根据pygame中的球移动制作一条线

Question

当球移动时，我如何让pygame画一条线？目前我有它，所以当你使用箭头时，一个带有黑色边框的大红球在屏幕周围移动。我想要的是让用户按下一个按钮然后它基本上想要triger pygame画一条线然后如果用户再次按下那个按钮它将不再画画然后如果他们按下按钮就会清除它。我想将我的当前代码纳入其中。我已经在pygame.draw上进行了研究并在pygame中绘图而没有运气。 这是我目前的代码：

import os,sys 
import pygame as pg


DIRECTDICT = {pg.K_LEFT  : (-1, 0),
          pg.K_RIGHT : ( 1, 0),
          pg.K_UP    : ( 0,-1),
          pg.K_DOWN  : ( 0, 1)}

class Player:

    def __init__(self,rect,speed):
          self.rect = pg.Rect(rect)
          self.speed = speed
          self.movement = [0,0]
          self.make_image()
    def make_image(self):

         self.image = pg.Surface((self.rect.size)).convert_alpha()
         self.image.fill((0,0,0,0))
         pg.draw.ellipse(self.image,(0,0,0),(1,1,self.rect.size[0]-2,self.rect.size[1]-2))
          pg.draw.ellipse(self.image,(255,0,0),(6,6,self.rect.size[0]-12,self.rect.size[1]-12))
    def update(self,Surf):

         self.rect.move_ip(self.movement)
    self.draw(Surf)
def draw(self,Surf):
    Surf.blit(self.image,self.rect)


def quit_game():

     pg.quit();sys.exit()

def game(Player):

    for event in pg.event.get():
          Player.movement = [0,0]
          keys = pg.key.get_pressed()
    if event.type == pg.QUIT or keys[pg.K_ESCAPE]:
         quit_game()
    for key in DIRECTDICT:
        if keys[key]:
            for i in (0,1):
                Player.movement[i] += DIRECTDICT[key][i]*Player.speed

def main(Surf,Player):

       game(Player) 
       Surf.fill((255,255,255)) 
       Player.update(Surf) 
       pg.display.update() 


if __name__ == "__main__":
      os.environ['SDL_VIDEO_CENTERED'] = '1' 
      Surface = pg.display.set_mode((500,500))
      pg.init()
      Myclock = pg.time.Clock() 
      Myplayer = Player((250,250,100,100),3)  
      while 1:
              main(Surface,Myplayer)  
              Myclock.tick(60) 

Answer 1

您必须保持一个状态，指示是否应该绘制线条。此外，您还需要一个存储玩家位置的列表，以便您可以在这些点之间画一条线。

import os,sys 
import pygame as pg


DIRECTDICT = {pg.K_LEFT  : (-1, 0),
          pg.K_RIGHT : ( 1, 0),
          pg.K_UP    : ( 0,-1),
          pg.K_DOWN  : ( 0, 1)}


class Player:

    def __init__(self,rect,speed):
          self.rect = pg.Rect(rect)
          self.speed = speed
          self.movement = [0,0]
          self.make_image()
    def make_image(self):

         self.image = pg.Surface((self.rect.size)).convert_alpha()
         self.image.fill((0,0,0,0))
         pg.draw.ellipse(self.image,(0,0,0),(1,1,self.rect.size[0]-2,self.rect.size[1]-2))
         pg.draw.ellipse(self.image,(255,0,0),(6,6,self.rect.size[0]-12,self.rect.size[1]-12))
    def update(self,Surf):

        self.rect.move_ip(self.movement)
        self.draw(Surf)

    def draw(self,Surf):
        Surf.blit(self.image,self.rect)


def quit_game():

     pg.quit();sys.exit()

state = 0
points = []
def game(Player):
    global state
    global points
    keys = pg.key.get_pressed()
    for event in pg.event.get():
        if event.type == pg.QUIT or keys[pg.K_ESCAPE]:
            quit_game()
        ### change state when space is pressed
        if event.type == pg.KEYDOWN and event.key == pg.K_SPACE:
            if state == 0:
                state = 1
            elif state == 1:
                state = 2
            else:
                ### clear the points list
                state = 0
                points = []
    Player.movement = [0,0]
    for key in DIRECTDICT:
        if keys[key]:
            for i in (0,1):
                Player.movement[i] += DIRECTDICT[key][i]*Player.speed

### helper method to get each element of a list and each previous element
def offset(iterable):
    prev = None
    for elem in iterable:
        yield prev, elem
        prev = elem

def main(Surf,Player):
       global state
       global points
       game(Player) 
       Surf.fill((255,255,255)) 
       Player.update(Surf) 
       ### in state 1, start "collecting" the player position
       if state == 1:
           points.append(Player.rect.center)
       ### in state 1 and 2, draw the line
       if state in (1, 2):
           for p1, p2 in offset(points):
                if p1 and p2:
                   pg.draw.line(Surf, (255,0,0), p1, p2)
       pg.display.update() 


if __name__ == "__main__":
      os.environ['SDL_VIDEO_CENTERED'] = '1' 
      Surface = pg.display.set_mode((500,500))
      pg.init()
      Myclock = pg.time.Clock() 
      Myplayer = Player((250,250,100,100),3)  
      while 1:
              main(Surface,Myplayer)  
              Myclock.tick(60) 

（P.S。：您的代码/缩进非常混乱，您的问题不是100％明确，但您应该明白这一点。）