Part V — Rendering¶
Rendering takes a game value and a layout and returns ordinary canvas command data. Canvas objects do not enter the game rules. That lets you inspect the picture before the browser draws it.
(defn render-commands [game layout]
(let [base (chrome-commands game layout)
board (append-commands base (board-lines layout))
p1 (add-pieces board layout (get (get game :board) :p1) :p1)
p2 (add-pieces p1 layout (get (get game :board) :p2) :p2)]
(append-commands p2 (winner-commands game layout))))
Practical — change the picture, not the rules¶
Change the colour used for a player piece and run the file. The game state and legal-move logic remain exactly the same; only the command data changes. This is why rendering stays a separate concern.