public void testIteratorOverEmptyCollection()
{
sizableArray<move> foo = new sizableArray<move>(5);
if (foo.Length != 0)
throw new Exception("Iterator length not zero while iterating over an empty collection");
foreach (move thisMove in foo)
throw new Exception("Iterator returned something while iterating over an empty collection");
}
public override sizableArray<square> getCoveredSquares(baseBoard onThis)
{
sizableArray<square> toRet = new sizableArray<square>(20);
getSquaresCoveredForVector(toRet, onThis, vectorDirection.left);
getSquaresCoveredForVector(toRet, onThis, vectorDirection.down);
getSquaresCoveredForVector(toRet, onThis, vectorDirection.right);
getSquaresCoveredForVector(toRet, onThis, vectorDirection.up);
return toRet;
}
public override sizableArray<move> getPossibleMoves(baseBoard onThis)
{
sizableArray<move> toRet = new sizableArray<move>(20);
getMovesForVector(toRet, onThis, vectorDirection.left);
getMovesForVector(toRet, onThis, vectorDirection.down);
getMovesForVector(toRet, onThis, vectorDirection.right);
getMovesForVector(toRet, onThis, vectorDirection.up);
return toRet;
}
public override sizableArray<square> getCoveredSquares(baseBoard parentBoard)
{
sizableArray<square> toRet = new sizableArray<square>(8);
foreach (squarePosOffset potentialSquare in potentialSquares)
{
int posX = position.x + potentialSquare.x;
int posY = position.y + potentialSquare.y;
if (IsOnBoard(potentialSquare.x, potentialSquare.y))
toRet.Add( parentBoard[posX, posY] );
}
return toRet;
}
public override sizableArray<move> getPossibleMoves(baseBoard onThis)
{
sizableArray<move> possibleMoves = new sizableArray<move>(potentialSquares.Length + 2);
findFreeOrCapturableIfOnBoard(possibleMoves, onThis, potentialSquares);
if (canCastle(onThis, true))
{
// Castling kingside is possible. It is represented as a two-space move by the king.
possibleMoves.Add(new move(this, onThis[position.right(2)]));
}
if (canCastle(onThis, false))
{
// Likewise, queenside.
possibleMoves.Add(new move(this, onThis[position.left(2)]));
}
return possibleMoves;
}
public override sizableArray<square> getCoveredSquares(baseBoard parentBoard)
{
sizableArray<square> toRet = new sizableArray<square>(2);
int direction = (colour == pieceColour.white) ? 1 : -1;
if ((position.y + direction < baseBoard.sizeY) &&
(position.y + direction > -1))
{
// Check the two diagonals
if (position.x > 0)
{
toRet.Add( parentBoard[position.up(direction).leftOne()] );
}
if (position.x < baseBoard.sizeX - 1)
{
toRet.Add( parentBoard[position.up(direction).rightOne()] );
}
}
return toRet;
}
public static void testListsAreOfSameMoves(List<move> expectedmoves, sizableArray<move> actualMoves)
{
Assert.AreEqual(expectedmoves.Count, actualMoves.Length, "Incorrect amount of moves");
foreach (move thisPossibleMove in actualMoves)
{
for (int i = 0; i < expectedmoves.Count; i++)
{
move thisExpectedMove = expectedmoves[i];
if ((thisExpectedMove.srcPos.isSameSquareAs(thisPossibleMove.srcPos) &&
(thisExpectedMove.dstPos.isSameSquareAs(thisPossibleMove.dstPos))))
{
expectedmoves.Remove(thisExpectedMove);
break;
}
}
}
Assert.AreEqual(0, expectedmoves.Count, "Unexpected move found");
}
public override lineAndScore findBestMove()
{
sizableArray<move> movesToConsider = getMoves(colToMove);
// Filter out any moves in to check
sizableArray<move> movesNotIntoCheck = new sizableArray<move>(movesToConsider.Length);
pieceColour movingCol = colToMove;
foreach (move consideredMove in movesToConsider)
{
doMove(consideredMove);
if (!isPlayerInCheck(movingCol))
movesNotIntoCheck.Add(consideredMove);
undoMove(consideredMove);
}
// and then select a random move.
int rndNum = rnd.Next(movesNotIntoCheck.Length);
move randomMove = movesNotIntoCheck[rndNum];
return new lineAndScore(new move[] { randomMove }, 0, null);
}
public void testIterator()
{
sizableArray<move> foo = new sizableArray<move>(5);
move move1 = new move(new square(0,0), new square(1,1));
move move2 = new move(new square(1,1), new square(2,2));
foo.Add(move1);
foo.Add(move2);
bool move1seen = false;
bool move2seen = false;
foreach (move iterated in foo)
{
Debug.WriteLine("Iterated object " + iterated);
if (iterated == move1)
{
if (move1seen)
throw new Exception("Move one iterated twice");
move1seen = true;
}
else if (iterated == move2)
{
if (move2seen)
throw new Exception("Move two iterated twice");
move2seen = true;
}
else if (iterated == null)
throw new Exception("Iterator returned null");
else
throw new Exception("Iterator returned something crazy");
}
if (!move1seen || !move2seen)
throw new Exception("Iterator did not iterate over all elements");
}
public override sizableArray<move> getPossibleMoves(baseBoard onThis)
{
sizableArray<move> toRet = new sizableArray<move>(40);
int direction;
if (colour == pieceColour.white)
direction = +1;
else
direction = -1;
// We can capture upward diagonally, if immediate diagonal upward squares
// contain an enemy piece.
if ((position.y + direction < baseBoard.sizeY) &&
(position.y + direction > -1) )
{
// Check for en passant. En passant can never cause a promotion.
if (position.x > 0)
{
square adjacentLeft = onThis[position.leftOne()];
if (canEnPassantTo(adjacentLeft, onThis))
toRet.Add(new move(onThis[position], onThis[position.up(direction).leftOne()], adjacentLeft));
}
if (position.x < baseBoard.sizeX - 1)
{
square adjacentRight = onThis[position.rightOne()];
if (canEnPassantTo(adjacentRight, onThis))
toRet.Add(new move(onThis[position], onThis[position.up(direction).rightOne()], adjacentRight));
}
// And we can move forward two if we haven't moved this piece yet, and both
// squares are empty. It is assumed that this can't cause a promotion, so explicitly
// prevent this move from moving in to the back row.
if (movedCount == 0)
{
if (position.y + (direction * 2) < baseBoard.sizeY &&
position.y + (direction * 2) > -1)
{
// check back row
if (position.y != (colour == pieceColour.white ? 7 : 0))
{
if (onThis[position.up(direction * 2)].type == pieceType.none &&
onThis[position.up(direction * 1)].type == pieceType.none)
toRet.Add(new move(onThis[position], onThis[position.up(direction*2)]));
}
}
}
// All of the other moves could cause a promotion, so call addPawnMovesToSquare so that
// promoting moves are added.
// Check the two diagonals
if (position.x > 0)
{
if (onThis[position.up(direction).leftOne()].containsPieceNotOfColour(colour))
addPawnMovesToSquare(toRet, onThis[position], onThis[position.up(direction).leftOne()]);
}
if (position.x < baseBoard.sizeX - 1)
{
if (onThis[position.up(direction).rightOne()].containsPieceNotOfColour(colour))
addPawnMovesToSquare(toRet, onThis[position], onThis[position.up(direction).rightOne()]);
}
// We can move forward one if that square is empty.
if (onThis[position.up(direction)].type == pieceType.none)
{
if (onThis[position.up(direction)].type == pieceType.none)
addPawnMovesToSquare(toRet, onThis[position], onThis[position.up(direction)]);
}
}
return toRet;
}
private void prioritizeMoves(sizableArray<move> movesToConsider, int depthLeft)
{
// Bring any moves which are 'probably good' to the top of our list. Hold an array of bools, and set
// each one which corresponds to a good move, so that we can avoid moving anything twice.
bool[] movesReordered = new bool[movesToConsider.Length];
int[] reorderedMovesToConsider = new int[movesToConsider.Length];
int reorderedCount = 0;
int n = 0;
if (_killerStore != null)
{
// If one of these moves caused a cutoff last time, consider that move first.
foreach (move consideredMove in movesToConsider)
{
if (_killerStore.contains(consideredMove, depthLeft))
{
movesReordered[n] = true;
reorderedMovesToConsider[reorderedCount++] = n;
}
n++;
}
}
// Consider any capturing or pawn promotions first, too
n = 0;
foreach (move thisMove in movesToConsider)
{
if (thisMove.isCapture || // captures are good.
thisMove.isPawnPromotion) // pawn promotions are good.
{
if (movesReordered[n] == false)
{
movesReordered[n] = true;
reorderedMovesToConsider[reorderedCount++] = n;
}
}
n++;
}
// Swap any good moves such that they are at the top
int swapCount = 0;
for (int i = 0; i < reorderedCount; i++)
movesToConsider.bringToPosition(reorderedMovesToConsider[i], swapCount++);
}
public void add(int x, int y)
{
// This is slightly complicated by the fact that any new piece could block other pieces
// from threatening squares. Because of this, we keep per-piece 'threat lists' containing
// the a list of squares threatened by the given piece, and if a piece is placed in to a
// square threatened by another piece, we then re-evaluate the threatening pieces.
// Find squares which threaten the square we are placing in to, and stash them in another
// list
sizableArray<int> piecesToRecalc = new sizableArray<int>(piecesWhichThreatenSquare[x, y].Count);
piecesToRecalc.AddRange( piecesWhichThreatenSquare[x, y] );
// Now, add the new pieces threatened squares
sizableArray<square> potentialDestSquares = _parentBoard[x, y].getCoveredSquares(_parentBoard);
// Since our threat map is always stored from white's viewpoint, we should add or subtract
// depending if threatened pieces are white or black.
int mapAddition = _parentBoard[x, y].colour == pieceColour.white ? 1 : -1;
// Now cycle through each move and apply them to our map, and to the piece.
//_parentBoard[x, y].coveredSquares.Clear();
foreach (square potentialDstSq in potentialDestSquares)
{
// Add the threatened squares to our threat map
this[potentialDstSq.position] += mapAddition;
speedySquareList piecesWhichThreatenThisSq = piecesWhichThreatenSquare[potentialDstSq.position.x, potentialDstSq.position.y];
// update our list of pieces threatening each square
piecesWhichThreatenThisSq[squarePos.flatten(x, y)] = true;
// and our list of squares covered by piece
_parentBoard[x, y].coveredSquares[potentialDstSq.position.flatten()] = true;
}
// and then recalculate pieces that need it. To save time, we don't re-evaluate everything-
// we just remove extra squares based on the piece.
foreach (int toRecalcPos in piecesToRecalc)
{
square toRecalc = _parentBoard[toRecalcPos];
int toRecalcAddition = toRecalc.colour == pieceColour.white ? 1 : -1;
// Knights can never be blocked from accessing squares.
if (toRecalc.type == pieceType.knight)
continue;
//Pawns can always access their two attack squares.
if (toRecalc.type == pieceType.pawn)
continue;
// Remove covered squares which are on the other 'side' of us - for example, if a rook
// is to our left, remove squares to our right from it.
int offX = toRecalc.position.x - x;
int offY = toRecalc.position.y - y;
int sx;
if (offX < 0)
sx = +1;
else if (offX > 0)
sx = -1;
else
sx = 0;
int sy;
if (offY < 0)
sy = +1;
else if (offY > 0)
sy = -1;
else
sy = 0;
// Look right up to the edge for all pieces apart from the king, which can look only
// one square in each direction.
int limitx = DoktorChessAIBoard.sizeX;
int limity = DoktorChessAIBoard.sizeY;
if (toRecalc.type == pieceType.king)
{
limitx = toRecalc.position.x + (sx * 2);
limity = toRecalc.position.x + (sy * 2);
if (limitx > DoktorChessAIBoard.sizeX)
limitx = DoktorChessAIBoard.sizeX;
if (limity > DoktorChessAIBoard.sizeY)
limity = DoktorChessAIBoard.sizeY;
}
//Debug.WriteLine( toRecalc.type + toRecalc.position + ":");
int removex = x + sx;
int removey = y + sy;
while(removex >= 0 && removex < limitx &&
removey >= 0 && removey < limity )
{
squarePos toRemoveSqPos = new squarePos(removex, removey);
this[toRemoveSqPos] -= toRecalcAddition;
speedySquareList piecesWhichThreatenThisSq = piecesWhichThreatenSquare[removex, removey];
piecesWhichThreatenThisSq[toRecalc.position] = false;
toRecalc.coveredSquares[ toRemoveSqPos ] = false;
//Debug.WriteLine("Removed now-blocked " + pos);
// we can threaten one piece, but no farther.
if (_parentBoard[removex, removey].type != pieceType.none)
break;
removex += sx;
removey += sy;
}
}
sanityCheck();
}
public void remove(square toRemove)
{
int posDirection = toRemove.colour == pieceColour.white ? 1 : -1;
// Remove the actual piece, and what it threatens.
foreach (int threatenedSquareFlat in toRemove.coveredSquares )
{
squarePos threatenedSquare = squarePos.unflatten(threatenedSquareFlat);
this[threatenedSquare] -= posDirection;
// The removed piece no longer threatens this square.
piecesWhichThreatenSquare[threatenedSquare.x, threatenedSquare.y][toRemove.position] = false;
}
toRemove.coveredSquares.Clear();
// and now force a re-evaluation of things that threatened this square.
sizableArray<int> piecesToRecalc = new sizableArray<int>(piecesWhichThreatenSquare[toRemove.position.x, toRemove.position.y].Count);
piecesToRecalc.AddRange(piecesWhichThreatenSquare[toRemove.position.x, toRemove.position.y]);
foreach (int toRecalcFlat in piecesToRecalc)
{
square toRecalc = _parentBoard[squarePos.unflatten(toRecalcFlat)];
// Knights can never be blocked from accessing squares.
if (toRecalc.type == pieceType.knight)
continue;
//Pawns can always access their two attack squares.
if (toRecalc.type == pieceType.pawn)
continue;
int toRecalcAddition = toRecalc.colour == pieceColour.white ? 1 : -1;
// Remove covered squares which are on the other 'side' of us - for example, if a rook
// is to our left, remove squares to our right from it.
int offX = toRecalc.position.x - toRemove.position.x;
int offY = toRecalc.position.y - toRemove.position.y;
int sx;
if (offX < 0)
sx = +1;
else if (offX > 0)
sx = -1;
else
sx = 0;
int sy;
if (offY < 0)
sy = +1;
else if (offY > 0)
sy = -1;
else
sy = 0;
// Look right up to the edge for all pieces apart from the king, which can look only
// one square in each direction.
int limitx = DoktorChessAIBoard.sizeX;
int limity = DoktorChessAIBoard.sizeY;
if (toRecalc.type == pieceType.king)
{
limitx = toRecalc.position.x + (2 * sx);
limity = toRecalc.position.x + (2 * sx);
if (limitx > DoktorChessAIBoard.sizeX)
limitx = DoktorChessAIBoard.sizeX;
if (limity > DoktorChessAIBoard.sizeY)
limity = DoktorChessAIBoard.sizeY;
}
//Debug.WriteLine(toRecalc.type + " @ " + toRecalc.position + ":");
int removex = toRemove.position.x + sx;
int removey = toRemove.position.y + sy;
while(removex >= 0 && removex < limitx &&
removey >= 0 && removey < limity )
{
squarePos pos = new squarePos(removex, removey);
this[pos] += toRecalcAddition;
piecesWhichThreatenSquare[removex, removey][toRecalc.position] = true;
toRecalc.coveredSquares[pos.flatten()] = true;
//Debug.WriteLine("Added discovered " + pos);
// we can threaten one piece, but no farther.
if (_parentBoard[removex, removey].type != pieceType.none)
break;
removex += sx;
removey += sy;
}
}
sanityCheck();
}
protected void getSquaresCoveredForVector(sizableArray<square> addTo, baseBoard onThis, vectorDirection dir)
{
if (addTo == null)
addTo = new sizableArray<square>(8);
loopConfig lcfg = new loopConfig(position, dir);
int x = lcfg.startX;
int y = lcfg.startY;
while ((x != lcfg.finishX) && (y != lcfg.finishY))
{
squarePos sqPos = new squarePos(x, y);
// If the square is empty, we can move to it..
if (onThis[sqPos].type == pieceType.none)
{
addTo.Add( onThis[sqPos] );
}
else
{
// the square is occupied by some piece. We are covering it, but we cannot go any further.
addTo.Add( onThis[sqPos] );
break;
}
x += lcfg.directionX;
y += lcfg.directionY;
}
return;
}
protected sizableArray<move> findFreeOrCapturableIfOnBoard(sizableArray<move> returnArray, baseBoard onThis, squarePosOffset[] potentialSquareOffsets)
{
if (returnArray == null)
returnArray = new sizableArray<move>(potentialSquareOffsets.Length);
foreach (squarePosOffset potentialSquareOffset in potentialSquareOffsets)
{
if (!IsOnBoard(potentialSquareOffset.x, potentialSquareOffset.y))
continue;
square destSquare = onThis[potentialSquareOffset.x + position.x, potentialSquareOffset.y + position.y];
if (destSquare.type == pieceType.none)
{
// Square is free.
returnArray.Add(new move(this, destSquare));
}
else
{
if (destSquare.colour != this.colour)
{
// We can capture.
returnArray.Add(new move(this, destSquare));
}
}
}
return returnArray;
}
/// <summary>
/// Find moves in a given direction, including captures
/// </summary>
/// <param name="addTo"></param>
/// <param name="onThis">The board to move on</param>
/// <param name="dir">The vectorDirection to move in</param>
/// <returns>A List<move> of moves</returns>
public sizableArray<move> getMovesForVector(sizableArray<move> addTo, baseBoard onThis, vectorDirection dir)
{
if (addTo == null)
addTo = new sizableArray<move>(8);
loopConfig lcfg = new loopConfig(position, dir);
int x = lcfg.startX;
int y = lcfg.startY;
while ((x != lcfg.finishX) && (y != lcfg.finishY))
{
squarePos sqPos = new squarePos(x, y);
// If the square is empty, we can move to it..
if (onThis[sqPos].type == pieceType.none)
{
addTo.Add(new move(onThis[position], onThis[sqPos]));
}
else
{
if (onThis[sqPos].colour != colour )
{
// the square is occupied by an enemy piece. we can move to it,
// but no further.
addTo.Add(new move(onThis[position], onThis[sqPos]));
}
break;
}
x += lcfg.directionX;
y += lcfg.directionY;
}
return addTo;
}
private void addPawnMovesToSquare(sizableArray<move> moveList, square src, square dst)
{
// If we are moving in to the end row, we should promote. Handle this.
if (dst.position.y == (colour == pieceColour.white ? 7 : 0) )
{
// OK. Promotions it is.
pieceType[] promotionOptions = new[] {
pieceType.queen,
pieceType.rook,
pieceType.knight,
pieceType.bishop
};
foreach (pieceType promotionOption in promotionOptions)
{
moveList.Add(new move(src, dst, promotionOption));
}
}
else
{
moveList.Add(new move(src, dst));
}
}
/// <summary>
/// Return a collecetion of all moves one player may be able to make.
/// Note that moves in to check will also be returned.
/// </summary>
/// <param name="toMoveColour">Side to examine</param>
/// <returns></returns>
public sizableArray<move> getMoves(pieceColour toMoveColour)
{
List<square> occupiedSquares = getPiecesForColour(toMoveColour);
// Generously guess the size of this array
sizableArray<move> possibleMoves = new sizableArray<move>(occupiedSquares.Count * 50);
// Add all moves from all pieces
foreach (square occupiedSquare in occupiedSquares)
possibleMoves.AddRange(occupiedSquare.getPossibleMoves(this));
return possibleMoves;
}
