让我们放弃一切，从头开始，利用 pygame 的功能，如精灵和矢量数学。
我们从 pygame 游戏的基本框架开始，一个简单的窗口：
import pygame
def main():
screen = pygame.display.set_mode((640, 480))
clock = pygame.time.Clock()
while True:
events = pygame.event.get()
for e in events:
if e.type == pygame.QUIT:
return
screen.fill(pygame.Color('grey'))
pygame.display.flip()
clock.tick(60)
if __name__ == '__main__':
main()
我们的游戏将有不同的场景（标题场景、游戏场景、游戏结束场景），所以现在让我们实现它们：
import pygame
import pygame.freetype
pygame.init()
FONT = pygame.freetype.SysFont(None, 32)
class SimpleScene:
def __init__(self, text, background, next_scene):
if background:
self.background = pygame.image.load(background).convert()
else:
self.background = pygame.Surface((640, 480))
self.background.fill(pygame.Color('white'))
if text:
FONT.render_to(self.background, (100, 200), text, pygame.Color('black'))
FONT.render_to(self.background, ( 99, 199), text, pygame.Color('red'))
self.next_scene = next_scene
def start(self):
pass
def draw(self, screen):
screen.blit(self.background, (0, 0))
def update(self, events, dt):
for event in events:
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
return self.next_scene
class Game:
def __init__(self):
self.background = pygame.image.load('background.png').convert()
def start(self):
pass
def draw(self, screen):
screen.blit(self.background, (0, 0))
def update(self, events, dt):
for event in events:
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
return 'VICTORY'
def main():
screen = pygame.display.set_mode((640, 480))
clock = pygame.time.Clock()
scenes = {
'TITLE': SimpleScene('PRESS SPACE TO START', 'background.png', 'GAME'),
'GAME': Game(),
'VICTORY': SimpleScene('YOU WIN!', None, 'TITLE'),
'DEFEAT': SimpleScene('YOU LOSE!', None, 'TITLE'),
}
scene = scenes['TITLE']
dt = 0
while True:
events = pygame.event.get()
for e in events:
if e.type == pygame.QUIT:
return
next_scene = scene.update(events, dt)
if next_scene:
scene = scenes[next_scene]
scene.start()
scene.draw(screen)
pygame.display.flip()
dt = clock.tick(60)
if __name__ == '__main__':
main()
This allows us to cycle through the game scenes by pressing space.
现在让我们实现核心游戏。首先，我们需要一些精灵，所以让我们创建一个Actor类并准备游戏场景来显示和重置我们的精灵。我们使用 pygame 的一些基本内容，例如Sprite class https://www.pygame.org/docs/ref/sprite.html#pygame.sprite.Sprite.
...
class Actor(pygame.sprite.Sprite):
def __init__(self, image, pos, direction):
super().__init__()
self.image = image
self.rect = self.image.get_rect(center=pos)
self.pos = pygame.Vector2(*pos)
self.direction = pygame.Vector2(*direction)
class Game:
def __init__(self):
self.background = pygame.image.load('background.png').convert()
self.images = {
'tobi': pygame.image.load('tobi.png').convert_alpha(),
'naruto': pygame.image.load('naruto.png').convert_alpha(),
'kunai': pygame.image.load('kunai.png').convert_alpha()
}
self.sprites = pygame.sprite.Group()
def start(self):
self.sprites.empty()
self.sprites.add(Actor(self.images['naruto'], (50, 150), (0, 0)))
self.sprites.add(Actor(self.images['tobi'], (450, 300), (0, 0)))
def draw(self, screen):
screen.blit(self.background, (0, 0))
self.sprites.draw(screen)
def update(self, events, dt):
for event in events:
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
return 'VICTORY'
self.sprites.update()
...
是时候采取一些行动了。让我们在演员中实现一些行为。我们为我们想要的每种不同类型的行为创建函数。一种是让 Tobi 在屏幕上移动，一种是让火影忍者通过键盘控制，一种是让苦无来控制。
由于我们使用Vector精灵的位置和方向的类，只是一个减法问题，使苦无向鼠标位置移动。
这是完整的代码：
import pygame
import pygame.freetype
pygame.init()
FONT = pygame.freetype.SysFont(None, 32)
class SimpleScene:
def __init__(self, text, background, next_scene):
if background:
self.background = pygame.image.load(background).convert()
else:
self.background = pygame.Surface((640, 480))
self.background.fill(pygame.Color('white'))
if text:
FONT.render_to(self.background, (100, 200), text, pygame.Color('black'))
FONT.render_to(self.background, ( 99, 199), text, pygame.Color('red'))
self.next_scene = next_scene
def start(self):
pass
def draw(self, screen):
screen.blit(self.background, (0, 0))
def update(self, events, dt):
for event in events:
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
return self.next_scene
def tobi_ai(self, dt):
self._update_pos(dt)
# change direction when hitting the edge of the screen
display = pygame.display.get_surface().get_rect()
if self.rect.bottom > display.bottom or self.rect.top < 0: self.direction.y *= -1
if self.rect.right > display.right or self.rect.left < 0: self.direction.x *= -1
self._keep_on_screen()
def player_ai(self, dt):
# alter direction if arrow keys are pressed
self.direction = pygame.Vector2()
pressed = pygame.key.get_pressed()
if pressed[pygame.K_UP] or pressed[pygame.K_w]: self.direction += (0, -1)
if pressed[pygame.K_DOWN] or pressed[pygame.K_s]: self.direction += (0, 1)
if pressed[pygame.K_LEFT] or pressed[pygame.K_a]: self.direction += (-1, 0)
if pressed[pygame.K_RIGHT] or pressed[pygame.K_d]: self.direction += (1, 0)
self._update_pos(dt)
self._keep_on_screen()
def kunai_ai(self, dt):
self._update_pos(dt)
display = pygame.display.get_surface().get_rect()
# just fly around and die if out of screen
if not display.contains(self.rect):
self.kill()
class Actor(pygame.sprite.Sprite):
def __init__(self, image, pos, direction=(0, 0), speed=20, behaviour=None, rotate=False):
super().__init__()
self.image = image
self.rect = self.image.get_rect(center=pos)
# using vectors for position and direction makes it easy to calculate movement and rotation
self.pos = pygame.Vector2(*pos)
self.direction = pygame.Vector2(*direction)
if rotate:
self.image = pygame.transform.rotate(self.image, self.direction.angle_to(pygame.Vector2(1,0)))
self.speed = speed
self.behaviour = behaviour
def update(self, dt):
if self.behaviour:
self.behaviour(self, dt)
def _update_pos(self, dt):
if self.direction.length() > 0:
self.pos = self.pos + (self.direction.normalize() * self.speed * dt/100)
self.rect.center = int(self.pos.x), int(self.pos.y)
def _keep_on_screen(self):
self.rect.center = self.pos
display = pygame.display.get_surface().get_rect()
self.rect.clamp_ip(display)
self.pos.x, self.pos.y = self.rect.center
class Game:
def __init__(self):
self.background = pygame.image.load('background.png').convert()
self.images = {
'tobi': pygame.image.load('tobi.png').convert_alpha(),
'naruto': pygame.image.load('naruto.png').convert_alpha(),
'kunai': pygame.image.load('kunai.png').convert_alpha()
}
self.sprites = pygame.sprite.Group()
self.kunais = pygame.sprite.Group()
def start(self):
self.sprites.empty()
self.kunais.empty()
self.naruto = Actor(self.images['naruto'], (50, 150), behaviour=player_ai)
self.tobi = Actor(self.images['tobi'], (450, 300), (1, 1), behaviour=tobi_ai)
self.sprites.add(self.naruto)
self.sprites.add(self.tobi)
self.player_lives = 10
self.enemy_lives = 3
def draw(self, screen):
screen.blit(self.background, (0, 0))
self.sprites.draw(screen)
FONT.render_to(screen, (430, 10), 'Naruto:' , pygame.Color('red'))
FONT.render_to(screen, (550, 10), str(self.player_lives), pygame.Color('red'))
FONT.render_to(screen, (430, 50), 'Tobi:', pygame.Color('red'))
FONT.render_to(screen, (550, 50), str(self.enemy_lives), pygame.Color('red'))
def update(self, events, dt):
for event in events:
if event.type == pygame.MOUSEBUTTONDOWN:
kunai = Actor(self.images['kunai'],
self.naruto.pos,
event.pos-self.naruto.pos,
speed=35,
behaviour=kunai_ai,
rotate=True)
self.sprites.add(kunai)
self.kunais.add(kunai)
self.sprites.update(dt)
# kunai hits tobi
# we use https://www.pygame.org/docs/ref/sprite.html#pygame.sprite.spritecollide
# for collition detection
for sprite in pygame.sprite.spritecollide(self.tobi, self.kunais, True):
self.enemy_lives -= 1
if self.enemy_lives <= 0:
return 'VICTORY'
# tobi hits naruto
if self.tobi.rect.colliderect(self.naruto.rect):
self.player_lives -= 1
if self.player_lives <= 0:
return 'DEFEAT'
self.naruto.pos = pygame.Vector2(50, 150)
self.tobi.pos.x = max(self.tobi.pos.x, 400)
def main():
screen = pygame.display.set_mode((640, 480))
clock = pygame.time.Clock()
scenes = {
'TITLE': SimpleScene('PRESS SPACE TO START', 'background.png', 'GAME'),
'GAME': Game(),
'VICTORY': SimpleScene('YOU WIN!', None, 'TITLE'),
'DEFEAT': SimpleScene('YOU LOSE!', None, 'TITLE'),
}
scene = scenes['TITLE']
dt = 0
while True:
events = pygame.event.get()
for e in events:
if e.type == pygame.QUIT:
return
next_scene = scene.update(events, dt)
if next_scene:
scene = scenes[next_scene]
scene.start()
scene.draw(screen)
pygame.display.flip()
dt = clock.tick(60)
if __name__ == '__main__':
main()
现在我们有了一个可重玩且易于扩展的简单游戏。请随意使用此代码进行任何您喜欢的操作。
