what we know:
a bird ---- SKSpriteNode
bird origin frame is (x:0 y:0 width:62 height:62)
and we want:
bird ------> Parabolic motion
what we do in our code:
touchesBegan{
let path = UIBezierPath()
path.addQuadCurve(to: targetpoint, controlPoint:controlpoint)
bird.run(SKAction.follow(path.cgPath, duration: 0.2))
}
after that the bird's width and height change to (width:82 height:82)
but i do nothing with width and height, why the value of them change?
