Zooming and scrolling in SpriteKit

Question

I am new to SpriteKit. I need to display an image via UIImageView OR SpriteNode (it is a background image for a game). However, I need the user to be able to zoom in to the

Answer 1

I have created my own method for zooming a specific node without having to zoom the entire scene and this is the basics of it, however it is not perfect (and in fact I have created its own help request here: Zooming an SKNode inconsistent )

This if statement goes in the touchesMoved method of the scene:

   if (touches.count == 2) {
        // this means there are two fingers on the screen
        NSArray *fingers = [touches allObjects];
        CGPoint fingOneCurr = [fingers[0] locationInNode:self];
        CGPoint fingOnePrev = [fingers[0] previousLocationInNode:self];
        CGPoint fingTwoCurr = [fingers[1] locationInNode:self];
        CGPoint fingTwoPrev = [fingers[1] previousLocationInNode:self];

        BOOL yPinch = fingOneCurr.y > fingOnePrev.y && fingTwoCurr.y < fingTwoPrev.y;
        BOOL yUnpinch = fingOneCurr.y < fingOnePrev.y && fingTwoCurr.y > fingTwoPrev.y;

        BOOL xPinch = fingOneCurr.x > fingOnePrev.x && fingTwoCurr.x < fingTwoPrev.x;
        BOOL xUnpinch = fingOneCurr.x < fingOnePrev.x && fingTwoCurr.x > fingTwoPrev.x;

        if (xUnpinch | yUnpinch) {
            if (YES) NSLog(@"This means an unpinch is happening");
            mapScale = mapScale +.02;
            [map setScale:mapScale];
        }

        if (xPinch | yPinch) {
            if (YES) NSLog(@"This means a pinch is happening");
            mapScale = mapScale - .02;
            [map setScale:mapScale];
        }
    }

The only problem I am having with it is inconsistent behavior and unsmooth scrolling. I use the word 'only' in that sense with great liberalness.