Rewrite Cocos2d (objective-c) on Coco2d-x (c + +)

Question

Please help, I can not rewrite this code to objective-c on C++ cocos2d (objective-c):

- (void) ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
    {
        [_touches unionSet:touches];
    }

    - (void) ccTouchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
    {
        [_touches minusSet:touches];
    }

    - (void) ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
    {
        [_touches minusSet:touches];
    }

    - (void) ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
    {
        for (UITouch * touch in touches)
        {
            [self pinchZoomWithMovedTouch:touch];
        }
    }

    - (void) pinchZoomWithMovedTouch: (UITouch *) movedTouch
    {
        CGFloat minDistSqr = CGFLOAT_MAX;
        UITouch * nearestTouch = nil;
        UIView * mainView = [[CCDirector sharedDirector] view];
        CGPoint newLocation = [movedTouch locationInView:mainView];
        for (UITouch * touch in _touches)
        {
            if (touch != movedTouch)
            {
                CGFloat distSqr = sqrOfDistanceBetweenPoints([touch locationInView:mainView],newLocation);
                if (distSqr < minDistSqr)
                {
                    minDistSqr = distSqr;
                    nearestTouch = touch;
                }
            }
        }
        if (nearestTouch)
        {
            CGFloat prevDistSqr = sqrOfDistanceBetweenPoints([nearestTouch locationInView:mainView],
                                                             [movedTouch previousLocationInView:mainView]);
            CGFloat pinchDiff = sqrtf(minDistSqr) - sqrtf(prevDistSqr);
            scal1+= pinchDiff * kPinchZoomCoeff;
            if (scal1>=1 &&(scal1<=3)) {
                            self.scale += pinchDiff * kPinchZoomCoeff; // kPinchZoomCoeff is constant = 1.0 / 200.0f Adjust it for your needs
                scal1=self.scale;
            }

            scal1=self.scale;
            NSLog(@"Scale   %f",self.scale);
            }
    }

    CGFloat sqrOfDistanceBetweenPoints(CGPoint p1, CGPoint p2)
    {
        CGPoint diff = ccpSub(p1, p2);
        return diff.x * diff.x + diff.y * diff.y;
    }

I just started learning cocos2d-x and therefore difficult to rewrite) I would be very grateful if someone can help rewrite this code to cocos2d-x

Answer 1

CCSet in cocos2d-x don't have methods to join two sets or remove objects from one set in another. You can use touch delegate instead of standard delegate and use methods:

 virtual bool ccTouchBegan (CCTouch *pTouch, CCEvent *pEvent);
virtual bool ccTouchMoved (CCTouch *pTouch, CCEvent *pEvent);
virtual void ccTouchEnded (CCTouch *pTouch, CCEvent *pEvent);

Then you can add or remove every single touch from or to _touches.

If you want use touch delegate you must override registerWithTouchDispatcher();

void Strona::registerWithTouchDispatcher() {
CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate(this, this->getTouchPriority(), true);
}

Or you can simply iterate in every touch in touches from ccTouchesBegan and add every touch from touches to _touches.