Adjudicate Xiangqi material draws with Advisor-less Cannons

[xboard.git] / backend.c

diff --git a/backend.c b/backend.c
index f5f9f99..95563f0 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -6640,8 +6640,10 @@ Adjudicate(ChessProgramState *cps)
                         case BlackRook:
                              NrBR++; break;
                         case WhiteQueen:
+                        case WhiteCannon:
                              NrWQ++; break;
                         case BlackQueen:
+                        case BlackCannon:
                              NrBQ++; break;
                         case EmptySquare: 
                              break;
@@ -6763,7 +6765,10 @@ Adjudicate(ChessProgramState *cps)
                 if( NrPieces == 2 || gameInfo.variant != VariantXiangqi && 
                                     gameInfo.variant != VariantShatranj && // [HGM] baring will remain possible
                        (NrPieces == 3 && NrWN+NrBN+NrWB+NrBB == 1 ||
-                        NrPieces == NrBB+NrWB+2 && bishopsColor != 3)) // [HGM] all Bishops (Ferz!) same color
+                        NrPieces == NrBB+NrWB+2 && bishopsColor != 3) // [HGM] all Bishops (Ferz!) same color
+                                 || gameInfo.variant == VariantXiangqi &&
+                       (NrPieces == 3 && (NrWQ==1 && NrWB==0 && NrBB<2 || NrBQ==1 && NrBB==0 && NrWB<2) ||
+                        NrPieces == 4 && NrWQ==1 && NrBQ==1 && NrWB==0 && NrBB==0))
                 {    /* KBK, KNK, KK of KBKB with like Bishops */
 
                      /* always flag draws, for judging claims */
@@ -6897,6 +6902,17 @@ Adjudicate(ChessProgramState *cps)
                 if( count == backwardMostMove )
                     count -= initialRulePlies;
                 count = forwardMostMove - count; 
+               if(gameInfo.variant == VariantXiangqi && ( count >= 100 || count >= 2*appData.ruleMoves ) ) {
+                       // adjust reversible move counter for checks in Xiangqi
+                       int i = forwardMostMove - count, inCheck = 0, lastCheck;
+                       if(i < backwardMostMove) i = backwardMostMove;
+                       while(i <= forwardMostMove) {
+                               lastCheck = inCheck; // check evasion does not count
+                               inCheck = (MateTest(boards[i], PosFlags(i)) == MT_CHECK);
+                               if(inCheck || lastCheck) count--; // check does not count
+                               i++;
+                       }
+               }
                 if( count >= 100)
                          boards[forwardMostMove][EP_STATUS] = EP_RULE_DRAW;
                          /* this is used to judge if draw claims are legal */
@@ -8581,7 +8597,7 @@ MakeMove(fromX, fromY, toX, toY, promoChar)
         if( (boards[forwardMostMove][fromY][fromX] == WhitePawn ||
              boards[forwardMostMove][fromY][fromX] == BlackPawn   ) &&
              boards[forwardMostMove][toY][toX] == EmptySquare
-             && fromX != toX )
+             && fromX != toX && fromY != toY)
                 fprintf(serverMoves, ":%c%c:%c%c", AAA+fromX, ONE+fromY, AAA+toX, ONE+fromY);
         // promotion suffix
         if(promoChar != NULLCHAR)