_append(g.s, g.h/2, g.w/2-i);
 282 }
 283
 284 void quit (void) {
 285         screen_setup(0);
 286         for (struct snake* s = g.s; s;) {
 287                 struct snake* tmp = s->next;
 288                 free (s);
 289                 s = tmp;
 290         }
 291         for (struct item* i = g.i; i;) {
 292                 struct item* tmp = i->next;
 293                 free (i);
 294                 i = tmp;
 295         }
 296 }
 297
 298 enum esc_states {
 299         START,
 300         ESC_SENT,
 301         CSI_SENT,
 302         MOUSE_EVENT,
 303 };
 304 int getctrlseq (void) {
 305         int c;
 306         int state = START;
 307         int offset = 0x20; /* never sends control chars as data */
 308         while ((c = getchar()) != EOF) {
 309                 switch (state) {
 310                 case START:
 311                         switch (c) {
 312                         case '\033': state=ESC_SENT; break;
 313                         default: return c;
 314                         }
 315                         break;
 316                 case ESC_SENT:
 317                         switch (c) {
 318                         case '[': state=CSI_SENT; break;
 319                         default: return CTRSEQ_INVALID;
 320                         }
 321                         break;
 322                 case CSI_SENT:
 323                         switch (c) {
 324                         case 'A': return CTRSEQ_CURSOR_UP;
 325                         case 'B': return CTRSEQ_CURSOR_DOWN;
 326                         case 'C': return CTRSEQ_CURSOR_RIGHT;
 327                         case 'D': return CTRSEQ_CURSOR_LEFT;
 328                         default: return CTRSEQ_INVALID;
 329                         }
 330                         break;
 331                 default:
 332                         return CTRSEQ_INVALID;
 333                 }
 334         }
 335         return 2;
 336 }
 337
 338 void move_ph (int line, int col) {
 339         /* move printhead to zero-indexed position */
 340         printf ("\033[%d;%dH", line+1, col+1);
 341 }
 342
 343 void clamp_fieldsize (void) {
 344         /* clamp field size to terminal size and mouse maximum: */
 345         struct winsize w;
 346         ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
 347
 348         if (g.w < 1) g.w = 1;
 349         if (g.h < 1) g.h = 1;
 350
 351         if (COL_OFFSET + g.w*CW + COL_OFFSET > w.ws_col)
 352                 g.w = (w.ws_col - COL_OFFSET - COL_OFFSET)/CW; //TODO: does not work in `-d' (in xterm)
 353         if (LINE_OFFSET + g.h + LINES_AFTER > w.ws_row)
 354                 g.h = w.ws_row - (LINE_OFFSET+LINES_AFTER);
 355 }
 356
 357 void timer_setup (int enable) {
 358         static struct itimerval tbuf;
 359         tbuf.it_interval.tv_sec  = 0;//TODO: make configurable, TODO: speed up
 360         tbuf.it_interval.tv_usec = (1000000/g.f)-1; /*WARN: 1 <= g.f <= 999999*/
 361
 362         if (enable) {
 363                 g.t = time(NULL);
 364                 tbuf.it_value.tv_sec  = tbuf.it_interval.tv_sec;
 365                 tbuf.it_value.tv_usec = tbuf.it_interval.tv_usec;
 366                 if (setitimer(ITIMER_REAL, &tbuf, NULL) == -1) {
 367                         perror("setitimer");
 368                         exit(1);
 369                 }
 370         } else {
 371                 tbuf.it_value.tv_sec  = 0;
 372                 tbuf.it_value.tv_usec = 0;
 373                 if ( setitimer(ITIMER_REAL, &tbuf, NULL) == -1 ) {
 374                         perror("setitimer");
 375                         exit(1);
 376                 }
 377         }
 378
 379 }
 380
 381 void signal_setup (void) {
 382         struct sigaction saction;
 383
 384         saction.sa_handler = signal_handler;
 385         sigemptyset(&saction.sa_mask);
 386         saction.sa_flags = 0;
 387         if (sigaction(SIGALRM, &saction, NULL) < 0 ) {
 388                 perror("SIGALRM");
 389                 exit(1);
 390         }
 391
 392         if (sigaction(SIGINT, &saction, NULL) < 0 ) {
 393                 perror ("SIGINT");
 394                 exit (1);
 395         }
 396 }
 397
 398 void signal_handler (int signum) {
 399         //int dtime;
 400         switch (signum) {
 401         case SIGALRM:
 402                 //dtime = difftime (time(NULL), g.t);
 403                 //move_ph (1, g.w*CW-(CW%2)-3-(dtime>999));
 404                 //printf ("[%03d]", g.t?dtime:0);
 405                 snake_advance();
 406                 break;
 407         case SIGINT:
 408                 exit(128+SIGINT);
 409         }
 410 }
 411
 412 void screen_setup (int enable) {
 413         if (enable) {
 414                 raw_mode(1);
 415                 printf ("\033[s\033[?47h"); /* save cursor, alternate screen */
 416                 printf ("\033[H\033[J"); /* reset cursor, clear screen */
 417                 printf ("\033[?25l"); /* hide cursor */
 418                 //print (op.scheme->init_seq); /* swich charset, if necessary */
 419         } else {
 420                 //print (op.scheme->reset_seq); /* reset charset, if necessary */
 421                 printf ("\033[?25h"); /* show cursor */
 422                 printf ("\033[?47l\033[u"); /* primary screen, restore cursor */
 423                 raw_mode(0);
 424         }
 425 }
 426
 427 /* http://users.csc.calpoly.edu/~phatalsk/357/lectures/code/sigalrm.c */
 428 void raw_mode(int enable) {
 429         static struct termios saved_term_mode;
 430         struct termios raw_term_mode;
 431
 432         if (enable) {
 433                 tcgetattr(STDIN_FILENO, &saved_term_mode);
 434                 raw_term_mode = saved_term_mode;
 435                 raw_term_mode.c_lflag &= ~(ICANON | ECHO);
 436                 raw_term_mode.c_cc[VMIN] = 1 ;
 437                 raw_term_mode.c_cc[VTIME] = 0;
 438                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw_term_mode);
 439         } else {
 440                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_term_mode);
 441         }
 442 }