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I can't find the tutorials of joints class in the Box2D for iPhone. I am unable to run a Testbed for iPhone Box2D.

(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
       if (_mouseJoint!=NULL)return;
       UITouch *mytouch=[touches anyObject];
       CGPoint location=[mytouch locationInView:[mytouch view]];
       location=[[CCDirector sharedDirector]convertToGL:location];
        b2Vec2 locationWorld=b2Vec2(location.x/PTM_RATIO,location.y/PTM_RATIO);
 //ristrict the player within the ground limit  keep stucking the player with grounditself..... 
if (_playerFixture->TestPoint(locationWorld))
    b2MouseJointDef md;
    _mouseJoint=(b2MouseJoint *)_world->CreateJoint(&md);

-(void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
if (_mouseJoint == NULL) return;
UITouch *myTouch = [touches anyObject];
CGPoint location = [myTouch locationInView:[myTouch view]];
location = [[CCDirector sharedDirector] convertToGL:location];
if (location.y<240.00&&location.y>=20.0f)
    b2Vec2 locationWorld = b2Vec2(location.x/PTM_RATIO, location.y/PTM_RATIO);

- (void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event 
if (_mouseJoint) 

    _mouseJoint = NULL;


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Is iOS Box2D that different than "real" Box2D? – user744 May 3 '11 at 20:39
Freezing Fire, it would help if you'd say what in particular isn't clear about the Box2D manual (which has a huge section on joints), or why Emanuele's tutorials aren't good for you. – user744 May 5 '11 at 11:00
@joe Wreschnig: I Have updated my question ==> here problem is that ==>with use of mouse joint i move the object through the screen and due to the mouse joint object don't getting rigid to the place where my hand is moving and also i am not getting any setter method for ==> b2Vec2 GetReactionForce(float32 inv_dt) const; as i think this is the responsible method for the ball having more elasticity prooperty – NIKHIL May 5 '11 at 12:52
up vote 1 down vote accepted

Emanuele Feronato has some great joint tutorials for box2d. The tutorials are in Actionscript 3, but the basic principles are the same.

BTW, the as3 port of box2d sticks pretty closely to the naming convention of the original c++ box2d, so you'll just have to change syntax a bit to use it on the iPhone.

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I've read those, and I think they're far more confusing and shallow than the proper Box2D manual. – user744 May 4 '11 at 5:51
no actually good tutorials and understandable also thank you very much – NIKHIL May 7 '11 at 5:24

Some joint tutorials here:

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