cocos2d and box2d : sprite touch not get properly

box2d-iphone, ccsprite, cocos2d-iphone, iphone, touch

Solution

Use below method to get the top most touched object based on z-order

-(b2Body *) getTopTouchBody:(b2Vec2)location{

    b2Body *touchObject;
    int zOrder = 0;
    for (b2Body* b = _world->GetBodyList(); b; b = b->GetNext())
    {
        b2Fixture *f = b->GetFixtureList();
        BOOL isinsize = f->TestPoint(location);
        CCSprite *sprite = (CCSprite *)b->GetUserData();
        if (isinsize) {
            if (sprite.zOrder > zOrder) {
                zOrder = sprite.zOrder;
                touchObject = b;
            }
        }
    }
    return  touchObject;
}

Problem

I have added 7 sprites and give them tag and zorder.. but i can't get touch on third object and at last there is only one object remained then i get touch of it.. But when i added 6 sprites i'll get touch properly. all sprites positions are same but zorder is different.. i can't understand what is problem.. I have used query callback class to get touch.. here i add some of my code.. code of adding sprite.. ``` zIndex = 7; for(int i = 0; i<zIndex; i++) { CCSprite *paddle = [CCSprite spriteWithFile:[NSString stringWithFormat:@"%d.png",i+1]]; paddle.position = ccp(winSize.width/2, winSize.height/2); [self addChild:paddle z:zIndex-i tag:i+1]; [mutArrSprites addObject:paddle]; NSLog(@"Z = %d tag = %d ",zIndex-i , i+1); } for(CCSprite *sprite in mutArrSprites) { [self addUserDataToNode:sprite]; } ``` in touchbegan method ``` 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); // Make a small box. b2AABB aabb; b2Vec2 d; d.Set(0.001f, 0.001f); aabb.lowerBound = locationWorld - d; aabb.upperBound = locationWorld + d; // Query the world for overlapping shapes. QueryCallback callback(locationWorld); _world->QueryAABB(&callback, aabb); b2Body *body = callback.m_object; if (body) { //pick the body CCSprite *sprite = (CCSprite *)body->GetUserData(); [self reorderChild:sprite z:zIndex++]; b2MouseJointDef md; md.bodyA = _groundBody; md.bodyB = body; md.target = locationWorld; md.collideConnected = true; md.maxForce = 1000.0f * body->GetMass(); _mouseJoint = (b2MouseJoint *)_world->CreateJoint(&md); body->SetAwake(true); } ```

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