Move node left and right without snapping to touch

Question

I have a sprite node on the screen, that the player is able to move left and right. I know how to make it move left and right using touchesMoved, however, if the player touches a location the node snaps to that location. For example, if the node was on the left side of the screen, and the player touched the right side of the screen, the node would immediately move to the touch location. I don't want this behavior. I only want to the node to move when the player is moving their finger left or right, not when they touch a location. Below is the code I currently use. There isn't any code that would affect the playerNode x position in the touchesBegan or touchesEnded function.

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    for touch in touches
    {
        if game.state == .game
        {
            let position = touch.location(in: playableArea)

            game.playerNode.position.x = position.x

        }
    }
}

How can I stop this behavior from happening, and only have the node move when the players finger is moving left or right?

Joseph Kessler Joseph Kessler · Accepted Answer · 2018-07-06T00:11:18

I ended up resolving my issue. I knew that I had to essentially move the node relative to the touch location, but I wasn't sure how to do that. This is how I got it working.

First I created a variable that would be equal to the players touch location. This variable gets set in touchesBegan.

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?)
{
        if game.state == .game
        {
            let position = touch.location(in: playableArea)

            playerTouchPosition = position
        }
}

I use this variable as the starting point of the touch. When the player moves their finger, it calculates how much the player moved their finger relative to the starting point. For example, if the player touched at the X value of 100, and moved their finger to the X value of 120, it would calculate that the player moved their finger by 20. After finding that value, I set the playerTouchPosition to the position of touchesMoved. This is to make the next move be relative to the previous touch. Then I move the players node by the amount the player moved their finger.

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    for touch in touches
    {
        if game.state == .game
        {
            let position = touch.location(in: playableArea)
            let newX : CGFloat!

            if position.x > playerTouchPosition.x
            {
                newX = position.x - playerTouchPosition.x
            }else
            {
                newX = -(playerTouchPosition.x - position.x)
            }

            playerTouchPosition = position

            game.playerNode.position.x = game.playerNode.position.x + newX

        }
    }
}

This stopped the players node from immediately moving to where ever the touch locations X value was.

Move node left and right without snapping to touch

1 Answers