如何实现粒子引擎
use*_*231 5 python refactoring pygame particle-system
所以我制作了一个吸烟的粒子引擎,我很高兴,我认为它非常适合我的游戏.
我现在需要将它实现到我的游戏中,我遇到了一些麻烦.我想知道是否有人可以解释我将如何在我的游戏中使用我的粒子引擎.
我在下面添加了我的代码(用于冒烟和我的游戏文件).
我希望将粒子与游戏文件分开,但在我的游戏中调用它.
最终,我想在引擎中制作更多粒子效果,我也可以调用它.
有人可以帮忙吗？它可能需要一些调整才能工作.
粒子代码:
import pygame,random
from pygame.locals import *
xmax = 1000 #width of window
ymax = 600 #height of window
class Smoke():
def __init__(self, startx, starty, col):
self.x = startx
self.y = random.randint(0, starty)
self.col = col
self.sx = startx
self.sy = starty
def move(self):
if self.y < 0:
self.x = self.sx
self.y = self.sy
else:
self.y -= 1
self.x += random.randint(-1, 2)
def main():
pygame.init()
screen = pygame.display.set_mode((xmax,ymax))
black = (0,0,0)
grey = (145,145,145)
light_grey = (192,192,192)
dark_grey = (183, 183, 183)
clock = pygame.time.Clock()
particles = []
for part in range(600):
if part % 2 > 0: col = grey
#elif part % 5 > 0: col = dark_grey
elif part % 3 > 0: col = dark_grey
else: col = light_grey
particles.append( Smoke(0, 500, col) )
exitflag = False
while not exitflag:
for event in pygame.event.get():
if event.type == QUIT:
exitflag = True
elif event.type == KEYDOWN:
if event.key == K_ESCAPE:
exitflag = True
screen.fill(black)
for p in particles:
p.move()
pygame.draw.circle(screen, p.col, (p.x, p.y), 15)
pygame.display.flip()
clock.tick(80)
pygame.quit()
if __name__ == "__main__":
main()
游戏代码
import pygame
from pygame import *
WIN_WIDTH = 1120 - 320
WIN_HEIGHT = 960 - 320
HALF_WIDTH = int(WIN_WIDTH / 2)
HALF_HEIGHT = int(WIN_HEIGHT / 2)
DISPLAY = (WIN_WIDTH, WIN_HEIGHT)
DEPTH = 0
FLAGS = 0
CAMERA_SLACK = 30
levels = {0: {'level': [
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" E ",
" PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPPP PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPP P",
" PPPP P",
" PPPP PPPPPPP",
" PPPPPPPPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPPPPP",
"PPPPP PPPP PPPPPPP",
"PPP PPPP PPPPPPP",
"PPP PPPP PPPPPPP",
"PPP PPPP PPPPPPP",
"PPP PPPPP PPPP PPPPPPP",
"PPP PPPP",
"PPP PPPP",
"PPP PPPP",
"PPP PPPPPPPPPPPPPPPPPP",
"PPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",],
'enemies': [(9, 38)]},
1: {'level': [
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" E ",
" PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPPP PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPP P",
" PPPP P",
" PPPP PPPPPPP",
" PPPPPPPPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPPPPP",
"PPPPP PPPP PPPPPPP",
"PPP PPPPPPPPPPP PPPPPPP",
"PPP PPPP PPPPPPP",
"PPP PPPP PPPPPPP",
"PPP PPPPPPPP PPPP PPPPPPP",
"PPP PPPP",
"PPP PPPP",
"PPP PPPPP PPPP",
"PPP P PPPPPPPPPPPPPPPPPP",
"PPP P PPPPPPPPPPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",],
'enemies': [(9, 38), (18, 38), (15, 15)]}}
class Scene(object):
def __init__(self):
pass
def render(self, screen):
raise NotImplementedError
def update(self):
raise NotImplementedError
def handle_events(self, events):
raise NotImplementedError
class GameScene(Scene):
def __init__(self, levelno):
super(GameScene, self).__init__()
self.bg = Surface((32,32))
self.bg.convert()
self.bg.fill(Color("#0094FF"))
up = left = right = False
self.entities = pygame.sprite.Group()
self.player = Player(5, 40)
self.player.scene = self
self.platforms = []
self.levelno = levelno
levelinfo = levels[levelno]
self.enemies = [Enemy(*pos) for pos in levelinfo['enemies']]
level = levelinfo['level']
total_level_width = len(level[0]) * 32
total_level_height = len(level) * 32
# build the level
x = 0
y = 0
for row in level:
for col in row:
if col == "P":
p = Platform(x, y)
self.platforms.append(p)
self.entities.add(p)
if col == "E":
e = ExitBlock(x, y)
self.platforms.append(e)
self.entities.add(e)
x += 32
y += 32
x = 0
self.camera = Camera(complex_camera, total_level_width, total_level_height)
self.entities.add(self.player)
for e in self.enemies:
self.entities.add(e)
def render(self, screen):
for y in range(20):
for x in range(25):
screen.blit(self.bg, (x * 32, y * 32))
for e in self.entities:
screen.blit(e.image, self.camera.apply(e))
def update(self):
pressed = pygame.key.get_pressed()
up, left, right = [pressed[key] for key in (K_UP, K_LEFT, K_RIGHT)]
self.player.update(up, left, right, self.platforms)
for e in self.enemies:
e.update(self.platforms)
self.camera.update(self.player)
def exit(self):
if self.levelno+1 in levels:
self.manager.go_to(GameScene(self.levelno+1))
else:
self.manager.go_to(CustomScene("You win!"))
def die(self):
self.manager.go_to(CustomScene("You lose!"))
def handle_events(self, events):
for e in events:
if e.type == KEYDOWN and e.key == K_ESCAPE:
self.manager.go_to(TitleScene())
class CustomScene(object):
def __init__(self, text):
self.text = text
super(CustomScene, self).__init__()
self.font = pygame.font.SysFont('Arial', 56)
def render(self, screen):
# ugly!
screen.fill((0, 200, 0))
text1 = self.font.render(self.text, True, (255, 255, 255))
screen.blit(text1, (200, 50))
def update(self):
pass
def handle_events(self, events):
for e in events:
if e.type == KEYDOWN:
self.manager.go_to(TitleScene())
class TitleScene(object):
def __init__(self):
super(TitleScene, self).__init__()
self.font = pygame.font.SysFont('Arial', 56)
self.sfont = pygame.font.SysFont('Arial', 32)
def render(self, screen):
# ugly!
screen.fill((0, 200, 0))
text1 = self.font.render('Crazy Game', True, (255, 255, 255))
text2 = self.sfont.render('> press space to start <', True, (255, 255, 255))
screen.blit(text1, (200, 50))
screen.blit(text2, (200, 350))
def update(self):
pass
def handle_events(self, events):
for e in events:
if e.type == KEYDOWN and e.key == K_SPACE:
self.manager.go_to(GameScene(0))
class SceneMananger(object):
def __init__(self):
self.go_to(TitleScene())
def go_to(self, scene):
self.scene = scene
self.scene.manager = self
def main():
pygame.init()
screen = pygame.display.set_mode(DISPLAY, FLAGS, DEPTH)
pygame.display.set_caption("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
timer = pygame.time.Clock()
running = True
manager = SceneMananger()
while running:
timer.tick(60)
if pygame.event.get(QUIT):
running = False
return
manager.scene.handle_events(pygame.event.get())
manager.scene.update()
manager.scene.render(screen)
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):
try:
return target.rect.move(self.state.topleft)
except AttributeError:
return map(sum, zip(target, 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(x*32, y*32, 32, 32)
def update(self, up, left, right, platforms):
if self.rect.top > 1440 or self.rect.top < 0:
self.scene.die()
if self.rect.left > 1408 or self.rect.right < 0:
self.scene.die()
if up:
if self.onGround:
self.yvel = 0
self.yvel -= 10 # only jump if on the ground
if left:
self.xvel = -10
if right:
self.xvel = 10
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
if 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):
self.scene.exit()
return False
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
return True
class Enemy(Entity):
def __init__(self, x, y):
Entity.__init__(self)
self.yVel = 0
self.xVel = 2 # start moving immediately
self.image = Surface((32,32))
self.image.fill(Color("#00FF00"))
self.image.convert()
self.rect = Rect(x*32, y*32, 32, 32)
self.onGround = False
def update(self, platforms):
if not self.onGround:
self.yVel += 0.3
# no need for right_dis to be a member of the class,
# since we know we are moving right if self.xVel > 0
right_dis = self.xVel > 0
# create a point at our left (or right) feet
# to check if we reached the end of the platform
m = (1, 1) if right_dis else (-1, 1)
p = self.rect.bottomright if right_dis else self.rect.bottomleft
fp = map(sum, zip(m, p))
# if there's no platform in front of us, change the direction
collide = any(p for p in platforms if p.rect.collidepoint(fp))
if not collide:
self.xVel *= -1
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 xVel > 0:
self.rect.right = p.rect.left
self.xVel *= -1 # hit wall, so change direction
if xVel < 0:
self.rect.left = p.rect.right
self.xVel *= -1 # hit wall, so change direction
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], pygame.SRCALPHA, 32) #makes blocks invisible for much better artwork
self.image = Surface((32,32)) #makes blocks visible for building levels
self.image.convert()
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 = Surface((32,32)) #makes blocks visible for building levels
self.image.convert()
self.rect = Rect(x, y, 32, 32)
if __name__ == "__main__":
main()
slo*_*oth 14
谨防!长帖!
粒子
首先,我们来看看你的Smoke课程.它包含一些烟雾行为,但也包含你的主循环.让我们通过创建一个Particle除了表示粒子之外什么都不做的泛型类来解决这个问题:
class Particle():
def __init__(self, col, size, *strategies):
self.x, self.y = 0, 0
self.col = col
self.alive = 0
self.strategies = strategies
self.size = size
def kill(self):
self.alive = -1 # alive -1 means dead
def move(self):
for s in self.strategies:
s(self)
这堂课没什么用.它是通用的,它将所有行为(简单函数)传递给它的__init__函数,并且粒子在move方法中将这些函数应用于自身.
粒子的行为
现在我们的粒子类是灵活的,让我们考虑粒子应该如何表现,以便它们看起来像烟雾.
烟雾粒子应该上升,所以让我们创建一个向上移动粒子的函数:
def ascending(speed):
def _ascending(particle):
particle.y -= speed
return _ascending
烟雾粒子应该在某个时刻死亡,所以让我们写一个在某种条件下杀死它的函数:
def kill_at(max_x, max_y):
def _kill_at(particle):
if particle.x < -max_x or particle.x > max_x or particle.y < -max_y or particle.y > max_y:
particle.kill()
return _kill_at
我们需要跟踪粒子的存活时间(后来派上用场),所以我们需要一个让粒子老化的函数:
def age(amount):
def _age(particle):
particle.alive += amount
return _age
当烟雾上升时,它不应该是一条直线(多么无聊!),但它应该散开:
def fan_out(modifier):
def _fan_out(particle):
d = particle.alive / modifier
d += 1
particle.x += random.randint(-d, d)
return _fan_out
太好了!现在我们的烟雾可以散开,但它仍然有点无聊,所以让我们写一个模拟一点风的功能:
def wind(direction, strength):
def _wind(particle):
if random.randint(0,100) < strength:
particle.x += direction
return _wind
我们现在有一堆描述粒子行为的函数.所有这些都很小而且独立.您可以创建无限量的它们并根据需要组合它们以创建不同的粒子.
烟
实际创建一些粒子的时间:进入烟雾机!
def smoke_machine():
colors = {0: grey,
1: dark_grey,
2: light_grey}
def create():
for _ in xrange(random.choice([0,0,0,0,0,0,0,1,2,3])):
behaviour = age(1), ascending(1), fan_out(400), wind(1, 15), kill_at(1000, 1000)
p = Particle(colors[random.randint(0, 2)], random.randint(10, 15), *behaviour)
yield p
while True:
yield create()
那到底是什么意思？简单.它是一个不断发射新粒子的发生器.每当有人想要检索下一个项目时,它就会调用它的嵌套create函数.该函数依次根据输入列表返回0到3个粒子random.choice.这是一个很好的方式,它说它返回0粒子,有70%的几率,1或2或3粒子,每粒粒子有10%的几率.
在下一行中,我们定义了粒子的行为.它只是一个功能元组.注意每个函数调用如何返回其嵌套函数.这样就可以参数化这些函数.
最后一步是为粒子随机分配颜色和大小.
您可以从命令行进行测试,看看它是如何工作的:
>>> s=smoke_machine()
>>> list(next(s))
[]
>>> list(next(s))
[<particle.Particle instance at 0x02AD94B8>, <particle.Particle instance at 0x02
AD9030>]
>>> list(next(s))
[]
>>> list(next(s))
[]
>>> list(next(s))
[<particle.Particle instance at 0x02AD9030>]
>>> list(next(s))
[<particle.Particle instance at 0x02AD9418>, <particle.Particle instance at 0x02
AD93C8>]
>>> list(next(s))
[<particle.Particle instance at 0x02AD9030>]
看看我们每次在发电机上调用下一次时,它最多返回3个粒子.
把它们放在一起
我们如何将我们的烟机与我们的游戏结合起来？让我们写一个为我们处理它的类:
class Emitter(object):
def __init__(self, pos=(0, 0)):
self.particles = []
self.pos = pos
self.factories = []
def add_factory(self, factory, pre_fill=300):
self.factories.append(factory)
tmp = []
for _ in xrange(pre_fill):
n = next(factory)
tmp.extend(n)
for p in tmp:
p.move()
self.particles.extend(tmp)
def update(self):
for f in self.factories:
self.particles.extend(next(f))
for p in self.particles[:]:
p.move()
if p.alive == -1:
self.particles.remove(p)
def draw(self, screen, position_translater_func):
for p in self.particles:
target_pos = position_translater_func(map(sum, zip((p.x, p.y), self.pos)))
pygame.draw.circle(screen, p.col, target_pos, int(p.size))
发射器可以容纳一堆工厂函数(比如我们的smoke_machine),每次更新它时,它都会将这些工厂的粒子添加到它,self.particles这样它就可以将它们绘制到屏幕上.让我们详细看一些函数:
如果我们添加一个新工厂add_factory,我们称之为factory并pre_fill提前移动其粒子300(或任何).这样,一些粒子已经存在.
If we want to draw the particles, we have to calculate thier positions using the position of the Emitter. Also, we need to adjust this position using the camera of the game, so we just accept a function as parameter that translates our position to the correct final position so that our particles scroll accordingly within the game.
We don't need big changes to the game class to use the Emitter now. We just create a new list in the GameScene called self.emitter, and an Emitter and add the smoke_machine factory to it.
In the render method we call
for e in self.emitter:
e.draw(screen, self.camera.apply)
and in the update method we call
for e in self.emitter:
e.update()
and we are done!
Action !
complete listing:
game.py
omitted some classes because I hit the 30000 character limit :-)
import pygame
from pygame import *
from particle import Emitter, smoke_machine
WIN_WIDTH = 1120 - 320
WIN_HEIGHT = 960 - 320
HALF_WIDTH = int(WIN_WIDTH / 2)
HALF_HEIGHT = int(WIN_HEIGHT / 2)
DISPLAY = (WIN_WIDTH, WIN_HEIGHT)
DEPTH = 0
FLAGS = 0
CAMERA_SLACK = 30
levels = {0: {'level': [
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" E ",
" PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPPP PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPP P",
" PPPP P",
" PPPP PPPPPPP",
" PPPPPPPPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPPPPP",
"PPPPP PPPP PPPPPPP",
"PPP PPPP PPPPPPP",
"PPP PPPP PPPPPPP",
"PPP PPPP PPPPPPP",
"PPP PPPPP PPPP PPPPPPP",
"PPP PPPP",
"PPP PPPP",
"PPP PPPP",
"PPP PPPPPPPPPPPPPPPPPP",
"PPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP S PPPPPPPPPPPPPPPPPP",],
'enemies': [(9, 38)]},
1: {'level': [
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" ",
" E ",
" PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPPP PPPPPPPPPPPPPPPP",
" PPPPPPPPPPPPPPPP",
" PPPP P",
" PPPP P",
" PPPP PPPPPPP",
" PPPPPPPPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPPPPP",
" PPPP PPPPPPP",
"PPPPP PPPP PPPPPPP",
"PPP PPPPPPPPPPP PPPPPPP",
"PPP PPPP PPPPPPP",
"PPP PPPP PPPPPPP",
"PPP PPPPPPPP PPPP PPPPPPP",
"PPP PPPP",
"PPP PPPP",
"PPP PPPPP PPPP",
"PPP P PPPPPPPPPPPPPPPPPP",
"PPP P PPPPPPPPPPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",
"PPPPPPPPPPPPPPP PPPPPPPPPPPPPPPPPP",],
'enemies': [(9, 38), (18, 38), (15, 15)]}}
...
class GameScene(Scene):
def __init__(self, levelno):
super(GameScene, self).__init__()
self.bg = Surface((32,32))
self.bg.convert()
self.bg.fill(Color("#0094FF"))
up = left = right = False
self.entities = pygame.sprite.Group()
self.player = Player(5, 40)
self.player.scene = self
self.platforms = []
self.levelno = levelno
levelinfo = levels[levelno]
self.enemies = [Enemy(*pos) for pos in levelinfo['enemies']]
level = levelinfo['level']
total_level_width = len(level[0]) * 32
total_level_height = len(level) * 32
self.emitter = []
# build the level
x = 0
y = 0
for row in level:
for col in row:
if col == "P":
p = Platform(x, y)
self.platforms.append(p)
self.entities.add(p)
if col == "E":
e = ExitBlock(x, y)
self.platforms.append(e)
self.entities.add(e)
if col == "S":
e = Emitter((x, total_level_height))
e.add_factory(smoke_machine())
self.emitter.append(e)
x += 32
y += 32
x = 0
self.camera = Camera(complex_camera, total_level_width, total_level_height)
self.entities.add(self.player)
for e in self.enemies:
self.entities.add(e)
def render(self, screen):
for y in range(20):
for x in range(25):
screen.blit(self.bg, (x * 32, y * 32))
for e in self.emitter:
e.draw(screen, self.camera.apply)
for e in self.entities:
screen.blit(e.image, self.camera.apply(e))
def update(self):
for e in self.emitter:
e.update()
pressed = pygame.key.get_pressed()
up, left, right = [pressed[key] for key in (K_UP, K_LEFT, K_RIGHT)]
self.player.update(up, left, right, self.platforms)
for e in self.enemies:
e.update(self.platforms)
self.camera.update(self.player)
def exit(self):
if self.levelno+1 in levels:
self.manager.go_to(GameScene(self.levelno+1))
else:
self.manager.go_to(CustomScene("You win!"))
def die(self):
self.manager.go_to(CustomScene("You lose!"))
def handle_events(self, events):
for e in events:
if e.type == KEYDOWN and e.key == K_ESCAPE:
self.manager.go_to(TitleScene())
...
if __name__ == "__main__":
main()
particle.py
import pygame,random
def ascending(speed):
def _ascending(particle):
particle.y -= speed
return _ascending
def kill_at(max_x, max_y):
def _kill_at(particle):
if particle.x < -max_x or particle.x > max_x or particle.y < -max_y or particle.y > max_y:
particle.kill()
return _kill_at
def age(amount):
def _age(particle):
particle.alive += amount
return _age
def fan_out(modifier):
def _fan_out(particle):
d = particle.alive / modifier
d += 1
particle.x += random.randint(-d, d)
return _fan_out
def wind(direction, strength):
def _wind(particle):
if random.randint(0,100) < strength:
particle.x += direction
return _wind
class Particle():
def __init__(self, col, size, *strategies):
self.x, self.y = 0, 0
self.col = col
self.alive = 0
self.strategies = strategies
self.size = size
def kill(self):
self.alive = -1 # alive -1 means dead
def move(self):
for s in self.strategies:
s(self)
black = (0,0,0)
grey = (145,145,145)
light_grey = (192,192,192)
dark_grey = (183, 183, 183)
def smoke_machine():
colors = {0: grey,
1: dark_grey,
2: light_grey}
def create():
for _ in xrange(random.choice([0,0,0,0,0,0,0,1,2,3])):
behaviour = ascending(1), kill_at(1000, 1000), fan_out(400), wind(1, 15), age(1)
p = Particle(colors[random.randint(0, 2)], random.randint(10, 15), *behaviour)
yield p
while True:
yield create()
class Emitter(object):
def __init__(self, pos=(0, 0)):
self.particles = []
self.pos = pos
self.factories = []
def add_factory(self, factory, pre_fill=300):
self.factories.append(factory)
tmp = []
for _ in xrange(pre_fill):
n = next(factory)
tmp.extend(n)
for p in tmp:
p.move()
self.particles.extend(tmp)
def update(self):
for f in self.factories:
self.particles.extend(next(f))
for p in self.particles[:]:
p.move()
if p.alive == -1:
self.particles.remove(p)
def draw(self, screen, position_translater_func):
for p in self.particles:
target_pos = position_translater_func(map(sum, zip((p.x, p.y), self.pos)))
pygame.draw.circle(screen, p.col, target_pos, int(p.size))
Conclusion
We have successfully integrated the particles in the game. We have done this by writting small, self-contained functions that describe different behavioral patterns, and composed them by using a factory function.
And while doing this, we learned about closures, generators, the SRP, the factory- and the strategy pattern.
We could now easily add new behaviours, e.g. changing colors, or create new particle factories that behave totally different, but use our exiting functions.
For example, try using this function that will let the particles grow
def grow(amount):
def _grow(particle):
if random.randint(0,100) < particle.alive / 20:
particle.size += amount
return _grow
by adding grow(0.5) to the list of behaviours in the smoke_machine
Small change, impressive effect.
What a nice day!
P.S.: You can find a faster version (and bugfixes) at this repository. It uses numpy, itertools, psyco and pygame.surfarray and eschews the random module for massive speed improvement.
- +1很棒(很长)回答,真棒!工厂和发电机很棒!喜欢这个答案! (3认同)