问题描述
我正在制作一个 Covid 模拟器,需要我的球随机移动。但是,我希望它们保持在选择的第一个随机方向上移动,并且只有在碰到另一个单元格或碰到墙壁时才改变方向。
我目前的代码如下:
import random
import pygame
# --- constants --- (UPPER_CASE_NAMES)
GREEN1 = (0,255,0) # Healthy cells
RED = (255,0) # Infected cells
GREEN2 = (0,100,0) # Healthy cells not susecptible
BLACK = (0,0) # Dead cells
WHITE = (255,255)
BACKGROUND_COLOR = (225,198,153)
SCREEN_SIZE = (800,800)
# --- classes --- (CamelCaseNames)
# class keeep only one cell so it should has name `Cell` instead of `Cells`
class Cell(pygame.sprite.Sprite):
def __init__(self,color,speed,width,height):
super().__init__()
self.color = color
self.speed = speed
self.image = pygame.Surface([width,height])
self.image.fill(WHITE)
self.image.set_colorkey(WHITE)
self.radius = width // 2 # 25
center = [width // 2,height // 2]
pygame.draw.circle(self.image,self.color,center,self.radius,width=0)
self.rect = self.image.get_rect()
self.rect.x = random.randint(0,400)
self.rect.y = random.randint(50,700)
self.pos = pygame.math.Vector2(self.rect.center)
self.dir = pygame.math.Vector2(1,0).rotate(random.randrange(360))
def update(self):
self.pos += self.dir * self.speed
if self.pos.x - self.radius < 0 or self.pos.x + self.radius > SCREEN_SIZE[0]:
self.dir.x *= -1
if self.pos.y - self.radius < 0 or self.pos.y + self.radius > SCREEN_SIZE[1]:
self.dir.y *= -1
for other_cell in all_cells:
if all_cells != self:
distance_vec = self.pos - other_cell.pos
if 0 < distance_vec.length_squared() < (self.radius * 2) ** 2:
self.dir.reflect_ip(distance_vec)
other_cell.dir.reflect_ip(distance_vec)
self.rect.centerx = round(self.pos.x)
self.rect.centery = round(self.pos.y)
# --- functions --- (lower_case_names)
# empty
# --- main --- (lower_case_names)
pygame.init()
screen = pygame.display.set_mode(SCREEN_SIZE)
pygame.display.set_caption("Covid-19 Simualtion")
speed = [0.5,-0.5]
# - objects -
all_cells = pygame.sprite.Group() # PEP8: lower_case_name
for _ in range(5):
cell = Cell(GREEN1,5,10,10) # PEP8: lower_case_name
all_cells.add(cell)
# - loop -
clock = pygame.time.Clock()
end = False
while not end:
# - events -
for event in pygame.event.get():
if event.type == pygame.QUIT:
end = True
# - upadates (without draws) -
all_cells.update()
# - draws (without updates) -
screen.fill(BACKGROUND_COLOR)
pygame.draw.rect(screen,BLACK,(0,50,400,700),3)
all_cells.draw(screen)
pygame.display.flip()
clock.tick(30) # to use less cpu
# - end
pygame.quit() # some system may need it to close window
我想知道是否有办法做到这一点,非常感谢您的帮助。提前致谢。我尝试将下面的第一个答案复制到我的 pycharm 中,但它没有用,所以现在我已经把我的完整代码放在了一个部分,以防万一。抱歉之前没有全部放上
解决方法
我建议使用 pygame.math.Vector2
。将属性 pos
和 dir
(位置和方向)添加到类 Cell
。以 rect
属性的中心设置位置并生成具有随机方向的向量:
class Cell(pygame.sprite.Sprite):
def __init__(self,color,speed,width,height):
# [...]
self.pos = pygame.math.Vector2(self.rect.center)
self.dir = pygame.math.Vector2(1,0).rotate(random.randrange(360))
改变方法update
中的位置。将方向向量 dir
和 speed
的乘积添加到位置 (pos
)。通过四舍五入 (round
) 位置向量来更新矩形的位置:
class Cell(pygame.sprite.Sprite):
# [...]
def update(self):
self.pos += self.dir * self.speed
self.rect.centerx = round(self.pos.x)
self.rect.centery = round(self.pos.y)
请参阅 How to make ball bounce off wall with Pygame? 并将建议应用于您的代码:
class Cell(pygame.sprite.Sprite):
# [...]
def update(self):
self.pos += self.dir * self.speed
if self.pos.x - self.radius < 0:
self.pos.x = self.radius
self.dir.x = abs(self.dir.x)
elif self.pos.x + self.radius > 400:
self.pos.x = 400 - self.radius
self.dir.x = -abs(self.dir.x)
if self.pos.y - self.radius < 50:
self.pos.y = 50 + self.radius
self.dir.y = abs(self.dir.y)
elif self.pos.y + self.radius > 700:
self.pos.y = 700 - self.radius
self.dir.y = -abs(self.dir.y)
self.rect.centerx = round(self.pos.x)
self.rect.centery = round(self.pos.y)
见Pygame how to let balls collide。测试以查看单元格是否发生碰撞并在检测到碰撞时反射方向向量:
class Cell(pygame.sprite.Sprite):
# [...]
def update(self):
self.pos += self.dir * self.speed
# [...]
for other_cell in all_cells:
if all_cells != self:
distance_vec = self.pos - other_cell.pos
if 0 < distance_vec.length_squared() < (self.radius*2) ** 2:
self.dir.reflect_ip(distance_vec)
other_cell.dir.reflect_ip(distance_vec)
self.rect.centerx = round(self.pos.x)
self.rect.centery = round(self.pos.y)
另见Collision and Intersection - Circle and circle
完整示例:
import random
import pygame
GREEN1 = (0,255,0) # Healthy cells
RED = (255,0) # Infected cells
GREEN2 = (0,100,0) # Healthy cells not susecptible
BLACK = (0,0) # Dead cells
WHITE = (255,255)
BACKGROUND_COLOR = (225,198,153)
SCREEN_SIZE = (800,800)
speed = [0.5,-0.5]
class Cell(pygame.sprite.Sprite):
def __init__(self,height):
super().__init__()
self.color = color
self.speed = speed
self.image = pygame.Surface([width,height])
self.image.fill(WHITE)
self.image.set_colorkey(WHITE)
self.radius = width // 2 # 5
center = [width // 2,height // 2]
pygame.draw.circle(self.image,self.color,center,self.radius,width=0)
self.rect = self.image.get_rect()
self.rect.x = random.randint(0,400)
self.rect.y = random.randint(50,700)
self.pos = pygame.math.Vector2(self.rect.center)
self.dir = pygame.math.Vector2(1,0).rotate(random.randrange(360))
def update(self):
self.pos += self.dir * self.speed
border_rect = pygame.Rect(0,50,400,700)
if self.pos.x - self.radius < border_rect.left:
self.pos.x = border_rect.left + self.radius
self.dir.x = abs(self.dir.x)
elif self.pos.x + self.radius > border_rect.right:
self.pos.x = border_rect.right - self.radius
self.dir.x = -abs(self.dir.x)
if self.pos.y - self.radius < border_rect.top:
self.pos.y = border_rect.top + self.radius
self.dir.y = abs(self.dir.y)
elif self.pos.y + self.radius > border_rect.bottom:
self.pos.y = border_rect.bottom - self.radius
self.dir.y = -abs(self.dir.y)
for other_cell in all_cells:
if all_cells != self:
distance_vec = self.pos - other_cell.pos
if 0 < distance_vec.length_squared() < (self.radius*2) ** 2:
self.dir.reflect_ip(distance_vec)
other_cell.dir.reflect_ip(distance_vec)
self.rect.centerx = round(self.pos.x)
self.rect.centery = round(self.pos.y)
pygame.init()
screen = pygame.display.set_mode(SCREEN_SIZE)
pygame.display.set_caption("Covid-19 Simualtion")
all_cells = pygame.sprite.Group() # PEP8: lower_case_name
for i in range(100):
cell = Cell(GREEN1,5,10,10) # PEP8: lower_case_name
all_cells.add(cell)
clock = pygame.time.Clock()
end = False
while not end:
for event in pygame.event.get():
if event.type == pygame.QUIT:
end = True
all_cells.update()
screen.fill(BACKGROUND_COLOR)
pygame.draw.rect(screen,BLACK,(0,700),3)
all_cells.draw(screen)
pygame.display.flip()
clock.tick(30) # to use less CPU