SKSpriteNode旋转不正常

Question

我想通过使用UIRrotationGestureRecognizer旋转SKSpriteNode。我已经实现了一个代码，但有时候，当我旋转节点时，它跳转到一个不是它应该是的那个旋转。在这里，你有代码：

- (void) handleRotation:(UIRotationGestureRecognizer *) rotationrecognizer{ 

    CGFloat initialrotation = 0.0; 

    if (rotationrecognizer.state == UIGestureRecognizerStateBegan) { 

     CGPoint touchLocation = [rotationrecognizer locationInView:rotationrecognizer.view]; 
     touchLocation = [self convertPointFromView:touchLocation]; 
     [self selectNodeForTouch:touchLocation]; 

     initialrotation = selected.zRotation; 
    } 

    else if (rotationrecognizer.state == UIGestureRecognizerStateChanged) {   

     CGFloat angle = initialrotation + rotationrecognizer.rotation; 
     selected.zRotation = angle;  

    } 
} 

Answer 1

您在每次调用重置初始旋转0 ...你应该，如果你需要它驻留移动这是您的观点的伊娃。

你现在写的方式，即设置“角度”的线是有效等于这个：

CGFloat angle = 0 + rotationrecognizer.rotation; 

相反，你应该做到以下（其中initialRotation初始定义为私人伊娃）：

- (void) handleRotation:(UIRotationGestureRecognizer *) rotationrecognizer{ 

    if (rotationrecognizer.state == UIGestureRecognizerStateBegan) { 

     CGPoint touchLocation = [rotationrecognizer locationInView:rotationrecognizer.view]; 
     touchLocation = [self convertPointFromView:touchLocation]; 
     [self selectNodeForTouch:touchLocation]; 

     _initialrotation = selected.zRotation; 
    } 

    else if (rotationrecognizer.state == UIGestureRecognizerStateChanged) {   

     CGFloat angle = _initialrotation + rotationrecognizer.rotation; 
     selected.zRotation = angle;  

    } 
}