cocos2d for iPhone

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

1. 

   jbhewitt
   Member

   Hey guys,

   I'm a ObjC newbie so sorry if I sound silly here!

   I'm working with the Box2D example code. Basically I want to make a box2d world with dynamic and static objects. When you touch/click on a static object it disappears.

   I can delete the object using world->DestroyBody(shapeBody), but the Cocos2D sprite is still there.

   b2Body* shapeBody = shapes[i]->GetBody();
   if (shapeBody->IsStatic() == false && shapeBody->GetMass() > 0.0f) {
   // other code goes here
   } else {
   world->DestroyBody(shapeBody);
   }

   My question is, how do I determine which sprite I should delete? I could then use a command like [self removeChild:THESHAPESPRITETODELETE cleanup:1];

   The Box2D example code uses standard sprite instead of atlas sprite.

   I've been searching the net and found Johnny's example of using Box2D here: http://johnehartzog.com/2009/07/using-box2d-physics-engine-with-cocos2d-iphone/ , and he seems to flag an array of some sort.

   I really need to learn more ObjC. :P

   Posted 2 years ago #
2. 

   steve
   Member

   Look at his

   removeDeadActors()

   method. He stores a reference to the cocos2d object on the Box2D object so he can later retrieve the cocos2d object in that method and remove it.

   Posted 2 years ago #
3. 

   sroske
   Member

   Box2D bodies have a userData property just for this purpose, see http://box2d.org/manual.html#d0e397 for more.

   Posted 2 years ago #
4. 

   jbhewitt
   Member

   Ok, so I had a dig around and wrote this code:

   world->DestroyBody(shapeBody);
   AtlasSprite* myActor = (AtlasSprite*) shapeBody->GetUserData();
   id mgr = [self getChildByTag:kTagSpriteManager];
   [mgr removeChild:myActor cleanup:YES];

   It works!

   Posted 2 years ago #

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