Fix default of Chu Chess piece promotions

[xboard.git] / backend.c

diff --git a/backend.c b/backend.c
index a9abaa8..39ec535 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -5313,13 +5313,15 @@ void
 Sweep (int step)
 {
     ChessSquare king = WhiteKing, pawn = WhitePawn, last = promoSweep;
+    static int toggleFlag;
     if(gameInfo.variant == VariantKnightmate) king = WhiteUnicorn;
     if(gameInfo.variant == VariantSuicide || gameInfo.variant == VariantGiveaway) king = EmptySquare;
     if(promoSweep >= BlackPawn) king = WHITE_TO_BLACK king, pawn = WHITE_TO_BLACK pawn;
     if(gameInfo.variant == VariantSpartan && pawn == BlackPawn) pawn = BlackLance, king = EmptySquare;
     if(fromY != BOARD_HEIGHT-2 && fromY != 1) pawn = EmptySquare;
+    if(!step) toggleFlag = Partner(&last); // piece has shogi-promotion
     do {
-       if(step && !Partner(&promoSweep)) promoSweep -= step;
+       if(step && !(toggleFlag && Partner(&promoSweep))) promoSweep -= step;
        if(promoSweep == EmptySquare) promoSweep = BlackPawn; // wrap
        else if((int)promoSweep == -1) promoSweep = WhiteKing;
        else if(promoSweep == BlackPawn && step < 0) promoSweep = WhitePawn;
@@ -6457,7 +6459,7 @@ HasPromotionChoice (int fromX, int fromY, int toX, int toY, char *promoChoice, i
     /* [HGM] rewritten IsPromotion to only flag promotions that offer a choice */
     /* [HGM] add Shogi promotions */
     int promotionZoneSize=1, highestPromotingPiece = (int)WhitePawn;
-    ChessSquare piece;
+    ChessSquare piece, partner;
     ChessMove moveType;
     Boolean premove;
 
@@ -6542,8 +6544,9 @@ HasPromotionChoice (int fromX, int fromY, int toX, int toY, char *promoChoice, i
     }
     // give caller the default choice even if we will not make it
     *promoChoice = ToLower(PieceToChar(defaultPromoChoice));
-    if(IS_SHOGI(gameInfo.variant)) *promoChoice = (defaultPromoChoice == piece ? '=' : '+');
-    if(gameInfo.variant == VariantChuChess) *promoChoice = (piece == WhitePawn || piece == BlackPawn ? 'q' : '+');
+    partner = piece; // pieces can promote if the pieceToCharTable says so
+    if(IS_SHOGI(gameInfo.variant)) *promoChoice = (defaultPromoChoice == piece && sweepSelect ? '=' : '+'); // obsolete?
+    else if(Partner(&partner))     *promoChoice = (defaultPromoChoice == piece && sweepSelect ? NULLCHAR : '+');
     if(        sweepSelect && gameInfo.variant != VariantGreat
                           && gameInfo.variant != VariantGrand
                           && gameInfo.variant != VariantSuper) return FALSE;
@@ -6555,6 +6558,7 @@ HasPromotionChoice (int fromX, int fromY, int toX, int toY, char *promoChoice, i
     if(appData.testLegality && !premove) {
        moveType = LegalityTest(boards[currentMove], PosFlags(currentMove),
                        fromY, fromX, toY, toX, IS_SHOGI(gameInfo.variant) || gameInfo.variant == VariantChuChess ? '+' : NULLCHAR);
+        if(moveType == IllegalMove) *promoChoice = NULLCHAR; // could be the fact we promoted was illegal
        if(moveType != WhitePromotion && moveType  != BlackPromotion)
            return FALSE;
     }
@@ -7209,14 +7213,15 @@ ChessSquare gatingPiece = EmptySquare; // exported to front-end, for dragging
 int
 CanPromote (ChessSquare piece, int y)
 {
+        int zone = (gameInfo.variant == VariantChuChess ? 3 : 1);
        if(gameMode == EditPosition) return FALSE; // no promotions when editing position
        // some variants have fixed promotion piece, no promotion at all, or another selection mechanism
        if(IS_SHOGI(gameInfo.variant)          || gameInfo.variant == VariantXiangqi ||
           gameInfo.variant == VariantSuper    || gameInfo.variant == VariantGreat   ||
           gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
          gameInfo.variant == VariantMakruk   || gameInfo.variant == VariantASEAN) return FALSE;
-       return (piece == BlackPawn && y == 1 ||
-               piece == WhitePawn && y == BOARD_HEIGHT-2 ||
+       return (piece == BlackPawn && y <= zone ||
+               piece == WhitePawn && y >= BOARD_HEIGHT-1-zone ||
                piece == BlackLance && y == 1 ||
                piece == WhiteLance && y == BOARD_HEIGHT-2 );
 }
@@ -7487,8 +7492,11 @@ LeftClick (ClickType clickType, int xPix, int yPix)
        toY = y;
     }
 
+    piece = boards[currentMove][fromY][fromX];
+
     saveAnimate = appData.animate;
     if (clickType == Press) {
+       if(gameInfo.variant == VariantChuChess && piece != WhitePawn && piece != BlackPawn) defaultPromoChoice = piece;
        if(gameMode == EditPosition && boards[currentMove][fromY][fromX] == EmptySquare) {
            // must be Edit Position mode with empty-square selected
            fromX = x; fromY = y; DragPieceBegin(xPix, yPix, FALSE); dragging = 1; // consider this a new attempt to drag
@@ -7504,9 +7512,8 @@ LeftClick (ClickType clickType, int xPix, int yPix)
        if(marker[y][x] == 5) return; // [HGM] lion: to-click on cyan square; defer action to release
        if(legal[y][x] == 2 || HasPromotionChoice(fromX, fromY, toX, toY, &promoChoice, FALSE)) {
          if(appData.sweepSelect) {
-           ChessSquare piece = boards[currentMove][fromY][fromX];
            promoSweep = defaultPromoChoice;
-           if(PieceToChar(CHUPROMOTED piece) == '+') promoSweep = CHUPROMOTED piece;
+           if(gameInfo.variant != VariantChuChess && PieceToChar(CHUPROMOTED piece) == '+') promoSweep = CHUPROMOTED piece;
            selectFlag = 0; lastX = xPix; lastY = yPix;
            Sweep(0); // Pawn that is going to promote: preview promotion piece
            sweepSelecting = 1;
@@ -7522,7 +7529,7 @@ LeftClick (ClickType clickType, int xPix, int yPix)
            ClearHighlights();
        }
     } else if(sweepSelecting) { // this must be the up-click corresponding to the down-click that started the sweep
-       sweepSelecting = 0;
+       sweepSelecting = 0; appData.animate = FALSE; // do not animate, a selected piece already on to-square
        if (appData.animate || appData.highlightLastMove) {
            SetHighlights(fromX, fromY, toX, toY);
        } else {
@@ -7538,6 +7545,7 @@ LeftClick (ClickType clickType, int xPix, int yPix)
            ClearHighlights();
        }
 #endif
+       if(gameInfo.variant == VariantChuChess && piece != WhitePawn && piece != BlackPawn) defaultPromoChoice = piece;
        if(marker[y][x] == 5) { // [HGM] lion: this was the release of a to-click or drag on a cyan square
          dragging *= 2;            // flag button-less dragging if we are dragging
          MarkTargetSquares(1);
@@ -7604,7 +7612,7 @@ LeftClick (ClickType clickType, int xPix, int yPix)
            DisplayMessage("Click in holdings to choose piece", "");
            return;
        }
-       PromotionPopUp();
+       PromotionPopUp(promoChoice);
     } else {
        int oldMove = currentMove;
        UserMoveEvent(fromX, fromY, toX, toY, promoChoice);