将 SKSpriteNode 移动到触摸方向

Question

这里有游戏的打印屏幕：

我有一个静态的 SKSpriteNode（播放器），它正在旋转到触摸的方向。这是我的代码：

class GameplayScene: SKScene, SKPhysicsContactDelegate {

static let Pi = CGFloat(Double.pi)
static let DegreesToRadians = Pi / 180

override func touchesMoved(_ touches: Set<UITouch>, with event: 
UIEvent?) {
    let curTouch = touches.first! as UITouch
    let curPoint = curTouch.location(in: self)

    let deltaX = self.player.position.x - curPoint.x
    let deltaY = self.player.position.y - curPoint.y
    let angle = atan2(deltaY, deltaX)

    self.player.zRotation = angle + 90 * GameplayScene.DegreesToRadians
}
}

现在，我想每秒从与屏幕触摸方向相同的玩家身上发射子弹。当子弹移出屏幕时，我想实现“SKAction.removeFromParent”。

这是我的 fireMissile 函数：

func fireMissile() {
    let missile = SKSpriteNode(color: .yellow, size: CGSize(width: 20, 
    height: 5))
    missile.name = "Missile"
    missile.position = CGPoint(x: player.position.x + 30, y: 
    player.position.y)
    missile.zPosition = 2
    missile.physicsBody = SKPhysicsBody(rectangleOf: missile.size)
    missile.physicsBody?.isDynamic = false
    missile.physicsBody?.categoryBitMask = ColliderType.Bullet
    missile.physicsBody?.collisionBitMask = ColliderType.Enemy
    missile.physicsBody?.contactTestBitMask = ColliderType.Enemy

    self.addChild(missile)

}

Answer 1

对于计时器，您需要使用这个：

run(SKAction.repeatForever(SKAction.sequence([SKAction.run {
        yourFunction()
        }, SKAction.wait(forDuration: 1)])), withKey: "key")

至于导弹射击，按顺序添加SKActions。第一个应该把子弹放在你的玩家面前，第二个会移动导弹，第三个会删除，但由于顺序，这只会在其他行之后运行。如果您想稍后在动画中间停止它，请确保您有此序列的键。应该看起来像这样：

missile.zRotation = player.zRotation
missile.position = CGPoint(x:player.size.width/2*cos(player.zRotation)+player.position.x ,y:player.size.height*sin(player.zRotation)+player.position.y)
 missile.run(SKAction.sequence([SKAction.move(to: CGPoint(x:frame.size.width*cos(player.zRotation)+player.position.x ,y:frame.size.height*sin(player.zRotation)+player.position.y), duration: 0.5), SKAction.removeFromParent()]), withKey: "move")