问题描述
我试图通过使用乌龟来制作这个蛇游戏（还没有食物）。长度为 1 时，它仍然很快，但随着时间的推移，它运行得越来越慢。
from turtle import Turtle,Screen
SIZE = 500
GRID_NUM = 20
GRID_SIZE = SIZE // GRID_NUM
screen = Screen()
screen.setup(SIZE,SIZE)
screen.bgcolor('black')
screen.setworldcoordinates(10,8,SIZE + 2,SIZE)
class Snake:
def __init__(self):
self.head = init_turtle()
self.head.setpos((GRID_SIZE // 2 + GRID_SIZE * 9,GRID_SIZE // 2 + GRID_SIZE * 10))
self.body = []
self.direction = 0 # 0 = left,1 = up,2 = right,3 = down
self.speed = 100 * len(self.body) if len(self.body) > 0 else 100
def levelup(self):
if len(self.body) == 0:
self.body.append(self.head.clone())
else:
self.body.append(self.body[len(self.body) - 1].clone())
def update(self):
for i in range(len(self.body) - 1,-1,-1):
if i == 0:
self.body[i].setpos(self.head.pos())
else:
self.body[i].setpos(self.body[i - 1].pos())
def init_turtle():
turtle = Turtle()
turtle.shape('square')
turtle.shapesize(1.25)
turtle.color('red')
turtle.pencolor('#404040')
turtle.speed('fastest')
turtle.up()
return turtle
def init_border():
def border():
turtle = init_turtle()
for _ in range(4):
turtle.down()
turtle.forward(SIZE)
turtle.left(90)
yield(0)
turtle.penup()
turtle.hideturtle()
def horizontal():
turtle = init_turtle()
for x in range(GRID_SIZE,SIZE,GRID_SIZE):
turtle.goto(x,0)
turtle.pendown()
turtle.goto(x,SIZE)
turtle.penup()
yield(0)
turtle.hideturtle()
def vertical():
turtle = init_turtle()
for y in range(GRID_SIZE,GRID_SIZE):
turtle.goto(0,y)
turtle.pendown()
turtle.goto(SIZE,y)
turtle.penup()
yield(0)
turtle.hideturtle()
generator1 = border()
generator2 = horizontal()
generator3 = vertical()
while(next(generator1,1) + next(generator2,1) + next(generator3,1) < 3):
pass
def start_game():
snake = Snake()
def pop():
snake.body.pop()
def right():
snake.direction = 0
def up():
snake.direction = 1
def left():
snake.direction = 2
def down():
snake.direction = 3
def exit():
screen.bye()
screen.onkey(pop,'q')
screen.onkey(left,'Left')
screen.onkey(up,'Up')
screen.onkey(right,'Right')
screen.onkey(down,'Down')
screen.onkey(exit,'Escape')
screen.onkey(snake.levelup,'Return')
screen.listen()
while True:
snake.update()
snake.head.setheading(snake.direction * 90)
snake.head.forward(GRID_SIZE)
print('snake',snake.head.pos())
init_border()
start_game()
screen.mainloop()
起初我认为问题的原因是定义了很多功能，但我不知道。另外我是python的新手，所以我不知道任何类型的优化方法。
有什么优化这个程序的想法吗？
解决方法
我们可以通过在屏幕外绘制并发送显式更新来加速长蛇。下面是您的代码的返工，它只是这样做，并包括一个临时补丁，使蛇在一个正方形中移动，因此您只需点击即可查看蛇受其他身体部位的影响：
from turtle import Turtle,Screen
SIZE = 525
GRID_NUM = 20
GRID_SIZE = SIZE // GRID_NUM
RIGHT,UP,LEFT,DOWN = range(4)
class Snake:
def __init__(self):
self.head = init_turtle()
self.head.setpos(GRID_NUM//2,GRID_NUM//2)
self.direction = LEFT
self.body = []
def levelup(self):
if self.body:
self.body.append(self.body[-1].clone())
else:
self.body.append(self.head.clone())
def update(self):
for i in range(len(self.body) - 1,-1,-1):
if i == 0:
self.body[i].setposition(self.head.position())
else:
self.body[i].setposition(self.body[i - 1].position())
def init_turtle():
turtle = Turtle()
turtle.shape('square')
print(GRID_SIZE)
turtle.shapesize((GRID_SIZE - 1) / 20)
turtle.color('#404040','red')
turtle.speed('fastest')
turtle.penup()
return turtle
def init_border():
def border():
turtle = init_turtle()
turtle.goto(-0.5,-0.5)
for _ in range(4):
turtle.pendown()
turtle.forward(GRID_NUM)
turtle.left(90)
turtle.penup()
turtle.hideturtle()
def vertical():
turtle = init_turtle()
for x in range(GRID_NUM):
turtle.goto(x - 0.5,-0.5)
turtle.pendown()
turtle.goto(x - 0.5,GRID_NUM - 0.5)
turtle.penup()
yield 0
turtle.hideturtle()
def horizontal():
turtle = init_turtle()
for y in range(GRID_NUM):
turtle.goto(-0.5,y + 0.5)
turtle.pendown()
turtle.goto(GRID_NUM - 0.5,y + 0.5)
turtle.penup()
yield 0
turtle.hideturtle()
border()
generator1 = horizontal()
generator2 = vertical()
while next(generator1,1) + next(generator2,1) < 2:
pass
def start_game():
snake = Snake()
def right():
snake.direction = RIGHT
def up():
snake.direction = UP
def left():
snake.direction = LEFT
def down():
snake.direction = DOWN
screen.onkey(snake.body.pop,'q')
screen.onkey(left,'Left')
screen.onkey(up,'Up')
screen.onkey(right,'Right')
screen.onkey(down,'Down')
screen.onkey(screen.bye,'Escape')
screen.onkey(snake.levelup,'Return')
screen.listen()
while True:
snake.update()
snake.head.setheading(snake.direction * 90)
snake.head.forward(1)
# Run snake around in a square for testing purposes
x,y = snake.head.position()
if round(x) == 1 and snake.direction == LEFT:
up()
elif round(y) == GRID_NUM - 2 and snake.direction == UP:
right()
elif round(x) == GRID_NUM - 2 and snake.direction == RIGHT:
down()
elif round(y) == 1 and snake.direction == DOWN:
left()
screen.update()
screen = Screen()
screen.setup(SIZE,SIZE)
screen.bgcolor('black')
screen.setworldcoordinates(-0.75,-0.75,GRID_NUM + 0.25,GRID_NUM + 0.25)
init_border()
screen.tracer(False)
start_game()
screen.mainloop() # never reached!
我推荐这两种方法，因为当您添加食物和边界检测时，主循环只会变得更复杂（更慢）。
我更改了您的坐标系，使其以蛇为中心。也就是说，forward(1) 在网格上移动一格而不必进行数学运算。如果您无论如何都要弄乱坐标，为什么不调整它们以发挥最大的优势。