is-you/game.scm

(import (scheme base)
        (scheme inexact)
        (hoot ffi)
        (hoot debug)
        (dom canvas)
        (dom document)
        (dom element)
        (dom event)
        (dom image)
        (dom media)
        (dom window)
        (console))


(define game-width    640.0)
(define game-height   480.0)

(define canvas (get-element-by-id "canvas"))
(define context (get-context canvas "2d"))

(define *element-x* (/ game-width 2.0))

;; Draw
(define (draw prev-time)
  (clear-rect context 0.0 0.0 game-width game-height)
  (set-fill-color! context "#140c1c")
  (set-text-align! context "center")
  (set-font! context "bold 24px monospace")
  (fill-text context "Hello, World! :)" *element-x* (/ game-height 2.0))
  (request-animation-frame draw-callback))
(define draw-callback (procedure->external draw))

(set-element-width! canvas (exact game-width))
(set-element-height! canvas (exact game-height))

(request-animation-frame draw-callback)

(dprint "game-height" game-height)
(console-log canvas)

;; Input
(define key:left "ArrowLeft")
(define key:right "ArrowRight")

(define (on-key-down event)
  (let ((key (keyboard-event-code event)))
    (cond
     ((string=? key key:left)
      (dprint "key:" key)
      (set! *element-x* (- *element-x* 10)))
     ((string=? key key:right)
      (dprint "key:" key)
      (set! *element-x* (+ *element-x* 10))))))

(add-event-listener! (current-document) "keydown"
                     (procedure->external on-key-down))