public static MoveSummary CanKnightMove(Board board, Square from, Square to)
{
var isSameColor = board[from].Color == board[to].Color;
var isCapturing = board[to].IsNone() ?
false :
!isSameColor;
var isMovePossible =
!isSameColor &&
MoveProperty.AbsDeltaX(from, to) *
MoveProperty.AbsDeltaY(from, to) == 2;
return(MoveSummaryBuilder.DefaultMoveSummary(isCapturing, isMovePossible, to));
}
private static bool CanCapture(
Color pawnColor,
Board board,
Square from, Square to)
{
// white: b2 -> a3 || c3; from.y - to.y == 1; |from.x - to.x| == 1
// black: b7 -> a6 || c6; from.y - to.y == -1; |from.x == to.x| == 1
var step = GetPawnStep(pawnColor);
return
(!board[to].IsNone() &&
MoveProperty.AbsDeltaX(from, to) == 1 &&
MoveProperty.DeltaY(from, to) == step);
}
private static bool CanEnPassantCapture(
ChessGame game,
Color pawnColor,
Square from, Square to)
{
if (game.EnPassantTargetSquare.IsNone())
{
return(false);
}
var step = GetPawnStep(pawnColor);
return
(to == game.EnPassantTargetSquare &&
MoveProperty.AbsDeltaX(from, to) == 1 &&
MoveProperty.DeltaY(from, to) == step);
}
private static bool CanDefaultMove(Square from, Square to, bool isSameColor) => !isSameColor && MoveProperty.AbsDeltaX(from, to) <= 1 && MoveProperty.AbsDeltaY(from, to) <= 1;