//Given a state, an initial position and a target position, returns true if the white player
//can move a checker from the initial position to the target position, or false if not.
private static bool IsLegalToMoveToPosition(GameBoardState state, int fromPosition, int toPosition)
{
//If the target position is between -5 and 0, then the white player is trying to bear off a checker
if (toPosition <= 0 && toPosition >= -5)
{
return(IsLegalToBearOff(state, fromPosition, toPosition));
}
//If not, make sure the position is on the board and that there are less than two enemy checkers there
if (toPosition < 1 || toPosition > 24)
{
return(false);
}
return(state.getMainBoard()[toPosition - 1] > -2);
}
internal static string CreateXmlForGameBoardState(GameBoardState state, string rootTag)
{
if (state == null)
{
throw new ArgumentNullException("state");
}
if (rootTag == null)
{
throw new ArgumentNullException("rootTag");
}
//Separating each element of the array with a space, and removes trailing spaces
var board = state.getMainBoard().Select(i => i + " ").Aggregate((a, b) => a + b).Trim();
//Wrap the board with tags
board = "<board>" + board + "</board>";
int whiteGoal = state.GetCheckersOnPosition(White.BearOffPositionID());
int whiteBar = state.GetCheckersOnPosition(White.GetBar());
//The agreed format is that black checkers on bar and target should be represented as negative
int blackGoal = state.GetCheckersOnPosition(Black.BearOffPositionID());
blackGoal = Math.Min(blackGoal, blackGoal * -1);
int blackBar = state.GetCheckersOnPosition(Black.GetBar());
blackBar = Math.Min(blackBar, blackBar * -1);
//Wrap each of the above four values in their own tags
var rest = String.Format("<whiteGoal>{0}</whiteGoal><whiteBar>{1}</whiteBar><blackGoal>{2}</blackGoal><blackBar>{3}</blackBar>",
whiteBar, whiteGoal, blackBar, blackGoal);
//Wrapping the entire message in the supplied root tags
if (rootTag == "")
{
return(board + rest);
}
else
{
return(String.Format("<{0}>" + board + rest + "</{0}>", rootTag));
}
}
//Given a state and a position, returns true if it is legal for the white player can move a checker from that position
private static bool IsLegalToMoveFromPosition(GameBoardState state, int position)
{
//If the position is the bar, there has to be at least one checker on the bar
if (position == WHITE.GetBar())
{
return(state.getCheckersOnBar(WHITE) > 0);
}
//If not, there cannot be any checkers on the bar, the position has to be on the board, and there has to be at
//least one checker on that position
else
{
if (state.getCheckersOnBar(WHITE) > 0)
{
return(false);
}
if (position < 1 || position > 24)
{
return(false);
}
return(state.getMainBoard()[position - 1] > 0);
}
}
