Allow two Pawns per file in Tori Shogi

When the board has 7 ranks it is assumed to be Tori Shogi, and the
requirement for maximally one Pawn per file is relaxed to two.

diff --git a/moves.c b/moves.c
index 2e772e1..f780f85 100644 (file)
--- a/moves.c
+++ b/moves.c
@@ -1530,9 +1530,9 @@ if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt
             piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
             piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
         if(piece == WhitePawn || piece == BlackPawn) {
-            int r;
+            int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
             for(r=1; r<BOARD_HEIGHT-1; r++)
-                if(board[r][ft] == piece) return IllegalMove; // or there already is a Pawn in file
+                if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
             // should still test if we mate with this Pawn
         }
     } else if(gameInfo.variant == VariantSChess) { // only back-rank drops