Coffeescript Game Tutorial the Keyboard

키보드 이벤트를 추가한 코드이다.

rightDown = false
leftDown = false

# set rightDown or leftDown if the right or left key are down
document.onkeydown = (evt) ->
switch evt.keyCode
when 39 then rightDown = true
when 37 then leftDown = true

# and unset then when the right or left key is released
document.onkeyup = (evt) ->
switch evt.keyCode
when 39 then rightDown = false
when 37 then leftDown = false

draw = ->
clear()
circle(x, y, 10)

# move the paddle if left or right is currently pressed
paddlex += 5 if rightDown
paddlex -= 5 if leftDown
rect(paddlex, HEIGHT-paddleh, paddlew, paddleh)

dx = -dx if x + dx > WIDTH or x + dx < 0
if y + dy < 0 then dy = -dy
else if y + dy > HEIGHT
if x > paddlex and x < paddlex + paddlew
dy = -dy
else
# game over, so stop the animation
clearInterval(intervalId)

x += dx;
y += dy;

window.onload = ->
init()

Reference