homework one

red.py

"""將左右碰撞移動的紅色方塊, 改為先移動到水平畫面中心點位置後, 接著上下碰撞移動"""

from browser import html
from browser import document as doc
import browser.timer

canvas = html.CANVAS(width = 400, height = 100)
canvas.id = "game-board3"
brython_div = doc["brython_div"]
brython_div <= canvas
ctx = canvas.getContext("2d")
px = 0
py = 50
width = 20
height = 20
speed = 2
speedy = 2

def game():
    global px, py, width, height, speed, speedy
    ctx.clearRect(px, py, width, height)
    ctx.fillStyle = "red"
    px += speed
    if px > 200:
        speed = 0
        py += speedy
    if py < 0 or (py + height) > canvas.height:
        speedy = -speedy
    ctx.fillRect(px, py, width, height)
    
browser.timer.set_interval(game, 10)