Allow setting up position from scratch

The position string in Bonanza's native 'new' command can now have a new
format, starting with 'SU' in stead of 'PI', which adds the mentioned pieces
to an empty board, rather than deleting them from the standard initial
position. Holdings pieces are encoded by '00' for square coordinates.
A '+' or '-' embedded in the string can be used to switch between Sente
and Gote. (By default it assumes Sente, so all Gote pieces could be mentioned
at the end after a single '-'.)

diff --git a/csa.c b/csa.c
index cbf1bf6..f1f0479 100644 (file)
--- a/csa.c
+++ b/csa.c
@@ -462,7 +462,13 @@ read_board_rep1( const char *str_line, min_posi_t *pmin_posi )
   char str_piece[3];
   int piece, ifile, irank, isquare;
   signed char board[nsquare];
+  int add = 0, color = -1;
 
+  if( *str_line == 'S' ) { // [HGM] setup: allow 'SU' representation that adds pieces in stead of removing them
+    add = 1;
+    for ( isquare = 0; isquare < nsquare; isquare++ ) board[isquare] = empty;
+    pmin_posi->hand_white = pmin_posi->hand_black = 0;
+  } else
   memcpy( board, &min_posi_no_handicap.asquare, nsquare );
 
   for ( p = str_line + 2; p[0] != '\0'; p += 4 )
@@ -472,6 +478,18 @@ read_board_rep1( const char *str_line, min_posi_t *pmin_posi )
          str_error = str_bad_board;
          return -2;
        }
+      if( add && p[0] == '+' ) // [HGM] setup: change color
+       {
+         color = 1;
+         p -= 3;
+         continue;
+       }
+      if( add && p[0] == '-' )
+       {
+         color = -1;
+         p -= 3;
+         continue;
+       }
       str_piece[0] = p[2];
       str_piece[1] = p[3];
       str_piece[2] = '\0';
@@ -481,12 +499,24 @@ read_board_rep1( const char *str_line, min_posi_t *pmin_posi )
       ifile        = 9 - ifile;
       irank        = irank - 1;
       isquare      = irank * nfile + ifile;
+      if ( add && piece != -2 && p[0] == '0' && p[1] == '0' )
+       { // [HGM] setup: holdings
+           static int unit[] = {0, 1, 1<<5, 1<<8, 1<<11, 1<<14, 1<<17, 1<<19};
+           if(piece < 1 || piece > 7) { // only unpromoted in hand!
+               str_error = str_bad_board;
+               return -2;
+           }
+           if(color > 0) pmin_posi->hand_black += unit[piece];
+           else          pmin_posi->hand_white += unit[piece];
+           continue;
+       }
       if ( piece == -2 || ifile < file1 || ifile > file9 || irank < rank1
-          || irank > rank9 || abs(board[isquare]) != piece )
+          || irank > rank9 || abs(board[isquare]) != (add ? empty : piece) )
        {
          str_error = str_bad_board;
          return -2;
        }
+      if( add ) board[isquare] = piece*color; else
       board[isquare] = empty;
     }