绕着正方形滚动一个圆

近一个月后，我仍然停留在这个问题上，我设法决定圆圈（或我所说的行人）是否应该向左/向右或向上/向下移动，但我需要有可能移动行人around一座建筑物（这意味着他们必须转角，基本上无论方向如何，他们只需要转90度

非常感谢

import numpy as np
import random
import keyboard
from Box2D.b2 import world, polygonShape, circleShape, edgeShape, staticBody, dynamicBody, kinematicBody, revoluteJoint, wheelJoint
from Box2D import b2Vec2, b2FixtureDef, b2PolygonShape, b2CircleShape, b2Dot, b2EdgeShape, b2Contact,b2ContactFilter,b2Filter,b2ContactListener,b2GetPointStates


import pygame
from pygame import HWSURFACE, DOUBLEBUF, RESIZABLE, VIDEORESIZE
from pygame.locals import (QUIT, KEYDOWN, K_ESCAPE)
pygame.init()

box2world = world(contactListener = MyContactListener(), gravity = (0.0, 0.0), doSleep = True)

class Pedestrian():
    def __init__(self,box2world, position = None):

        if position == None:
            position = [5,5]

        self.position = position
        self.box2world = box2world
        self.Current_Position = []
        self.body = self.box2world.CreateDynamicBody(position = position, 
                                                       angle = 0.0,
                                                       fixtures = b2FixtureDef(
                                                            shape = b2CircleShape(radius = 0.5),
                                                            density = 2,
                                                            friction = 0.3,
                                                            ))


class Building():
    def __init__(self, box2world,shape, position, sensor= None):
        self.box2world = box2world
        self.shape = shape
        self.position = position

        if sensor == None:
            sensor = False
        self.corners = [((self.position[0] + self.shape[0]), (self.position[1] + self.shape[1])),
                        ((self.position[0] + self.shape[0]), (self.position[1] - self.shape[1])),
                        ((self.position[0] - self.shape[0]), (self.position[1] - self.shape[1])),
                        ((self.position[0] - self.shape[0]), (self.position[1] + self.shape[1]))]

        self.sensor = sensor
        self.footprint = self.box2world.CreateStaticBody(position = position,
                                                           angle = 0.0,
                                                           fixtures = b2FixtureDef(
                                                               shape = b2PolygonShape(box=(self.shape)),
                                                               density = 1000,
                                                               friction = 1000))


############################################################## Pygame visualisation
PPM = 10
SCREEN_WIDTH, SCREEN_HEIGHT = 640, 480
SCREEN_OFFSETX, SCREEN_OFFSETY = SCREEN_WIDTH/16, SCREEN_HEIGHT
POS_X = SCREEN_WIDTH/PPM/3
POS_Y = SCREEN_HEIGHT/PPM/3
MAX_AMOUNT_PEDESTRIANS = 10
FPS = 24
TIME_STEP = 1.0 / FPS
k = 0

screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT), HWSURFACE|DOUBLEBUF|RESIZABLE)
pygame.display.set_caption('Top Down Car Using OOP')
colors = {dynamicBody: (133, 187, 101, 0),  staticBody: (15, 0, 89, 0)}

walkers = [] 

skyscraper  = Building(box2world,shape = (5,5), position =  (POS_X + 3, POS_Y + 5))

def fix_vertices(vertices):
    return [(int(SCREEN_OFFSETX + v[0]), int(SCREEN_OFFSETY - v[1])) for v in vertices]


def _draw_polygon(polygon, screen, body, fixture):
    transform = body.transform
    vertices = fix_vertices([transform * v * PPM for v in polygon.vertices])
    pygame.draw.polygon(
        screen, [c / 2.0 for c in colors[body.type]], vertices, 0)
    pygame.draw.polygon(screen, colors[body.type], vertices, 1)
polygonShape.draw = _draw_polygon


def _draw_circle(circle, screen, body, fixture):
    position = fix_vertices([body.transform * circle.pos * PPM])[0]
    pygame.draw.circle(screen, colors[body.type],
                       position, int(circle.radius * PPM))
circleShape.draw = _draw_circle

running = True
while running:
    for event in pygame.event.get():
        if event.type == QUIT or (event.type == KEYDOWN and event.key == K_ESCAPE):
            running = False

    screen.fill((255, 255, 255, 255))
    for body in box2world.bodies:
        for fixture in body.fixtures:
            fixture.shape.draw(screen, body, fixture)

    if k <= MAX_AMOUNT_PEDESTRIANS:
        walkers.append(Pedestrian(box2world, position = (skyscraper.position[0] -random.randint(-skyscraper.shape[0],skyscraper.shape[0]),\
                            skyscraper.position[1] -random.randint(-skyscraper.shape[1],skyscraper.shape[1]))))
        k = k+1
    for walker in walkers:
        pedestrian_walk(walker,skyscraper)
    # Simulate dynamic equation in each step
    TIME_STEP = 1.0 / FPS
    box2world.Step(TIME_STEP, 10, 10)

    # Flip the screen and try to keep at the target FPS
    pygame.display.flip() # Update the full display Surface to the screen
    pygame.time.Clock().tick(FPS)

pygame.quit()
print('Done!')

所以基本上有两个目标，一是让行人转弯（可能我必须在施加垂直力之前施加与他们现在正在移动的方向平行的力，这样他们就会立即停下来并then转但我不知道该怎么做（或者可能有不同的解决方案，这就是我问的原因）

另一个目标是在 for 循环中执行此操作，因为在我的游戏中有四个建筑物...我尝试将其放入 for 循环中但失败了（如果需要，我可以稍后发布我的 for 循环，但请我需要解决我的第一个问题。

免责声明你们中的一些人可能会注意到，在我的第二个用户帐户下，GameDev.StackExchange.com 上出现了几乎相同的问题，我不知道为什么创建另一个帐户，但我知道这不是一个好的解决方案，对此我感到抱歉。我只是想请你不要谈论我为什么创建新帐户以及它很糟糕......我知道这一点，我再次为此感到抱歉......

我在这里提出问题的原因是我认为这里是一个更好的地方，有两个原因，第一：它更多的是算法问题而不是游戏开发问题，第二：SO 比 GameDev 更忙，我被困在这个问题上很长一段时间了，所以我真的需要帮助

EDIT：我设法将此属性添加到建筑类并将其实现到行人行走函数中，它偶尔会起作用，但我该如何改进它呢？或者也许让它更“Pythonic” 非常感谢

def pedestrian_walk(Pedestrian, Building):
    if Pedestrian.body.position[0] <= Building.position[0] and Building.position[1] - Building.shape[1] < Pedestrian.position[1] < Building.position[1] + Building.shape[1]:
        Pedestrian.body.__SetLinearVelocity(b2Vec2(0,10))
    elif Pedestrian.body.position[0] > Building.position[0] and Building.position[1] - Building.shape[1] < Pedestrian.position[1] < Building.position[1] + Building.shape[1]:
        Pedestrian.body.__SetLinearVelocity(b2Vec2(0,-10))
    elif Pedestrian.body.position[1] > Building.position[1] and Building.position[0] - Building.shape[0] < Pedestrian.position[0] < Building.position[0] + Building.shape[0]:
        Pedestrian.body.__SetLinearVelocity(b2Vec2(10,0))
    elif Pedestrian.body.position[1] <= Building.position[1] and Building.position[0] - Building.shape[0] < Pedestrian.position[0] < Building.position[0] + Building.shape[0]:
        Pedestrian.body.__SetLinearVelocity(b2Vec2(-10,0))

    if ((Building.corners[0][0] -0.5 <= Pedestrian.body.position[0] <= Building.corners[0][0] + 0.5 and\
        Building.corners[0][1] -0.5 <= Pedestrian.body.position[1] <= Building.corners[0][1] + 0.5)):
        Pedestrian.body.__SetLinearVelocity(b2Vec2(-100,100))
        print("Changing direction")
    elif((Building.corners[1][0] -0.5 <= Pedestrian.body.position[0] <= Building.corners[1][0] + 0.5 and\
        Building.corners[1][1] -0.5 <= Pedestrian.body.position[1] <= Building.corners[1][1] + 0.5)):
        Pedestrian.body.__SetLinearVelocity(b2Vec2(-100,200))
        print("Changing direction")
    elif((Building.corners[2][0] -0.5 <= Pedestrian.body.position[0] <= Building.corners[2][0] + 0.5 and\
        Building.corners[2][1] -0.5 <= Pedestrian.body.position[1] <= Building.corners[2][1] + 0.5)):
        Pedestrian.body.__SetLinearVelocity(b2Vec2(-100,200))
        print("Changing direction")
    elif((Building.corners[3][0] -0.5 <= Pedestrian.body.position[0] <= Building.corners[3][0] + 0.5 and\
        Building.corners[3][1] -0.5 <= Pedestrian.body.position[1] <= Building.corners[3][1] + 0.5)):
        Pedestrian.body.__SetLinearVelocity(b2Vec2(-100,200))
        print("Changing direction")

很难说出你的代码应该做什么。但有些事情很可能是不对的。在

Which_Skyscraper = Skyscrapers[random.randint(0,len(Skyscrapers)-1)].position
Random_Skyscraper = Skyscrapers[random.randint(0,len(Skyscrapers)-1)]
Johnnie_Walkers.append(Pedestrian(Box_2_World, position = \
    (Which_Skyscraper[0] -random.randint(-Random_Skyscraper.shape[0],Random_Skyscraper.shape[0]), \
    Which_Skyscraper[1] -random.randint(-Random_Skyscraper.shape[1],Random_Skyscraper.shape[1]))))

你确实创造了行人。不过定位很奇怪。你随机选取一栋建筑（Which_Skyscraper）并将其与另一个随机选取的建筑物（Random_Skyscraper）。这些建筑物可能偶然相同，但更可能是不同的。我认为你打算将行人放置在建筑物内，这需要随机抽取建筑物一次。

更糟糕的是建筑物和行人的损毁

# Make the pedestrian walk
Tick_Counter = Tick_Counter + 1
Random_Johnnie = random.randint(0,len(Johnnie_Walkers)-1)

if abs(Skyscrapers[Random_Johnnie].position[1] - Johnnie_Walkers[Random_Johnnie].position[0]) >= \
        Skyscrapers[Random_Johnnie].shape[1]/2 +1:
    Johnnie_Walkers[Random_Johnnie].body.ApplyForce(b2Vec2(5,0), \
    Johnnie_Walkers[Random_Johnnie].body.worldCenter,True)

elif ...

在这里你可以得到行人的随机索引random.randint(0,len(Johnnie_Walkers)-1)然后将其应用于建筑物列表Skyscrapers[Random_Johnnie].shape[1]/2这是无稽之谈。约翰尼二世与 3 号街的建筑物无关。

还有更难以理解的代码，例如重置滴答计数器Tick_Counter = 0如果无法施加武力。

一些一般提示：

让你的代码可读。正确命名变量。Random_Johnnie可能只在你耳中听起来很有趣。每个人都可以看到索引是随机选择的。但没有任何迹象表明它将用于什么用途。关于什么person_to_start_walking？同样适用于Which_Skyscraper。关于什么building_where_to_generate_person？代码将如何阅读？好多了。

从类似 C 的语言更改为 python 时，一个非常重要的问题是，（几乎）从不使用索引，学会使用引用，它们甚至比索引更便宜。像循环一样for building in buildings:并且在你的情况下使用random.choice()随机挑选人员或建筑物时。这样你就不会意外地在建筑集合上使用人员索引。

另外 - 使用临时变量而不是长嵌套表达式。它更容易阅读，特别是如果它们有好名字的话。不要命名某物Which_Skyscraper如果它是一个位置。