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我正在使用Ray Wenderlich的2D游戏开发书,并利用本书中的一个函数来控制sprite的移动,这里称为'乘客'。本书中的例子是在x和y轴上移动精灵,因为我只需要沿着x轴移动精灵,但是我无法使它工作。仅在x轴上移动Sprite
这里是“我的”代码 - 以及我使用
func move(sprite: SKSpriteNode, velocity: CGPoint){
let amountToMove = CGPoint(x: velocity.x * CGFloat(dt),
y: velocity.y * CGFloat(dt))
sprite.position = CGPoint(
x: sprite.position.x + amountToMove.x,
y: sprite.position.y + amountToMove.y)
}
func movePassengerToward(location: CGPoint) {
let offset = CGPoint(x: location.x - passenger.position.x, y: location.y - passenger.position.y)
let length = sqrt(Double(offset.x * offset.x + offset.y * offset.y))
let direction = CGPoint(x: offset.x/CGFloat(length),
y: offset.y/CGFloat(length))
velocity = CGPoint(x: direction.x * passengerMovePointsPerSec,
y: direction.y * passengerMovePointsPerSec)
}
,我触发来自更新循环这些功能这样的代码:
if let lastTaxiLocation = lastTaxiLocation {
let diff = lastTaxiLocation - passenger.position
if diff.length() <= passengerMovePointsPerSec * CGFloat(dt){
passenger.position = lastTaxiLocation
velocity = CGPoint.zero
} else {
move(sprite: passenger, velocity: velocity)
print("update loop")
}
}
没有人有这种想法问题?