cocos2d for iPhone

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

1. 

   Kahless
   Member

   Hi everyone,

   I am having an issue when i store a bunch of my sprites with chipmunk bodies off screen and i stack them all in the one spot waiting to used they drop the frame rate right down to about 10 fps. if i store them spaced appart it doesnt drop the fps but that isnt convenient for what i want. The frame rate goes back to normal when i have them moving around and apart, but as soon as they end up stacked again the fps drops. I have a feeling it has something to do with the chipmunk bodies but i am not sure what or how to fix it, the sprites are controlled by actions and the chipmunk bodies are updated to follow, i am really just using chipmunk for collision detection.
   If anyone has any thought on the matter it would be appreciated to hear them.

   Posted 2 years ago #
2. 

   natanavra
   Member

   You have a good feeling, your chipmunk bodies are constantly colliding...
   You should do something like this :

   -(void)setupChipmunk {
        ...........
        cpSpaceAddCollisionPairFunction(space, 1, 1, &cancelCollision, nil); //Instead of the 1, put your shape collision type number...
        ................
   }

   And put this function outside of your @implementation declare, but in the same file...

   static int cancelCollision (cpShape *a, cpShape *b, cpContact *contacts,
   						     int numContacts, cpFloat normal_coef, void *data) {
   
        //Do Nothing
        return 0;
   }

   Posted 2 years ago #
3. 

   Kahless
   Member

   Awsome that worked perfectly!
   You are the man Natanavra.

   Posted 2 years ago #
4. 

   natanavra
   Member

   I'm glad I could help, and I'm glad I'm acknowledged as a man (jk).

   Posted 2 years ago #
5. 

   just.danne
   Member

   Thanks! this code solved the same problem for me.

   note:

   I had to change,
   cpSpaceAddCollisionPairFunction
   to
   cpSpaceAddCollisionPairFunc

   Posted 2 years ago #
6. 

   mobilebros
   Moderator

   What would really speed it up would be to remove them (shapes & bodies) from the chipmunk space until needed and then add them back. I'm just not suggesting you destroy and re-create, but rather just temporarily removing them.

   Posted 2 years ago #
7. 

   just.danne
   Member

   @mobilebros, I wan't to try this but I create 30 instances of a shape at init. How do I remove or add a specific instance of a shape & body?

   Posted 2 years ago #
8. 

   just.danne
   Member

   solved it by storing the shapes like this:

   [myMutableArray addObject:[NSValue valueWithPointer:myShape]];

   and recovering the shape like this:

   myShape = [[myMutableArray objectAtIndex:i] pointerValue];

   cpSpaceRemoveBody (space,myShape->body);
   cpSpaceRemoveShape(space, myShape);

   Posted 2 years ago #
9. 

   mobilebros
   Moderator

   Yep, that would work just fine.

   Posted 2 years ago #

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