cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   tron_thomas
   Member

   I have an object that gets added to the CC3World of my application, which acts a container for other node objects that it will manage. The nodes in this container need to be rendered, however because they are no added directly into the world they will not be drawn without explicitly being ask to draw.

   I tried implementing drawWithVisitor: for the container and forwarding that call onto the managed nodes. This seem to basically do nothing it ends up in CC3Node's drawWithVisitor: which appears to just be an empty stub method.

   What is the proper way for my container node to draw its sub nodes?

   Posted 3 months ago #
2. 

   Bill Hollings
   Moderator

   @tron_thomas

   The structural CC3Node that you are adding will automatically draw the child nodes (it's a recursive hierarchy).

   You don't need to do anything other than use addChild: on the structural CC3Node to add the drawable nodes to it, and addChild: on the world to add the structural node to the world.

   For example, see the Beach Ball or the LandingCraft in the CC3DemoMashUp.

   And of course, the CC3World needs to be attached to a CC3Layer, which in turns is plugged into the cocos2d CCDirector activity loop. See the AppDelegate class in the cocos3d template or any of the demo apps to see how that should be set up.

   ...Bill

   Posted 3 months ago #
3. 

   tron_thomas
   Member

   I had not been using addChild: as I had set up my class with specific members for the added nodes, however I suspect addChild: will work just as well. I'm not sure how that will affect how easy it is to access a particular node in the contain. It might work fine.

   I'm still curious if the container had not been node itself, how it could have rendered the nodes it contains.

   Posted 3 months ago #
4. 

   Bill Hollings
   Moderator

   @tron_thomas

   Frankly...you'd have to replicate a fair chunk of code. ;-)

   The nodes are hierarchical, and the transforms and other behaviour of parent nodes affect child nodes. The updating and drawing routines are handled by visitor patterns traversing the node hierarchy.

   If you want to extend a class to track individual nodes, subclass CCNode. If you want to keep child nodes in instance variables, do so, but add them as children too by invoking the addChild: and removeChild: methods from the accessor methods of those instance variables. That way, the hierarchy visitor pattern will still work, and you can access the children directly.

   There are actually a couple of examples of this type of design pattern in use in cocos3d. The wireframeBoxNode and descriptorNode properties access very specific child nodes. In those cases, the access is via name retrievals, but they could just as easily have been stored in specific instance variables.

   ...Bill

   Posted 3 months ago #

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