Using logic in your update methods - python-2.7

Question

I'm working on a little game with some fellow students and I'm wanting some guidance on how to handle the problem...
With my code what it boils down to is I want to call into use the Boss_Shoot Class where the Boss class update() starts printing "should be shooting" .. the print statement statements seen through out are nothing more then a "placeholder of sorts...
As always Thanks so much!
class Boss(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.image.load("sprites/boss.png")
self.rect = self.image.get_rect()
self.dx = 1
self.dy = 1
self.shoot= True
def update(self):
if self.rect.centerx >= 600:
self.rect.centerx -= self.dx
elif self.rect.centerx <= 600:
print "should be shooting"
self.rect.centery -= self.dy
self.checkBounds()
def checkBounds(self):
if self.rect.top <= 0:
self.dy *= -1
print
if self.rect.bottom >= 500:
self.dy *= -1
class Boss_Shoot(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.Surface((20, 20))
self.image.fill((255, 0, 0))
self.rect = self.image.get_rect()
self.rect.center = (320, 240)
self.dy =2
def update(self):
if self.shoot == True:
print "shooting"
for i in range(100):
print "wtf man"
self.rect.x = random.randrange(1000, 3000)
self.rect.y = random. randrange(10, 490)
self.rect.x -= 5
self.rect.y +=self.dy

Answer 1

You need a way your actors (or Sprites, or whatever you call your "entities") can communicate with the global state of your game.
You didn't show all your code, so I assume everything is in one file.
Somewhere in your code, you probably have a list of all actors (and if you don't, you should create one). Let's assume it's defined as:
actors = []
Maybe you use a single list, maybe you want to use pygame's Group class.
I further assume you call the update() method on all actors in your mainloop, like:
for a in actors:
a.update()
(or, if you use pygame's Group class, something like mygroup.update()).
Now, in the update() method of Boss, just create a new instance of Boss_Shoot, and add it to the list of actors, like:
def update(self):
if self.rect.centerx >= 600:
self.rect.centerx -= self.dx
elif self.rect.centerx <= 600:
actors.append(Boss_Shoot())
You probably want to pass the position of Boss to the Boss_Shoot constructor so the bullet (or whatever) doesn't randomly appear on the screen (if you want to).
I prefer encapsulating the gamestate into a seperate dict or class, and pass that down to each actor so each actor can register/unregister itself from the world, something like:
class State(object):
def __init__(self):
self._actors = []
def register(self, actor):
self._actors.append(actor)
def unregister(self, actor):
self._actors.remove(actor)
def update(self):
for a in self._actors:
a.update()
...
class Boss(pygame.sprite.Sprite):
def __init__(self, state):
self.state = state
self.state.register(self)
...
def update(self):
if self.rect.centerx >= 600:
self.rect.centerx -= self.dx
elif self.rect.centerx <= 600:
self.state.register(Boss_Shoot(self.state))
class Boss_Shoot(pygame.sprite.Sprite):
def __init__(self, state):
self.state = state
self.state.register(self)
...
while True:
state.update()
state.draw(screen)
...
You'll get the idea.