仅当玩家沿Y轴向上行驶时才移动地视差

Question

So essentially, Im making a platformjumper game. when the player collides with a platform, the player gets a forcebump in upwards in y-axis. The code down below that i got gives simulates the view following the player. It also follows the player when hes heading downwards in y-axis. I dont want that. Only want the midground, foreground and background to move down when the player is heading upwards.

Gamescene.swift:

class GameScene: SKScene, SKPhysicsContactDelegate {

var background:SKNode!
var midground:SKNode!
var foreground:SKNode!




required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)

}

override init(size: CGSize){
    super.init(size: size)

    background = createBackground()
    addChild(background)

    midground = createMidground()
    addChild(midground)

    foreground = SKNode()
    addChild(foreground)

    player = createPlayer()
    foreground.addChild(player)

}

override func update(currentTime: CFTimeInterval) {

    if player.position.y > 200{
        background.position = CGPoint(x: 0, y: -((player.position.y - 200)/10))
        midground.position = CGPoint(x: 0, y: -((player.position.y - 200)/4))
        foreground.position = CGPoint(x: 0, y: -((player.position.y) - 200))
    }

}

Answer 1

You could check the Player Position.

    var PlayerPosition1 = 0

override func update(currentTime: CFTimeInterval) {

    if player.position.y > 200{
        if player.position.y > PlayerPosition1{
            background.position = CGPoint(x: 0, y: -((player.position.y - 200)/10))
            midground.position = CGPoint(x: 0, y: -((player.position.y - 200)/4))
            foreground.position = CGPoint(x: 0, y: -((player.position.y) - 200))
        }
    }

    PlayerPosition1 = player.position.y
}

Something like that should work ..

Edit: Ah okay .. it's not really a "lag" .. the background just moves back to the "old" position when touching the platform.. try this:

var PlayerMaxY = CGFloat()

    if player.position.y > 200 {
        if player.position.y > PlayerMaxY{
            PlayerMaxY = player.position.y
            background.position = CGPoint(x: 0, y: -((player.position.y - 200)/10))
            midground.position = CGPoint(x: 0, y: -((player.position.y - 200)/4))
            forefround.position = CGPoint(x: 0, y: -((player.position.y - 200)))
        }
    }