射击游戏中的自动射击(Swift 4- SpriteKit)

Question

我正在用Xcode做一个游戏项目。我已经编写了让飞船发射射弹的代码，但我不知道该用什么函数来使飞船自动射击。

你能帮我一下吗？提前谢谢你！

下面是我的代码，来自GameScene：

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {

    let projectile = SKSpriteNode(imageNamed: "projectile")
    projectile.zPosition = 1
    projectile.position = CGPoint(x: player.position.x, y: player.position.y)

    projectile.physicsBody = SKPhysicsBody(circleOfRadius: projectile.size.width/2)
    projectile.physicsBody?.isDynamic = true
    projectile.physicsBody?.categoryBitMask = PhysicsCategory.Projectile
    projectile.physicsBody?.contactTestBitMask = PhysicsCategory.Monster
    projectile.physicsBody?.collisionBitMask = PhysicsCategory.None
    projectile.physicsBody?.usesPreciseCollisionDetection = true
    self.addChild(projectile)
    let action = SKAction.moveTo(x: self.frame.width + projectile.size.width, duration: 0.5)

    projectile.run(action, completion: {
        projectile.removeAllActions()
        projectile.removeFromParent()
    })

}

Answer 1

根据杰克的评论，我假设你希望这艘船“自动”开火，而不是在按住手指的时候重复。

您可以使用更新功能来控制自动射击。在我的示例中，更新命令每1秒触发一次。

private var updateTime: Double = 0

override func update(_ currentTime: TimeInterval) {

    if updateTime == 0 {
        updateTime = currentTime
    }

    if currentTime - updateTime > 1 {
        self.shoot()
        updateTime = currentTime
    }
}

func shoot() {

    let projectile = SKSpriteNode(imageNamed: "projectile")
    projectile.zPosition = 1
    projectile.position = CGPoint(x: player.position.x, y: player.position.y)

    projectile.physicsBody = SKPhysicsBody(circleOfRadius: projectile.size.width/2)
    projectile.physicsBody?.isDynamic = true
    projectile.physicsBody?.categoryBitMask = PhysicsCategory.Projectile
    projectile.physicsBody?.contactTestBitMask = PhysicsCategory.Monster
    projectile.physicsBody?.collisionBitMask = PhysicsCategory.None
    projectile.physicsBody?.usesPreciseCollisionDetection = true
    self.addChild(projectile)
    let action = SKAction.moveTo(x: self.frame.width + projectile.size.width, duration: 0.5)

    projectile.run(action, completion: {
        projectile.removeAllActions()
        projectile.removeFromParent()
    })
}