Mouse handler functions for the Quil Reversi game

reversi-quil-mouse.clj

(defn announce-winner [msg board]
  "Sets the winner of the Reversi game"
  (let [p (winner board)]
    (cond
      (= :w p) (set-message msg (str "White Wins!"))
      (= :b p) (set-message msg (str "Black Wins!"))
      :else
      (set-message msg "It's a Tie!"))))

(defn parse-mouse-pos [x y]
  "Returns the row and column corresponding to the mouse position."
  [(quot y (+ piece-size gap-size))
   (quot x (+ piece-size gap-size))])

(defn mouse-clicked [board piece game-over msg]
  "Attempts to play the specified piece in the square the user clicked."
  (if (= 0 (@msg 0)) ; handle mouse click only if we're not showing a message
    (let [move (parse-mouse-pos (mouse-x) (mouse-y))]
      (if (move-valid? @board @piece move)
        (do
          (swap! board #(place-piece % @piece move))
          (cond
            (game-over? @board) (do
                                  (announce-winner msg @board)
                                  (reset! game-over true))
            (empty? (take 1 (valid-moves @board (opposite-piece @piece)))) (set-message msg "Still your turn!")
            :else (swap! piece opposite-piece)))
        (set-message msg "Invalid move!")))))