// Is piece on square (x,y) immobilized?
isImmobilized([x,y])
{
- // Final check: is this knight immobilized?
- let foundImmobilizer = false;
- let neutralized = false;
- outerLoop:
- for (let step of steps)
- {
- const [i2,j2] = [i+step[0],j+step[1]];
- if (i2>=0 && i2<sizeX && j2>=0 && j2<sizeY
- && this.board[i2][j2] != V.EMPTY
- && this.getColor(i2,j2) == oppCol
- && this.getPiece(i2,j2) == V.IMMOBILIZER)
- {
- foundImmobilizer = true;
- // Moving is possible only if this immobilizer is neutralized
- for (let step2 of steps)
- {
- const [i3,j3] = [i2+step2[0],j2+step2[1]];
- if (i3>=0 && i3<sizeX && j3>=0 && j3<sizeY
- && this.board[i3][j3] != V.EMPTY && this.getColor(i3,j3) == color
- && [V.BISHOP,V.IMMOBILIZER].includes(this.getPiece(i3,j3)))
- {
- neutralized = true;
- break outerLoop;
- }
- }
- }
- }
- if (!foundImmobilizer || neutralized)
- return false;
-
const piece = this.getPiece(x,y);
const color = this.getColor(x,y);
const oppCol = this.getOppCol(color);
{
const oppPiece = this.getPiece(i,j);
if (oppPiece == V.BISHOP && piece == V.IMMOBILIZER)
- return [];
+ return true;
if (oppPiece == V.IMMOBILIZER && ![V.BISHOP,V.IMMOBILIZER].includes(piece))
{
// Moving is impossible only if this immobilizer is not neutralized
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;
+ if ([V.BISHOP,V.IMMOBILIZER].includes(this.getPiece(i2,j2)))
+ return false;
}
}
- return []; //immobilizer isn't neutralized
+ return true; //immobilizer isn't neutralized
}
}
}
+ return false;
}
getPotentialMovesFrom([x,y])
// isAttacked() is OK because the immobilizer doesn't take
- // TODO: check if any pawn can reach capturing square + !immobilized
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
- && this.board[i1][j1]!=VariantRules.EMPTY
- && this.board[i2][j2]!=VariantRules.EMPTY
- && colors.includes(this.getColor(i1,j1))
- && colors.includes(this.getColor(i2,j2))
- && [this.getPiece(i1,j1),this.getPiece(i2,j2)].includes(VariantRules.PAWN))
+ && j1>=0 && j1<sizeY && j2>=0 && j2<sizeY)
{
- return true;
+ 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;
}
- // TODO: check if enemy's rook can reach capturing squares + !immobilized
isAttackedByRook([x,y], colors)
{
+ // King must be on same column or row,
+ // and a rook should be able to reach a capturing square
const [sizeX,sizeY] = VariantRules.size;
- // King must be on same column and a rook on same row (or reverse)
- if (x == this.kingPos[colors[0]][0]) //using colors[0], only element in this case
- {
- // Look for enemy rook on this column
- for (let i=0; i<sizeY; i++)
- {
- if (this.board[x][i] != VariantRules.EMPTY
- && colors.includes(this.getColor(x,i))
- && this.getPiece(x,i) == VariantRules.ROOK)
- {
- return true;
- }
- }
- }
- else if (y == this.kingPos[colors[0]][1])
+ // 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 enemy rook on this row
+ // Look for the enemy rook (maximum 1)
for (let i=0; i<sizeX; i++)
{
- if (this.board[i][y] != VariantRules.EMPTY
- && colors.includes(this.getColor(i,y))
- && this.getPiece(i,y) == VariantRules.ROOK)
+ for (let j=0; j<sizeY; j++)
{
- return true;
+ 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;
+ }
+ }
}
}
}
projects / vchess.git / commitdiff
