-import { ChessRules } from "@/base_rules";
+import { ChessRules, Move, PiPo } from "@/base_rules";
-export const VariantRules = class CheckeredRules extends ChessRules {
+export class CheckeredRules extends ChessRules {
static board2fen(b) {
const checkered_codes = {
p: "s",
super.setOtherVariables(fen);
// Local stack of non-capturing checkered moves:
this.cmoves = [];
- const cmove = fen.split(" ")[5];
+ const cmove = V.ParseFen(fen).cmove;
if (cmove == "-") this.cmoves.push(null);
else {
this.cmoves.push({
static IsGoodFlags(flags) {
// 4 for castle + 16 for pawns
- return !!flags.match(/^[01]{20,20}$/);
+ return !!flags.match(/^[a-z]{4,4}[01]{16,16}$/);
}
setFlags(fenflags) {
super.setFlags(fenflags); //castleFlags
this.pawnFlags = {
- w: [...Array(8).fill(true)], //pawns can move 2 squares?
- b: [...Array(8).fill(true)]
+ w: [...Array(8)], //pawns can move 2 squares?
+ b: [...Array(8)]
};
- const flags = fenflags.substr(4); //skip first 4 digits, for castle
+ const flags = fenflags.substr(4); //skip first 4 letters, for castle
for (let c of ["w", "b"]) {
for (let i = 0; i < 8; i++)
this.pawnFlags[c][i] = flags.charAt((c == "w" ? 0 : 8) + i) == "1";
getPotentialMovesFrom([x, y]) {
let standardMoves = super.getPotentialMovesFrom([x, y]);
const lastRank = this.turn == "w" ? 0 : 7;
- // King has to be treated differently (for castles)
+ // King is treated differently: it never turn checkered
if (this.getPiece(x, y) == V.KING) return standardMoves;
let moves = [];
standardMoves.forEach(m => {
if (
Math.abs(m.end.x - m.start.x) == 2 &&
!this.pawnFlags[this.turn][m.start.y]
- )
+ ) {
return; //skip forbidden 2-squares jumps
+ }
if (
this.board[m.end.x][m.end.y] == V.EMPTY &&
m.vanish.length == 2 &&
return; //checkered pawns cannot take en-passant
}
}
- if (m.vanish.length == 1) moves.push(m);
- // No capture
+ if (m.vanish.length == 1)
+ // No capture
+ moves.push(m);
else {
// A capture occured (m.vanish.length == 2)
m.appear[0].c = "c";
moves.push(m);
if (
- m.appear[0].p != m.vanish[1].p && //avoid promotions (already treated):
+ // Avoid promotions (already treated):
+ m.appear[0].p != m.vanish[1].p &&
(m.vanish[0].p != V.PAWN || m.end.x != lastRank)
) {
// Add transformation into captured piece
}
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 pawnColor = this.getColor(x, y); //can be checkered
-
- const finalPieces =
- x + shiftX == lastRank
- ? [V.ROOK, V.KNIGHT, V.BISHOP, V.QUEEN]
- : [V.PAWN];
- if (this.board[x + shiftX][y] == V.EMPTY) {
- // One square forward
- for (let piece of finalPieces) {
- moves.push(
- this.getBasicMove([x, y], [x + shiftX, y], {
- c: pawnColor,
- p: piece
- })
- );
- }
- if (
- x == startRank &&
- this.board[x + 2 * shiftX][y] == V.EMPTY
- ) {
- // Two squares jump
- moves.push(this.getBasicMove([x, y], [x + 2 * shiftX, y]));
- }
- }
- // Captures
- for (let shiftY of [-1, 1]) {
- if (
- y + shiftY >= 0 &&
- y + shiftY < sizeY &&
- this.board[x + shiftX][y + shiftY] != V.EMPTY &&
- this.canTake([x, y], [x + shiftX, y + shiftY])
- ) {
- for (let piece of finalPieces) {
- moves.push(
- this.getBasicMove([x, y], [x + shiftX, y + shiftY], {
- c: pawnColor,
- p: piece
- })
- );
- }
- }
- }
-
- // En passant
- const Lep = this.epSquares.length;
- const epSquare = this.epSquares[Lep - 1]; //always at least one element
- if (
- !!epSquare &&
- epSquare.x == x + shiftX &&
- Math.abs(epSquare.y - y) == 1
- ) {
- let enpassantMove = this.getBasicMove([x, y], [epSquare.x, epSquare.y]);
- enpassantMove.vanish.push({
- x: x,
- y: epSquare.y,
- p: "p",
- c: this.getColor(x, epSquare.y)
+ let moves = super.getPotentialPawnMoves([x, y]);
+ // Post-process: set right color for checkered moves
+ if (this.getColor(x, y) == 'c')
+ moves.forEach(m => {
+ m.appear[0].c = 'c'; //may be done twice if capture
+ m.vanish[0].c = 'c';
});
- moves.push(enpassantMove);
- }
-
return moves;
}
// Does m2 un-do m1 ? (to disallow undoing checkered moves)
oppositeMoves(m1, m2) {
return (
- m1 &&
+ !!m1 &&
m2.appear[0].c == "c" &&
m2.appear.length == 1 &&
m2.vanish.length == 1 &&
return false;
}
+ // colors: array, generally 'w' and 'c' or 'b' and 'c'
+ isAttacked(sq, colors) {
+ if (!Array.isArray(colors)) colors = [colors];
+ return (
+ this.isAttackedByPawn(sq, colors) ||
+ this.isAttackedByRook(sq, colors) ||
+ this.isAttackedByKnight(sq, colors) ||
+ this.isAttackedByBishop(sq, colors) ||
+ this.isAttackedByQueen(sq, colors) ||
+ this.isAttackedByKing(sq, colors)
+ );
+ }
+
isAttackedByPawn([x, y], colors) {
for (let c of colors) {
- const color = c == "c" ? this.turn : c;
+ const color = (c == "c" ? this.turn : c);
let pawnShift = color == "w" ? 1 : -1;
if (x + pawnShift >= 0 && x + pawnShift < 8) {
for (let i of [-1, 1]) {
return false;
}
+ isAttackedBySlideNJump([x, y], colors, piece, steps, oneStep) {
+ for (let step of steps) {
+ let rx = x + step[0],
+ ry = y + step[1];
+ while (V.OnBoard(rx, ry) && this.board[rx][ry] == V.EMPTY && !oneStep) {
+ rx += step[0];
+ ry += step[1];
+ }
+ if (
+ V.OnBoard(rx, ry) &&
+ this.getPiece(rx, ry) === piece &&
+ colors.includes(this.getColor(rx, ry))
+ ) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ isAttackedByRook(sq, colors) {
+ return this.isAttackedBySlideNJump(sq, colors, V.ROOK, V.steps[V.ROOK]);
+ }
+
+ isAttackedByKnight(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.KNIGHT,
+ V.steps[V.KNIGHT],
+ "oneStep"
+ );
+ }
+
+ isAttackedByBishop(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq, colors, V.BISHOP, V.steps[V.BISHOP]);
+ }
+
+ isAttackedByQueen(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.QUEEN,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP])
+ );
+ }
+
+ isAttackedByKing(sq, colors) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ colors,
+ V.KING,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
+ "oneStep"
+ );
+ }
+
underCheck(color) {
return this.isAttacked(this.kingPos[color], [V.GetOppCol(color), "c"]);
}
"c"
]);
let res = kingAttacked
- ? [JSON.parse(JSON.stringify(this.kingPos[color]))] //need to duplicate!
+ ? [JSON.parse(JSON.stringify(this.kingPos[color]))]
: [];
this.turn = color;
return res;
}
- updateVariables(move) {
- super.updateVariables(move);
+ postPlay(move) {
+ super.postPlay(move);
// Does this move turn off a 2-squares pawn flag?
- const secondRank = [1, 6];
- if (secondRank.includes(move.start.x) && move.vanish[0].p == V.PAWN)
+ if ([1, 6].includes(move.start.x) && move.vanish[0].p == V.PAWN)
this.pawnFlags[move.start.x == 6 ? "w" : "b"][move.start.y] = false;
+ this.cmoves.push(this.getCmove(move));
}
- getCurrentScore() {
- if (this.atLeastOneMove())
- // game not over
- return "*";
+ postUndo(move) {
+ super.postUndo(move);
+ this.cmoves.pop();
+ }
+ getCurrentScore() {
+ if (this.atLeastOneMove()) return "*";
const color = this.turn;
// Artifically change turn, for checkered pawns
this.turn = V.GetOppCol(this.turn);
}
static GenRandInitFen(randomness) {
+ // Add 16 pawns flags + empty cmove:
return ChessRules.GenRandInitFen(randomness)
- // Add 16 pawns flags + empty cmove:
- .replace(" w 0 1111", " w 0 11111111111111111111 -");
+ .slice(0, -2) + "1111111111111111 - -";
}
static ParseFen(fen) {
- return Object.assign({}, ChessRules.ParseFen(fen), {
- cmove: fen.split(" ")[5]
- });
+ return Object.assign(
+ ChessRules.ParseFen(fen),
+ { cmove: fen.split(" ")[5] }
+ );
}
getFen() {
const L = this.cmoves.length;
- const cmoveFen = !this.cmoves[L - 1]
- ? "-"
- : ChessRules.CoordsToSquare(this.cmoves[L - 1].start) +
- ChessRules.CoordsToSquare(this.cmoves[L - 1].end);
+ const cmoveFen =
+ !this.cmoves[L - 1]
+ ? "-"
+ : ChessRules.CoordsToSquare(this.cmoves[L - 1].start) +
+ ChessRules.CoordsToSquare(this.cmoves[L - 1].end);
return super.getFen() + " " + cmoveFen;
}
getFlagsFen() {
let fen = super.getFlagsFen();
// Add pawns flags
- for (let c of ["w", "b"]) {
- for (let i = 0; i < 8; i++) fen += this.pawnFlags[c][i] ? "1" : "0";
- }
+ for (let c of ["w", "b"])
+ for (let i = 0; i < 8; i++) fen += (this.pawnFlags[c][i] ? "1" : "0");
return fen;
}
- // TODO (design): this cmove update here or in (un)updateVariables ?
- play(move) {
- this.cmoves.push(this.getCmove(move));
- super.play(move);
- }
-
- undo(move) {
- this.cmoves.pop();
- super.undo(move);
- }
-
static get SEARCH_DEPTH() {
return 2;
}
return "0-0";
}
- // Translate final square
const finalSquare = V.CoordsToSquare(move.end);
-
const piece = this.getPiece(move.start.x, move.start.y);
+ let notation = "";
if (piece == V.PAWN) {
// Pawn move
- let notation = "";
if (move.vanish.length > 1) {
// Capture
const startColumn = V.CoordToColumn(move.start.y);
- notation =
- startColumn +
- "x" +
- finalSquare +
- "=" +
- move.appear[0].p.toUpperCase();
- } //no capture
- else {
- notation = finalSquare;
- if (move.appear.length > 0 && piece != move.appear[0].p)
- //promotion
- notation += "=" + move.appear[0].p.toUpperCase();
- }
- return notation;
+ notation = startColumn + "x" + finalSquare;
+ } else notation = finalSquare;
+ } else {
+ // Piece movement
+ notation =
+ piece.toUpperCase() +
+ (move.vanish.length > 1 ? "x" : "") +
+ finalSquare;
}
- // Piece movement
- return (
- piece.toUpperCase() +
- (move.vanish.length > 1 ? "x" : "") +
- finalSquare +
- (move.vanish.length > 1 ? "=" + move.appear[0].p.toUpperCase() : "")
- );
+ if (move.appear[0].p != move.vanish[0].p)
+ notation += "=" + move.appear[0].p.toUpperCase();
+ return notation;
}
};