pawnlogic

chess/src/chess/Board.java

@@ -104,6 +104,64 @@ class Board {
 
         return piece.moves(coord, this);
     }
+
+    // Is the selected space free? (either nothing there, or an enemy piece).
+    boolean isFree(Coord coord, Util.Col col) {
+        return this.get(coord) == null || this.get(coord).col != col;
+    }
+
+    // Is the selected space actually free?
+    boolean isActuallyFree(Coord coord) { return this.get(coord) == null; }
+
+    // Is the selected space occupied by an enemy piece?
+    boolean isOccupiedByEnemy(Coord coord, Util.Col col) {
+        Piece piece = this.get(coord);
+        return piece != null && piece.col != col;
+    }
+
+    // Return the line of free spaces above.
+    ArrayList<Coord> getLineAbove(Coord coord) {
+        ArrayList<Coord> line = new ArrayList<>();
+        for (int y = coord.y - 1; y >= 0; y--) {
+            Coord next = new Coord(coord.x, y);
+            if (!this.isFree(next, Util.Col.WHITE)) break;
+            line.add(next);
+        }
+        return line;
+    }
+
+    // Return the line of free spaces below.
+    ArrayList<Coord> getLineBelow(Coord coord) {
+        ArrayList<Coord> line = new ArrayList<>();
+        for (int y = coord.y + 1; y < Util.boardW; y++) {
+            Coord next = new Coord(coord.x, y);
+            if (!this.isFree(next, Util.Col.WHITE)) break;
+            line.add(next);
+        }
+        return line;
+    }
+
+    // Return the line of free spaces to the left.
+    ArrayList<Coord> getLineLeft(Coord coord) {
+        ArrayList<Coord> line = new ArrayList<>();
+        for (int x = coord.x - 1; x >= 0; x--) {
+            Coord next = new Coord(x, coord.y);
+            if (!this.isFree(next, Util.Col.WHITE)) break;
+            line.add(next);
+        }
+        return line;
+    }
+
+    // Return the line of free spaces to the right.
+    ArrayList<Coord> getLineRight(Coord coord) {
+        ArrayList<Coord> line = new ArrayList<>();
+        for (int x = coord.x + 1; x < Util.boardW; x++) {
+            Coord next = new Coord(x, coord.y);
+            if (!this.isFree(next, Util.Col.WHITE)) break;
+            line.add(next);
+        }
+        return line;
+    }
 }
 
 // Information layered over the board.

chess/src/chess/Piece.java

@@ -37,19 +37,23 @@ class Pawn extends Piece {
     ArrayList<Coord> moves(Coord coord, Board board) {
         ArrayList<Coord> moves = new ArrayList<Coord>();
         if (coord.rel(this.col).y == 1) {
-            moves.add(new Coord(
+            Coord move = new Coord(
                 coord.x, coord.y + (this.col.equals(Col.BLACK) ? 2 : -2)
-            ));
+            );
+
+            if (board.isActuallyFree(move)) moves.add(move);
         }
-        if (!board
-                 .get(new Coord(
-                     coord.x + 1,
-                     coord.y + (this.col.equals(Col.BLACK) ? 1 : -1)
-                 ))
-                 .col.equals(this.col)) {}
-        moves.add(
-            new Coord(coord.x, coord.y + (this.col.equals(Col.BLACK) ? 1 : -1))
-        );
+
+        Coord move =
+            new Coord(coord.x, coord.y + (this.col.equals(Col.BLACK) ? 1 : -1));
+        if (board.isActuallyFree(move)) moves.add(move);
+
+        Coord attack1 = new Coord(coord.x + 1, move.y);
+        Coord attack2 = new Coord(coord.x - 1, move.y);
+
+        if (board.isOccupiedByEnemy(attack1, this.col)) moves.add(attack1);
+        if (board.isOccupiedByEnemy(attack2, this.col)) moves.add(attack2);
+
         return moves;
     }
 }

chess/src/chess/Player.java

@@ -44,7 +44,7 @@ class Player extends Actor {
                     "clicked on bad space with something selected"
                 );
                 this.board.undisplayMoves(moves);
-                this.board.unselect(coord);
+                this.board.unselect(this.selected);
                 this.selected = null;
                 return;
             }