rotation - 使用getRotationMatrix()和getOrientation()查找方向

Question

我试图获得指向摄像机的矢量相对于磁北的方向。我的印象是我需要使用从getOrientation()返回的值，但是我不确定它们代表什么。我从getOrientation()得到的值不预测的地改变当我改变了电话的朝向(旋转90度，不被改变90度的值)。我需要知道getOrientation()返回的值是什么意思。我到目前为止所写的内容如下:

package com.example.orientation;

import android.app.Activity;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.Toast;

public class Orientation extends Activity{

 private SensorManager mSM;
 private mSensorEventListener mSEL;

    float[] inR = new float[16];
    float[] outR= new float[16];
    float[] I = new float[16];
    float[] gravity = new float[3];
    float[] geomag = new float[3];
    float[] orientVals = new float[3];

    final float pi = (float) Math.PI;
    final float rad2deg = 180/pi;    

 /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mSM = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        mSEL = new mSensorEventListener();  

        mSM.registerListener(mSEL, 
       mSM.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
       SensorManager.SENSOR_DELAY_NORMAL);

     mSM.registerListener(mSEL, 
       mSM.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD), 
       SensorManager.SENSOR_DELAY_NORMAL);

 }



 private class mSensorEventListener implements SensorEventListener{

  @Override
  public void onAccuracyChanged(Sensor arg0, int arg1) {}

  @Override
  public void onSensorChanged(SensorEvent event) {

   // If the sensor data is unreliable return
   if (event.accuracy == SensorManager.SENSOR_STATUS_UNRELIABLE)
    return;

   // Gets the value of the sensor that has been changed
   switch (event.sensor.getType()){  
   case Sensor.TYPE_ACCELEROMETER:
    gravity = event.values.clone();
    break;
   case Sensor.TYPE_MAGNETIC_FIELD:
    geomag = event.values.clone();
    break;
   }

   // If gravity and geomag have values then find rotation matrix
   if (gravity != null && geomag != null){

    // checks that the rotation matrix is found
    boolean success = SensorManager.getRotationMatrix(inR, I, gravity, geomag);
    if (success){

     // Re-map coordinates so y-axis comes out of camera
     SensorManager.remapCoordinateSystem(inR, SensorManager.AXIS_X, 
       SensorManager.AXIS_Z, outR);

     // Finds the Azimuth and Pitch angles of the y-axis with 
     // magnetic north and the horizon respectively
     SensorManager.getOrientation(outR, orientVals);
     float azimuth = orientVals[0]*rad2deg;
     float pitch = orientVals[1]*rad2deg;
     float roll = orientVals[2]*rad2deg;

     // Displays a pop up message with the azimuth and inclination angles
     String endl = System.getProperty("line.separator");
     Toast.makeText(getBaseContext(), 
       "Rotation:" +
       outR[0] + " " + outR[1] + " " + outR[2] + endl +
       outR[4] + " " + outR[5] + " " + outR[6] + endl +
       outR[8] + " " + outR[9] + " " + outR[10] + endl +endl +
       "Azimuth: " + azimuth + " degrees" + endl + 
       "Pitch: " + pitch + " degrees" + endl +
       "Roll: " + roll + " degrees", 
       Toast.LENGTH_LONG).show();
    } /*else
     Toast.makeText(getBaseContext(), 
       "Get Rotation Matrix Failed", Toast.LENGTH_LONG).show();*/
   }   
  }

    }

}

我看了sensorManager类的文档，但是并没有帮助解决这个问题。如果有人可以帮助我从中获得意义，我将不胜感激。我正在运行Android 2.1的Nexus One上进行测试

Answer 1

因为我是Android的新手，所以我使用Toast在屏幕上显示信息。我将其更改为仅更新 View 上的文本，这似乎可以解决问题。我还发现我假设的orientVals实际上是正确的。对于我所需要的，不使用卷。也没有意识到有一种方法可以将rad转换为内置的deg，所以我只是使用了这种方法。