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fpchess: Patch from Brian, verifies if a pawn threatens the king

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git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@1750 8e941d3f-bd1b-0410-a28a-d453659cc2b4
This commit is contained in:
sekelsenmat
2011-07-21 13:49:28 +00:00
parent f78b7dab10
commit b9f6e146a4
1 changed files with 37 additions and 0 deletions
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37
applications/fpchess/chessgame.pas
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@ -110,6 +110,7 @@ type
procedure DoCastle();
function ValidatePawnMove(AFrom, ATo: TPoint;
var AEnpassantSquare, AEnpassantSquareToClear: TPoint) : boolean;
function ValidatePawnSimpleCapture(AFrom,ATo: TPoint): Boolean;
function IsSquareOccupied(ASquare: TPoint): Boolean;
procedure UpdateTimes();
end;
@ -631,6 +632,40 @@ begin
end;
end;
//This function is used by IsKingInCheck. It makes the verification reversed
//(verify a black move in white turn and vice-versa) and don't change the enpassant
//variables.
function TChessGame.ValidatePawnSimpleCapture(AFrom,ATo: TPoint): Boolean;
begin
result:=false;
if not CurrentPlayerIsWhite then
begin
// Normal capture in the left
if (ATo.X = AFrom.X-1) and (ATo.Y = AFrom.Y+1) and IsSquareOccupied(ATo) then
begin
Result := True;
end
// Normal capture in the right
else if (ATo.X = AFrom.X+1) and (ATo.Y = AFrom.Y+1) and IsSquareOccupied(ATo) then
begin
Result := True;
end;
end
else
begin
// Capture a piece in the left
if (ATo.X = AFrom.X-1) and (ATo.Y = AFrom.Y-1) and IsSquareOccupied(ATo) then
begin
Result := True;
end
// Capture a piece in the right
else if (ATo.X = AFrom.X+1) and (ATo.Y = AFrom.Y-1) and IsSquareOccupied(ATo) then
begin
Result := True;
end
end;
end;
function TChessGame.IsSquareOccupied(ASquare: TPoint): Boolean;
begin
Result := Board[ASquare.X][ASquare.Y] <> ctEmpty;
@ -717,6 +752,7 @@ begin
ctWBishop: Result:= ValidateBishopMove(piecePos,AKingPos);
ctWQueen: Result:= ValidateQueenMove(piecePos,AKingPos);
ctWKing: Result:= ValidateKingMove(piecePos,AKingPos);
ctWPawn: Result:= ValidatePawnSimpleCapture(piecePos,AKingPos);
end;
end
else
@ -727,6 +763,7 @@ begin
ctBBishop: Result:= ValidateBishopMove(piecePos,AKingPos);
ctBQueen: Result:= ValidateQueenMove(piecePos,AKingPos);
ctBKing: Result:= ValidateKingMove(piecePos,AKingPos);
ctBPawn: Result:= ValidatePawnSimpleCapture(piecePos,AKingPos);
end;
end;
if (result) then exit();