king, copy board logic, getPseudoMoves

Piece.java

@@ -18,7 +18,30 @@ public abstract class Piece {
 
   public abstract ArrayList<Position> getLegalMoves(Board board);
 
+  public abstract ArrayList<Position> getPseudoLegalMoves(Board board);
+
+  public abstract Piece copy();
+
   public boolean colorMatches(Piece p) {
     return this.color.equals(p.color);
   }
+
+  public ArrayList<Position> slide(Board board, int dx, int dy) {
+    ArrayList<Position> positions = new ArrayList<>();
+    int step = 1;
+    while (true) {
+      Position test = new Position(pos.x + step * dx, pos.y + step * dy);
+      if (!Board.inBounds(test)) break;
+      if (board.isOpen(test)) {
+        positions.add(test);
+      } else if (board.getPiece(test).colorMatches(this)) {
+        break;
+      } else {
+        positions.add(test);
+        break;
+      }
+      step++;
+    }
+    return positions;
+  }
 }