我是swift的新手，我正在尝试编程pacman。我试图将pacman移动到滑动的方向，到目前为止我已设法将其移动到屏幕的边缘，问题是当我尝试移动它不是从屏幕的边缘而是在中间滑动动作，它只是到屏幕的边缘并移动到滑动方向，这是一个方向的代码：
var x = view.center.x
for var i = x; i > 17; i--
{
var origin: CGPoint = self.view.center
var move = CABasicAnimation(keyPath:"position.x")
move.speed = 0.13
move.fromValue = NSValue(nonretainedObject: view.center.x)
move.toValue = NSValue(nonretainedObject: i)
view.layer.addAnimation(move, forKey: "position")
view.center.x = i
}
问题是，我知道问题，当我向我想要的方向滑动for循环不会等待动画停止但它将在不到一秒的时间内完成循环，我需要一些延迟这里或其他代码。
答案 0 :(得分：0)
这是一个有趣的问题，所以我决定在SpriteKit中做一个例子。没有碰撞检测，路径查找或甚至路径。这仅仅是如何制作“吃豆人”的一个例子。滑动发生时改变方向。
我已将GameScene包括在内：
class GameScene: SKScene {
enum Direction {
case Left
case Right
case Up
case Down
}
lazy var openDirectionPaths = [Direction: UIBezierPath]()
lazy var closedDirectionPaths = [Direction: UIBezierPath]()
lazy var wasClosedPath = false
lazy var needsToUpdateDirection = false
lazy var direction = Direction.Right
lazy var lastChange: NSTimeInterval = NSDate().timeIntervalSince1970
var touchBeganPoint: CGPoint?
let pacmanSprite = SKShapeNode(circleOfRadius: 15)
override func didMoveToView(view: SKView) {
let radius: CGFloat = 15, diameter: CGFloat = 30, center = CGPoint(x:radius, y:radius)
func createPaths(startDegrees: CGFloat, endDegrees: CGFloat, inout dictionary dic: [Direction: UIBezierPath]) {
var path = UIBezierPath(arcCenter: center, radius: radius, startAngle: startDegrees.toRadians(), endAngle: endDegrees.toRadians(), clockwise: true)
path.addLineToPoint(center)
path.closePath()
dic[.Right] = path
for d: Direction in [.Up, .Left, .Down] {
path = path.pathByRotating(90)
dic[d] = path
}
}
createPaths(35, 315, dictionary: &openDirectionPaths)
createPaths(1, 359, dictionary: &closedDirectionPaths)
pacmanSprite.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame))
pacmanSprite.fillColor = UIColor.yellowColor()
pacmanSprite.lineWidth = 2
if let path = openDirectionPaths[.Right] {
pacmanSprite.path = path.CGPath
}
pacmanSprite.strokeColor = UIColor.blackColor()
self.addChild(pacmanSprite)
updateDirection()
// Blocks to stop 'Pacman' changing direction outside of a defined path?
//375/25 = 15 width
//666/37 = 18 height
}
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
touchBeganPoint = positionOfTouch(inTouches: touches)
}
override func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) {
if let touchStartPoint = touchBeganPoint,
touchEndPoint = positionOfTouch(inTouches: touches) {
if touchStartPoint == touchEndPoint {
return
}
let degrees = atan2(touchStartPoint.x - touchEndPoint.x,
touchStartPoint.y - touchEndPoint.y).toDegrees()
var oldDirection = direction
switch Int(degrees) {
case -135...(-45): direction = .Right
case -45...45: direction = .Down
case 45...135: direction = .Left
default: direction = .Up
}
if (oldDirection != direction) {
needsToUpdateDirection = true
}
}
}
override func touchesCancelled(touches: Set<NSObject>!, withEvent event: UIEvent!) {
touchBeganPoint = nil
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
if let nodes = self.children as? [SKShapeNode] {
for node in nodes {
let p = node.position
let s = node.frame.size
//let s = node.size
if p.x - s.width > self.size.width {
node.position.x = -s.width
}
if p.y - s.height > self.size.height {
node.position.y = -s.height
}
if p.x < -s.width {
node.position.x = self.size.width + (s.width / 2)
}
if p.y < -s.height {
node.position.y = self.size.height + (s.height / 2)
}
if needsToUpdateDirection || NSDate().timeIntervalSince1970 - lastChange > 0.25 {
if let path = wasClosedPath ? openDirectionPaths[direction]?.CGPath : closedDirectionPaths[direction]?.CGPath {
node.path = path
}
wasClosedPath = !wasClosedPath
lastChange = NSDate().timeIntervalSince1970
}
updateDirection()
}
}
}
// MARK:- Helpers
func positionOfTouch(inTouches touches: Set<NSObject>) -> CGPoint? {
for touch in (touches as! Set<UITouch>) {
let location = touch.locationInNode(self)
return location
}
return nil
}
func updateDirection() {
if !needsToUpdateDirection {
return
}
pacmanSprite.removeActionForKey("Move")
func actionForDirection() -> SKAction {
let Delta: CGFloat = 25
switch (direction) {
case .Up:
return SKAction.moveByX(0.0, y: Delta, duration: 0.1)
case .Down:
return SKAction.moveByX(0.0, y: -Delta, duration: 0.1)
case .Right:
return SKAction.moveByX(Delta, y: 0.0, duration: 0.1)
default:
return SKAction.moveByX(-Delta, y: 0.0, duration: 0.1)
}
}
let action = SKAction.repeatActionForever(actionForDirection())
pacmanSprite.runAction(action, withKey: "Move")
needsToUpdateDirection = false
}
}
存储库可以是variable declaration within the while loop C/C++
我已经添加了MIT许可证，因此您可以根据需要分叉此存储库。我希望这会有所帮助。