用触摸旋转雪碧 - Cocos2d

Question

有没有人有更好的方法来用一个手指旋转雪碧？我的问题是我不能让精灵在完全旋转两次后停止旋转，并且我周期性地将我的屏幕翻转180度（self.rotation = 180;）然后将其翻转（self.rotation = 0）。但是，当我将其翻转到180度时，精灵将无法正确旋转。

任何人有比这更好的想法？

CGFloat gRotation; 

- (void)update:(ccTime)delta 
{ 
    g.rotation = gRotation; 
} 
    - (void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event 
    { 
     UITouch *touch = [touches anyObject]; 
     CGPoint location = [touch locationInView:[touch view]]; 
     location = [[CCDirector sharedDirector] convertToGL:location]; 

     if (CGRectContainsPoint(g.boundingBox, location)) 
     { 
      CGPoint firstLocation = [touch previousLocationInView:[touch view]]; 
      CGPoint location = [touch locationInView:[touch view]]; 

      CGPoint touchingPoint = [[CCDirector sharedDirector] convertToGL:location]; 
      CGPoint firstTouchingPoint = [[CCDirector sharedDirector] convertToGL:firstLocation]; 

      CGPoint firstVector = ccpSub(firstTouchingPoint, g.position); 
      CGFloat firstRotateAngle = -ccpToAngle(firstVector); 
      CGFloat previousTouch = CC_RADIANS_TO_DEGREES(firstRotateAngle); 

      CGPoint vector = ccpSub(touchingPoint, g.position); 
      CGFloat rotateAngle = -ccpToAngle(vector); 
      CGFloat currentTouch = CC_RADIANS_TO_DEGREES(rotateAngle); 

      gRotation += currentTouch - previousTouch; 
     } 
    } 

感谢

编辑：

我进去GameConfig.h，改变#define GAME_AUTOROTATION kGameAutorotationUIViewController到#define GAME_AUTOROTATION kGameAutorotationNone

然后进去AppDelegate.m和改变#if GAME_AUTOROTATION == kGameAutorotationUIViewController到#if GAME_AUTOROTATION == kGameAutorotationNone

当我翻转屏幕时，修正了精灵的旋转，但是在两次完整旋转后我仍然无法停止精灵的旋转。

Answer 1

末添加一个新行：

gRotation += currentTouch - previousTouch; 
gRotation = fmod(gRotation,360.0); // <<< fix the angle 

这也许解决您的问题，因为角将保持在360范围内

用一个手指旋转的其他方式是UIPanGestureRecognizer（但你仍然需要保持角度在360范围内）：

UIPanGestureRecognizer *gestureRecognizer = [[[UIPanGestureRecognizer alloc] initWithTarget:layer action:@selector(handlePanFrom:)] autorelease]; 
[[[CCDirector sharedDirector] openGLView] addGestureRecognizer:gestureRecognizer]; 

... 

- (void)handlePanFrom:(UIPanGestureRecognizer *)recognizer 
{ 
    CGPoint translation = [recognizer translationInView:recognizer.view]; 
    ... 
} 

看看本教程的详细信息（其上拖拉，而是如何做锅手势）：

http://www.raywenderlich.com/2343/how-to-drag-and-drop-sprites-with-cocos2d