Implementation of pieces movements + captures in Ultima
[vchess.git] / public / javascripts / variants / Ultima.js
index 4612da1..d667643 100644 (file)
@@ -52,7 +52,33 @@ class UltimaRules extends ChessRules
 
        getPotentialMovesFrom([x,y])
        {
-               // TODO: pre-check: is thing on this square immobilized? If yes, return []
+               // Pre-check: is thing on this square immobilized?
+               // In this case add potential suicide as a move "taking the immobilizer"
+               const piece = this.getPiece(x,y);
+               const color = this.getColor(x,y);
+               const oppCol = this.getOppCol(color);
+               const V = VariantRules;
+               const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+               const [sizeX,sizeY] = V.size;
+               for (let step of adjacentSteps)
+               {
+                       const [i,j] = [x+step[0],y+step[1]];
+                       if (i>=0 && i<sizeX && j>=0 && j<sizeY && this.board[i][j] != V.EMPTY
+                               && this.getColor(i,j) == oppCol)
+                       {
+                               const oppPiece = this.getPiece(i,j);
+                               if (oppPiece == V.IMMOBILIZER
+                                       || (oppPiece == V.BISHOP && piece == V.IMMOBILIZER))
+                               {
+                                       return [ new Move({
+                                               appear: [],
+                                               vanish: [new PiPo({x:x,y:y,p:piece,c:color})],
+                                               start: {x:x,y:y},
+                                               end: {x:i,y:j}
+                                       }) ];
+                               }
+                       }
+               }
                switch (this.getPiece(x,y))
                {
                        case VariantRules.IMMOBILIZER:
@@ -60,11 +86,6 @@ class UltimaRules extends ChessRules
                        default:
                                return super.getPotentialMovesFrom([x,y]);
                }
-               // TODO: add potential suicides as a move "taking the immobilizer"
-               // TODO: add long-leaper captures
-               // TODO: mark matching coordinator/withdrawer/chameleon moves as captures
-               // (will be a bit tedious for chameleons)
-               // --> filter directly in functions below
        }
 
        getSlideNJumpMoves([x,y], steps, oneStep)
@@ -97,33 +118,243 @@ class UltimaRules extends ChessRules
                return moves;
        }
 
+       // Modify capturing moves among listed pawn moves
+       addPawnCaptures(moves, byChameleon)
+       {
+               const steps = VariantRules.steps[VariantRules.ROOK];
+               const [sizeX,sizeY] = VariantRules.size;
+               const color = this.turn;
+               const oppCol = this.getOppCol(color);
+               moves.forEach(m => {
+                       if (!!byChameleon && m.start.x!=m.end.x && m.start.y!=m.end.y)
+                               return; //chameleon not moving as pawn
+                       // Try capturing in every direction
+                       for (let step of steps)
+                       {
+                               const sq2 = [m.end.x+2*step[0],m.end.y+2*step[1]];
+                               if (sq2[0]>=0 && sq2[0]<sizeX && sq2[1]>=0 && sq2[1]<sizeY
+                                       && this.board[sq2[0]][sq2[1]] != VariantRules.EMPTY
+                                       && this.getColor(sq2[0],sq2[1]) == color)
+                               {
+                                       // Potential capture
+                                       const sq1 = [m.end.x+step[0],m.end.y+step[1]];
+                                       if (this.board[sq1[0]][sq1[1]] != VariantRules.EMPTY
+                                               && this.getColor(sq1[0],sq1[1]) == oppCol)
+                                       {
+                                               const piece1 = this.getPiece(sq1[0],sq1[1]);
+                                               if (!byChameleon || piece1 == VariantRules.PAWN)
+                                               {
+                                                       m.vanish.push(new PiPo({
+                                                               x:sq1[0],
+                                                               y:sq1[1],
+                                                               c:oppCol,
+                                                               p:piece1
+                                                       }));
+                                               }
+                                       }
+                               }
+                       }
+               });
+       }
+
+       // "Pincher"
        getPotentialPawnMoves([x,y])
        {
-               return super.getPotentialRookMoves([x,y]);
+               let moves = super.getPotentialRookMoves([x,y]);
+               this.addPawnCaptures(moves);
+               return moves;
+       }
+
+       addRookCaptures(moves, byChameleon)
+       {
+               const color = this.turn;
+               const oppCol = this.getOppCol(color);
+               const kp = this.kingPos[color];
+               moves.forEach(m => {
+                       // Check piece-king rectangle (if any) corners for enemy pieces
+                       if (m.end.x == kp[0] || m.end.y == kp[1])
+                               return; //"flat rectangle"
+                       const corner1 = [Math.max(m.end.x,kp[0]), Math.min(m.end.y,kp[1])];
+                       const corner2 = [Math.min(m.end.x,kp[0]), Math.max(m.end.y,kp[1])];
+                       for (let [i,j] of [corner1,corner2])
+                       {
+                               if (this.board[i][j] != VariantRules.EMPTY && this.getColor(i,j) == oppCol)
+                               {
+                                       const piece = this.getPiece(i,j);
+                                       if (!byChameleon || piece == VariantRules.ROOK)
+                                       {
+                                               m.vanish.push( new PiPo({
+                                                       x:i,
+                                                       y:j,
+                                                       p:piece,
+                                                       c:oppCol
+                                               }) );
+                                       }
+                               }
+                       }
+               });
        }
 
+       // Coordinator
        getPotentialRookMoves(sq)
        {
-               return super.getPotentialQueenMoves(sq);
+               let moves = super.getPotentialQueenMoves(sq);
+               this.addRookCaptures(moves);
+               return moves;
        }
 
+       // Long-leaper
+       getKnightCaptures(startSquare, byChameleon)
+       {
+               // Look in every direction for captures
+               const V = VariantRules;
+               const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+               const [sizeX,sizeY] = V.size;
+               const color = this.turn;
+               const oppCol = this.getOppCol(color);
+               let moves = [];
+               const [x,y] = [startSquare[0],startSquare[1]];
+               const piece = this.getPiece(x,y); //might be a chameleon!
+               outerLoop:
+               for (let step of steps)
+               {
+                       let [i,j] = [x+step[0], y+step[1]];
+                       while (i>=0 && i<sizeX && j>=0 && j<sizeY && this.board[i][j]==V.EMPTY)
+                       {
+                               i += step[0];
+                               j += step[1];
+                       }
+                       if (i<0 || i>=sizeX || j<0 || j>=sizeY || this.getColor(i,j)==color
+                               || (!!byChameleon && this.getPiece(i,j)!=V.KNIGHT))
+                       {
+                               continue;
+                       }
+                       // last(thing), cur(thing) : stop if "cur" is our color, or beyond board limits,
+                       // or if "last" isn't empty and cur neither. Otherwise, if cur is empty then
+                       // add move until cur square; if cur is occupied then stop if !!byChameleon and
+                       // the square not occupied by a leaper.
+                       let last = [i,j];
+                       let cur = [i+step[0],j+step[1]];
+                       let vanished = [ new PiPo({x:x,y:y,c:color,p:piece}) ];
+                       while (cur[0]>=0 && cur[0]<sizeX && cur[1]>=0 && cur[1]<sizeY)
+                       {
+                               if (this.board[last[0]][last[1]] != V.EMPTY)
+                               {
+                                       const oppPiece = this.getPiece(last[0],last[1]);
+                                       if (!!byChameleon && oppPiece != V.KNIGHT)
+                                               continue outerLoop;
+                                       // Something to eat:
+                                       vanished.push( new PiPo({x:last[0],y:last[1],c:oppCol,p:oppPiece}) );
+                               }
+                               if (this.board[cur[0]][cur[1]] != V.EMPTY)
+                               {
+                                       if (this.getColor(cur[0],cur[1]) == color
+                                               || this.board[last[0]][last[1]] != V.EMPTY) //TODO: redundant test
+                                       {
+                                               continue outerLoop;
+                                       }
+                               }
+                               else
+                               {
+                                       moves.push(new Move({
+                                               appear: [ new PiPo({x:cur[0],y:cur[1],c:color,p:piece}) ],
+                                               vanish: JSON.parse(JSON.stringify(vanished)), //TODO: required?
+                                               start: {x:x,y:y},
+                                               end: {x:cur[0],y:cur[1]}
+                                       }));
+                               }
+                               last = [last[0]+step[0],last[1]+step[1]];
+                               cur = [cur[0]+step[0],cur[1]+step[1]];
+                       }
+               }
+               return moves;
+       }
+
+       // Long-leaper
        getPotentialKnightMoves(sq)
        {
-               return super.getPotentialQueenMoves(sq);
+               return super.getPotentialQueenMoves(sq).concat(this.getKnightCaptures(sq));
        }
 
        getPotentialBishopMoves(sq)
        {
-               return super.getPotentialQueenMoves(sq);
+               let moves = super.getPotentialQueenMoves(sq)
+                       .concat(this.getKnightCaptures(sq,"asChameleon"));
+               // NOTE: no "addKingCaptures" because the king isn't captured
+               this.addPawnCaptures(moves, "asChameleon");
+               this.addRookCaptures(moves, "asChameleon");
+               this.addQueenCaptures(moves, "asChameleon");
+               // Post-processing: merge similar moves, concatenating vanish arrays
+               let mergedMoves = {};
+               const [sizeX,sizeY] = VariantRules.size;
+               moves.forEach(m => {
+                       const key = m.end.x + sizeX * m.end.y;
+                       if (!mergedMoves[key])
+                               mergedMoves[key] = m;
+                       else
+                       {
+                               for (let i=1; i<m.vanish.length; i++)
+                                       mergedMoves[key].vanish.push(m.vanish[i]);
+                       }
+               });
+               // Finally return an array
+               moves = [];
+               Object.keys(mergedMoves).forEach(k => { moves.push(mergedMoves[k]); });
+               return moves;
+       }
+
+       // Withdrawer
+       addQueenCaptures(moves, byChameleon)
+       {
+               if (moves.length == 0)
+                       return;
+               const [x,y] = [moves[0].start.x,moves[0].start.y];
+               const V = VariantRules;
+               const adjacentSteps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+               let capturingDirections = [];
+               const color = this.turn;
+               const oppCol = this.getOppCol(color);
+               const [sizeX,sizeY] = V.size;
+               adjacentSteps.forEach(step => {
+                       const [i,j] = [x+step[0],y+step[1]];
+                       if (i>=0 && i<sizeX && j>=0 && j<sizeY
+                               && this.board[i][j] != V.EMPTY && this.getColor(i,j) == oppCol
+                               && (!byChameleon || this.getPiece(i,j) == V.QUEEN))
+                       {
+                               capturingDirections.push(step);
+                       }
+               });
+               moves.forEach(m => {
+                       const step = [
+                               m.end.x!=x ? (m.end.x-x)/Math.abs(m.end.x-x) : 0,
+                               m.end.y!=y ? (m.end.y-y)/Math.abs(m.end.y-y) : 0
+                       ];
+                       // NOTE: includes() and even _.isEqual() functions fail...
+                       // TODO: this test should be done only once per direction
+                       if (capturingDirections.some(dir =>
+                               { return (dir[0]==-step[0] && dir[1]==-step[1]); }))
+                       {
+                               const [i,j] = [x-step[0],y-step[1]];
+                               m.vanish.push(new PiPo({
+                                       x:i,
+                                       y:j,
+                                       p:this.getPiece(i,j),
+                                       c:oppCol
+                               }));
+                       }
+               });
        }
 
        getPotentialQueenMoves(sq)
        {
-               return super.getPotentialQueenMoves(sq);
+               let moves = super.getPotentialQueenMoves(sq);
+               this.addQueenCaptures(moves);
+               return moves;
        }
 
        getPotentialImmobilizerMoves(sq)
        {
+               // Immobilizer doesn't capture
                return super.getPotentialQueenMoves(sq);
        }
 
@@ -146,12 +377,14 @@ class UltimaRules extends ChessRules
        isAttackedByRook(sq, colors)
        {
                // Enemy king must be on same file and a rook on same row (or reverse)
+               return false;
        }
 
        isAttackedByKnight(sq, colors)
        {
                // Square (x,y) must be on same line as a knight,
                // and there must be empty square(s) behind.
+               return false;
        }
 
        isAttackedByBishop(sq, colors)
@@ -159,12 +392,14 @@ class UltimaRules extends ChessRules
                // switch on piece nature on square sq: a chameleon attack as this piece
                // ==> call the appropriate isAttackedBy... (exception of immobilizers)
                // Other exception: a chameleon cannot attack a chameleon (seemingly...)
+               return false;
        }
 
        isAttackedByQueen(sq, colors)
        {
                // Square (x,y) must be adjacent to a queen, and the queen must have
                // some free space in the opposite direction from (x,y)
+               return false;
        }
 
        updateVariables(move)
@@ -179,6 +414,12 @@ class UltimaRules extends ChessRules
                }
        }
 
+       checkGameEnd()
+       {
+               // No valid move: game is lost (stalemate is a win)
+               return this.turn == "w" ? "0-1" : "1-0";
+       }
+
        static get VALUES() { //TODO: totally experimental!
                return {
                        'p': 1,
@@ -250,4 +491,15 @@ class UltimaRules extends ChessRules
        {
                return "0000"; //TODO: or "-" ?
        }
+
+       getNotation(move)
+       {
+               if (move.appear.length == 0)
+               {
+                       const startSquare =
+                               String.fromCharCode(97 + move.start.y) + (VariantRules.size[0]-move.start.x);
+                       return "^" + startSquare; //suicide
+               }
+               return super.getNotation(move);
+       }
 }