使用 Python 龟图形和图章的流畅动画

Question

是否有可能使用 Turtle Graphics 和 stamp() 方法获得比下面代码给出的更流畅的动画效果？

我曾尝试过在move_blocks中使用stamper.clearstamps(1)只清除第一个图章，并且每次只画新的方块，但结果看起来是一样的。我认为问题可能是在后台调用 Screen.update()，尽管我还没有确认这一点。

import turtle


def move_blocks():
    stamper.clearstamps()
    new_block = blocks[-1].copy()
    new_block[0] += 20
    if new_block[0] > 250:
        new_block[0] = - 250
    blocks.append(new_block)
    blocks.pop(0)

    for block in blocks:
        stamper.goto(block[0], block[1])
        stamper.stamp()

    screen.update()
    turtle.ontimer(move_blocks, 100)


screen = turtle.Screen()
screen.setup(500, 500)
screen.tracer(0)  # Turn off automatic animation

stamper = turtle.Turtle("square")
stamper.penup()

blocks = [[0, 0], [20, 0], [40, 0], [60, 0]]

for block in blocks:
    stamper.goto(block[0], block[1])
    stamper.stamp()

move_blocks()
turtle.done()

非常感谢任何帮助。

Answer 1

I think the problem might be that stamping calls Screen.update() in the background, although I haven't confirmed this.

这似乎是真的，而且很容易证实，但不一定是全部问题。下面是我对你的代码进行的修改，通过只删除失效的邮票 ID 来优化它，但它看起来并不比你的好。你可以看到我已经注释掉了 screen.update() 这没有什么区别：

from turtle import Screen, Turtle

def move_blocks():
    new_block = blocks.pop(0)
    new_block[0] = blocks[-1][0] + 20

    if new_block[0] > 250:
        new_block[0] = -250

    blocks.append(new_block)

    stamper.goto(new_block)
    stamper.clearstamp(ids.pop(0))
    ids.append(stamper.stamp())

    # screen.update()
    screen.ontimer(move_blocks, 100)

screen = Screen()
screen.setup(500, 500)
screen.tracer(0)  # Turn off automatic animation

stamper = Turtle('square')
stamper.hideturtle()
stamper.penup()

blocks = [[0, 0], [20, 0], [40, 0], [60, 0]]
ids = []

for block in blocks:
    stamper.goto(block)
    ids.append(stamper.stamp())

# screen.update()

move_blocks()

screen.exitonclick()

自作聪明，我想比较一下绘图和冲压，但结果是一样的，填充操作触发 screen.update() 并让我们回到起点：

from turtle import Screen, Turtle

CURSOR_SIZE = 20

def move_blocks():
    filler.clear()

    new_block = blocks.pop(0)
    new_block[0] = blocks[-1][0] + 20

    if new_block[0] > 250:
        new_block[0] = -250

    blocks.append(new_block)

    for block in blocks:
        fill(block)

    # screen.update()
    screen.ontimer(move_blocks, 100)

def fill(position):
    filler.goto(position)

    filler.begin_fill()
    for _ in range(4):
        filler.forward(CURSOR_SIZE)
        filler.left(90)
    filler.end_fill()

screen = Screen()
screen.setup(500, 500)
screen.tracer(0)  # Turn off automatic animation

filler = Turtle()
filler.hideturtle()
filler.penup()

blocks = [[0, 0], [20, 0], [40, 0], [60, 0]]

for block in blocks:
    fill(block)

# screen.update()

move_blocks()

screen.exitonclick()

最后，我做了一个在 tracer() 控制下的实现，程序员发起了 screen.update() 调用。我只是重塑光标并移动它以进行比较。这次把screen.update()注释掉就可以看出区别了

from turtle import Screen, Turtle

CURSOR_SIZE = 20
CURSOR_LENGTH = 80
STEP_SIZE = 1

def move():
    x = turtle.xcor() + STEP_SIZE

    if x - CURSOR_LENGTH/2 > 250:
        turtle.setx(-250 - CURSOR_LENGTH/2)
    else:
        turtle.forward(STEP_SIZE)

    screen.update()
    screen.ontimer(move, 5 * STEP_SIZE)

screen = Screen()
screen.setup(500, 500)
screen.tracer(0)  # Turn off automatic animation

turtle = Turtle()
turtle.shape('square')
turtle.shapesize(stretch_len=CURSOR_LENGTH/CURSOR_SIZE)
turtle.penup()

screen.update()

move()

screen.exitonclick()

但是，此实现指出，较早的视觉性能不佳也是由于步长过大造成的——如果您更改 STEPSIZE = CURSOR_SIZE，那么您将拥有相同的步长和相同的性能，如你的原创。

使用 Python 龟图形和图章的流畅动画

Smooth Animation with Python Turtle Graphics and Stamps

python

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turtle-graphics