Pygame：为什么我无法绘制圆形精灵

我创建了以下代码，但不知道为什么无法创建圆形精灵。我真的在网上到处找，发现了同样的事情，但当我尝试它时，它不起作用。我想我只需要在更新和其他代码行之间切换。我是 pygame 的新手，所以请非常明确。

谢谢

这是主要功能：

import pygame as pg
import random
import dots

############ Some color codes  ############

WHITE = (255, 255, 255)
BLUE = (0,   0, 255)
GREEN = (0, 255,   0)
RED = (255,   0,   0)
BLACK = (0, 0, 0)
GREY = (169, 169, 169)
TEXTCOLOR = (0,   0,  0)

###########################################

(width,height)=(800,800)
dotStartPos = (width/2, height/2)
goalPos = (int(width/2), 5)
alldotsaredead = False

# Initiliaze pygame #
pg.init()

# Make screen and filling it with color
window = pg.display.set_mode((width, height))

# Create dots sprite group
dotssprite = pg.sprite.Group()
goaldotsprite = pg.sprite.Group()

# Draw the goal dot
dot_goal=dots.Dots(RED,width/2,5,2,window,0,0)
goaldotsprite.add(dot_goal)
# pg.draw.circle(window, RED, goalPos, 5)



running = True
FONT = pg.font.Font("freesansbold.ttf", 15)
clock = pg.time.Clock()

# Creating dots
# for i in range(50):
#   x = random.randrange(width)
#   y = random.randrange(height)
#   my_dot=dots.Dots(BLUE,x,y,5,window,1,0)
#   dotssprite.add(my_dot)
my_dot=dots.Dots(BLUE,400,400,5,window,1,0)
dotssprite.add(my_dot)
pg.draw.circle(window,GREEN,(300,300),5)

# Function to update screen
def udpatescreen():
    window.fill(WHITE)
    dotssprite.draw(window)
    goaldotsprite.draw(window)
    pg.display.update()



# Function to update dots sprite
def rundots():
    dotssprite.update()

while running:
    for event in pg.event.get():
        if event.type==pg.QUIT:
            running = False
    if alldotsaredead is False:
        rundots()   

    udpatescreen()      

这是点类：

import pygame as pg
import random
vec = pg.math.Vector2

class Dots(pg.sprite.Sprite):
    def __init__(self,color,x,y,radius,window,id,step):
        pg.sprite.Sprite.__init__(self)
        self.maxspeed = 4
        self.window = window
        self.id = id
        self.color = color
        self.x = x
        self.y = y
        self.pos = vec (self.x,self.y)
        self.radius=radius
        self.image = pg.Surface((10, 10))
        self.rect = self.image.get_rect(center=self.pos)
        pg.draw.circle(self.image,self.color,self.rect.center,5)
        self.image.fill(color)
        self.vel = vec(0, 0)
        self.accel = vec(0, 0)
        self.dead = False

首先，你的精灵首先画圆，then用相同的颜色填充精灵。所以你看不到任何东西是正确的。

pg.draw.circle(self.image,self.color,self.rect.center,5)
self.image.fill(color)

它还在屏幕坐标（例如 200,200）处绘制圆圈，而位图只有 10x10 像素。我固定了坐标，并更改了Dot类根据给定的半径调整精灵圆的大小，因为尝试在 10x10 位图中绘制 100 半径的圆是没有意义的。

import pygame

# Window size
WINDOW_WIDTH      = 400
WINDOW_HEIGHT     = 400

# Colours
SKY_BLUE = ( 161, 255, 254 )
BLUE     = (   5,   5, 180 )
WHITE    = ( 255, 255, 255 )


# DOts Sprite
class Dots( pygame.sprite.Sprite ):
    def __init__(self,color,x,y,radius,window,id,step):
        pygame.sprite.Sprite.__init__(self)
        self.maxspeed = 4
        self.window   = window
        self.id       = id
        self.color    = color
        self.x        = x
        self.y        = y
        self.pos      = pygame.math.Vector2 (self.x,self.y)
        self.radius   = radius
        # Create the circle image
        self.image = pygame.Surface((self.radius*2, self.radius*2))
        self.rect  = self.image.get_rect(center=self.pos)
        self.image.fill(color)
        pygame.draw.circle(self.image, WHITE, (self.radius, self.radius), self.radius)
        self.vel   = pygame.math.Vector2(0, 0)
        self.accel = pygame.math.Vector2(0, 0)
        self.dead  = False



### MAIN
pygame.init()
window  = pygame.display.set_mode( ( WINDOW_WIDTH, WINDOW_HEIGHT ) )
pygame.display.set_caption("Circle Sprite")

# Add a circle
circle_sprite = Dots(BLUE,200,200, 30 ,window,1,0)
circle_sprite_group = pygame.sprite.GroupSingle()
circle_sprite_group.add( circle_sprite )

clock = pygame.time.Clock()
done = False
while not done:

    # Handle user-input
    for event in pygame.event.get():
        if ( event.type == pygame.QUIT ):
            done = True

    # Update the window, but not more than 60fps
    window.fill( SKY_BLUE )
    circle_sprite_group.draw( window )
    pygame.display.flip()

    # Clamp FPS
    clock.tick_busy_loop(60)

pygame.quit()

注：我也“宣传”过pg to pygame and vec to pygame.math.Vector2，我认为不值得为了节省一些击键而缩短这些。这确实会让以后阅读代码变得更加困难。