Day 51

Day 43-51 (chess application)/Chess.java

@@ -14,6 +14,12 @@ import javafx.scene.input.*;
 import javafx.scene.image.*;
 import javafx.geometry.*;
 
+//TODO:
+//	Prevent moving into check
+//	Add castling
+//	Add en passant
+//	Give feedback for check, checkmate, and stalemate.
+
 //Main class and GUI
 
 public class Chess extends Application {
@@ -27,6 +33,7 @@ public class Chess extends Application {
 
 	private GraphicsContext graphics;
 	private TextArea moveHistoryTextArea;
+	private Label feedback;
 
 	//Load images
 	private static final Image W_ROOK = new Image("img/w_rook_png_shadow_128px.png");
@@ -71,14 +78,20 @@ public class Chess extends Application {
 		hb.setAlignment(Pos.CENTER);
 		root.getChildren().add(hb);
 
+		//Add a label for feedback
+		feedback = new Label("");
+		HBox hb2 = new HBox(20, feedback);
+		hb2.setAlignment(Pos.CENTER);
+		root.getChildren().add(hb2);
+
 		//Set up buttons
 		Button undo = new Button("Undo");
 		Button reset = new Button("Reset");
 		Button aiMove = new Button("AI move");
-		HBox h = new HBox(20, undo, reset, aiMove);
-		h.setAlignment(Pos.CENTER);
-		h.setPadding(new Insets(10,10,10,10));
-		root.getChildren().add(h);
+		HBox hb3 = new HBox(20, undo, reset, aiMove);
+		hb3.setAlignment(Pos.CENTER);
+		hb3.setPadding(new Insets(10,10,10,10));
+		root.getChildren().add(hb3);
 
 		//Set up empty move history, game history,  notation history.
 		gameStateHistory = new ArrayList<GameState>();
@@ -107,10 +120,25 @@ public class Chess extends Application {
 	}
 
 	private void updateScreen() {
+		//Draw the board
 		for(int x = 0; x < 8; x++) {
 			for(int y = 0; y < 8; y++) {
 				graphics.setFill((x + y) % 2 == 0 ? Color.BURLYWOOD : Color.FORESTGREEN);
 				graphics.fillRect(50*x, 50*y, 50, 50);
+			}
+		}
+
+		//Show the last move made in red
+		if (!moveHistory.isEmpty()) {
+			graphics.setFill(new Color(1, 0, 0, .6));
+			Move m = moveHistory.get(moveHistory.size() - 1);
+			graphics.fillRect(50*m.getSourceCol(), 50*m.getSourceRow(), 50, 50);
+			graphics.fillRect(50*m.getDestCol(), 50*m.getDestRow(), 50, 50);
+		}
+
+		//Draw the pieces
+		for(int x = 0; x < 8; x++) {
+			for(int y = 0; y < 8; y++) {
 				Square s = board().getSquare(x, y);
 				if ( s.getType() ==  Square.PAWN && s.isWhite()) graphics.drawImage(W_PAWN, 50*x, 50*y, 50, 50);
 				if ( s.getType() ==  Square.PAWN && !s.isWhite()) graphics.drawImage(B_PAWN, 50*x, 50*y, 50, 50);
@@ -124,8 +152,18 @@ public class Chess extends Application {
 				if ( s.getType() ==  Square.QUEEN && !s.isWhite()) graphics.drawImage(B_QUEEN, 50*x, 50*y, 50, 50);
 				if ( s.getType() ==  Square.KING && s.isWhite()) graphics.drawImage(W_KING, 50*x, 50*y, 50, 50);
 				if ( s.getType() ==  Square.KING && !s.isWhite()) graphics.drawImage(B_KING, 50*x, 50*y, 50, 50);
+
 			}
 		}
+
+		//Highlight the selected square (if any) in yellow
+		if (clickRow != null) {
+			graphics.setFill(new Color(1, 1, 0, .5));
+			graphics.fillRect(50*clickCol, 50*clickRow, 50, 50);
+		}
+
+		//Update feedback
+		feedback.setText(board().getFeedback());
 	}
 
 	private GameState board() {
@@ -134,8 +172,6 @@ public class Chess extends Application {
 
 	//Reset to the intial game position.
 	public void reset(ActionEvent e) {
-		System.out.println(board().getAllPossibleMoves());
-
 		//Clear out all the histories
 		gameStateHistory = new ArrayList<GameState>();
 		gameStateHistory.add(new GameState()); //Set up the initial board
@@ -173,6 +209,8 @@ public class Chess extends Application {
 
 		//Refresh the board
 		updateScreen();
+
+		writeMoveHistoryForIndex(moveNotationHistory.size()-1);
 	}
 
 	//For the human moving
@@ -195,7 +233,6 @@ public class Chess extends Application {
 
 	//Undo button for the most recent move
 	public void undo(ActionEvent e) {
-		//Pop those 3 history object things and update the GUI.
 		if (gameStateHistory.size() <= 1) return; //can't pop the initial state.
 
 		//Pop those 3 history object things and update the GUI.
@@ -203,7 +240,22 @@ public class Chess extends Application {
 		moveHistory.remove(moveHistory.size() - 1);
 		moveNotationHistory.remove(moveNotationHistory.size() - 1);
 		clickRow = clickCol = null;
+		refreshMoveHistoryDisplay();
 		updateScreen();
 	}
 
+	private void refreshMoveHistoryDisplay() {
+		moveHistoryTextArea.setText("");
+		for(int i = 0; i < moveHistory.size(); i++) {
+			writeMoveHistoryForIndex(i);
+		}
+	}
+
+	private void writeMoveHistoryForIndex(int ply) {
+		GameState g = gameStateHistory.get(ply);
+		Move m = moveHistory.get(ply);
+		if (g.isWhitesTurn()) moveHistoryTextArea.appendText("\n" + (ply/2+1) +". "+m);
+		else moveHistoryTextArea.appendText("  " +m);
+	}
+
 }

Day 43-51 (chess application)/GameState.java

@@ -47,6 +47,14 @@ public class GameState {
 		boardSquares[move.getDestIndex()] = new Square(boardSquares[move.getSourceIndex()]);
 		boardSquares[move.getSourceIndex()] = new Square(Square.EMPTY);
 
+		//Queening (no underpromotion for now)
+		if ((move.getDestRow() == 0 || move.getDestRow() == 7) && boardSquares[move.getDestIndex()].getType() == Square.PAWN) {
+			boolean w = boardSquares[move.getDestIndex()].isWhite();
+			boardSquares[move.getDestIndex()] = new Square(Square.QUEEN, w);  //Make that pawn a queen
+		}
+
+		boardSquares[move.getDestIndex()].setHasMoved(); //For knowledge about moving pawns two squares and castling.
+
 	}
 
 
@@ -71,37 +79,50 @@ public class GameState {
 		for(int index = 0; index < boardSquares.length; index++) {
 			int type = boardSquares[index].getType();
 			boolean w = boardSquares[index].isWhite();
+			boolean pieceMoved = boardSquares[index].isMoved();
 			if (type == Square.OUT_OF_BOUNDS) continue;
 			if (type == Square.EMPTY) continue;
 
 			//For each square, find all possible places that piece can move to.
-			if (type == Square.KING) moves.addAll(findAllMovesFor(index, new int[] {1,-1,12,-12,13,-13,11,-11}, false));
-			if (type == Square.QUEEN) moves.addAll(findAllMovesFor(index, new int[] {1,-1,12,-12,13,-13,11,-11}, true));
-			if (type == Square.BISHOP) moves.addAll(findAllMovesFor(index, new int[] {13,-13,11,-11}, true));
-			if (type == Square.ROOK) moves.addAll(findAllMovesFor(index, new int[] {1,-1,12,-12}, true));
-			if (type == Square.KNIGHT) moves.addAll(findAllMovesFor(index, new int[] {10,14,23,25,-10,-14,-23,-25}, false));
-			if (type == Square.PAWN && w) moves.addAll(findAllMovesFor(index, new int[] {12}, false));
-			if (type == Square.PAWN && !w) moves.addAll(findAllMovesFor(index, new int[] {-12}, false));
+			if (type == Square.KING) moves.addAll(findAllMovesFor(index, new int[] {1,-1,12,-12,13,-13,11,-11}, 1, true, true));
+			if (type == Square.QUEEN) moves.addAll(findAllMovesFor(index, new int[] {1,-1,12,-12,13,-13,11,-11}, 99, true, true));
+			if (type == Square.BISHOP) moves.addAll(findAllMovesFor(index, new int[] {13,-13,11,-11}, 99, true, true));
+			if (type == Square.ROOK) moves.addAll(findAllMovesFor(index, new int[] {1,-1,12,-12}, 99, true, true));
+			if (type == Square.KNIGHT) moves.addAll(findAllMovesFor(index, new int[] {10,14,23,25,-10,-14,-23,-25}, 1, true, true));
+
+			//white
+			if (type == Square.PAWN && w && pieceMoved) moves.addAll(findAllMovesFor(index, new int[] {12}, 1, true, false));
+			if (type == Square.PAWN && w && !pieceMoved) moves.addAll(findAllMovesFor(index, new int[] {12}, 2, true, false));
+			if (type == Square.PAWN && w) moves.addAll(findAllMovesFor(index, new int[] {11, 13}, 1, false, true));
+
+			//black
+			if (type == Square.PAWN && !w && pieceMoved) moves.addAll(findAllMovesFor(index, new int[] {-12}, 1, true, false));
+			if (type == Square.PAWN && !w && !pieceMoved) moves.addAll(findAllMovesFor(index, new int[] {-12}, 2, true, false));
+			if (type == Square.PAWN && !w) moves.addAll(findAllMovesFor(index, new int[] {-11, -13}, 1, false, true));
 		}
 
 		return moves;
 	}
 
-	private ArrayList<Move> findAllMovesFor(int index, int[] directions, boolean canMoveMultipleSquares) {
+	///movementDistance is the number of times that piece can move in the given directions.
+	private ArrayList<Move> findAllMovesFor(int index, int[] directions, int movementDistance, boolean canMove, boolean canCapture) {
 		ArrayList<Move> moves = new ArrayList<Move>();
 		if (boardSquares[index].isWhite() != isWhitesTurn) return moves; //don't move other person's pieces!
 
 		//loop through the directions, see if they work - return the resulting arraylist.
 		for(int dir : directions) {
 			int destIndex = index;
+			int numMoves = movementDistance;
 			do {
 				destIndex += dir;
 				int type = boardSquares[destIndex].getType();
 				if (type == Square.OUT_OF_BOUNDS) break;
-				if (type == Square.EMPTY || boardSquares[destIndex].isWhite() != isWhitesTurn) {
+				if (type == Square.EMPTY && canMove ||
+					type != Square.EMPTY && type != Square.OUT_OF_BOUNDS && boardSquares[destIndex].isWhite() != isWhitesTurn && canCapture) {
 					moves.add(new Move(index, destIndex));
 				}
-			} while(boardSquares[destIndex].getType() == Square.EMPTY && canMoveMultipleSquares);
+				numMoves--;
+			} while(boardSquares[destIndex].getType() == Square.EMPTY && numMoves > 0);
 
 		}
 		return moves;
@@ -111,8 +132,8 @@ public class GameState {
 		return isWhitesTurn;
 	}
 
-	// returns something like "checkmate", "stalemate", etc.
+	// TODO: should also include information regarding check, checkmate, and stalemate.
 	public String getFeedback() {
-		return null;
+		return isWhitesTurn ? "White's turn" : "Black's turn";
 	}
 }

Day 43-51 (chess application)/Square.java

@@ -12,6 +12,8 @@ public class Square {
 
 	private int type; //one of the 8 constants above.
 	private boolean isWhite;
+	private boolean hasMoved;
+	private boolean isEnPassantSquare; //was jumped over by a pawn on the previous move.
 
 	//en passant boolean flag (for the square that would be "captured")
 	//boolean Knowledge of whether or not this piece moved yet (for castling)
@@ -20,6 +22,8 @@ public class Square {
 	public Square(Square s) {
 		type = s.type;
 		isWhite = s.isWhite;
+		hasMoved = s.hasMoved;
+		isEnPassantSquare = s.isEnPassantSquare;
 	}
 
 	public Square(int type) {
@@ -29,6 +33,29 @@ public class Square {
 	public Square(int type, boolean isWhite) {
 		this.type = type;
 		this.isWhite = isWhite;
+		hasMoved = false;
+		isEnPassantSquare = false;
+	}
+
+	public void clearEnPassant() {
+		isEnPassantSquare = false;
+	}
+
+	public boolean isEnPassantSquare() {
+		return isEnPassantSquare;
+	}
+
+	public void setEnPassantSquare(boolean whiteMovedPawnTwo) {
+		isEnPassantSquare = true;
+		isWhite = whiteMovedPawnTwo;
+	}
+
+	public void setHasMoved() {
+		hasMoved = true;
+	}
+
+	public boolean isMoved() {
+		return hasMoved;
 	}
 
 	//Positive values for white, negative for black, blank square is 0.