MORE CHESS.

chess/src/chess/Actor.java

@@ -2,8 +2,8 @@ package chess;
 
 // An actor is an entity capable of making descisions on the board.
 abstract class Actor {
-    ActorColor color;
+    ActorCol col;
 }
 
 // The color an Actor may assume.
-enum ActorColor { WHITE, BLACK }
+enum ActorCol { WHITE, BLACK }

chess/src/chess/Board.java

@@ -8,4 +8,26 @@ class Board {
 // Measured from top left.
 class Coord {
     int x, y;
+
+    Coord(int x, int y) {
+        this.x = x;
+        this.y = y;
+    }
+
+    // Return coordinates relative to the selected color's position on the
+    // board. White on top, black on bottom.
+    Coord rel(ActorCol col) {
+        return col.equals(ActorCol.BLACK)
+            ? new Coord(this.x, Util.boardW - this.y)
+            : this;
+    }
+
+    // Whether two Coords are equal.
+    public Boolean equals(Coord that) {
+        return this.x == that.x && this.y == that.y;
+    }
+
+    public int hashCode() {
+        return 31 * Integer.hashCode(this.x) + Integer.hashCode(this.y);
+    }
 }

chess/src/chess/Piece.java

@@ -1,6 +1,15 @@
 package chess;
 
-// A chess piece.
+// The piece types.
-abstract class Piece {}
+enum PieceType { PAWN, ROOK, KNIGHT, BISHOP, QUEEN, KING }
 
-class Pawn extends Piece {}
+// A chess piece.
+abstract class Piece {
+    PieceType type;
+
+    Piece(PieceType type) { this.type = type; }
+}
+
+class Pawn extends Piece {
+    Pawn() { super(PieceType.PAWN); }
+}

chess/src/chess/Util.java

@@ -0,0 +1,7 @@
+package chess;
+
+// Utility class.
+class Util {
+    // Width of a chessboard.
+    static int boardW = 8;
+}