Keep track of number of remaining checks

Another off-board square is now allocated forkeeping track of the number
of remaining checks each side can suffer before losing. When this double
counter is 0, counting is disabled. Otherwise each check will decrease
the count of the checked side, and when it reaches 0 the check will be
treated as a checkmate. In variant 3check the counters will be initialized
to 3, otherwise to 0.

diff --git a/backend.c b/backend.c
index ff0608b..ef6f839 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -6451,6 +6451,7 @@ InitPosition (int redraw)
       initialPosition[1][1] = initialPosition[2][1] =
       initialPosition[6][BOARD_WIDTH-2] = initialPosition[5][BOARD_WIDTH-2] = 1;
      }
+     initialPosition[CHECK_COUNT] = (gameInfo.variant == Variant3Check ? 0x303 : 0);
   if (appData.debugMode) {
     fprintf(debugFP, "shuffleOpenings = %d\n", shuffleOpenings);
   }
@@ -10030,7 +10031,7 @@ void
 ParseGameHistory (char *game)
 {
     ChessMove moveType;
-    int fromX, fromY, toX, toY, boardIndex;
+    int fromX, fromY, toX, toY, boardIndex, mask;
     char promoChar;
     char *p, *q;
     char buf[MSG_SIZ];
@@ -10191,15 +10192,18 @@ ParseGameHistory (char *game)
        strcat(moveList[boardIndex], "\n");
        boardIndex++;
        ApplyMove(fromX, fromY, toX, toY, promoChar, boards[boardIndex]);
+       mask = (WhiteOnMove(boardIndex) ? 0xFF : 0xFF00);
         switch (MateTest(boards[boardIndex], PosFlags(boardIndex)) ) {
          case MT_NONE:
          case MT_STALEMATE:
          default:
            break;
          case MT_CHECK:
-            if(!IS_SHOGI(gameInfo.variant))
-                strcat(parseList[boardIndex - 1], "+");
-           break;
+            if(boards[boardIndex][CHECK_COUNT]) boards[boardIndex][CHECK_COUNT] -= mask & 0x101;
+            if(!boards[boardIndex][CHECK_COUNT] || boards[boardIndex][CHECK_COUNT] & mask) {
+                if(!IS_SHOGI(gameInfo.variant)) strcat(parseList[boardIndex - 1], "+");
+                break;
+           }
          case MT_CHECKMATE:
          case MT_STAINMATE:
            strcat(parseList[boardIndex - 1], "#");
@@ -10589,7 +10593,7 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
 void
 MakeMove (int fromX, int fromY, int toX, int toY, int promoChar)
 {
-    int x = toX, y = toY;
+    int x = toX, y = toY, mask;
     char *s = parseList[forwardMostMove];
     ChessSquare p = boards[forwardMostMove][toY][toX];
 //    forwardMostMove++; // [HGM] bare: moved downstream
@@ -10685,15 +10689,18 @@ MakeMove (int fromX, int fromY, int toX, int toY, int promoChar)
     }
     CoordsToComputerAlgebraic(fromY, fromX, toY, toX, promoChar,
                              moveList[forwardMostMove - 1]);
+    mask = (WhiteOnMove(forwardMostMove) ? 0xFF : 0xFF00);
     switch (MateTest(boards[forwardMostMove], PosFlags(forwardMostMove)) ) {
       case MT_NONE:
       case MT_STALEMATE:
       default:
        break;
       case MT_CHECK:
-        if(!IS_SHOGI(gameInfo.variant))
-            strcat(parseList[forwardMostMove - 1], "+");
-       break;
+        if(boards[forwardMostMove][CHECK_COUNT]) boards[forwardMostMove][CHECK_COUNT] -= mask & 0x101;
+       if(!boards[forwardMostMove][CHECK_COUNT] || boards[forwardMostMove][CHECK_COUNT] & mask) {
+            if(!IS_SHOGI(gameInfo.variant)) strcat(parseList[forwardMostMove - 1], "+");
+            break;
+        }
       case MT_CHECKMATE:
       case MT_STAINMATE:
        strcat(parseList[forwardMostMove - 1], "#");

diff --git a/common.h b/common.h
index 7e74e06..16942e5 100644 (file)
--- a/common.h
+++ b/common.h
@@ -181,6 +181,7 @@ typedef char *String;
 #define BOARD_RGHT   (gameInfo.boardWidth + gameInfo.holdingsWidth)
 #define CASTLING     (BOARD_RANKS-1)           /* [HGM] hide in upper rank   */
 #define VIRGIN       (BOARD_RANKS-2)           /* [HGM] pieces not moved     */
+#define CHECK_COUNT  CASTLING][(BOARD_FILES-8) /* [HGM] in upper rank        */
 #define LAST_TO      CASTLING][(BOARD_FILES-7) /* [HGM] in upper rank        */
 #define TOUCHED_W    CASTLING][(BOARD_FILES-6) /* [HGM] in upper rank        */
 #define TOUCHED_B    CASTLING][(BOARD_FILES-5) /* [HGM] in upper rank        */