iphone - 使用加速度计在 cocos2d 中旋转精灵

Question

我在 cocos2d 上，我有一个精灵，我想用加速度计旋转。

我听说过 CMMotionManager。我想知道是否可以将其仅用于 2D 旋转，如果可以，如何？

Answer 1

把这个放在onEnter：

UIAccelerometer *accelerometer = [UIAccelerometer sharedAccelerometer];
accelerometer.updateInterval = 1.0/50.0; //update interval in sec...so 1/50= 20 ms
accelerometer.delegate = self;

你需要遵守UIAccelerometerDelegate这样的：

@interface MyClass:CCLayer <UIAccelerometerDelegate>

并在以下实施MyClass.m：

- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration    *)acceleration {
CCLOG(@"x = %f y = %f z = %f",acceleration.x,acceleration.y,acceleration.z);
mysprite.rotation=acceleration.x*20;
}

编辑：差点忘了...accelerometer.delegate = nil;放入onExit

请注意，每次加速度计更改值时都会调用该方法。在所有 3 个向量中

桌子上的卡片..我没有使用加速度计...曾经..但它应该看起来像这样...检查文档中的旋转属性并使用它进行一些操作

希望能帮助到你

PS：喜欢“对不起我的英语，我是法国人”的部分......搞笑

编辑：这是我对该代码的测试..并进行了一些修改..它工作得相当顺利..如果你不喜欢它玩弄这些值。

#import "cocos2d.h"

// HelloWorldLayer
UIAccelerationValue accelerationX;
UIAccelerationValue accelerationY;
float currentRawReading;
float calibrationOffset;

@interface HelloWorldLayer : CCLayer <UIAccelerometerDelegate>
{
    CCLabelTTF *label;
}

// returns a CCScene that contains the HelloWorldLayer as the only child
+(CCScene *) scene;

@end





#import "HelloWorldLayer.h"

// HelloWorldLayer implementation
@implementation HelloWorldLayer

+(CCScene *) scene
{
    // 'scene' is an autorelease object.
    CCScene *scene = [CCScene node];

    // 'layer' is an autorelease object.
    HelloWorldLayer *layer = [HelloWorldLayer node];

    // add layer as a child to scene
    [scene addChild: layer];

    // return the scene
    return scene;
}

#define kFilteringFactor .05


CGFloat RadiansToDegrees(CGFloat radians) {return radians *180/M_PI;};



// on "init" you need to initialize your instance
-(id) init
{
    // always call "super" init
    // Apple recommends to re-assign "self" with the "super" return value
    if( (self=[super init])) {

        UIAccelerometer *accel= [UIAccelerometer sharedAccelerometer];
        accel.delegate=self;
        accel.updateInterval=1/60;



        // create and initialize a Label
        label = [CCLabelTTF labelWithString:@"Hello World" fontName:@"Marker Felt" fontSize:64];

        // ask director the the window size
        CGSize size = [[CCDirector sharedDirector] winSize];

        // position the label on the center of the screen
        label.position =  ccp( size.width /2 , size.height/2 );
        label.flipY=YES; //i have absolutly no idea why the label is fliped :/
        label.flipX=YES;
        label.rotation=0;
        // add the label as a child to this Layer
        [self addChild: label];
    }
    return self;
}

-(void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration{

    CCLOG(@"acc called");
    accelerationX=acceleration.x *kFilteringFactor +accelerationX *(1-kFilteringFactor);
    accelerationY=acceleration.y*kFilteringFactor +accelerationY *(1-kFilteringFactor);
    currentRawReading=atan2(accelerationY, accelerationX);

    label.rotation=-RadiansToDegrees(currentRawReading);

}


// on "dealloc" you need to release all your retained objects
- (void) dealloc
{
    // in case you have something to dealloc, do it in this method
    // in this particular example nothing needs to be released.
    // cocos2d will automatically release all the children (Label)

    // don't forget to call "super dealloc"

    [super dealloc];
}
@end