cocos2d for iPhone

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

1. 

   cocosboy
   Member

   Hi I am using following function

   cpSpaceAddCollisionHandler(space, 1, 2, NULL, &TankCollisionOccured, NULL, NULL, NULL);

   to call the function "TankCollisionOccured" written bellow

   static int TankCollisionOccured(cpShape *a, cpShape *b, cpContact *contacts, int numContacts, cpFloat normal_coef, void *data)
   {
       cpSpaceRemoveShape(space, a);
   
       return 1;
   }

   in this function I am unable to use the space variable that have been defined in the .h file of my current game play class.

   How can i access it. i have to destroy the "cpShape *a, cpShape *b" shapes actually.

   thanks

   Posted 1 year ago #
2. 

   mobilebros
   Moderator

   If you used the newer (better) chipmunk you would not have this problem, as space is passed to you.

   Why don't you pass the space in as the last parameter (void *data).

   Posted 1 year ago #
3. 

   cocosboy
   Member

   you mean to say i will have to do some thing like this..

   while setting collision function

   cpSpaceAddCollisionHandler(space, 1, 2, NULL, &TankCollisionOccured, NULL, NULL, space);

   and function like this

   static int TankCollisionOccured (cpShape *a, cpShape *b, cpContact *contacts, int numContacts, cpFloat normal_coef, void *data)
   {
   	cpSpace *MySpace  = (cpSpace *) data;
   	cpSpaceRemoveShape(MySpace, a);
   	cpSpaceRemoveShape(MySpace, b);
   
   	return 1; //IGNORE the collision, return 1 if you want it to handle the collision
   }

   but its giving exception :(

   any suggestions?

   Posted 1 year ago #
4. 

   cocosboy
   Member

   I am unable to destroy these shapes. :(

   any help?

   Posted 1 year ago #
5. 

   cocosboy
   Member

   I have tried it like this as well

   here bg is the background image in which its children are my chipmunk sprites

   cpSpaceAddCollisionHandler(space, 1, 2, ObjectCollided, bg, NULL, NULL, NULL);

   and function

   static int ObjectCollided(cpArbiter *arb, cpSpace *space, CCSprite *bg, void *unused)
   {
   	cpShape *a, *b; cpArbiterGetShapes(arb, &a, &b);
   
   	CCSprite *tempSprite = (CCSprite *) a->data;
   	[bg removeChild:tempSprite cleanup:YES];
   
   	cpSpaceRemoveBody(space, a->body);
   	cpSpaceRemoveShape(space, a);
   	cpBodyFree(a->body);
   	cpShapeFree(a);
   	a->body = nil;
   	a = nil;
   //	cpBodyDestroy(a->body);
   //	cpShapeDestroy(a);
   
   	CCSprite *tempSprite1 = (CCSprite *) b->data;
   	[bg removeChild:tempSprite1 cleanup:YES];
   
   	cpSpaceRemoveBody(space, b->body);
   	cpSpaceRemoveShape(space, b);
   	cpBodyFree(b->body);
   	cpShapeFree(b);
   	b->body = nil;
   	b = nil;
   
   	return 0;
   
   }

   but nothing is working right here

   the functions

   cpSpaceRemoveBody(space, a->body);
   cpSpaceRemoveShape(space, a);
   cpBodyFree(a->body);
   cpShapeFree(a);
   a->body = nil;
   a = nil;

   are doing nothing, rather just giving exception. :( any suggestion

   Posted 1 year ago #
6. 

   cocosboy
   Member

   I did this from

   http://code.google.com/p/chipmunk-physics/wiki/CallbackSystem

   if any one needs help regarding this I can help.

   Thanks @mobilebros

   Posted 1 year ago #
7. 

   mobilebros
   Moderator

   Sorry I'm late... it looks like you went with the newer chipmunk anyway; I had forgotten that its pretty much illegal to remove/free a shape in a collision callback unless you follow that method from the link you sent. good luck.

   Posted 1 year ago #
8. 

   cocosboy
   Member

   thanks :)

   Posted 1 year ago #

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