Fix Alice chess
[vchess.git] / public / javascripts / variants / Alice.js
index a15c30c..b7f5a3e 100644 (file)
@@ -1,3 +1,4 @@
+// NOTE: alternative implementation, probably cleaner = use only 1 board
 class AliceRules extends ChessRules
 {
        static get ALICE_PIECES()
@@ -60,11 +61,10 @@ class AliceRules extends ChessRules
                }
        }
 
-       getBoardOfPiece([x,y])
+       // Build board of the given (mirror)side
+       getSideBoard(mirrorSide)
        {
                const V = VariantRules;
-               // Build board where the piece is
-               const mirrorSide = (Object.keys(V.ALICE_CODES).includes(this.getPiece(x,y)) ? 1 : 2);
                // Build corresponding board from complete board
                const [sizeX,sizeY] = V.size;
                let sideBoard = doubleArray(sizeX, sizeY, "");
@@ -82,22 +82,21 @@ class AliceRules extends ChessRules
                return sideBoard;
        }
 
-       // TODO: move board building one level up (findAllMoves()) to avoid re-building at every piece...
        // NOTE: castle & enPassant https://www.chessvariants.com/other.dir/alice.html
-       // --> Should be OK as is.
-       getPotentialMovesFrom([x,y])
+       getPotentialMovesFrom([x,y], sideBoard)
        {
-               let sideBoard = this.getBoardOfPiece([x,y]);
+               const pieces = Object.keys(VariantRules.ALICE_CODES);
+               const codes = Object.keys(VariantRules.ALICE_PIECES);
+               const mirrorSide = (pieces.includes(this.getPiece(x,y)) ? 1 : 2);
 
                // Search valid moves on sideBoard
                let saveBoard = this.board;
-               this.board = sideBoard;
+               this.board = sideBoard || this.getSideBoard(mirrorSide);
                let moves = super.getPotentialMovesFrom([x,y]);
                this.board = saveBoard;
 
                // Finally filter impossible moves
-               const mirrorSide = (Object.keys(VariantRules.ALICE_CODES).includes(this.getPiece(x,y)) ? 1 : 2);
-               return moves.filter(m => {
+               let res = moves.filter(m => {
                        if (m.appear.length == 2) //castle
                        {
                                // If appear[i] not in vanish array, then must be empty square on other board
@@ -113,8 +112,8 @@ class AliceRules extends ChessRules
                        {
                                // Attempt to capture
                                const piece = this.getPiece(m.end.x,m.end.y);
-                               if ((mirrorSide==1 && Object.keys(VariantRules.ALICE_PIECES).includes(piece))
-                                       || (mirrorSide==2 && Object.keys(VariantRules.ALICE_CODES).includes(piece)))
+                               if ((mirrorSide==1 && codes.includes(piece))
+                                       || (mirrorSide==2 && pieces.includes(piece)))
                                {
                                        return false;
                                }
@@ -133,22 +132,100 @@ class AliceRules extends ChessRules
                                });
                        }
                        // Fix en-passant captures
-                       if (m.vanish.length == 2 && this.board[m.end.x][m.end.y] == VariantRules.EMPTY)
+                       if (m.vanish[0].p == VariantRules.PAWN
+                               && m.vanish.length == 2 && this.board[m.end.x][m.end.y] == VariantRules.EMPTY)
+                       {
                                m.vanish[1].c = this.getOppCol(this.getColor(x,y));
+                               // In the special case of en-passant, if
+                               //  - board1 takes board2 : vanish[1] --> Alice
+                               //  - board2 takes board1 : vanish[1] --> normal
+                               let van = m.vanish[1];
+                               if (mirrorSide==1 && codes.includes(this.getPiece(van.x,van.y)))
+                                       van.p = VariantRules.ALICE_CODES[van.p];
+                               else if (mirrorSide==2 && pieces.includes(this.getPiece(van.x,van.y)))
+                                       van.p = VariantRules.ALICE_PIECES[van.p];
+                       }
                        return true;
                });
+               return res;
        }
 
-       underCheck(move)
+       filterValid(moves)
+       {
+               if (moves.length == 0)
+                       return [];
+               let sideBoard = [this.getSideBoard(1), this.getSideBoard(2)];
+               return moves.filter(m => { return !this.underCheck(m, sideBoard); });
+       }
+
+       getAllValidMoves()
        {
                const color = this.turn;
-               this.play(move);
-               let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
+               const oppCol = this.getOppCol(color);
+               var potentialMoves = [];
+               let [sizeX,sizeY] = VariantRules.size;
+               let sideBoard = [this.getSideBoard(1), this.getSideBoard(2)];
+               for (var i=0; i<sizeX; i++)
+               {
+                       for (var j=0; j<sizeY; j++)
+                       {
+                               if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) == color)
+                               {
+                                       const mirrorSide =
+                                               (Object.keys(VariantRules.ALICE_CODES).includes(this.getPiece(i,j)) ? 1 : 2);
+                                       Array.prototype.push.apply(potentialMoves,
+                                               this.getPotentialMovesFrom([i,j], sideBoard[mirrorSide-1]));
+                               }
+                       }
+               }
+               return this.filterValid(potentialMoves, sideBoard);
+       }
+
+       // Play on sideboards [TODO: only one sideBoard required]
+       playSide(move, sideBoard)
+       {
+               const pieces = Object.keys(VariantRules.ALICE_CODES);
+               move.vanish.forEach(psq => {
+                       const mirrorSide = (pieces.includes(psq.p) ? 1 : 2);
+                       sideBoard[mirrorSide-1][psq.x][psq.y] = VariantRules.EMPTY;
+               });
+               move.appear.forEach(psq => {
+                       const mirrorSide = (pieces.includes(psq.p) ? 1 : 2);
+                       const piece = (mirrorSide == 1 ? psq.p : VariantRules.ALICE_PIECES[psq.p]);
+                       sideBoard[mirrorSide-1][psq.x][psq.y] = psq.c + piece;
+                       if (piece == VariantRules.KING)
+                               this.kingPos[psq.c] = [psq.x,psq.y];
+               });
+       }
+
+       // Undo on sideboards
+       undoSide(move, sideBoard)
+       {
+               const pieces = Object.keys(VariantRules.ALICE_CODES);
+               move.appear.forEach(psq => {
+                       const mirrorSide = (pieces.includes(psq.p) ? 1 : 2);
+                       sideBoard[mirrorSide-1][psq.x][psq.y] = VariantRules.EMPTY;
+               });
+               move.vanish.forEach(psq => {
+                       const mirrorSide = (pieces.includes(psq.p) ? 1 : 2);
+                       const piece = (mirrorSide == 1 ? psq.p : VariantRules.ALICE_PIECES[psq.p]);
+                       sideBoard[mirrorSide-1][psq.x][psq.y] = psq.c + piece;
+                       if (piece == VariantRules.KING)
+                               this.kingPos[psq.c] = [psq.x,psq.y];
+               });
+       }
+
+       underCheck(move, sideBoard) //sideBoard arg always provided
+       {
+               const color = this.turn;
+               this.playSide(move, sideBoard); //no need to track flags
+               const kp = this.kingPos[color];
+               const mirrorSide = sideBoard[0][kp[0]][kp[1]] != VariantRules.EMPTY ? 1 : 2;
                let saveBoard = this.board;
-               this.board = sideBoard;
-               let res = this.isAttacked(this.kingPos[color], this.getOppCol(color));
+               this.board = sideBoard[mirrorSide-1];
+               let res = this.isAttacked(kp, this.getOppCol(color));
                this.board = saveBoard;
-               this.undo(move);
+               this.undoSide(move, sideBoard);
                return res;
        }
 
@@ -156,7 +233,10 @@ class AliceRules extends ChessRules
        {
                this.play(move);
                const color = this.turn; //opponent
-               let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
+               const pieces = Object.keys(VariantRules.ALICE_CODES);
+               const kp = this.kingPos[color];
+               const mirrorSide = (pieces.includes(this.getPiece(kp[0],kp[1])) ? 1 : 2);
+               let sideBoard = this.getSideBoard(mirrorSide);
                let saveBoard = this.board;
                this.board = sideBoard;
                let res = this.isAttacked(this.kingPos[color], this.getOppCol(color))
@@ -191,8 +271,11 @@ class AliceRules extends ChessRules
 
        checkGameEnd()
        {
+               const pieces = Object.keys(VariantRules.ALICE_CODES);
                const color = this.turn;
-               let sideBoard = this.getBoardOfPiece(this.kingPos[color]);
+               const kp = this.kingPos[color];
+               const mirrorSide = (pieces.includes(this.getPiece(kp[0],kp[1])) ? 1 : 2);
+               let sideBoard = this.getSideBoard(mirrorSide);
                let saveBoard = this.board;
                this.board = sideBoard;
                let res = "*";