Fixed movements

src/chess/Bishop.java

@@ -22,6 +22,6 @@ public class Bishop extends ChessPiece {
 
     @Override
     public ArrayList<Move> getMoves() {
-        return new ArrayList<Move>(super.getDiagonalMoves(b.size()));
+        return prune(super.getDiagonalMoves(b.size()));
     }
 }

src/chess/Board.java

@@ -56,8 +56,8 @@ public class Board {
             // if we were unable to set the piece down we failed to move the piece
             if (!set(m, selectedPiece))
                 return false;
+            selectedPiece.move(m);
             // run special conditions. Only matters for pieces which have special conditions, since is defaulted to empty body.
-            if (movedPiece != null)
             selectedPiece.applySpecialMove(m);
             set(x, y, null);
             return true;
@@ -66,6 +66,8 @@ public class Board {
     }
 
     public ChessPiece get(Move m){
+        if (m == null)
+            return null;
         return get(m.getX(), m.getY());
     }
 
@@ -78,10 +80,12 @@ public class Board {
     }
 
     public boolean set(Move m, ChessPiece piece) {
+        if (m == null)
+            return false;
         return set(m.getX(), m.getY(), piece);
     }
 
-    protected boolean set(int x, int y, ChessPiece piece){
+    public boolean set(int x, int y, ChessPiece piece){
         if (x < 0 || x >= board.length)
             return false;
         if (y < 0 || y >= board.length)
@@ -90,6 +94,14 @@ public class Board {
         return true;
     }
 
+    protected Move checkIfMoveValid(Move m, boolean isWhite){
+        if (m == null)
+            return null;
+        if (get(m) != null && get(m).isWhite == isWhite)
+            return null;
+        return m;
+    }
+
     public int size(){
         return board.length;
     }

src/chess/ChessPiece.java

@@ -8,7 +8,7 @@ public abstract class ChessPiece {
     protected Board b;
     protected int x, y;
     protected boolean isInDanger, isWhite;
-    protected boolean isFirstMove = true;
+    protected int moveCount = 0;
 
     public ChessPiece(Board b, boolean isWhite, int x, int y) {
         this.b = b;
@@ -29,11 +29,16 @@ public abstract class ChessPiece {
     }
 
     public boolean isFirstMove(){
-        return isFirstMove;
+        return moveCount < 1;
+    }
+    public boolean isSecondMove(){
+        return moveCount <= 1;
     }
 
-    public void setMoved(){
+    public void move(Move m){
-        isFirstMove = false;
+        this.x = m.getX();
+        this.y = m.getY();
+        this.moveCount++;
     }
 
     public abstract ArrayList<Move> getMoves();
@@ -42,26 +47,81 @@ public abstract class ChessPiece {
 
     protected ArrayList<Move> getCardinalMoves(int length){
         ArrayList<Move> moves = new ArrayList<Move>();
-        for (int i = 1; i <= length; i++){
         // cardinals
-            moves.add(new Move(x - i, y));
+        for (int i = 1; i <= length; i++){
-            moves.add(new Move(x + i, y));
+            if (add(moves, new Move(x - i, y)))
-            moves.add(new Move(x, y - i));
+                break;
-            moves.add(new Move(x, y + i));
+        }
+        for (int i = 1; i <= length; i++){
+            if (add(moves, new Move(x + i, y)))
+                break;
+        }
+        for (int i = 1; i <= length; i++){
+            if (add(moves, new Move(x, y - i)))
+                break;
+        }
+        for (int i = 1; i <= length; i++){
+            if (add(moves, new Move(x, y + i)))
+                break;
         }
         return moves;
     }
 
     protected ArrayList<Move> getDiagonalMoves(int length){
         ArrayList<Move> moves = new ArrayList<Move>();
+        // diagonals
         for (int i = 1; i <= length; i++){
-            // cardinals
+            if (add(moves, new Move(x - i, y - i)))
-            moves.add(new Move(x - i, y - i));
+                break;
-            moves.add(new Move(x + i, y + i));
+        }
-            moves.add(new Move(x + i, y - i));
+        for (int i = 1; i <= length; i++){
-            moves.add(new Move(x - i, y + i));
+            if (add(moves, new Move(x - i, y + i)))
+                break;
+        }
+        for (int i = 1; i <= length; i++){
+            if (add(moves, new Move(x + i, y - i)))
+                break;
+        }
+        for (int i = 1; i <= length; i++){
+            if (add(moves, new Move(x + i, y + i)))
+                break;
         }
         return moves;
     }
 
+    protected ArrayList<Move> prune(ArrayList<Move> moves){
+        var prunedMoves = new ArrayList<Move>();
+        // get rid of impossible moves
+        for (Move m : moves){
+            if (m == null)
+                continue;
+            if (m.getX() < 0 || m.getX() >= b.size())
+                continue;
+            if (m.getY() < 0 || m.getY() >= b.size())
+                continue;
+            prunedMoves.add(m);
+        }
+
+        return prunedMoves;
+    }
+
+    /**
+     * Checks to make sure that the proposed move is valid.
+     * @param moves array to add to
+     * @param move move to add to the array
+     * @return true if we need to stop here. (Break the loop)
+     */
+    private boolean add(ArrayList<Move> moves, Move move){
+        var m = b.get(move);
+        if (m != null && m.isWhite != isWhite) {
+            moves.add(b.checkIfMoveValid(move, isWhite));
+            return true;
+        } else {
+            if (m != null)
+                return true;
+            moves.add(b.checkIfMoveValid(move, isWhite));
+        }
+        return false;
+    }
+
 }

src/chess/King.java

@@ -25,22 +25,22 @@ public class King extends ChessPiece {
         ArrayList<Move> moves = new ArrayList<Move>();
         moves.addAll(super.getCardinalMoves(1));
         moves.addAll(super.getDiagonalMoves(1));
-        if (isFirstMove){
+        if (isFirstMove()){
             ChessPiece rook = null;
             // castling
             if (isWhite){
                 if ((rook = b.get(0, 0)) != null && checkIfRookValid(rook))
-                    moves.add(new Move(2, 0, Move.SpecialConditions.leftCastle));
+                    moves.add(b.checkIfMoveValid(new Move(2, 0, Move.SpecialConditions.leftCastle), isWhite));
                 if ((rook = b.get(b.size() - 1, 0)) != null && checkIfRookValid(rook))
-                    moves.add(new Move(b.size() - 2, 0, Move.SpecialConditions.rightCastle));
+                    moves.add(b.checkIfMoveValid(new Move(b.size() - 2, 0, Move.SpecialConditions.rightCastle), isWhite));
             } else {
                 if ((rook = b.get(0, b.size()-1)) != null && checkIfRookValid(rook))
-                    moves.add(new Move(2, b.size()-1, Move.SpecialConditions.leftCastle));
+                    moves.add(b.checkIfMoveValid(new Move(2, b.size()-1, Move.SpecialConditions.leftCastle), isWhite));
                 if ((rook = b.get(b.size() - 1, b.size()-1)) != null && checkIfRookValid(rook))
-                    moves.add(new Move(b.size() - 2, b.size()-1, Move.SpecialConditions.rightCastle));
+                    moves.add(b.checkIfMoveValid(new Move(b.size() - 2, b.size()-1, Move.SpecialConditions.rightCastle), isWhite));
             }
         }
-        return moves;
+        return prune(moves);
     }
 
     @Override
@@ -54,9 +54,9 @@ public class King extends ChessPiece {
 
     private void castleRight(){
         // casting has to move the rook on the right size of the king from white's perspective
-        if (this.isWhite)
+        if (this.isWhite) {
             b.set(b.size() - 3, 0, b.get(b.size() - 1, 0));
-        else
+        } else
             b.set(b.size()-3, b.size()-1, b.get(b.size()-1, b.size()-1));
     }
 

src/chess/Knight.java

@@ -23,14 +23,14 @@ public class Knight extends ChessPiece {
     @Override
     public ArrayList<Move> getMoves() {
         ArrayList<Move> moves = new ArrayList<Move>();
-        moves.add(new Move(x + 2, y + 1));
+        moves.add(b.checkIfMoveValid(new Move(x + 2, y + 1), isWhite));
-        moves.add(new Move(x + 2, y - 1));
+        moves.add(b.checkIfMoveValid(new Move(x + 2, y - 1), isWhite));
-        moves.add(new Move(x - 2, y + 1));
+        moves.add(b.checkIfMoveValid(new Move(x - 2, y + 1), isWhite));
-        moves.add(new Move(x - 2, y - 1));
+        moves.add(b.checkIfMoveValid(new Move(x - 2, y - 1), isWhite));
-        moves.add(new Move(x - 1, y - 2));
+        moves.add(b.checkIfMoveValid(new Move(x - 1, y - 2), isWhite));
-        moves.add(new Move(x + 1, y - 2));
+        moves.add(b.checkIfMoveValid(new Move(x + 1, y - 2), isWhite));
-        moves.add(new Move(x - 1, y + 2));
+        moves.add(b.checkIfMoveValid(new Move(x - 1, y + 2), isWhite));
-        moves.add(new Move(x + 1, y + 2));
+        moves.add(b.checkIfMoveValid(new Move(x + 1, y + 2), isWhite));
-        return moves;
+        return prune(moves);
     }
 }

src/chess/Pawn.java

@@ -24,38 +24,45 @@ public class Pawn extends ChessPiece {
     public ArrayList<Move> getMoves() {
         ArrayList<Move> moves = new ArrayList<Move>();
         if (isWhite) {
-            moves.add(new Move(x, y + 1));
+            moves.add(b.checkIfMoveValid(pawnForwardMoveValid(new Move(x, y + 1)), isWhite));
-            if (isFirstMove)
+            if (isFirstMove())
-                moves.add(new Move(x, y + 2));
+                moves.add(b.checkIfMoveValid(new Move(x, y + 2), isWhite));
         } else {
-            moves.add(new Move(x, y - 1));
+            moves.add(b.checkIfMoveValid(pawnForwardMoveValid(new Move(x, y - 1)), isWhite));
-            if (isFirstMove)
+            if (isFirstMove())
-                moves.add(new Move(x, y - 2));
+                moves.add(b.checkIfMoveValid(new Move(x, y - 2), isWhite));
         }
         ChessPiece neighbour = null;
 
         if (isWhite){
             // En passant
             if ((neighbour = b.get(x-1, y)) != null && checkNeighbourEnPassant(neighbour))
-                moves.add(new Move(x-1, y + 1, Move.SpecialConditions.leftEnPassant));
+                moves.add(b.checkIfMoveValid(pawnForwardMoveValid(new Move(x-1, y + 1, Move.SpecialConditions.leftEnPassant)), isWhite));
             // En passant
             if ((neighbour = b.get(x+1, y)) != null && checkNeighbourEnPassant(neighbour))
-                moves.add(new Move(x+1, + 1, Move.SpecialConditions.rightEnPassant));
+                moves.add(b.checkIfMoveValid(pawnForwardMoveValid(new Move(x+1, + 1, Move.SpecialConditions.rightEnPassant)), isWhite));
         } else {
             // unfortunately have to flip the direction depending on player type
             // En passant
             if ((neighbour = b.get(x-1, y)) != null && checkNeighbourEnPassant(neighbour))
-                moves.add(new Move(x-1, y - 1, Move.SpecialConditions.leftEnPassant));
+                moves.add(b.checkIfMoveValid(pawnForwardMoveValid(new Move(x-1, y - 1, Move.SpecialConditions.leftEnPassant)), isWhite));
             // En passant
             if ((neighbour = b.get(x+1, y)) != null && checkNeighbourEnPassant(neighbour))
-                moves.add(new Move(x+1, - 1, Move.SpecialConditions.rightEnPassant));
+                moves.add(b.checkIfMoveValid(pawnForwardMoveValid(new Move(x+1, - 1, Move.SpecialConditions.rightEnPassant)), isWhite));
         }
 
-        return moves;
+        return prune(moves);
+    }
+
+    private Move pawnForwardMoveValid(Move m){
+        // basically prevent a pawn from moving into the enemy head on.
+        if (b.get(m) != null)
+            return null;
+        return m;
     }
 
     private boolean checkNeighbourEnPassant(ChessPiece neighbour){
-        return neighbour instanceof Pawn && ((Pawn) neighbour).isFirstMove() && neighbour.isWhite != this.isWhite;
+        return neighbour instanceof Pawn && neighbour.isSecondMove() && neighbour.isWhite != this.isWhite;
     }
 
     @Override
@@ -69,15 +76,15 @@ public class Pawn extends ChessPiece {
 
     private void enPassantLeft(){
         if (isWhite)
-            b.set(x-1, y, null);
+            b.set(x, y-1, null);
         else
-            b.set(x+1, y, null);
+            b.set(x, y+1, null);
     }
 
     private void enPassantRight(){
         if (isWhite)
-            b.set(x+1, y, null);
+            System.out.println(b.set(x, y-1, null));
         else
-            b.set(x-1, y, null);
+            b.set(x, y-1, null);
     }
 }

src/chess/Queen.java

@@ -25,6 +25,6 @@ public class Queen extends ChessPiece {
         ArrayList<Move> moves = new ArrayList<Move>();
         moves.addAll(super.getCardinalMoves(b.size()));
         moves.addAll(super.getDiagonalMoves(b.size()));
-        return moves;
+        return prune(moves);
     }
 }

src/chess/Rook.java

@@ -20,6 +20,6 @@ public class Rook extends ChessPiece {
 
     @Override
     public ArrayList<Move> getMoves() {
-        return new ArrayList<Move>(super.getCardinalMoves(b.size()));
+        return prune(super.getCardinalMoves(b.size()));
     }
 }

src/ui/Display.java

@@ -51,7 +51,7 @@ public class Display extends JFrame implements MouseListener {
                 }
                 if (selectionPointX != -1 && selectionPointY != -1) {
                     int localPointX = (selectionPointX - xOffset) / width;
-                    int localPointY = (b.size() - 1) - ((selectionPointY - yOffset) / height);
+                    int localPointY = ((selectionPointY - yOffset) / height);
                     for (Move m : moves){
                         if (m.getX() == localPointX && m.getY() == localPointY){
                             b.movePiece(piece.getPosition(), new Move(localPointX, localPointY));
@@ -68,9 +68,10 @@ public class Display extends JFrame implements MouseListener {
         // handle user input (mouse clicking)
         if (selectionPointX != -1 && selectionPointY != -1){
             int localPointX = (selectionPointX - xOffset) / width;
-            int localPointY = (b.size()-1) - ((selectionPointY - yOffset) / height);
+            int localPointY = ((selectionPointY - yOffset) / height);
             var piece = b.get(localPointX, localPointY);
             if (piece != null) {
+                System.out.println(localPointX + " LL " + localPointY);
                 movingPointX = localPointX;
                 movingPointY = localPointY;
             }
@@ -80,7 +81,7 @@ public class Display extends JFrame implements MouseListener {
     }
 
     private void drawSelectionRect(Graphics g, Move m){
-        g.drawRect(xOffset + (m.getX() * width), yOffset + ((b.size()-1 - m.getY()) * height), width, height);
+        g.drawRect(xOffset + (m.getX() * width), yOffset + (m.getY() * height), width, height);
     }
 
     public boolean update(){