class UltimaRules extends ChessRules
{
- // TODO: think about move UI for "removing an immobilized piece from the board"
- // (extend game.js and feedback Rules.js with "there was a click, is it a move?")
+ static getPpath(b)
+ {
+ if (b[1] == "m") //'m' for Immobilizer (I is too similar to 1)
+ return "Ultima/" + b;
+ return b; //usual piece
+ }
- // TODO: Keep usual pieces names here (but comment with Ultima pieces names)
- // Just change moving + capturing modes.
+ initVariables(fen)
+ {
+ this.kingPos = {'w':[-1,-1], 'b':[-1,-1]};
+ const fenParts = fen.split(" ");
+ const position = fenParts[0].split("/");
+ for (let i=0; i<position.length; i++)
+ {
+ let k = 0;
+ for (let j=0; j<position[i].length; j++)
+ {
+ switch (position[i].charAt(j))
+ {
+ case 'k':
+ this.kingPos['b'] = [i,k];
+ break;
+ case 'K':
+ this.kingPos['w'] = [i,k];
+ break;
+ default:
+ let num = parseInt(position[i].charAt(j));
+ if (!isNaN(num))
+ k += (num-1);
+ }
+ k++;
+ }
+ }
+ this.epSquares = []; //no en-passant here
+ }
+
+ setFlags(fen)
+ {
+ // TODO: for compatibility?
+ this.castleFlags = {"w":[false,false], "b":[false,false]};
+ }
+
+ static get IMMOBILIZER() { return 'm'; }
+ // Although other pieces keep their names here for coding simplicity,
+ // keep in mind that:
+ // - a "rook" is a coordinator, capturing by coordinating with the king
+ // - a "knight" is a long-leaper, capturing as in draughts
+ // - a "bishop" is a chameleon, capturing as its prey
+ // - a "queen" is a withdrawer, capturing by moving away from pieces
+
+ getPotentialMovesFrom([x,y])
+ {
+ // Pre-check: is thing on this square immobilized?
+ 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;
+ outerLoop:
+ 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.BISHOP && piece == V.IMMOBILIZER)
+ return [];
+ if (oppPiece == V.IMMOBILIZER && ![V.BISHOP,V.IMMOBILIZER].includes(piece))
+ {
+ // Moving is impossible only if this immobilizer is not neutralized
+ for (let step2 of adjacentSteps)
+ {
+ const [i2,j2] = [i+step2[0],j+step2[1]];
+ if (i2>=0 && i2<sizeX && j2>=0 && j2<sizeY
+ && this.board[i2][j2] != V.EMPTY && this.getColor(i2,j2) == color)
+ {
+ const friendlyPiece = this.getPiece(i2,j2);
+ if ([V.BISHOP,V.IMMOBILIZER].includes(friendlyPiece))
+ break outerLoop;
+ }
+ }
+ return []; //immobilizer isn't neutralized
+ }
+ }
+ }
+ switch (this.getPiece(x,y))
+ {
+ case VariantRules.IMMOBILIZER:
+ return this.getPotentialImmobilizerMoves([x,y]);
+ default:
+ return super.getPotentialMovesFrom([x,y]);
+ }
+ }
+
+ getSlideNJumpMoves([x,y], steps, oneStep)
+ {
+ const color = this.getColor(x,y);
+ const piece = this.getPiece(x,y);
+ let moves = [];
+ const [sizeX,sizeY] = VariantRules.size;
+ outerLoop:
+ for (let step of steps)
+ {
+ let i = x + step[0];
+ let j = y + step[1];
+ while (i>=0 && i<sizeX && j>=0 && j<sizeY
+ && this.board[i][j] == VariantRules.EMPTY)
+ {
+ moves.push(this.getBasicMove([x,y], [i,j]));
+ if (oneStep !== undefined)
+ continue outerLoop;
+ i += step[0];
+ j += step[1];
+ }
+ // Only king can take on occupied square:
+ if (piece==VariantRules.KING && i>=0 && i<sizeX && j>=0
+ && j<sizeY && this.canTake([x,y], [i,j]))
+ {
+ moves.push(this.getBasicMove([x,y], [i,j]));
+ }
+ }
+ 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])
+ {
+ 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)
+ {
+ 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).concat(this.getKnightCaptures(sq));
+ }
+
+ getPotentialBishopMoves([x,y])
+ {
+ let moves = super.getPotentialQueenMoves([x,y])
+ .concat(this.getKnightCaptures([x,y],"asChameleon"));
+ this.addPawnCaptures(moves, "asChameleon");
+ this.addRookCaptures(moves, "asChameleon");
+ this.addQueenCaptures(moves, "asChameleon");
+ // Add king capture if it's within range
+ const oppKp = this.kingPos[this.getOppCol(this.turn)];
+ if (Math.abs(x-oppKp[0]) <= 1 && Math.abs(y-oppKp[1]) <= 1)
+ moves.push(this.getBasicMove([x,y],oppKp));
+ // 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)
+ {
+ let moves = super.getPotentialQueenMoves(sq);
+ this.addQueenCaptures(moves);
+ return moves;
+ }
+
+ getPotentialImmobilizerMoves(sq)
+ {
+ // Immobilizer doesn't capture
+ return super.getPotentialQueenMoves(sq);
+ }
+
+ getPotentialKingMoves(sq)
+ {
+ const V = VariantRules;
+ return this.getSlideNJumpMoves(sq,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
+ }
+
+ atLeastOneMove()
+ {
+ if (this.kingPos[this.turn][0] < 0)
+ return false;
+ return super.atLeastOneMove();
+ }
+
+ underCheck(move)
+ {
+ return false; //there is no check
+ }
+
+ getCheckSquares(move)
+ {
+ const c = this.getOppCol(this.turn); //opponent
+ const saveKingPos = this.kingPos[c]; //king might be taken
+ this.play(move);
+ // The only way to be "under check" is to have lost the king (thus game over)
+ let res = this.kingPos[c][0] < 0
+ ? [ JSON.parse(JSON.stringify(saveKingPos)) ]
+ : [ ];
+ this.undo(move);
+ return res;
+ }
+
+ updateVariables(move)
+ {
+ // Just update king(s) position(s)
+ const piece = this.getPiece(move.start.x,move.start.y);
+ const c = this.getColor(move.start.x,move.start.y);
+ if (piece == VariantRules.KING && move.appear.length > 0)
+ {
+ this.kingPos[c][0] = move.appear[0].x;
+ this.kingPos[c][1] = move.appear[0].y;
+ }
+ // Does this move takes opponent's king?
+ const oppCol = this.getOppCol(c);
+ for (let i=1; i<move.vanish.length; i++)
+ {
+ if (move.vanish[i].p == VariantRules.KING)
+ {
+ this.kingPos[oppCol] = [-1,-1];
+ break;
+ }
+ }
+ }
+
+ unupdateVariables(move)
+ {
+ super.unupdateVariables(move);
+ const c = this.getColor(move.start.x,move.start.y);
+ const oppCol = this.getOppCol(c);
+ if (this.kingPos[oppCol][0] < 0)
+ {
+ // Last move took opponent's king
+ for (let i=1; i<move.vanish.length; i++)
+ {
+ const psq = move.vanish[i];
+ if (psq.p == 'k')
+ {
+ this.kingPos[oppCol] = [psq.x, psq.y];
+ break;
+ }
+ }
+ }
+ }
+
+ checkGameEnd()
+ {
+ // Stalemate, or our king disappeared
+ return this.turn == "w" ? "0-1" : "1-0";
+ }
+
+ static get VALUES() { //TODO: totally experimental!
+ return {
+ 'p': 1,
+ 'r': 2,
+ 'n': 5,
+ 'b': 3,
+ 'q': 3,
+ 'm': 5,
+ 'k': 1000
+ };
+ }
+
+ static get SEARCH_DEPTH() { return 2; } //TODO?
+
+ static get THRESHOLD_MATE() {
+ return 500; //checkmates evals may be slightly below 1000
+ }
+
+ static GenRandInitFen()
+ {
+ let pieces = { "w": new Array(8), "b": new Array(8) };
+ // Shuffle pieces on first and last rank
+ for (let c of ["w","b"])
+ {
+ let positions = _.range(8);
+ // Get random squares for every piece, totally freely
+
+ let randIndex = _.random(7);
+ const bishop1Pos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ randIndex = _.random(6);
+ const bishop2Pos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ randIndex = _.random(5);
+ const knight1Pos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ randIndex = _.random(4);
+ const knight2Pos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ randIndex = _.random(3);
+ const queenPos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ randIndex = _.random(2);
+ const kingPos = positions[randIndex];
+ positions.splice(randIndex, 1);
+
+ randIndex = _.random(1);
+ const rookPos = positions[randIndex];
+ positions.splice(randIndex, 1);
+ const immobilizerPos = positions[0];
+
+ pieces[c][bishop1Pos] = 'b';
+ pieces[c][bishop2Pos] = 'b';
+ pieces[c][knight1Pos] = 'n';
+ pieces[c][knight2Pos] = 'n';
+ pieces[c][queenPos] = 'q';
+ pieces[c][kingPos] = 'k';
+ pieces[c][rookPos] = 'r';
+ pieces[c][immobilizerPos] = 'm';
+ }
+ return pieces["b"].join("") +
+ "/pppppppp/8/8/8/8/PPPPPPPP/" +
+ pieces["w"].join("").toUpperCase() +
+ " 0000"; //TODO: flags?!
+ }
+
+ getFlagsFen()
+ {
+ return "0000"; //TODO: or "-" ?
+ }
}
projects / vchess.git / blobdiff