import { ChessRules } from "@/base_rules";
-export const VariantRules = class BerolinaRules extends ChessRules
-{
- // En-passant after 2-sq jump
- getEpSquare(moveOrSquare)
- {
- if (!moveOrSquare)
- return undefined;
- if (typeof moveOrSquare === "string")
- {
- const square = moveOrSquare;
- if (square == "-")
- return undefined;
- // Enemy pawn initial column must be given too:
- let res = [];
- const epParts = square.split(",");
- res.push(V.SquareToCoords(epParts[0]));
- res.push(V.ColumnToCoord(epParts[1]));
- return res;
- }
- // Argument is a move:
- const move = moveOrSquare;
- const [sx,ex,sy] = [move.start.x,move.end.x,move.start.y];
- if (this.getPiece(sx,sy) == V.PAWN && Math.abs(sx - ex) == 2)
- {
- return
- [
- {
- x: (ex + sx)/2,
- y: (move.end.y + sy)/2
- },
- move.end.y
- ];
- }
- return undefined; //default
- }
+export class BerolinaRules extends ChessRules {
+ // En-passant after 2-sq jump
+ getEpSquare(moveOrSquare) {
+ if (!moveOrSquare) return undefined;
+ if (typeof moveOrSquare === "string") {
+ const square = moveOrSquare;
+ if (square == "-") return undefined;
+ // Enemy pawn initial column must be given too:
+ let res = [];
+ const epParts = square.split(",");
+ res.push(V.SquareToCoords(epParts[0]));
+ res.push(V.ColumnToCoord(epParts[1]));
+ return res;
+ }
+ // Argument is a move:
+ const move = moveOrSquare;
+ const [sx, ex, sy] = [move.start.x, move.end.x, move.start.y];
+ if (this.getPiece(sx, sy) == V.PAWN && Math.abs(sx - ex) == 2) {
+ return [
+ {
+ x: (ex + sx) / 2,
+ y: (move.end.y + sy) / 2
+ },
+ // The arrival column must be remembered, because
+ // potentially two pawns could be candidates to be captured:
+ // one on our left, and one on our right.
+ move.end.y
+ ];
+ }
+ return undefined; //default
+ }
- // Special pawns movements
- getPotentialPawnMoves([x,y])
- {
- const color = this.turn;
- let moves = [];
- const [sizeX,sizeY] = [V.size.x,V.size.y];
- const shiftX = (color == "w" ? -1 : 1);
- const firstRank = (color == 'w' ? sizeX-1 : 0);
- const startRank = (color == "w" ? sizeX-2 : 1);
- const lastRank = (color == "w" ? 0 : sizeX-1);
- const finalPieces = x + shiftX == lastRank
- ? [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN]
- : [V.PAWN];
+ static IsGoodEnpassant(enpassant) {
+ if (enpassant != "-") {
+ const epParts = enpassant.split(",");
+ const epSq = V.SquareToCoords(epParts[0]);
+ if (isNaN(epSq.x) || isNaN(epSq.y) || !V.OnBoard(epSq)) return false;
+ const arrCol = V.ColumnToCoord(epParts[1]);
+ if (isNaN(arrCol) || arrCol < 0 || arrCol >= V.size.y) return false;
+ }
+ return true;
+ }
- // One square diagonally
- for (let shiftY of [-1,1])
- {
- if (this.board[x+shiftX][y+shiftY] == V.EMPTY)
- {
- for (let piece of finalPieces)
- {
- moves.push(this.getBasicMove([x,y], [x+shiftX,y+shiftY],
- {c:color,p:piece}));
- }
- if (x == startRank && y+2*shiftY>=0 && y+2*shiftY<sizeY
- && this.board[x+2*shiftX][y+2*shiftY] == V.EMPTY)
- {
- // Two squares jump
- moves.push(this.getBasicMove([x,y], [x+2*shiftX,y+2*shiftY]));
- }
- }
- }
- // Capture
- if (this.board[x+shiftX][y] != V.EMPTY
- && this.canTake([x,y], [x+shiftX,y]))
- {
- for (let piece of finalPieces)
- moves.push(this.getBasicMove([x,y], [x+shiftX,y], {c:color,p:piece}));
- }
+ getEnpassantFen() {
+ const L = this.epSquares.length;
+ if (!this.epSquares[L - 1]) return "-"; //no en-passant
+ return (
+ V.CoordsToSquare(this.epSquares[L - 1][0]) +
+ "," +
+ V.CoordToColumn(this.epSquares[L - 1][1])
+ );
+ }
- // En passant
- const Lep = this.epSquares.length;
- const epSquare = this.epSquares[Lep-1]; //always at least one element
- if (!!epSquare && epSquare[0].x == x+shiftX && epSquare[0].y == y
- && Math.abs(epSquare[1] - y) == 1)
- {
- let enpassantMove = this.getBasicMove([x,y], [x+shiftX,y]);
- enpassantMove.vanish.push({
- x: x,
- y: epSquare[1],
- p: 'p',
- c: this.getColor(x,epSquare[1])
- });
- moves.push(enpassantMove);
- }
+ // Special pawns movements
+ getPotentialPawnMoves([x, y]) {
+ const color = this.turn;
+ let moves = [];
+ const [sizeX, sizeY] = [V.size.x, V.size.y];
+ const shiftX = color == "w" ? -1 : 1;
+ const startRank = color == "w" ? sizeX - 2 : 1;
+ const lastRank = color == "w" ? 0 : sizeX - 1;
+ const finalPieces =
+ x + shiftX == lastRank
+ ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN]
+ : [V.PAWN];
- return moves;
- }
+ // One square diagonally
+ for (let shiftY of [-1, 1]) {
+ if (this.board[x + shiftX][y + shiftY] == V.EMPTY) {
+ for (let piece of finalPieces) {
+ moves.push(
+ this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
+ c: color,
+ p: piece
+ })
+ );
+ }
+ if (
+ V.PawnSpecs.twoSquares &&
+ x == startRank &&
+ y + 2 * shiftY >= 0 &&
+ y + 2 * shiftY < sizeY &&
+ this.board[x + 2 * shiftX][y + 2 * shiftY] == V.EMPTY
+ ) {
+ // Two squares jump
+ moves.push(
+ this.getBasicMove([x, y], [x + 2 * shiftX, y + 2 * shiftY])
+ );
+ }
+ }
+ }
+ // Capture
+ if (
+ this.board[x + shiftX][y] != V.EMPTY &&
+ this.canTake([x, y], [x + shiftX, y])
+ ) {
+ for (let piece of finalPieces) {
+ moves.push(
+ this.getBasicMove([x, y], [x + shiftX, y], { c: color, p: piece })
+ );
+ }
+ }
- isAttackedByPawn([x,y], colors)
- {
- for (let c of colors)
- {
- let pawnShift = (c=="w" ? 1 : -1);
- if (x+pawnShift>=0 && x+pawnShift<V.size.x)
- {
- if (this.getPiece(x+pawnShift,y)==V.PAWN
- && this.getColor(x+pawnShift,y)==c)
- {
- return true;
- }
- }
- }
- return false;
- }
+ // Next condition so that other variants could inherit from this class
+ if (V.PawnSpecs.enPassant) {
+ // En passant
+ const Lep = this.epSquares.length;
+ const epSquare = this.epSquares[Lep - 1]; //always at least one element
+ if (
+ !!epSquare &&
+ epSquare[0].x == x + shiftX &&
+ epSquare[0].y == y
+ ) {
+ let enpassantMove = this.getBasicMove([x, y], [x + shiftX, y]);
+ enpassantMove.vanish.push({
+ x: x,
+ y: epSquare[1],
+ p: "p",
+ c: this.getColor(x, epSquare[1])
+ });
+ moves.push(enpassantMove);
+ }
+ }
- getNotation(move)
- {
- const piece = this.getPiece(move.start.x, move.start.y);
- if (piece == V.PAWN)
- {
- // Pawn move
- const finalSquare = V.CoordsToSquare(move.end);
- let notation = "";
- if (move.vanish.length == 2) //capture
- notation = "Px" + finalSquare;
- else
- {
- // No capture: indicate the initial square for potential ambiguity
- const startSquare = V.CoordsToSquare(move.start);
- notation = startSquare + finalSquare;
- }
- if (move.appear[0].p != V.PAWN) //promotion
- notation += "=" + move.appear[0].p.toUpperCase();
- return notation;
- }
- return super.getNotation(move); //all other pieces are orthodox
- }
-}
+ return moves;
+ }
+
+ isAttackedByPawn([x, y], color) {
+ let pawnShift = (color == "w" ? 1 : -1);
+ if (x + pawnShift >= 0 && x + pawnShift < V.size.x) {
+ if (
+ this.getPiece(x + pawnShift, y) == V.PAWN &&
+ this.getColor(x + pawnShift, y) == color
+ ) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ static get SEARCH_DEPTH() {
+ return 2;
+ }
+
+ getNotation(move) {
+ const piece = this.getPiece(move.start.x, move.start.y);
+ if (piece == V.PAWN) {
+ // Pawn move
+ const finalSquare = V.CoordsToSquare(move.end);
+ let notation = "";
+ if (move.vanish.length == 2)
+ // Capture
+ notation = "Px" + finalSquare;
+ else {
+ // No capture: indicate the initial square for potential ambiguity
+ const startSquare = V.CoordsToSquare(move.start);
+ notation = startSquare + finalSquare;
+ }
+ if (move.appear[0].p != V.PAWN)
+ // Promotion
+ notation += "=" + move.appear[0].p.toUpperCase();
+ return notation;
+ }
+ return super.getNotation(move); //all other pieces are orthodox
+ }
+};
projects / vchess.git / blobdiff