按住按钮发射射弹

Question

在我的游戏中，我想要做的是在保持射击按钮的同时，不断地发射弹丸。我一直使用的是一个简单的touchesBegan和touchesMoved (也就是touchesBegan)解决方案。因此，我遇到的问题是:只有在按住按钮时才射击一次，但如果在按住按钮时移动触点(它调用touchesMoved方法)，则一次只能发射多个弹丸。

我需要帮助的是:如何在按住按钮的同时不断地射击这些弹丸，就像你在触摸向下的方法中所做的那样？希望我所要求的是可能的。

Answer 1

您可以使用touchesBegan和touchesEnded函数来跟踪按下按钮的时间。然后利用update函数对SKScene进行延迟发射。

逻辑是在按下按钮时将布尔shooting设置为true。shooting在touchesEnded中被设置为false。这样我们就能跟踪触觉。然后，在update函数中，如果shooting变量为真，则发射弹丸。

在目标C中

//GameScene.h

@property (nonatomic,strong) SKSpriteNode *shootButton;

//GameScene.m

BOOL shooting = false;
CFTimeInterval lastShootingTime = 0;
CFTimeInterval delayBetweenShots = 0.5;

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    CGPoint location = [touch locationInNode:self];

    if  ([self nodeAtPoint:location] == self.shootButton)
    {
        shooting = true;
        NSLog(@"start shooting");
    }

}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    CGPoint location = [touch locationInNode:self];

    if  ([self nodeAtPoint:location] == self.shootButton)
    {
        shooting = false;
        NSLog(@"stop shooting");
    }
}


-(void)shoot
{
    // Projectile code
    NSLog(@"shooting");
}

-(void)update:(NSTimeInterval)currentTime {

    if (shooting)
    {
        NSTimeInterval delay = currentTime - lastShootingTime;
        if (delay >= delayBetweenShots) {
            [self shoot];
            lastShootingTime = currentTime;
        }
    }
}

斯威夫特

var shootButton : SKSpriteNode!

var shooting = false
var lastShootingTime : CFTimeInterval = 0
var delayBetweenShots : CFTimeInterval = 0.5

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
    let touch: AnyObject? = touches.anyObject()
    if let location = touch?.locationInNode(self)
    {
        if self.nodeAtPoint(location) == shootButton
        {
            self.shooting = true
            println("start shooting")
        }
    }
}

override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
    let touch: AnyObject? = touches.anyObject()
    if let location = touch?.locationInNode(self)
    {
        if self.nodeAtPoint(location) == shootButton
        {
            self.shooting = false
            println("stop shooting")
        }
    }
}

func shoot()
{
    // Projectile code
    println("shooting")
}

override func update(currentTime: NSTimeInterval) {

    if shooting
    {
        let delay = currentTime - lastShootingTime
        if delay >= delayBetweenShots {
            shoot()
            lastShootingTime = currentTime
        }
    }
}

您可以调整delayBetweenShots变量以更改触发所需的速度。