如何檢測cocos2d中的震動事件？

Question

我想檢測iPad的cocos2d中的搖晃動作。

我發現了一篇很有前途的文章，並試圖實現它，但失敗了。 http://www.softvelopment.com/index.php/blogs/2010/03/19/3-adding-shake-recongnition-to-cocos2d-iphone-library-

具體來說，我不知道我應該把聽者放在哪裏。另外，還有什麼其他好方法可以讓iPad使用cocos2d來檢測搖晃嗎？

Answer 1

也許下面的代碼可以幫助你。我發現它有一段時間（不記得在哪裏）並清理乾淨。您可以調整didAccelerate中的值（當前爲0.8和0.2），以確定它對抖動的敏感程度，以及您必須保持設備再次抖動的穩定程度。

頁眉

@protocol ShakeHelperDelegate 
-(void) onShake; 
@end 

@interface ShakeHelper : NSObject <UIAccelerometerDelegate> 
{ 
    BOOL histeresisExcited; 
    UIAcceleration* lastAcceleration; 

    NSObject<ShakeHelperDelegate>* delegate; 
} 

+(id) shakeHelperWithDelegate:(NSObject<ShakeHelperDelegate>*)del; 
-(id) initShakeHelperWithDelegate:(NSObject<ShakeHelperDelegate>*)del; 

@end 

實施

#import "ShakeHelper.h" 


@interface ShakeHelper (Private) 
@end 

@implementation ShakeHelper 

// Ensures the shake is strong enough on at least two axes before declaring it a shake. 
// "Strong enough" means "greater than a client-supplied threshold" in G's. 
static BOOL AccelerationIsShaking(UIAcceleration* last, UIAcceleration* current, double threshold) 
{ 
    double 
    deltaX = fabs(last.x - current.x), 
    deltaY = fabs(last.y - current.y), 
    deltaZ = fabs(last.z - current.z); 

    return 
    (deltaX > threshold && deltaY > threshold) || 
    (deltaX > threshold && deltaZ > threshold) || 
    (deltaY > threshold && deltaZ > threshold); 
} 

+(id) shakeHelperWithDelegate:(NSObject<ShakeHelperDelegate>*)del 
{ 
    return [[[self alloc] initShakeHelperWithDelegate:del] autorelease]; 
} 

-(id) initShakeHelperWithDelegate:(NSObject<ShakeHelperDelegate>*)del 
{ 
    if ((self = [super init])) 
    { 
     delegate = del; 
     [UIAccelerometer sharedAccelerometer].delegate = self; 
    } 

    return self; 
} 

-(void) accelerometer:(UIAccelerometer*)accelerometer didAccelerate:(UIAcceleration*)acceleration 
{ 
    if (lastAcceleration) 
    { 
     if (!histeresisExcited && AccelerationIsShaking(lastAcceleration, acceleration, 0.8)) 
     { 
      histeresisExcited = YES; 

      [delegate onShake]; 
     } 
     else if (histeresisExcited && !AccelerationIsShaking(lastAcceleration, acceleration, 0.2)) 
     { 
      histeresisExcited = NO; 
     } 
    } 

    [lastAcceleration release]; 
    lastAcceleration = [acceleration retain]; 
} 

-(void) dealloc 
{ 
    CCLOG(@"dealloc %@", self); 

    [UIAccelerometer sharedAccelerometer].delegate = nil; 
    [lastAcceleration release]; 
    [super dealloc]; 
} 

@end 

你使用這樣的：

[ShakeHelper shakeHelperWithDelegate:self]; 

顯然，自對象需要實現ShakeHelperDelegate協議。每當檢測到抖動時，Shake消息都將發送到委託對象。