我想阻止屏幕背景图像随播放器移动，但我不知道该怎么做。下面是一个示例，当玩家移动时，背景图像也会随之移动。我只希望相机与玩家一起移动，而背景是静止的。任何人都可以帮忙吗？
例子：
代码：
import pygame
from pygame import *
WIN_WIDTH = 800
WIN_HEIGHT = 640
HALF_WIDTH = int(WIN_WIDTH / 2)
HALF_HEIGHT = int(WIN_HEIGHT / 2)
DISPLAY = (WIN_WIDTH, WIN_HEIGHT)
DEPTH = 0
FLAGS = 0
CAMERA_SLACK = 30
def main():
pygame.init()
screen = pygame.display.set_mode(DISPLAY, FLAGS, DEPTH)
pygame.display.set_caption("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
timer = pygame.time.Clock()
up = left = right = False
entities = pygame.sprite.Group()
player = Player(32, 32)
platforms = []
x = 0
y = 0
level = [
"PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP",
"P P",
"P P",
"P P",
"P P",
"P P",
"P P",
"P P",
"P P",
"P P",
"P P",
"P P",
"P P",
"P P",
"P P",
"P P",
"P PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPPP PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPPPPPPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPP PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPP PPPPPPP",
"PPPPP PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPP PPPPPPP",
"P PPPPP PPPP PPPPPPP",
"P PPPP",
"P PPPP",
"P PPPP",
"P PPPPPPPPPPPPPPPPPP",
"P PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP",]
total_level_width = len(level[0]) * 32
total_level_height = len(level) * 32
#print(total_level_width, total_level_height)
background = pygame.image.load("Untitled.png")
# build the level
for row in level:
for col in row:
if col == "P":
p = Platform(x, y)
platforms.append(p)
entities.add(p)
if col == "E":
e = ExitBlock(x, y)
platforms.append(e)
entities.add(e)
x += 32
y += 32
x = 0
camera = Camera(complex_camera, total_level_width, total_level_height)
entities.add(player)
while 1:
timer.tick(60)
for e in pygame.event.get():
if e.type == QUIT: raise SystemExit, "QUIT"
if e.type == KEYDOWN and e.key == K_ESCAPE:
raise SystemExit, "ESCAPE"
if e.type == KEYDOWN and e.key == K_UP:
up = True
if e.type == KEYDOWN and e.key == K_LEFT:
left = True
if e.type == KEYDOWN and e.key == K_RIGHT:
right = True
if e.type == KEYUP and e.key == K_UP:
up = False
if e.type == KEYUP and e.key == K_LEFT:
left = False
if e.type == KEYUP and e.key == K_RIGHT:
right = False
# draw background
screen.blit(background, (0,0))
#draw entities
for e in entities:
screen.blit(e.image, camera.apply(e))
# update player, update camera, and refresh
player.update(up, left, right, platforms)
camera.update(player)
pygame.display.flip()
class Camera(object):
def __init__(self, camera_func, width, height):
self.camera_func = camera_func
self.state = Rect(0, 0, width, height)
def apply(self, target):
return target.rect.move(self.state.topleft)
def update(self, target):
self.state = self.camera_func(self.state, target.rect)
def complex_camera(camera, target_rect):
l, t, _, _ = target_rect
_, _, w, h = camera
l, t, _, _ = -l + HALF_WIDTH, -t +HALF_HEIGHT, w, h
l = min(0, l) # stop scrolling left
l = max(-(camera.width - WIN_WIDTH), l) # stop scrolling right
t = max(-(camera.height-WIN_HEIGHT), t) # stop scrolling bottom
return Rect(l, t, w, h)
class Entity(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
class Player(Entity):
def __init__(self, x, y):
Entity.__init__(self)
self.xvel = 0
self.yvel = 0
self.onGround = False
self.image = Surface((32,32))
self.image.fill(Color("#0000FF"))
self.image.convert()
self.rect = Rect(200, 1200, 32, 32)
def update(self, up, left, right, platforms):
print(self.yvel)
if up:
if self.onGround:
self.yvel = 0
self.yvel -= 10 # only jump if on the ground
if left:
self.xvel = -8
if right:
self.xvel = 8
if not self.onGround:
self.yvel += 0.3 # only accelerate with gravity if in the air
if self.yvel > 80: self.yvel = 80 # max falling speed
if not(left or right):
self.xvel = 0
self.rect.left += self.xvel # increment in x direction
self.collide(self.xvel, 0, platforms) # do x-axis collisions
self.rect.top += self.yvel # increment in y direction
self.onGround = False; # assuming we're in the air
self.collide(0, self.yvel, platforms) # do y-axis collisions
def collide(self, xvel, yvel, platforms):
for p in platforms:
if pygame.sprite.collide_rect(self, p):
if isinstance(p, ExitBlock):
pygame.event.post(pygame.event.Event(QUIT))
if xvel > 0: self.rect.right = p.rect.left
if xvel < 0: self.rect.left = p.rect.right
if yvel > 0:
self.rect.bottom = p.rect.top
self.onGround = True
if yvel < 0:
self.rect.top = p.rect.bottom
class Platform(Entity):
def __init__(self, x, y):
Entity.__init__(self)
self.image = Surface((32, 32))
self.image.convert()
self.image.fill(Color("#FFFFFF"))
self.rect = Rect(x, y, 32, 32)
def update(self):
pass
class ExitBlock(Platform):
def __init__(self, x, y):
Platform.__init__(self, x, y)
self.image = pygame.image.load("bush.png")
if __name__ == "__main__":
main()