gomoku/makemove.c

   1 /*      $NetBSD: makemove.c,v 1.5 1999/09/08 21:17:49 jsm Exp $ */
   2
   3 /*
   4  * Copyright (c) 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Ralph Campbell.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #include <sys/cdefs.h>
  40 #ifndef lint
  41 #if 0
  42 static char sccsid[] = "@(#)makemove.c  8.2 (Berkeley) 5/3/95";
  43 #else
  44 __RCSID("$NetBSD: makemove.c,v 1.5 1999/09/08 21:17:49 jsm Exp $");
  45 #endif
  46 #endif /* not lint */
  47
  48 #include "gomoku.h"
  49
  50                 /* direction deltas */
  51 const int     dd[4] = {
  52         MRIGHT, MRIGHT+MDOWN, MDOWN, MDOWN+MLEFT
  53 };
  54
  55 const int       weight[5] = { 0, 1, 7, 22, 100 };
  56
  57 /*
  58  * Return values:
  59  *      MOVEOK  everything is OK.
  60  *      RESIGN  Player resigned.
  61  *      ILLEGAL Illegal move.
  62  *      WIN     The the winning move was just played.
  63  *      TIE     The game is a tie.
  64  */
  65 int
  66 makemove(us, mv)
  67         int us, mv;
  68 {
  69         struct spotstr *sp, *fsp;
  70         union comboval *cp;
  71         struct spotstr *osp;
  72         struct combostr *cbp, *cbp1;
  73         union comboval *cp1;
  74         int i, f, r, d, n;
  75         int space, val, bmask;
  76
  77         /* check for end of game */
  78         if (mv == RESIGN)
  79                 return(RESIGN);
  80
  81         /* check for illegal move */
  82         sp = &board[mv];
  83         if (sp->s_occ != EMPTY)
  84                 return(ILLEGAL);
  85
  86         /* make move */
  87         sp->s_occ = us;
  88         movelog[movenum - 1] = mv;
  89         if (++movenum == BSZ * BSZ)
  90                 return(TIE);
  91
  92         /* compute new frame values */
  93         sp->s_wval = 0;
  94         osp = sp;
  95         for (r = 4; --r >= 0; ) {                       /* for each direction */
  96             d = dd[r];
  97             fsp = osp;
  98             bmask = BFLAG << r;
  99             for (f = 5; --f >= 0; fsp -= d) {           /* for each frame */
 100                 if (fsp->s_occ == BORDER)
 101                     goto nextr;
 102                 if (fsp->s_flg & bmask)
 103                     continue;
 104
 105                 /* remove this frame from the sorted list of frames */
 106                 cbp = fsp->s_frame[r];
 107                 if (cbp->c_next) {
 108                         if (sortframes[BLACK] == cbp)
 109                             sortframes[BLACK] = cbp->c_next;
 110                         if (sortframes[WHITE] == cbp)
 111                             sortframes[WHITE] = cbp->c_next;
 112                         cbp->c_next->c_prev = cbp->c_prev;
 113                         cbp->c_prev->c_next = cbp->c_next;
 114                 }
 115
 116                 /* compute old weight value for this frame */
 117                 cp = &fsp->s_fval[BLACK][r];
 118                 if (cp->s <= 0x500)
 119                     val = weight[5 - cp->c.a - cp->c.b];
 120                 else
 121                     val = 0;
 122                 cp = &fsp->s_fval[WHITE][r];
 123                 if (cp->s <= 0x500)
 124                     val += weight[5 - cp->c.a - cp->c.b];
 125
 126                 /* compute new combo value for this frame */
 127                 sp = fsp;
 128                 space = sp->s_occ == EMPTY;
 129                 n = 0;
 130                 for (i = 5; --i >= 0; sp += d) {        /* for each spot */
 131                     if (sp->s_occ == us)
 132                         n++;
 133                     else if (sp->s_occ == EMPTY)
 134                         sp->s_wval -= val;
 135                     else {
 136                         /* this frame is now blocked, adjust values */
 137                         fsp->s_flg |= bmask;
 138                         fsp->s_fval[BLACK][r].s = MAXCOMBO;
 139                         fsp->s_fval[WHITE][r].s = MAXCOMBO;
 140                         while (--i >= 0) {
 141                             sp += d;
 142                             if (sp->s_occ == EMPTY)
 143                                 sp->s_wval -= val;
 144                         }
 145                         goto nextf;
 146                     }
 147                 }
 148
 149                 /* check for game over */
 150                 if (n == 5)
 151                     return(WIN);
 152
 153                 /* compute new value & combo number for this frame & color */
 154                 fsp->s_fval[!us][r].s = MAXCOMBO;
 155                 cp = &fsp->s_fval[us][r];
 156                 /* both ends open? */
 157                 if (space && sp->s_occ == EMPTY) {
 158                     cp->c.a = 4 - n;
 159                     cp->c.b = 1;
 160                 } else {
 161                     cp->c.a = 5 - n;
 162                     cp->c.b = 0;
 163                 }
 164                 val = weight[n];
 165                 sp = fsp;
 166                 for (i = 5; --i >= 0; sp += d)          /* for each spot */
 167                     if (sp->s_occ == EMPTY)
 168                         sp->s_wval += val;
 169
 170                 /* add this frame to the sorted list of frames by combo value */
 171                 cbp1 = sortframes[us];
 172                 if (!cbp1)
 173                     sortframes[us] = cbp->c_next = cbp->c_prev = cbp;
 174                 else {
 175                     cp1 = &board[cbp1->c_vertex].s_fval[us][cbp1->c_dir];
 176                     if (cp->s <= cp1->s) {
 177                         /* insert at the head of the list */
 178                         sortframes[us] = cbp;
 179                     } else {
 180                         do {
 181                             cbp1 = cbp1->c_next;
 182                             cp1 = &board[cbp1->c_vertex].s_fval[us][cbp1->c_dir];
 183                             if (cp->s <= cp1->s)
 184                                 break;
 185                         } while (cbp1 != sortframes[us]);
 186                     }
 187                     cbp->c_next = cbp1;
 188                     cbp->c_prev = cbp1->c_prev;
 189                     cbp1->c_prev->c_next = cbp;
 190                     cbp1->c_prev = cbp;
 191                 }
 192
 193             nextf:
 194                 ;
 195             }
 196
 197             /* both ends open? */
 198             if (fsp->s_occ == EMPTY) {
 199                 cp = &fsp->s_fval[BLACK][r];
 200                 if (cp->c.b) {
 201                     cp->c.a += 1;
 202                     cp->c.b = 0;
 203                 }
 204                 cp = &fsp->s_fval[WHITE][r];
 205                 if (cp->c.b) {
 206                     cp->c.a += 1;
 207                     cp->c.b = 0;
 208                 }
 209             }
 210
 211         nextr:
 212             ;
 213         }
 214
 215         update_overlap(osp);
 216
 217         return(MOVEOK);
 218 }
 219
 220 /*
 221  * fix up the overlap array due to updating spot osp.
 222  */
 223 void
 224 update_overlap(osp)
 225         struct spotstr *osp;
 226 {
 227         struct spotstr *sp, *sp1, *sp2;
 228         int i, f, r, r1, d, d1, n;
 229         int a, b, bmask, bmask1;
 230         struct spotstr *esp;
 231         char *str;
 232
 233         esp = NULL;
 234         for (r = 4; --r >= 0; ) {                       /* for each direction */
 235             d = dd[r];
 236             sp1 = osp;
 237             bmask = BFLAG << r;
 238             for (f = 0; f < 6; f++, sp1 -= d) {         /* for each frame */
 239                 if (sp1->s_occ == BORDER)
 240                     break;
 241                 if (sp1->s_flg & bmask)
 242                     continue;
 243                 /*
 244                  * Update all other frames that intersect the current one
 245                  * to indicate whether they still overlap or not.
 246                  * Since F1 overlap F2 == F2 overlap F1, we only need to
 247                  * do the rows 0 <= r1 <= r. The r1 == r case is special
 248                  * since the two frames can overlap at more than one point.
 249                  */
 250                 str = &overlap[(a = sp1->s_frame[r] - frames) * FAREA];
 251                 sp2 = sp1 - d;
 252                 for (i = f + 1; i < 6; i++, sp2 -= d) {
 253                     if (sp2->s_occ == BORDER)
 254                         break;
 255                     if (sp2->s_flg & bmask)
 256                         continue;
 257                     /*
 258                      * count the number of empty spots to see if there is
 259                      * still an overlap.
 260                      */
 261                     n = 0;
 262                     sp = sp1;
 263                     for (b = i - f; b < 5; b++, sp += d) {
 264                         if (sp->s_occ == EMPTY) {
 265                             esp = sp;   /* save the intersection point */
 266                             n++;
 267                         }
 268                     }
 269                     b = sp2->s_frame[r] - frames;
 270                     if (n == 0) {
 271                         if (sp->s_occ == EMPTY) {
 272                             str[b] &= 0xA;
 273                             overlap[b * FAREA + a] &= 0xC;
 274                             intersect[a * FAREA + b] = n = sp - board;
 275                             intersect[b * FAREA + a] = n;
 276                         } else {
 277                             str[b] = 0;
 278                             overlap[b * FAREA + a] = 0;
 279                         }
 280                     } else if (n == 1) {
 281                         if (sp->s_occ == EMPTY) {
 282                             str[b] &= 0xAF;
 283                             overlap[b * FAREA + a] &= 0xCF;
 284                         } else {
 285                             str[b] &= 0xF;
 286                             overlap[b * FAREA + a] &= 0xF;
 287                         }
 288                         intersect[a * FAREA + b] = n = esp - board;
 289                         intersect[b * FAREA + a] = n;
 290                     }
 291                     /* else no change, still multiple overlap */
 292                 }
 293
 294                 /* the other directions can only intersect at spot osp */
 295                 for (r1 = r; --r1 >= 0; ) {
 296                     d1 = dd[r1];
 297                     bmask1 = BFLAG << r1;
 298                     sp = osp;
 299                     for (i = 6; --i >= 0; sp -= d1) {   /* for each spot */
 300                         if (sp->s_occ == BORDER)
 301                             break;
 302                         if (sp->s_flg & bmask1)
 303                             continue;
 304                         b = sp->s_frame[r1] - frames;
 305                         str[b] = 0;
 306                         overlap[b * FAREA + a] = 0;
 307                     }
 308                 }
 309             }
 310         }
 311 }