move.c

   1 #include <ctype.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5
   6 #include "board.h"
   7 #include "move.h"
   8
   9
  10 /* The S_OFFBOARD margin is not addressable by coordinates. */
  11
  12 static char asdf[] = "abcdefghjklmnopqrstuvwxyz";
  13
  14 char *
  15 coord2str(coord_t c, struct board *board)
  16 {
  17         return strdup(coord2sstr(c, board));
  18 }
  19
  20 char *
  21 coord2sstr(coord_t c, struct board *board)
  22 {
  23         static char *b;
  24         static char bl[10][4];
  25         static int bi;
  26         if (is_pass(c)) {
  27                 return "pass";
  28         } else if (is_resign(c)) {
  29                 return "resign";
  30         } else {
  31                 /* Some GTP servers are broken and won't grok lowercase coords */
  32                 b = bl[bi]; bi = (bi + 1) % 10;
  33                 snprintf(b, 4, "%c%d", toupper(asdf[coord_x(c, board) - 1]), coord_y(c, board));
  34                 return b;
  35         }
  36 }
  37
  38 /* No sanity checking */
  39 coord_t *
  40 str2coord(char *str, int size)
  41 {
  42         if (!strcasecmp(str, "pass")) {
  43                 return coord_pass();
  44         } else if (!strcasecmp(str, "resign")) {
  45                 return coord_resign();
  46         } else {
  47                 char xc = tolower(str[0]);
  48                 return coord_init(xc - 'a' - (xc > 'i') + 1, atoi(str + 1), size);
  49         }
  50 }
  51
  52
  53 int
  54 coord_edge_distance(coord_t c, struct board *b)
  55 {
  56         int x = coord_x(c, b), y = coord_y(c, b);
  57         int dx = x > board_size(b) / 2 ? board_size(b) - x : x;
  58         int dy = y > board_size(b) / 2 ? board_size(b) - y : y;
  59         return (dx < dy ? dx : dy) - 1 /* S_OFFBOARD */;
  60 }