Sprite Kit - Determine vector of swipe gesture to flick sprite

Question

I have a game where circular objects shoot up from the bottom of the screen and I would like to be able to swipe them to flick them in the direction of my swipe. My issue is, I

Answer 1

There is another way to do it, you can add a pan gesture and then get the velocity from it:

First add pan gesture in your view:

UIPanGestureRecognizer *gestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanFrom:)];
    [self.view addGestureRecognizer:gestureRecognizer];

Then handle the gesture:

- (void)handlePanFrom:(UIPanGestureRecognizer *)recognizer
{
    if (recognizer.state == UIGestureRecognizerStateBegan) {
        CGPoint location = [recognizer locationInView:recognizer.view];
        if ([_object containsPoint:location]){
            self.movingObject = YES;
            <.. object start moving ..>
        }

    } else if (recognizer.state == UIGestureRecognizerStateChanged) {

        if (!self.movingObject)
            return;

        CGPoint translation = [recognizer translationInView:recognizer.view];
        object.position = CGPointMake(object.position.x + translation.x, object.position.y + translation.y);

        [recognizer setTranslation:CGPointZero inView:recognizer.view];

    } else if (recognizer.state == UIGestureRecognizerStateEnded) {

        if (!self.movingObject)
            return;

        self.movingObject = NO;
        float force = 1.0f;
        CGPoint gestureVelocity = [recognizer velocityInView:recognizer.view];
        CGVector impulse = CGVectorMake(gestureVelocity.x * force, gestureVelocity.y * force);

        <.. Move object with that impulse using an animation..>
    }
}