mines_2017.c

   1 /*******************************************************************************
   2  minesviiper 0.3.11
   3  By Tobias Girstmair, 2015 - 2017
   4
   5  ./minesviiper -w 16 -h 16 -m 40
   6  (see ./minesviiper -\? for full list of options)
   7
   8  MOUSE MODE: - left click to open and choord
   9              - right click to flag/unflag
  10  VI MODE:    - hjkl to move cursor left/down/up/right
  11              - bduw to jump left/down/up/right by 5 cells
  12              - space to open and choord
  13              - i to flag/unflag
  14
  15  GNU GPL v3, see LICENSE or https://www.gnu.org/licenses/gpl-3.0.txt
  16 *******************************************************************************/
  17
  18
  19 #define _POSIX_C_SOURCE 2 /*for getopt, sigaction in c99*/
  20 #include <signal.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <sys/time.h>
  24 #include <termios.h>
  25 #include <time.h>
  26 #include <unistd.h>
  27
  28 #include "schemes.h"
  29
  30 #define LINE_OFFSET 3
  31 #define COL_OFFSET 2
  32 #define BIG_MOVE 5
  33
  34 #define MIN(a,b) (a>b?b:a)
  35 #define MAX(a,b) (a>b?a:b)
  36 #define printm(num, str) for (int i = 0; i < num; i++) fputs (str, stdout)
  37 #define print(str) fputs (str, stdout)
  38
  39 struct minecell {
  40         unsigned m:2; /* mine?1:killmine?2:0 */
  41         unsigned o:1; /* open?1:0 */
  42         unsigned f:2; /* flagged?1:questioned?2:0 */
  43         unsigned n:4; /* 0<= neighbours <=8 */
  44 };
  45 struct minefield {
  46         struct minecell **c;
  47         int w; /* width */
  48         int h; /* height */
  49         int m; /* number of mines */
  50
  51         int f; /* flags counter */
  52         int t; /* time of game start */
  53         int p[2]; /* cursor position {line, col} */
  54 } f;
  55
  56 struct opt {
  57         struct minescheme* scheme;
  58         int mode; /* allow flags? quesm? */
  59 } op;
  60
  61 void fill_minefield (int, int);
  62 void move (int, int);
  63 int getch (unsigned char*);
  64 int getctrlseq (unsigned char*);
  65 int everything_opened ();
  66 int wait_mouse_up (int, int);
  67 void partial_show_minefield (int, int, int);
  68 void show_minefield (int);
  69 int get_neighbours (int, int, int);
  70 int uncover_square (int, int);
  71 void flag_square (int, int);
  72 int choord_square (int, int);
  73 struct minecell** alloc_array (int, int);
  74 void free_field ();
  75 int screen2field_l (int);
  76 int screen2field_c (int);
  77 int field2screen_l (int);
  78 int field2screen_c (int);
  79 void quit();
  80 void signal_handler (int signum);
  81
  82 enum modes {
  83         NORMAL,
  84         REDUCED,
  85         SHOWMINES,
  86 };
  87 enum flagtypes {
  88         NOFLAG,
  89         FLAG,
  90         QUESM,
  91 };
  92 enum fieldopenstates {
  93         CLOSED,
  94         OPENED,
  95 };
  96 enum event {
  97         /* for getctrlseq() */
  98         CTRSEQ_NULL    =  0,
  99         CTRSEQ_EOF     = -1,
 100         CTRSEQ_INVALID = -2,
 101         CTRSEQ_MOUSE   = -3,
 102         /* for getch() */
 103         CTRSEQ_MOUSE_LEFT   = -4,
 104         CTRSEQ_MOUSE_MIDDLE = -5,
 105         CTRSEQ_MOUSE_RIGHT  = -6,
 106 };
 107 enum mine_types {
 108         NO_MINE,
 109         STD_MINE,
 110         DEATH_MINE,
 111 };
 112
 113 void signal_handler (int signum) {
 114         switch (signum) {
 115         case SIGALRM:
 116                 move (1, f.w*op.scheme->cell_width-(op.scheme->cell_width%2)-3);
 117                 printf ("[%03d]", f.t?(int)difftime (time(NULL), f.t):0);
 118                 break;
 119         case SIGINT:
 120                 exit(128+SIGINT);
 121         }
 122 }
 123
 124 /* http://users.csc.calpoly.edu/~phatalsk/357/lectures/code/sigalrm.c */
 125 struct termios saved_term_mode;
 126 struct termios set_raw_term_mode() {
 127         struct termios cur_term_mode, raw_term_mode;
 128
 129         tcgetattr(STDIN_FILENO, &cur_term_mode);
 130         raw_term_mode = cur_term_mode;
 131         raw_term_mode.c_lflag &= ~(ICANON | ECHO);
 132         raw_term_mode.c_cc[VMIN] = 1 ;
 133         raw_term_mode.c_cc[VTIME] = 0;
 134         tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw_term_mode);
 135
 136         return cur_term_mode;
 137 }
 138 void restore_term_mode(struct termios saved_term_mode) {
 139         tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_term_mode);
 140 }
 141
 142
 143 int main (int argc, char** argv) {
 144         struct itimerval tbuf;
 145         struct sigaction saction;
 146         saved_term_mode = set_raw_term_mode();
 147
 148         atexit (*quit);
 149
 150         saction.sa_handler = signal_handler;
 151         sigemptyset(&saction.sa_mask);
 152         saction.sa_flags   = 0;
 153         if (sigaction(SIGALRM, &saction, NULL) < 0 ) {
 154                 perror("SIGALRM");
 155                 exit(1);
 156         }
 157         tbuf.it_interval.tv_sec  = 1;
 158         tbuf.it_interval.tv_usec = 0;
 159         tbuf.it_value.tv_sec  = 1;
 160         tbuf.it_value.tv_usec = 0;
 161
 162         if (sigaction(SIGINT, &saction, NULL) < 0 ) {
 163                 perror ("SIGINT");
 164                 exit (1);
 165         }
 166         /* end screen setup */
 167
 168         /* setup defaults */
 169         f.w = 30;
 170         f.h = 16;
 171         f.m = 99;
 172
 173         op.scheme = &symbols_mono;
 174         op.mode = FLAG;
 175         /* end defaults */
 176         /* parse options */
 177         int optget;
 178         opterr = 0; /* don't print message on unrecognized option */
 179         while ((optget = getopt (argc, argv, "+w:h:m:nfqcdx")) != -1) {
 180                 switch (optget) {
 181                 case 'w': f.w        = atoi (optarg); break;
 182                 case 'h': f.h        = atoi (optarg); break;
 183                 case 'm': f.m        = atoi (optarg); break;
 184                 case 'n': op.mode    = NOFLAG; break;
 185                 case 'f': op.mode    = FLAG; break; /*default*/
 186                 case 'q': op.mode    = QUESM; break;
 187                 case 'c': op.scheme  = &symbols_col1; break;
 188                 case 'd': op.scheme  = &symbols_doublewidth; break;
 189                 case '?':
 190                         fprintf (stderr, "%s [OPTIONS]\n"
 191                         "OPTIONS:\n"
 192                         "    w(idth)\n"
 193                         "    h(eight)\n"
 194                         "    m(ines)\n"
 195                         "    n(o flagging)\n"
 196                         "    f(lagging)\n"
 197                         "    q(uestion marks)\n"
 198                         "    c(olored symbols)\n"
 199                         "    d(oublewidth symbols)\n"
 200                         "\n"
 201                         "hjkl: move 1 left/down/up/right\n"
 202                         "bduw: move 5 left/down/up/right\n"
 203                         "left mouse/space: open/choord\n"
 204                         "right mouse/i: flag/unflag\n", argv[0]);
 205                         return 1;
 206                 }
 207         }
 208         /* end parse options*/
 209         /* check boundaries */
 210         if (f.m > (f.w-1) * (f.h-1)) {
 211                 f.m = (f.w-1) * (f.h-1);
 212                 fprintf (stderr, "too many mines. reduced to %d.\r\n", f.m);
 213         }
 214         /* end check */
 215
 216 newgame:
 217         f.c = alloc_array (f.h, f.w);
 218
 219         f.f = 0;
 220         f.t = 0;
 221         f.p[0] = 0;
 222         f.p[1] = 0;
 223
 224         int is_newgame = 1;
 225         int cheatmode = 0;
 226
 227         printf ("\033[H\033[J");
 228
 229         show_minefield (NORMAL);
 230
 231         /* enable mouse, hide cursor */
 232         printf ("\033[?1000h\033[?25l");
 233         while (1) {
 234                 int l, c;
 235                 int action;
 236                 unsigned char mouse[3];
 237
 238                 action = getch(mouse);
 239                 switch (action) {
 240                 case CTRSEQ_MOUSE_LEFT:
 241                         f.p[0] = screen2field_l (mouse[2]);
 242                         f.p[1] = screen2field_c (mouse[1]);
 243                         /* :D clicked: TODO: won't work in single-width mode! */
 244                         if (mouse[2] == LINE_OFFSET-1 &&
 245                            (mouse[1] == f.w+COL_OFFSET ||
 246                             mouse[1] == f.w+COL_OFFSET+1)) {
 247                                 free_field ();
 248                                 goto newgame;
 249                         }
 250                         if (f.p[1] < 0 || f.p[1] >= f.w ||
 251                             f.p[0] < 0 || f.p[0] >= f.h) break; /*out of bound*/
 252                         /* fallthrough */
 253                 case ' ':
 254                         if (is_newgame) {
 255                                 is_newgame = 0;
 256                                 fill_minefield (f.p[0], f.p[1]);
 257                                 f.t = time(NULL);
 258                                 tbuf.it_value.tv_sec  = 1;
 259                                 tbuf.it_value.tv_usec = 0;
 260                                 if (setitimer(ITIMER_REAL, &tbuf, NULL) == -1) {
 261                                         perror("setitimer");
 262                                         exit(1);
 263                                 }
 264                         }
 265
 266                         if (f.c[f.p[0]][f.p[1]].f == FLAG  ) break;
 267                         if (f.c[f.p[0]][f.p[1]].o == CLOSED) {
 268                                 if (uncover_square (f.p[0], f.p[1])) goto lose;
 269                         } else if (get_neighbours (f.p[0], f.p[1], 1) == 0) {
 270                                 if (choord_square (f.p[0], f.p[1])) goto lose;
 271                         }
 272                         if (everything_opened())  goto win;
 273                         break;
 274                 case CTRSEQ_MOUSE_RIGHT:
 275                         f.p[0] = screen2field_l (mouse[2]);
 276                         f.p[1] = screen2field_c (mouse[1]);
 277                         if (f.p[1] < 0 || f.p[1] >= f.w ||
 278                             f.p[0] < 0 || f.p[1] >= f.h) break; /*out of bound*/
 279                         /* fallthrough */
 280                 case 'i':
 281                         if (f.c[f.p[0]][f.p[1]].o == CLOSED)
 282                                 flag_square (f.p[0], f.p[1]);
 283                         break;
 284                 case 'h':
 285                         partial_show_minefield (f.p[0], f.p[1], NORMAL);
 286                         if (f.p[1] > 0)   f.p[1]--;
 287                         move (f.p[0]+LINE_OFFSET, field2screen_c(f.p[1]));
 288                         fputs (op.scheme->mouse_highlight, stdout);
 289                         break;
 290                 case 'j':
 291                         partial_show_minefield (f.p[0], f.p[1], NORMAL);
 292                         if (f.p[0] < f.h-1) f.p[0]++;
 293                         move (f.p[0]+LINE_OFFSET, field2screen_c(f.p[1]));
 294                         fputs (op.scheme->mouse_highlight, stdout);
 295                         break;
 296                 case 'k':
 297                         partial_show_minefield (f.p[0], f.p[1], NORMAL);
 298                         if (f.p[0] > 0)   f.p[0]--;
 299                         move (f.p[0]+LINE_OFFSET, field2screen_c(f.p[1]));
 300                         fputs (op.scheme->mouse_highlight, stdout);
 301                         break;
 302                 case 'l':
 303                         partial_show_minefield (f.p[0], f.p[1], NORMAL);
 304                         if (f.p[1] < f.w-1) f.p[1]++;
 305                         move (f.p[0]+LINE_OFFSET, field2screen_c(f.p[1]));
 306                         fputs (op.scheme->mouse_highlight, stdout);
 307                         break;
 308                 case 'w':
 309                         partial_show_minefield (f.p[0], f.p[1], NORMAL);
 310                         f.p[1] += BIG_MOVE;
 311                         if (f.p[1] >= f.w) f.p[1] = f.w-1;
 312                         move (f.p[0]+LINE_OFFSET, field2screen_c(f.p[1]));
 313                         fputs (op.scheme->mouse_highlight, stdout);
 314                         break;
 315                 case 'b':
 316                         partial_show_minefield (f.p[0], f.p[1], NORMAL);
 317                         f.p[1] -= BIG_MOVE;
 318                         if (f.p[1] < 0)   f.p[1] = 0;
 319                         move (f.p[0]+LINE_OFFSET, field2screen_c(f.p[1]));
 320                         fputs (op.scheme->mouse_highlight, stdout);
 321                         break;
 322                 case 'u':
 323                         partial_show_minefield (f.p[0], f.p[1], NORMAL);
 324                         f.p[0] -= BIG_MOVE;
 325                         if (f.p[0] < 0)   f.p[0] = 0;
 326                         move (f.p[0]+LINE_OFFSET, field2screen_c(f.p[1]));
 327                         fputs (op.scheme->mouse_highlight, stdout);
 328                         break;
 329                 case 'd':
 330                         partial_show_minefield (f.p[0], f.p[1], NORMAL);
 331                         f.p[0] += BIG_MOVE;
 332                         if (f.p[0] >= f.h-1) f.p[0] = f.h-1;
 333                         move (f.p[0]+LINE_OFFSET, field2screen_c(f.p[1]));
 334                         fputs (op.scheme->mouse_highlight, stdout);
 335                         break;
 336                 case 'q':
 337                         goto quit;
 338                 case '\014': /* Ctrl-L -- redraw */
 339                         show_minefield (NORMAL);
 340                         break;
 341                 case '\\':
 342                         if (is_newgame) {
 343                                 is_newgame = 0;
 344                                 fill_minefield (-1, -1);
 345                                 f.t = time(NULL);
 346                                 setitimer (ITIMER_REAL, &tbuf, NULL);
 347                         }
 348                         show_minefield (cheatmode?NORMAL:SHOWMINES);
 349                         cheatmode = !cheatmode;
 350                         break;
 351                 }
 352         }
 353
 354 win:
 355 lose:
 356         /* stop timer: */
 357         tbuf.it_value.tv_sec  = 0;
 358         tbuf.it_value.tv_usec = 0;
 359         if ( setitimer(ITIMER_REAL, &tbuf, NULL) == -1 ) {
 360                 perror("setitimer");
 361                 exit(1);
 362         }
 363         show_minefield (SHOWMINES);
 364         int gotaction;
 365         do {
 366                 unsigned char mouse[3];
 367                 gotaction = getch(mouse);
 368                 /* :D clicked: TODO: won't work in single-width mode! */
 369                 if (gotaction==CTRSEQ_MOUSE_LEFT && mouse[2]==LINE_OFFSET-1 &&
 370                    (mouse[1]==f.w+COL_OFFSET || mouse[1]==f.w+COL_OFFSET+1)) {
 371                         free_field ();
 372                         goto newgame;
 373                 } else if (gotaction == 'q') {
 374                         goto quit;
 375                 }
 376         } while (1);
 377
 378 quit:
 379         return 0;
 380 }
 381
 382 void quit () {
 383         move(f.h+LINE_OFFSET+2, 0);
 384         /* disable mouse, show cursor */
 385         printf ("\033[?9l\033[?25h");
 386         free_field ();
 387         restore_term_mode(saved_term_mode);
 388 }
 389
 390 /* I haven't won as long as a cell exists, that
 391     - I haven't opened, and
 392     - is not a mine */
 393 int everything_opened () {
 394         for (int row = 0; row < f.h; row++)
 395                 for (int col = 0; col < f.w; col++)
 396                         if (f.c[row][col].o == CLOSED &&
 397                                 f.c[row][col].m == NO_MINE  ) return 0;
 398         return 1;
 399 }
 400
 401 int wait_mouse_up (int l, int c) {
 402         unsigned char mouse2[3];
 403         int level = 1;
 404         int l2, c2;
 405
 406         /* show :o face */
 407         move (1, field2screen_c (f.w/2)-1); print (":o");
 408
 409         if (!(l < 0 || l >= f.h || c < 0 || c >= f.w)) {
 410                 /* show a pushed-in button if cursor is on minefield */
 411                 move (l+LINE_OFFSET, field2screen_c(c));
 412                 fputs (op.scheme->mouse_highlight, stdout);
 413         }
 414
 415         while (level > 0) {
 416                 if (getctrlseq (mouse2) == CTRSEQ_MOUSE) {
 417                         /* ignore mouse wheel events: */
 418                         if (mouse2[0] & 0x40) continue;
 419
 420                         else if (mouse2[0]&3 == 3) level--; /* release event */
 421                         else level++; /* another button pressed */
 422                 }
 423         }
 424
 425         move (1, field2screen_c (f.w/2)-1); print (":D");
 426         if (!(l < 0 || l >= f.h || c < 0 || c >= f.w)) {
 427                 partial_show_minefield (l, c, NORMAL);
 428         }
 429         c2 = screen2field_c(mouse2[1]);
 430         l2 = screen2field_l(mouse2[2]);
 431         return ((l2 == l) && (c2 == c));
 432 }
 433
 434 int choord_square (int line, int col) {
 435         for (int l = MAX(line-1, 0); l <= MIN(line+1, f.h-1); l++) {
 436                 for (int c = MAX(col-1, 0); c <= MIN(col+1, f.w-1); c++) {
 437                         if (f.c[l][c].f != FLAG) {
 438                                 if (uncover_square (l, c))
 439                                          return 1;
 440                         }
 441                 }
 442         }
 443
 444         return 0;
 445 }
 446
 447 int uncover_square (int l, int c) {
 448         f.c[l][c].o = OPENED;
 449         partial_show_minefield (l, c, NORMAL);
 450
 451         if (f.c[l][c].m) {
 452                 f.c[l][c].m = DEATH_MINE;
 453                 return 1;
 454         }
 455
 456         /* check for chording */
 457         if (f.c[l][c].n == 0) {
 458                 for (int choord_l = -1; choord_l <= 1; choord_l++) {
 459                         for (int choord_c = -1; choord_c <= 1; choord_c++) {
 460                                 int newl = l + choord_l;
 461                                 int newc = c + choord_c;
 462                                 if (newl >= 0 && newl < f.h &&
 463                                     newc >= 0 && newc < f.w &&
 464                                     f.c[newl][newc].o == CLOSED &&
 465                                     uncover_square (newl, newc)) {
 466                                          return 1;
 467                                 }
 468                         }
 469                 }
 470         }
 471
 472         return 0;
 473 }
 474
 475 void flag_square (int l, int c) {
 476         /* cycles through flag/quesm/noflag (uses op.mode to detect which ones
 477         are allowed) */
 478         f.c[l][c].f = (f.c[l][c].f + 1) % (op.mode + 1);
 479         if (f.c[l][c].f==FLAG) f.f++;
 480         else f.f--;
 481         partial_show_minefield (l, c, NORMAL);
 482         move (1, op.scheme->cell_width);
 483         printf ("[%03d]", f.f);
 484 }
 485
 486 void fill_minefield (int l, int c) {
 487         srand (time(0));
 488         int mines_set = f.m;
 489         while (mines_set) {
 490                 int line = rand() % f.h;
 491                 int col = rand() % f.w;
 492
 493                 if (f.c[line][col].m) {
 494                 /* skip if field already has a mine */
 495                         continue;
 496                 } else if ((line == l) && (col == c)) {
 497                 /* don't put a mine on the already opened (first click) field */
 498                         continue;
 499                 } else {
 500                         mines_set--;
 501                         f.c[line][col].m = STD_MINE;
 502                 }
 503         }
 504
 505         /* precalculate neighbours */
 506         for (int l=0; l < f.h; l++)
 507                 for (int c=0; c < f.w; c++)
 508                         f.c[l][c].n = get_neighbours (l, c, NORMAL);
 509 }
 510
 511 void move (int line, int col) {
 512         printf ("\033[%d;%dH", line+1, col+1);
 513 }
 514
 515 void partial_show_minefield (int l, int c, int mode) {
 516         move (l+LINE_OFFSET, field2screen_c(c));
 517
 518         if      (f.c[l][c].f == FLAG      ) print (op.scheme->field_flagged);
 519         else if (f.c[l][c].f == QUESM     ) print (op.scheme->field_question);
 520         else if (f.c[l][c].o == CLOSED    ) print (op.scheme->field_closed);
 521         else if (f.c[l][c].m == STD_MINE ||
 522                  f.c[l][c].m == DEATH_MINE) print (op.scheme->mine_normal);
 523         else    /*.......................*/ print (op.scheme->number[f.c[l][c].n]);
 524 }
 525
 526 void show_minefield (int mode) {
 527         int dtime;
 528
 529         move (0,0);
 530
 531         if (f.t == 0) {
 532                 dtime = 0;
 533         } else {
 534                 dtime = difftime (time(NULL), f.t);
 535         }
 536
 537         /* first line */
 538         print (op.scheme->border_top_l);
 539         printm (f.w*op.scheme->cell_width,op.scheme->border_top_m);
 540         printf ("%s\r\n", op.scheme->border_top_r);
 541         /* second line */
 542         print (op.scheme->border_status_l);
 543         printf("[%03d]", f.f);
 544         printm (f.w*op.scheme->cell_width/2-6, " ");
 545         printf ("%s", mode==SHOWMINES?":C":":D");
 546         printm (f.w*op.scheme->cell_width/2-6, " ");
 547         printf ("[%03d]", dtime);
 548         print (op.scheme->border_status_r);
 549         print ("\r\n");
 550         /* third line */
 551         print (op.scheme->border_spacer_l);
 552         printm (f.w*op.scheme->cell_width,op.scheme->border_spacer_m);
 553         print (op.scheme->border_spacer_r);
 554         print ("\r\n");
 555         /* main body */
 556         for (int l = 0; l < f.h; l++) {
 557                 print (op.scheme->border_field_l);
 558                 for (int c = 0; c < f.w; c++) {
 559                         if (mode == SHOWMINES) {
 560                                 if      (f.c[l][c].f == FLAG &&
 561                                          f.c[l][c].m              ) print (op.scheme->field_flagged);
 562                                 else if (f.c[l][c].f == FLAG &&
 563                                          f.c[l][c].m == NO_MINE   ) print (op.scheme->mine_wrongf);
 564                                 else if (f.c[l][c].m == STD_MINE  ) print (op.scheme->mine_normal);
 565                                 else if (f.c[l][c].m == DEATH_MINE) print (op.scheme->mine_death);
 566                                 else if (f.c[l][c].o == CLOSED    ) print (op.scheme->field_closed);
 567                                 else    /*.......................*/ print (op.scheme->number[f.c[l][c].n]);
 568                         } else {
 569                                 if      (f.c[l][c].f == FLAG      ) print (op.scheme->field_flagged);
 570                                 else if (f.c[l][c].f == QUESM     ) print (op.scheme->field_question);
 571                                 else if (f.c[l][c].o == CLOSED    ) print (op.scheme->field_closed);
 572                                 else if (f.c[l][c].m == STD_MINE  ) print (op.scheme->mine_normal);
 573                                 else if (f.c[l][c].m == DEATH_MINE) print (op.scheme->mine_death);
 574                                 else    /*.......................*/ print (op.scheme->number[f.c[l][c].n]);
 575                         }
 576                 }
 577                 print (op.scheme->border_field_r); print ("\r\n");
 578         }
 579         /* last line */
 580         print (op.scheme->border_bottom_l);
 581         printm (f.w*op.scheme->cell_width,op.scheme->border_bottom_m);
 582         print (op.scheme->border_bottom_r);
 583         print ("\r\n");
 584 }
 585
 586 int get_neighbours (int line, int col, int reduced_mode) {
 587         /* counts mines surrounding a square
 588            modes: 0=normal; 1=reduced */
 589
 590         int count = 0;
 591
 592         for (int l = MAX(line-1, 0); l <= MIN(line+1, f.h-1); l++) {
 593                 for (int c = MAX(col-1, 0); c <= MIN(col+1, f.w-1); c++) {
 594                         if (!l && !c) continue;
 595
 596                         count += !!f.c[l][c].m;
 597                         count -= reduced_mode * f.c[l][c].f==FLAG;
 598                 }
 599         }
 600         return count;
 601 }
 602
 603 struct minecell** alloc_array (int lines, int cols) {
 604         struct minecell** a = malloc (lines * sizeof(struct minecell*));
 605         if (a == NULL) return NULL;
 606         for (int l = 0; l < lines; l++) {
 607                 a[l] = calloc (cols, sizeof(struct minecell));
 608                 if (a[l] == NULL) goto unalloc;
 609         }
 610
 611         return a;
 612 unalloc:
 613         for (int l = 0; l < lines; l++)
 614                 free (a[l]);
 615         return NULL;
 616 }
 617
 618 void free_field () {
 619         for (int l = 0; l < f.h; l++) {
 620                 free (f.c[l]);
 621         }
 622         free (f.c);
 623 }
 624
 625 int screen2field_l (int l) {
 626         return (l-LINE_OFFSET) - 1;
 627 }
 628 /* some trickery is required to extract the mouse position from the cell width,
 629 depending on wheather we are using full width characters or double line width.
 630 WARN: tested only with scheme.cell_width = 1 and scheme.cell_width = 2. */
 631 int screen2field_c (int c) {
 632         return (c-COL_OFFSET+1 - 2*(op.scheme->cell_width%2))/2 - op.scheme->cell_width/2;
 633 }
 634 int field2screen_l (int l) {
 635         return 0; //TODO: is never used, therefore not implemented
 636 }
 637 int field2screen_c (int c) {
 638         return (op.scheme->cell_width*c+COL_OFFSET - (op.scheme->cell_width%2));
 639 }
 640
 641 enum esc_states {
 642         START,
 643         ESC_SENT,
 644         CSI_SENT,
 645         MOUSE_EVENT,
 646 };
 647 int getctrlseq (unsigned char* buf) {
 648         int c;
 649         int state = START;
 650         int offset = 0x20; /* never sends control chars as data */
 651         while ((c = getchar()) != EOF) {
 652                 switch (state) {
 653                 case START:
 654                         switch (c) {
 655                         case '\033': state=ESC_SENT; break;
 656                         default: return c;
 657                         }
 658                         break;
 659                 case ESC_SENT:
 660                         switch (c) {
 661                         case '[': state=CSI_SENT; break;
 662                         default: return CTRSEQ_INVALID;
 663                         }
 664                         break;
 665                 case CSI_SENT:
 666                         switch (c) {
 667                         case 'M': state=MOUSE_EVENT; break;
 668                         default: return CTRSEQ_INVALID;
 669                         }
 670                         break;
 671                 case MOUSE_EVENT:
 672                         buf[0] = c - offset;
 673                         buf[1] = getchar() - offset;
 674                         buf[2] = getchar() - offset;
 675                         return CTRSEQ_MOUSE;
 676                 default:
 677                         return CTRSEQ_INVALID;
 678                 }
 679         }
 680         return 2;
 681 }
 682
 683 int getch(unsigned char* buf) {
 684 /* returns a character, EOF, or constant for an escape/control sequence - NOT
 685 compatible with the ncurses implementation of same name */
 686         int action = getctrlseq(buf);
 687         int l, c;
 688         switch (action) {
 689         case CTRSEQ_MOUSE:
 690                 l = screen2field_l (buf[2]);
 691                 c = screen2field_c (buf[1]);
 692
 693                 if (buf[0] > 3) break; /* ignore all but left/middle/right/up */
 694                 int success = wait_mouse_up(l, c);
 695
 696                 /* mouse moved while pressed: */
 697                 if (!success) return CTRSEQ_INVALID;
 698
 699                 switch (buf[0]) {
 700                 case 0: return CTRSEQ_MOUSE_LEFT;
 701                 case 1: return CTRSEQ_MOUSE_MIDDLE;
 702                 case 2: return CTRSEQ_MOUSE_RIGHT;
 703                 }
 704         }
 705
 706         return action;
 707 }