bool ChessMove::IsValidMoveRook(const ChessBoard& board) const{
if (endX==startX){
int deltaY = 1;
if (startY > endY){deltaY = -1;}
for (int i = startY+deltaY; GetCondition(i, startY, endY); i+=deltaY)
if (board.GetPiece(startX, i)) return false;
return true;
} else if (endY==startY){
int deltaX = 1;
if (startX > endX){deltaX = -1;}
for (int i = startX+deltaX; GetCondition(i, startX, endX); i+=deltaX)
if (board.GetPiece(i, startY)) return false;
return true;
}
return false;
}
bool ChessMove::IsValidMovePawn(const ChessBoard& board) const{
ChessPiece* pawn = board.GetPiece(startX, startY);
ChessColor color = pawn->GetColor();
int delta = GetDelta(color);
int startingRow = GetStartingRow(color);
ChessPiece* occupyingPiece = board.GetPiece(endX, endY);
if (occupyingPiece){
return abs(startX-endX)==1 && startY+delta==endY;
} else if (endX==startX){
if (startingRow==startY){
return endY==startingRow+delta || (!board.GetPiece(endX, startingRow+delta) && endY==startingRow+delta*2);
} else {
return endY==startY+delta;
}
}
return false;
}
bool ChessMove::IsValidCastleMove(const ChessBoard& board) const{
ChessPiece* king = board.GetPiece(startX, startY);
if (king->GetMoveCount() != 0) return false;
if (abs(startX-endX) != 2 || startY != endY) return false;
int x = 7;
int delta = 1;
if (startX > endX){
x = 0;
delta = -1;
}
ChessPiece* rook = board.GetPiece(x, startY);
if (rook && rook->GetMoveCount() != 0) return false;
ChessColor opposingColor = SwitchColor(king->GetColor());
for (int i = startX; GetCondition(i, startX, x); i += delta){
if ((board.GetPiece(i, startY) && i != startX)
|| board.UnderAttack(opposingColor,i,startY)) return false;
}
return true;
}
bool ChessMove::IsValidMoveBishop(const ChessBoard & board) const{
int i = -1, j = -1;
int deltaX = 1, deltaY = 1;
if (endX < startX && endY > startY){deltaX = -1;}
else if (endX > startX && endY < startY){deltaY = -1;}
else if (endX < startX && endY < startY){deltaX = -1; deltaY = -1;}
for (i = startX+deltaX, j = startY+deltaY; GetConditionBishop(i,j); i+=deltaX, j+=deltaY)
if (board.GetPiece(i, j)) return false;
return i==endX && j==endY;
}
bool ChessMove::IsValidMove(const ChessBoard& board) const{
if (endX < 0 || endX > 7 || endY < 0 || endY > 7)
return false;
ChessPiece* startPiece = board.GetPiece(startX, startY);
ChessPiece* occupyingPiece = board.GetPiece(endX, endY);
ChessColor color = startPiece->GetColor();
if (occupyingPiece && occupyingPiece->GetColor() == color)
return false;
switch (startPiece->GetRank()){
case PAWN:
return IsValidMovePawn(board) || IsValidEnPassantMove(board, GetDelta(color), GetStartingRow(color));
case ROOK:
return IsValidMoveRook(board);
case KNIGHT:
return IsValidMoveKnight();
case BISHOP:
return IsValidMoveBishop(board);
case QUEEN:
return IsValidMoveBishop(board) || IsValidMoveRook(board);
case KING:
return IsValidMoveKing() || IsValidCastleMove(board);
}
return false;
}
void PawnMove::SelectPossibleMove(ChessBoard & board, QPoint & pos, const int player)
{
auto get_end_y = [player, pos, board] (const int step) -> int {
int k = (player == PLAYER_ONE) ? 1 : -1;
int end_y = pos.y() + k * step;
if(end_y < 0) end_y = 0;
if(end_y >= ChessBoard::MAX_ROWS) end_y = ChessBoard::MAX_ROWS - 1;
return end_y;
};
int col = pos.x();
int row = pos.y();
int row1 = get_end_y(1);
if(board.IsFreeCell(row1, col))
board.SetSelectedCell(row1, col, true);
int capture_col = col - 1;
if( capture_col >= 0 ) {
if(board.IsNotFreeAndNotMine(row1, capture_col, player))
board.SetSelectedCell(row1, capture_col, true);
}
capture_col = col + 1;
if( capture_col < ChessBoard::MAX_ROWS ) {
if(board.IsNotFreeAndNotMine(row1, capture_col, player))
board.SetSelectedCell(row1, capture_col, true);
}
int row2 = get_end_y(2);
if(board.IsFreeCell(row2, col)) {
if(board.GetPiece(row, col) == PiecesManager::PIECE_WHITE_PAWN) {
if( row == 1 ) {
board.SetSelectedCell(row2, col, true);
}
}
else if( row == 6 ) {
board.SetSelectedCell(row2, col, true);
}
}
}
bool ChessMove::IsValidEnPassantMove(const ChessBoard& board, int delta, int startingRow) const{
if (startY != startingRow+delta*3 || abs(startX-endX) != 1 || startY+delta != endY) return false;
if (board.GetPiece(endX, endY)) return false;
ChessPiece* potentialPawn = board.GetPiece(endX, startY);
return potentialPawn && potentialPawn->GetRank()==PAWN && potentialPawn->GetMoveCount()==1;
}
bool ChessMove::PutsInCheck(const ChessBoard& board) const{
ChessBoard boardCopy(board);
ChessPiece* pieceCopy(board.GetPiece(startX,startY));
return (boardCopy.DoMove(*this))->InCheck(pieceCopy->GetColor());
}
