Allow e.p. capture on triple-Push
[xboard.git] / backend.c
index fe70fd2..2c7933e 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -848,7 +848,7 @@ InitEngine (ChessProgramState *cps, int n)
     if(cps->tidy == NULL) cps->tidy = (char*) malloc(MSG_SIZ);
     TidyProgramName(cps->program, cps->host, cps->tidy);
     cps->matchWins = 0;
-    ASSIGN(cps->variants, appData.variant);
+    ASSIGN(cps->variants, appData.noChessProgram ? "" : appData.variant);
     cps->analysisSupport = 2; /* detect */
     cps->analyzing = FALSE;
     cps->initDone = FALSE;
@@ -1202,7 +1202,7 @@ InitBackEnd1 ()
        return;
 
       case VariantNormal:     /* definitely works! */
-       if(strcmp(appData.variant, "normal") && appData.chessProgram) { // [HGM] hope this is an engine-defined variant
+       if(strcmp(appData.variant, "normal") && !appData.noChessProgram) { // [HGM] hope this is an engine-defined variant
          safeStrCpy(engineVariant, appData.variant, MSG_SIZ);
          return;
        }
@@ -2108,14 +2108,14 @@ StringToVariant (char *e)
     int wnum = -1;
     VariantClass v = VariantNormal;
     int i, found = FALSE;
-    char buf[MSG_SIZ];
+    char buf[MSG_SIZ], c;
     int len;
 
     if (!e) return v;
 
     /* [HGM] skip over optional board-size prefixes */
-    if( sscanf(e, "%dx%d_", &i, &i) == 2 ||
-        sscanf(e, "%dx%d+%d_", &i, &i, &i) == 3 ) {
+    if( sscanf(e, "%dx%d_%c", &i, &i, &c) == 3 ||
+        sscanf(e, "%dx%d+%d_%c", &i, &i, &i, &c) == 4 ) {
         while( *e++ != '_');
     }
 
@@ -2125,7 +2125,7 @@ StringToVariant (char *e)
     } else
     for (i=0; i<sizeof(variantNames)/sizeof(char*); i++) {
       if (p = StrCaseStr(e, variantNames[i])) {
-       if(p && i >= VariantShogi && isalpha(p[strlen(variantNames[i])])) continue;
+       if(p && i >= VariantShogi && (p != e || isalpha(p[strlen(variantNames[i])]))) continue;
        v = (VariantClass) i;
        found = TRUE;
        break;
@@ -6551,7 +6551,7 @@ HasPromotionChoice (int fromX, int fromY, int toX, int toY, char *promoChoice, i
         int p = piece >= BlackPawn ? BLACK_TO_WHITE piece : piece;
         promotionZoneSize = BOARD_HEIGHT/3;
         highestPromotingPiece = (p >= WhiteLion || PieceToChar(piece + 22) == '.') ? WhitePawn : WhiteLion;
-    } else if(gameInfo.variant == VariantShogi || gameInfo.variant == VariantChuChess) {
+    } else if(gameInfo.variant == VariantShogi) {
         promotionZoneSize = BOARD_HEIGHT/3;
         highestPromotingPiece = (int)WhiteAlfil;
     } else if(gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess) {
@@ -8908,6 +8908,7 @@ FakeBookMove: // [HGM] book: we jump here to simulate machine moves after book h
       /* For variants we don't have   */       && gameInfo.variant != VariantBerolina
       /* correct rules for, we cannot */       && gameInfo.variant != VariantCylinder
       /* enforce legality on our own! */       && gameInfo.variant != VariantUnknown
+                                               && gameInfo.variant != VariantGreat
                                                && gameInfo.variant != VariantFairy    ) return;
       if(piece < EmptySquare) {
         pieceDefs = TRUE;
@@ -9888,7 +9889,7 @@ ParseGameHistory (char *game)
 void
 ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
 {
-  ChessSquare captured = board[toY][toX], piece, king; int p, oldEP = EP_NONE, berolina = 0;
+  ChessSquare captured = board[toY][toX], piece, king; int p, rookX, oldEP = EP_NONE, berolina = 0;
   int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
 
     /* [HGM] compute & store e.p. status and castling rights for new position */
@@ -9931,8 +9932,8 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
       if( board[fromY][fromX] == WhitePawn ) {
            if(fromY != toY) // [HGM] Xiangqi sideway Pawn moves should not count as 50-move breakers
               board[EP_STATUS] = EP_PAWN_MOVE;
-           if( toY-fromY==2) {
-               board[EP_FILE] = (fromX + toX)/2; board[EP_RANK] = (fromY + toY)/2;
+           if( toY-fromY>=2) {
+               board[EP_FILE] = (fromX + toX)/2; board[EP_RANK] = toY - 1 | 128*(toY - fromY > 2);
                if(toX>BOARD_LEFT   && board[toY][toX-1] == BlackPawn &&
                        gameInfo.variant != VariantBerolina || toX < fromX)
                      board[EP_STATUS] = toX | berolina;
@@ -9944,8 +9945,8 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
       if( board[fromY][fromX] == BlackPawn ) {
            if(fromY != toY) // [HGM] Xiangqi sideway Pawn moves should not count as 50-move breakers
               board[EP_STATUS] = EP_PAWN_MOVE;
-           if( toY-fromY== -2) {
-               board[EP_FILE] = (fromX + toX)/2; board[EP_RANK] = (fromY + toY)/2;
+           if( toY-fromY<= -2) {
+               board[EP_FILE] = (fromX + toX)/2; board[EP_RANK] = toY + 1 | 128*(fromY - toY > 2);
                if(toX>BOARD_LEFT   && board[toY][toX-1] == WhitePawn &&
                        gameInfo.variant != VariantBerolina || toX < fromX)
                      board[EP_STATUS] = toX | berolina;
@@ -10009,15 +10010,17 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
         && toY == fromY && toX > fromX+1) {
        board[fromY][fromX] = EmptySquare;
         board[toY][toX] = king;
-        board[toY][toX-1] = board[fromY][BOARD_RGHT-1];
-        board[fromY][BOARD_RGHT-1] = EmptySquare;
+       for(rookX=BOARD_RGHT-1; board[toY][rookX] == DarkSquare && rookX > toX + 1; rookX--);
+        board[toY][toX-1] = board[fromY][rookX];
+        board[fromY][rookX] = EmptySquare;
     } else if (board[fromY][fromX] == king
         && fromX != BOARD_LEFT && fromX != BOARD_RGHT-1 // [HGM] cylinder */
                && toY == fromY && toX < fromX-1) {
        board[fromY][fromX] = EmptySquare;
         board[toY][toX] = king;
-        board[toY][toX+1] = board[fromY][BOARD_LEFT];
-        board[fromY][BOARD_LEFT] = EmptySquare;
+       for(rookX=BOARD_LEFT; board[toY][rookX] == DarkSquare && rookX < toX - 1; rookX++);
+        board[toY][toX+1] = board[fromY][rookX];
+        board[fromY][rookX] = EmptySquare;
     } else if ((board[fromY][fromX] == WhitePawn && gameInfo.variant != VariantXiangqi ||
                 board[fromY][fromX] == WhiteLance && gameInfo.variant != VariantSuper && gameInfo.variant != VariantChu)
                && toY >= BOARD_HEIGHT-promoRank && promoChar // defaulting to Q is done elsewhere
@@ -10036,8 +10039,10 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
               && (board[toY][toX] == EmptySquare)) {
        board[fromY][fromX] = EmptySquare;
        board[toY][toX] = WhitePawn;
-       captured = board[toY - 1][toX];
-       board[toY - 1][toX] = EmptySquare;
+       if(toY == board[EP_RANK] - 128 + 1)
+           captured = board[toY - 2][toX], board[toY - 2][toX] = EmptySquare;
+       else
+           captured = board[toY - 1][toX], board[toY - 1][toX] = EmptySquare;
     } else if ((fromY == BOARD_HEIGHT-4)
               && (toX == fromX)
                && gameInfo.variant == VariantBerolina
@@ -10056,15 +10061,17 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
                && toY == fromY && toX > fromX+1) {
        board[fromY][fromX] = EmptySquare;
         board[toY][toX] = king;
-        board[toY][toX-1] = board[fromY][BOARD_RGHT-1];
-        board[fromY][BOARD_RGHT-1] = EmptySquare;
+       for(rookX=BOARD_RGHT-1; board[toY][rookX] == DarkSquare && rookX > toX + 1; rookX--);
+        board[toY][toX-1] = board[fromY][rookX];
+        board[fromY][rookX] = EmptySquare;
     } else if (board[fromY][fromX] == king
         && fromX != BOARD_LEFT && fromX != BOARD_RGHT-1 // [HGM] cylinder */
                && toY == fromY && toX < fromX-1) {
        board[fromY][fromX] = EmptySquare;
         board[toY][toX] = king;
-        board[toY][toX+1] = board[fromY][BOARD_LEFT];
-        board[fromY][BOARD_LEFT] = EmptySquare;
+       for(rookX=BOARD_LEFT; board[toY][rookX] == DarkSquare && rookX < toX - 1; rookX++);
+        board[toY][toX+1] = board[fromY][rookX];
+        board[fromY][rookX] = EmptySquare;
     } else if (fromY == 7 && fromX == 3
               && board[fromY][fromX] == BlackKing
               && toY == 7 && toX == 5) {
@@ -10097,8 +10104,10 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
               && (board[toY][toX] == EmptySquare)) {
        board[fromY][fromX] = EmptySquare;
        board[toY][toX] = BlackPawn;
-       captured = board[toY + 1][toX];
-       board[toY + 1][toX] = EmptySquare;
+       if(toY == board[EP_RANK] - 128 - 1)
+           captured = board[toY + 2][toX], board[toY + 2][toX] = EmptySquare;
+       else
+           captured = board[toY + 1][toX], board[toY + 1][toX] = EmptySquare;
     } else if ((fromY == 3)
               && (toX == fromX)
                && gameInfo.variant == VariantBerolina
@@ -12857,7 +12866,7 @@ LoadGame (FILE *f, int gameNumber, char *title, int useList)
        if (!err) numPGNTags++;
 
         /* [HGM] PGNvariant: automatically switch to variant given in PGN tag */
-        if(gameInfo.variant != oldVariant) {
+        if(gameInfo.variant != oldVariant && (gameInfo.variant != VariantNormal || gameInfo.variantName == NULL || *gameInfo.variantName == NULLCHAR)) {
             startedFromPositionFile = FALSE; /* [HGM] loadPos: variant switch likely makes position invalid */
            ResetFrontEnd(); // [HGM] might need other bitmaps. Cannot use Reset() because it clears gameInfo :-(
            InitPosition(TRUE);
@@ -12876,6 +12885,8 @@ LoadGame (FILE *f, int gameNumber, char *title, int useList)
            return FALSE;
          }
          CopyBoard(boards[0], initial_position);
+         if(*engineVariant) // [HGM] for now, assume FEN in engine-defined variant game is default initial position
+           CopyBoard(initialPosition, initial_position);
          if (blackPlaysFirst) {
            currentMove = forwardMostMove = backwardMostMove = 1;
            CopyBoard(boards[1], initial_position);
@@ -17870,7 +17881,7 @@ PositionToFEN (int move, char *overrideCastling, int moveCounts)
             q = (boards[move][CASTLING][1] == BOARD_LEFT &&
                  boards[move][CASTLING][2] != NoRights  );
             if(handW) { // for S-Chess with pieces in hand, list virgin pieces between K and Q
-                for(i=BOARD_RGHT-1-k; i>=BOARD_LEFT+q && j; i--)
+                for(i=BOARD_RGHT-1-k; i>=BOARD_LEFT+q; i--)
                     if((boards[move][0][i] != WhiteKing || k+q == 0) &&
                         boards[move][VIRGIN][i] & VIRGIN_W) *p++ = i + AAA + 'A' - 'a';
             }
@@ -17881,7 +17892,7 @@ PositionToFEN (int move, char *overrideCastling, int moveCounts)
             q = (boards[move][CASTLING][4] == BOARD_LEFT &&
                  boards[move][CASTLING][5] != NoRights  );
             if(handB) {
-                for(i=BOARD_RGHT-1-k; i>=BOARD_LEFT+q && j; i--)
+                for(i=BOARD_RGHT-1-k; i>=BOARD_LEFT+q; i--)
                     if((boards[move][BOARD_HEIGHT-1][i] != BlackKing || k+q == 0) &&
                         boards[move][VIRGIN][i] & VIRGIN_B) *p++ = i + AAA;
             }