Cocos2dx 2.x 安卓重力检测 旋转屏幕

在充电的情况下，玩手机的时候，屏幕一般需要特定的旋转方向。

功能实现分成两部分：一部分根据手机重力方向X,Y,Z得出所需要的角度；另一方面根据旋转角度，设置屏幕旋转方向。

通过监听手机相对于X,Z方向的值，算出绕着某一轴的角度。X,Y方向分别平行于手机界面，Z垂直于手机界面。

本文以绕Y轴旋转为例，如需绕Z轴只需把Y和Z互换，一般情况下只会要求这两种情况。

代码借鉴网上的。

package com.gamemaster.orientation;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.os.Handler;

public class OrientationSensorListener implements SensorEventListener {
	 private static final int _DATA_X = 0;
     private static final int _DATA_Y = 1;
     private static final int _DATA_Z = 2;
     
     public static final int ORIENTATION_UNKNOWN = -1;
     
     private Handler rotateHandler;
     
     
     
	public OrientationSensorListener(Handler handler) {
		rotateHandler = handler;
	}

	public void onAccuracyChanged(Sensor arg0,int arg1) {
		// TODO Auto-generated method stub

	}

	public void onSensorChanged(SensorEvent event) {
		float[] values = event.values;
        int orientation = ORIENTATION_UNKNOWN;
        float X = -values[_DATA_X];
        float Y = -values[_DATA_Y];
        float Z = -values[_DATA_Z];  
        float magnitude = X*X + Z*Z;
        // Don't trust the angle if the magnitude is small compared to the y value
        if (magnitude * 4 >= Y*Y) {
            float OneEightyOverPi = 57.29577957855f;
            float angle = (float)Math.atan2(-Z,X) * OneEightyOverPi;
            orientation = 90 - (int)Math.round(angle);
            // normalize to 0 - 359 range
            while (orientation >= 360) {
                orientation -= 360;
            } 
            while (orientation < 0) {
                orientation += 360;
            }
        }
        
        if (rotateHandler!=null) {
			rotateHandler.obtainMessage(888,orientation,0).sendToTarget();
		}

	}

}

第二部分 根据旋转角度，设置屏幕方向。

package com.gamemaster.orientation;

import android.app.Activity;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

public class ChangeOrientationHandler extends Handler {

	private Activity activity;

	public ChangeOrientationHandler(Activity ac) {
		super();
		activity = ac;
	}
	
	@Override
	public void handleMessage(Message msg) {  
		if (msg.what==888) {
			int orientation = msg.arg1;
			if (orientation>70&&orientation<135) {
				activity.setRequestedOrientation(8);
			}else if (orientation>135&&orientation<225){
				//activity.setRequestedOrientation(9); 
			}else if (orientation>225&&orientation<290){
				activity.setRequestedOrientation(0);
			}else if ((orientation>315&&orientation<360)||(orientation>0&&orientation<45)){
				//activity.setRequestedOrientation(1); 
			}
		}
		
		super.handleMessage(msg);        		
	}
	
}

在Cocos2dxActivity中的onCreate外面添加

private Handler handler;
    private OrientationSensorListener listener;
	private SensorManager sm;
	private Sensor sensor;

在onCreate函数里面添加

handler = new ChangeOrientationHandler(this); 
	    sm = (SensorManager)getSystemService(Context.SENSOR_SERVICE);
	    sensor = sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);       
	    listener = new OrientationSensorListener(handler);
	    sm.registerListener(listener,sensor,SensorManager.SENSOR_DELAY_UI);