Question

我的倒计时每秒使用每帧更新的InGameTime值进行更新。

这在视觉上很有效，因为我可以将游戏时间缩小到最接近的int。

...但是如何让我的应用在每秒钟后发出一声嘟嘟声？

以下是我的代码：

-(void) setTimer:(ccTime) delta{

    int timeInSeconds = (int)appDelegate.InGameTime;//Game time E.G: 8.2332432
    /*

            Stuff is here to display the tempTime

    */


    //The below effect plays the sound every frame, 
    //is there an equation that I can apply to appDelegate.InGameTime 
    //that will play it once a second?

    [[SimpleAudioEngine sharedEngine] playEffect:@"tick.mp3"];

}

Answer 1

-(void) setTimer:(ccTime) delta{

    static float timeSinceLastTick = 0.f;

    int timeInSeconds = (int)appDelegate.InGameTime;//Game time E.G: 8.2332432
    /*

        Stuff is here to display the tempTime

    */

    // if your delta is small and relatively constant, this 
    // should be real close to what you want.
    // other ways exist

    timeSinceLastTick += delta;
    if (timeSinceLastTick > 1.0f) {
       timeSinceLastTick=0.f;
       [[SimpleAudioEngine sharedEngine] playEffect:@"tick.mp3"];
    }

}

Answer 2

您可以这样做的一种方法是跟踪方法调用之间的时间量并将其与InGameTime相关联。

e.g。

- (void)setTimer:(ccTime) delta
{

    int timeInSeconds = (int)appDelegate.InGameTime;//Game time E.G: 8.2332432
    /*

        Stuff is here to display the tempTime

    */


    //The below effect plays the sound every frame, 
    //is there an equation that I can apply to appDelegate.InGameTime 
    //that will play it once a second?

    // beepTime is a float instance variable at first initialized to appDelegate.InGameTime - floor(appDelegate.InGameTime)
    beepTime += delta;

    if (beepTime >= 1.0f) // where 1.0f is the frequency of the beep
    {
        [[SimpleAudioEngine sharedEngine] playEffect:@"tick.mp3"];
        beepTime = appDelegate.InGameTime - floor(appDelegate.InGameTime); // should return a decimal from 0.0f to 1.0f
    }
}

我认为应该有效。让我知道。

Answer 3

为什么不使用计划方法？

http://www.cocos2d-iphone.org/api-ref/latest-stable/interface_c_c_node.html#a7e0c230d398bba56d690e025544cb745

您只需指定间隔，然后将要触发的代码放在块

中

//call startBeep function every 1 second
[self schedule:@selector(startBeep:) interval:1.0f];


- (void)startBeep:(ccTime) delta
{
[[SimpleAudioEngine sharedEngine] playEffect:@"tick.mp3"];
}

如何每秒钟播放一次Cocos2d

3 个答案: