Re: [pygame] global class instances?
Here's the way I typically handle this issue: Create a module (like your globals module, call it whatever you like) that you can use as a namespace to hold you global instances. These are typically called singletons. Then in the globals module, add a method called init() that sets up the global instances. Doing the imports inside the init() function is not strictly necessary, but it can be a nice way to avoid implicit module dependancies (since basically everything will import globals) which can cause crummy side-affects like circular imports as you add more modules that depend on one-another. def init(): from console import Console from fps import FPS from map import Map from mouse import Mouse from player import Player global console, fps, map, mouse, player console = Console() fps = FPS() map = Map() mouse = Mouse() player = Player() You can call globals.init() from your main initializer right after the basic pygame stuff is setup. When you refer to globals, you must use late binding, thus you cannot use "from globals import *" which attempts to bind the stuff in globals before it is initialized. Instead just use "import globals". So, for example, in the Player class when you want to refer to the mouse instance you need to use "globals.mouse" which will lookup the mouse object only after everything is setup properly. IMO it make the code easier to read too since it is clear where mouse is coming from. hth, -Casey On Nov 24, 2007, at 12:33 PM, Jake b wrote: I'm starting a basic game. I have a few classes. I'm having trouble figuring out how to handle some global class instances. Here's my current classes. FPS() = handles fps rendering, and calc's delta for time-based movement Player() = Player's class Console() = buffer that I can pass strings to, and it shows them on screen. Map() = stores map tile info, and renders it. Mouse() = some basic mouse helper functions, mouse location, etc... ZombieHuntMain() = The main entry point, main loop, etc. I want a few class instances to be global so that I don't have to pass a pointer in every constructor that needs them. ( Like I am doing right now in the snippet ) Right now I my game initialization looks like: # ZombieHunt.py : snippet of main logic class class ZombieHuntMain: """entry point. initialization, and game logic.""" def __init__(self, width=1024, height=768): """Initialize PyGame""" pygame.init() self.width, self.height = width, height self.screen = pygame.display.set_mode(( self.width, self.height )) # some of these should be accessible to any file that includes "Globals.py" self.console = Console() self.fps = FPS( self.console ) self.map = Map(self.console) self.mouse = Mouse(self.console, self.map) self.player = Player(self.console, self.map, self.mouse, self.fps) # add player to the sprite group self.unit_sprites = RenderPlain() self.unit_sprites.add( self.player ) So you can see that the constructor arguments are getting crazy. Most will want access to the Console() instance. And probably Map(). Maybe others. I tried just moving the constructors to Globals.py, but then pygame doesn't initialize in time for Console().__init__() to work. ( Fails because pygame fonts don't load in time ) I even tried "pygame.init()" before the line "from Globals import *", but It still seemed to not work. (And that seemed like a bad way to fix it ) I also tried creating the instances like normal ( same as in the above code ) as members of ZombieHuntMain, then in Globals.py create a reference to that instance: # grab pointer / reference of instance in ZombieHunt console = ZombieHuntMain.console But I couldn't get that to work, even with "from ZombieHunt import *" ( I don't know if ZombieHunt.py being the entry point has anything to do with that? If something else happens if you attempt to import the entry point ? ) (1) How would you organize the classes? (2) I'm going to be creating a sprite group: "bullet_sprites". Do you think my sprite groups should be global? Because I need to spawn bullets from within Player(). thanks, -- Jake
Re: [pygame] global class instances?
pygame.fps = FPS() import pygame print pygame.fps It's somewhat hacky but it works, because the import statement uses the already imported module if it exists. I tend to have one entry point that I pass to all constructors, as in the displaymanager example. Sometimes I'll make it a part of the class instead: class DisplayManager: def test(self): print "I am the root object" class ObjectInstance: def test(self): self.root.test() #initialization code at end of main.py root = DisplayManager() ObjectInstance.root = root a = ObjectInstance() a.test() On Nov 24, 2007 12:48 PM, Ghislain Leveque <[EMAIL PROTECTED]> wrote: > 2007/11/24, Jake b <[EMAIL PROTECTED]>: > > (2) I'm going to be creating a sprite group: "bullet_sprites". Do you > > think my sprite groups should be global? Because I need to spawn > > bullets from within Player(). > > I don't know for your other question but may be really interested by > the answers. > > For this point, here is what I do : > - have a class named "DisplayManager" and instantiate it > - this instance sould be global or passed to every object in the > constructor (as you do now) > - this class has a method "create_bullet" that creates the bullet with > the right sprite group. This will also be the class that handle the > "draw" method and holds the sprites group, the pygame.display... > > hope that helps > > -- > Ghislain Lévêque >
Re: [pygame] global class instances?
2007/11/24, Jake b <[EMAIL PROTECTED]>: > (2) I'm going to be creating a sprite group: "bullet_sprites". Do you > think my sprite groups should be global? Because I need to spawn > bullets from within Player(). I don't know for your other question but may be really interested by the answers. For this point, here is what I do : - have a class named "DisplayManager" and instantiate it - this instance sould be global or passed to every object in the constructor (as you do now) - this class has a method "create_bullet" that creates the bullet with the right sprite group. This will also be the class that handle the "draw" method and holds the sprites group, the pygame.display... hope that helps -- Ghislain Lévêque
[pygame] global class instances?
I'm starting a basic game. I have a few classes. I'm having trouble figuring out how to handle some global class instances. Here's my current classes. FPS() = handles fps rendering, and calc's delta for time-based movement Player() = Player's class Console() = buffer that I can pass strings to, and it shows them on screen. Map() = stores map tile info, and renders it. Mouse() = some basic mouse helper functions, mouse location, etc... ZombieHuntMain() = The main entry point, main loop, etc. I want a few class instances to be global so that I don't have to pass a pointer in every constructor that needs them. ( Like I am doing right now in the snippet ) Right now I my game initialization looks like: # ZombieHunt.py : snippet of main logic class class ZombieHuntMain: """entry point. initialization, and game logic.""" def __init__(self, width=1024, height=768): """Initialize PyGame""" pygame.init() self.width, self.height = width, height self.screen = pygame.display.set_mode(( self.width, self.height )) # some of these should be accessible to any file that includes "Globals.py" self.console = Console() self.fps = FPS( self.console ) self.map = Map(self.console) self.mouse = Mouse(self.console, self.map) self.player = Player(self.console, self.map, self.mouse, self.fps) # add player to the sprite group self.unit_sprites = RenderPlain() self.unit_sprites.add( self.player ) So you can see that the constructor arguments are getting crazy. Most will want access to the Console() instance. And probably Map(). Maybe others. I tried just moving the constructors to Globals.py, but then pygame doesn't initialize in time for Console().__init__() to work. ( Fails because pygame fonts don't load in time ) I even tried "pygame.init()" before the line "from Globals import *", but It still seemed to not work. (And that seemed like a bad way to fix it ) I also tried creating the instances like normal ( same as in the above code ) as members of ZombieHuntMain, then in Globals.py create a reference to that instance: # grab pointer / reference of instance in ZombieHunt console = ZombieHuntMain.console But I couldn't get that to work, even with "from ZombieHunt import *" ( I don't know if ZombieHunt.py being the entry point has anything to do with that? If something else happens if you attempt to import the entry point ? ) (1) How would you organize the classes? (2) I'm going to be creating a sprite group: "bullet_sprites". Do you think my sprite groups should be global? Because I need to spawn bullets from within Player(). thanks, -- Jake
