// - a "bishop" is a chameleon, capturing as its prey
// - a "queen" is a withdrawer, capturing by moving away from pieces
+ // Is piece on square (x,y) immobilized?
+ isImmobilized([x,y])
+ {
+ 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 true;
+ 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)
+ {
+ if ([V.BISHOP,V.IMMOBILIZER].includes(this.getPiece(i2,j2)))
+ return false;
+ }
+ }
+ return true; //immobilizer isn't neutralized
+ }
+ }
+ }
+ return false;
+ }
+
getPotentialMovesFrom([x,y])
{
- // TODO: pre-check: is thing on this square immobilized? If yes, return []
+ // Pre-check: is thing on this square immobilized?
+ if (this.isImmobilized([x,y]))
+ return [];
switch (this.getPiece(x,y))
{
case VariantRules.IMMOBILIZER:
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)
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)
+ getPotentialBishopMoves([x,y])
{
- return super.getPotentialQueenMoves(sq);
+ let moves = super.getPotentialQueenMoves([x,y])
+ .concat(this.getKnightCaptures([x,y],"asChameleon"));
+ // No "king capture" because king cannot remain under check
+ 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);
}
isAttackedByPawn([x,y], colors)
{
- // Square (x,y) must be surrounded by two enemy pieces,
- // and one of them at least should be a pawn
+ // Square (x,y) must be surroundable by two enemy pieces,
+ // and one of them at least should be a pawn (moving).
+ const dirs = [ [1,0],[0,1],[1,1],[-1,1] ];
+ const steps = VariantRules.steps[VariantRules.ROOK]
+ .concat(VariantRules.steps[VariantRules.BISHOP]);
+ const [sizeX,sizeY] = VariantRules.size;
+ for (let dir of dirs)
+ {
+ const [i1,j1] = [x-dir[0],y-dir[1]]; //"before"
+ const [i2,j2] = [x+dir[0],y+dir[1]]; //"after"
+ if (i1>=0 && i1<sizeX && i2>=0 && i2<sizeX
+ && j1>=0 && j1<sizeY && j2>=0 && j2<sizeY)
+ {
+ if ((this.board[i1][j1]!=VariantRules.EMPTY
+ && colors.includes(this.getColor(i1,j1))
+ && this.board[i2][j2]==VariantRules.EMPTY)
+ ||
+ (this.board[i2][j2]!=VariantRules.EMPTY
+ && colors.includes(this.getColor(i2,j2))
+ && this.board[i1][j1]==VariantRules.EMPTY))
+ {
+ // Search a movable enemy pawn landing on the empty square
+ for (let step of steps)
+ {
+ let [ii,jj] = (this.board[i1][j1]==VariantRules.EMPTY ? [i1,j1] : [i2,j2]);
+ let [i3,j3] = [ii+step[0],jj+step[1]];
+ while (i3>=0 && i3<sizeX && j3>=0 && j3<sizeY
+ && this.board[i3][j3]==VariantRules.EMPTY)
+ {
+ i3 += step[0];
+ j3 += step[1];
+ }
+ if (i3>=0 && i3<sizeX && j3>=0 && j3<sizeY
+ && this.getPiece(i3,j3) == VariantRules.PAWN
+ && !this.isImmobilized([i3,j3]))
+ {
+ return true;
+ }
+ }
+ }
+ }
+ }
return false;
}
- isAttackedByRook(sq, colors)
+ isAttackedByRook([x,y], colors)
{
- // Enemy king must be on same file and a rook on same row (or reverse)
+ // King must be on same column or row,
+ // and a rook should be able to reach a capturing square
+ const [sizeX,sizeY] = VariantRules.size;
+ // colors contains only one element, giving the oppCol and thus king position
+ const sameRow = (x == this.kingPos[colors[0]][0]);
+ const sameColumn = (y == this.kingPos[colors[0]][1]);
+ if (sameRow || sameColumn)
+ {
+ // Look for the enemy rook (maximum 1)
+ for (let i=0; i<sizeX; i++)
+ {
+ for (let j=0; j<sizeY; j++)
+ {
+ if (this.board[i][j] != VariantRules.EMPTY
+ && this.getPiece(i,j) == VariantRules.ROOK)
+ {
+ if (this.isImmobilized([i,j]))
+ return false; //because only one rook
+ // Can it reach a capturing square?
+ // Easy but quite suboptimal way (TODO): generate all moves (turn is OK)
+ const moves = this.getPotentialMovesFrom([i,j]);
+ for (let move of moves)
+ {
+ if (sameRow && move.end.y == y || sameColumn && move.end.x == x)
+ return true;
+ }
+ }
+ }
+ }
+ }
+ return false;
}
- isAttackedByKnight(sq, colors)
+ isAttackedByKnight([x,y], colors)
{
// Square (x,y) must be on same line as a knight,
// and there must be empty square(s) behind.
+ const V = VariantRules;
+ const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
+ const [sizeX,sizeY] = V.size;
+ outerLoop:
+ for (let step of steps)
+ {
+ const [i0,j0] = [x+step[0],y+step[1]];
+ if (i0>=0 && i0<sizeX && j0>=0 && j0<sizeY && this.board[i0][j0] == V.EMPTY)
+ {
+ // Try in opposite direction:
+ 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 && colors.includes(this.getColor(i,j))
+ && this.getPiece(i,j) == V.KNIGHT)
+ {
+ if (!this.isImmobilized([i,j]))
+ return true;
+ }
+ }
+ }
+ return false;
}
- isAttackedByBishop(sq, colors)
+ isAttackedByBishop([x,y], colors)
{
- // 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...)
+ // We cheat a little here: since this function is used exclusively for king,
+ // it's enough to check the immediate surrounding of the square.
+ 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
+ && colors.includes(this.getColor(i,j)) && this.getPiece(i,j) == V.BISHOP)
+ {
+ return true; //bishops are never immobilized
+ }
+ }
+ return false;
}
- isAttackedByQueen(sq, colors)
+ isAttackedByQueen([x,y], 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)
+ 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 sq2 = [x+2*step[0],y+2*step[1]];
+ if (sq2[0]>=0 && sq2[0]<sizeX && sq2[1]>=0 && sq2[1]<sizeY
+ && this.board[sq2[0]][sq2[1]] == V.EMPTY)
+ {
+ const sq1 = [x+step[0],y+step[1]];
+ if (this.board[sq1[0]][sq1[1]] != V.EMPTY
+ && colors.includes(this.getColor(sq1[0],sq1[1]))
+ && this.getPiece(sq1[0],sq1[1]) == V.QUEEN
+ && !this.isImmobilized(sq1))
+ {
+ return true;
+ }
+ }
+ }
+ return false;
}
updateVariables(move)
{
- // Just update king position
+ // 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)
projects / vchess.git / blobdiff