Fix incheck by pawns for checkered

[vchess.git] / public / javascripts / base_rules.js

diff --git a/public/javascripts/base_rules.js b/public/javascripts/base_rules.js
index 9a4ef91..11de147 100644 (file)
--- a/public/javascripts/base_rules.js
+++ b/public/javascripts/base_rules.js
@@ -46,14 +46,14 @@ class ChessRules
        /////////////////
        // INITIALIZATION
 
-       // fen = "position flags epSquare movesCount"
+       // fen == "position flags"
        constructor(fen, moves)
        {
                this.moves = moves;
                // Use fen string to initialize variables, flags and board
-               this.initVariables(fen);
-               this.flags = VariantRules.GetFlags(fen);
                this.board = VariantRules.GetBoard(fen);
+               this.flags = VariantRules.GetFlags(fen);
+               this.initVariables(fen);
        }
 
        initVariables(fen)
@@ -98,14 +98,8 @@ class ChessRules
                                j++;
                        }
                }
-               let epSq = undefined;
-               if (fenParts[2] != "-")
-               {
-                       const digits = fenParts[2].split(","); //3,2 ...
-                       epSq = { x:Number.parseInt(digits[0]), y:Number.parseInt(digits[1]) };
-               }
+               const epSq = this.moves.length > 0 ? this.getEpSquare(this.lastMove) : undefined;
                this.epSquares = [ epSq ];
-               this.movesCount = Number.parseInt(fenParts[3]);
        }
 
        // Turn diagram fen into double array ["wb","wp","bk",...]
@@ -158,7 +152,7 @@ class ChessRules
                return L>0 ? this.moves[L-1] : null;
        }
        get turn() {
-               return this.movesCount%2==0 ? 'w' : 'b';
+               return this.moves.length%2==0 ? 'w' : 'b';
        }
 
        // Pieces codes
@@ -476,8 +470,8 @@ class ChessRules
 
        canIplay(color, sq)
        {
-               return ((color=='w' && this.movesCount%2==0)
-                               || (color=='b' && this.movesCount%2==1))
+               return ((color=='w' && this.moves.length%2==0)
+                               || (color=='b' && this.moves.length%2==1))
                        && this.getColor(sq[0], sq[1]) == color;
        }
 
@@ -629,6 +623,7 @@ class ChessRules
                return false;
        }
 
+       // Is color c under check after move ?
        underCheck(move, c)
        {
                this.play(move);
@@ -637,6 +632,17 @@ class ChessRules
                return res;
        }
 
+       // On which squares is color c under check (after move) ?
+       getCheckSquares(move, c)
+       {
+               this.play(move);
+               let res = this.isAttacked(this.kingPos[c], this.getOppCol(c))
+                       ? [ JSON.parse(JSON.stringify(this.kingPos[c])) ] //need to duplicate!
+                       : [ ];
+               this.undo(move);
+               return res;
+       }
+
        // Apply a move on board
        static PlayOnBoard(board, move)
        {
@@ -654,7 +660,7 @@ class ChessRules
                        board[psq.x][psq.y] = psq.c + psq.p;
        }
 
-       // Before move is played:
+       // Before move is played, update variables + flags
        updateVariables(move)
        {
                const piece = this.getPiece(move.start.x,move.start.y);
@@ -685,37 +691,33 @@ class ChessRules
                }
        }
 
-       play(move, ingame)
+       unupdateVariables(move)
        {
-               // Save flags (for undo)
-               move.flags = JSON.stringify(this.flags); //TODO: less costly
-               this.updateVariables(move);
+               // (Potentially) Reset king position
+               const c = this.getColor(move.start.x,move.start.y);
+               if (this.getPiece(move.start.x,move.start.y) == VariantRules.KING)
+                       this.kingPos[c] = [move.start.x, move.start.y];
+       }
 
+       play(move, ingame)
+       {
                if (!!ingame)
-               {
                        move.notation = this.getNotation(move);
-                       this.moves.push(move);
-               }
 
+               // Save flags (for undo)
+               move.flags = JSON.stringify(this.flags); //TODO: less costly?
+               this.updateVariables(move);
+               this.moves.push(move);
                this.epSquares.push( this.getEpSquare(move) );
                VariantRules.PlayOnBoard(this.board, move);
-               this.movesCount++;
        }
 
-       undo(move, ingame)
+       undo(move)
        {
                VariantRules.UndoOnBoard(this.board, move);
                this.epSquares.pop();
-               this.movesCount--;
-
-               if (!!ingame)
-                       this.moves.pop();
-
-               // Update king position, and reset stored/computed flags
-               const c = this.getColor(move.start.x,move.start.y);
-               if (this.getPiece(move.start.x,move.start.y) == VariantRules.KING)
-                       this.kingPos[c] = [move.start.x, move.start.y];
-
+               this.moves.pop();
+               this.unupdateVariables(move);
                this.flags = JSON.parse(move.flags);
        }
 
@@ -826,8 +828,7 @@ class ChessRules
 
        alphabeta(color, oppCol, depth, alpha, beta)
   {
-               const moves = this.getAllValidMoves(color);
-               if (moves.length == 0)
+               if (!this.atLeastOneMove(color))
                {
                        switch (this.checkGameEnd(color))
                        {
@@ -837,6 +838,7 @@ class ChessRules
                }
                if (depth == 0)
       return this.evalPosition();
+               const moves = this.getAllValidMoves(color);
     let v = color=="w" ? -1000 : 1000;
                if (color == "w")
                {
@@ -937,19 +939,14 @@ class ChessRules
                let fen = pieces[0].join("") +
                        "/pppppppp/8/8/8/8/PPPPPPPP/" +
                        pieces[1].join("").toUpperCase() +
-                       " 1111 - 0"; //flags + enPassant + movesCount
+                       " 1111"; //add flags
                return fen;
        }
 
        // Return current fen according to pieces+colors state
        getFen()
        {
-               const L = this.epSquares.length;
-               const epSq = this.epSquares[L-1]===undefined
-                       ? "-"
-                       : this.epSquares[L-1].x+","+this.epSquares[L-1].y;
-               return this.getBaseFen() + " " + this.getFlagsFen()
-                       + " " + epSq + " " + this.movesCount;
+               return this.getBaseFen() + " " + this.getFlagsFen();
        }
 
        getBaseFen()