Coffeescript Game Tutorial Bounce

공 튀기는 코드이다.

### BEGIN LIBRARY CODE ###

x = 150
y = 150
dx = 2
dy = 4
ctx = null
WIDTH = 0
HEIGHT = 0

init = ->
canvas = document.getElementById("myCanvas")
ctx = canvas.getContext("2d")
WIDTH = canvas.width
HEIGHT = canvas.height

setInterval(draw, 10)

circle = (x, y, r) ->
ctx.beginPath()
ctx.arc(x, y, r, 0, Math.PI*2, true)
ctx.closePath()
ctx.fill()

rect = (x, y, w, h) ->
ctx.beginPath()
ctx.rect(x, y, w, h)
ctx.closePath()
ctx.fill()

clear = ->
ctx.clearRect(0, 0, WIDTH, HEIGHT)

### END LIBRARY CODE ###

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

dx = -dx if x + dx > WIDTH or x + dx < 0
dy = -dy if y + dy > HEIGHT or y + dy < 0

x += dx;
y += dy;

window.onload = ->
init()

Reference