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1 /*
2  * Copyright (C) 2008 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.hardware;
18 
19 import android.os.Looper;
20 import android.os.Process;
21 import android.os.RemoteException;
22 import android.os.Handler;
23 import android.os.Message;
24 import android.os.ServiceManager;
25 import android.util.Log;
26 import android.util.SparseArray;
27 import android.util.SparseBooleanArray;
28 import android.util.SparseIntArray;
29 import android.view.IRotationWatcher;
30 import android.view.IWindowManager;
31 import android.view.Surface;
32 
33 import java.util.ArrayList;
34 import java.util.Collections;
35 import java.util.HashMap;
36 import java.util.List;
37 
38 /**
39  * <p>
40  * SensorManager lets you access the device's {@link android.hardware.Sensor
41  * sensors}. Get an instance of this class by calling
42  * {@link android.content.Context#getSystemService(java.lang.String)
43  * Context.getSystemService()} with the argument
44  * {@link android.content.Context#SENSOR_SERVICE}.
45  * </p>
46  * <p>
47  * Always make sure to disable sensors you don't need, especially when your
48  * activity is paused. Failing to do so can drain the battery in just a few
49  * hours. Note that the system will <i>not</i> disable sensors automatically when
50  * the screen turns off.
51  * </p>
52  *
53  * <pre class="prettyprint">
54  * public class SensorActivity extends Activity, implements SensorEventListener {
55  *     private final SensorManager mSensorManager;
56  *     private final Sensor mAccelerometer;
57  *
58  *     public SensorActivity() {
59  *         mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
60  *         mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
61  *     }
62  *
63  *     protected void onResume() {
64  *         super.onResume();
65  *         mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);
66  *     }
67  *
68  *     protected void onPause() {
69  *         super.onPause();
70  *         mSensorManager.unregisterListener(this);
71  *     }
72  *
73  *     public void onAccuracyChanged(Sensor sensor, int accuracy) {
74  *     }
75  *
76  *     public void onSensorChanged(SensorEvent event) {
77  *     }
78  * }
79  * </pre>
80  *
81  * @see SensorEventListener
82  * @see SensorEvent
83  * @see Sensor
84  *
85  */
86 public class SensorManager
87 {
88     private static final String TAG = "SensorManager";
89     private static final float[] mTempMatrix = new float[16];
90 
91     /* NOTE: sensor IDs must be a power of 2 */
92 
93     /**
94      * A constant describing an orientation sensor. See
95      * {@link android.hardware.SensorListener SensorListener} for more details.
96      *
97      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
98      */
99     @Deprecated
100     public static final int SENSOR_ORIENTATION = 1 << 0;
101 
102     /**
103      * A constant describing an accelerometer. See
104      * {@link android.hardware.SensorListener SensorListener} for more details.
105      *
106      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
107      */
108     @Deprecated
109     public static final int SENSOR_ACCELEROMETER = 1 << 1;
110 
111     /**
112      * A constant describing a temperature sensor See
113      * {@link android.hardware.SensorListener SensorListener} for more details.
114      *
115      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
116      */
117     @Deprecated
118     public static final int SENSOR_TEMPERATURE = 1 << 2;
119 
120     /**
121      * A constant describing a magnetic sensor See
122      * {@link android.hardware.SensorListener SensorListener} for more details.
123      *
124      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
125      */
126     @Deprecated
127     public static final int SENSOR_MAGNETIC_FIELD = 1 << 3;
128 
129     /**
130      * A constant describing an ambient light sensor See
131      * {@link android.hardware.SensorListener SensorListener} for more details.
132      *
133      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
134      */
135     @Deprecated
136     public static final int SENSOR_LIGHT = 1 << 4;
137 
138     /**
139      * A constant describing a proximity sensor See
140      * {@link android.hardware.SensorListener SensorListener} for more details.
141      *
142      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
143      */
144     @Deprecated
145     public static final int SENSOR_PROXIMITY = 1 << 5;
146 
147     /**
148      * A constant describing a Tricorder See
149      * {@link android.hardware.SensorListener SensorListener} for more details.
150      *
151      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
152      */
153     @Deprecated
154     public static final int SENSOR_TRICORDER = 1 << 6;
155 
156     /**
157      * A constant describing an orientation sensor. See
158      * {@link android.hardware.SensorListener SensorListener} for more details.
159      *
160      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
161      */
162     @Deprecated
163     public static final int SENSOR_ORIENTATION_RAW = 1 << 7;
164 
165     /**
166      * A constant that includes all sensors
167      *
168      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
169      */
170     @Deprecated
171     public static final int SENSOR_ALL = 0x7F;
172 
173     /**
174      * Smallest sensor ID
175      *
176      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
177      */
178     @Deprecated
179     public static final int SENSOR_MIN = SENSOR_ORIENTATION;
180 
181     /**
182      * Largest sensor ID
183      *
184      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
185      */
186     @Deprecated
187     public static final int SENSOR_MAX = ((SENSOR_ALL + 1)>>1);
188 
189 
190     /**
191      * Index of the X value in the array returned by
192      * {@link android.hardware.SensorListener#onSensorChanged}
193      *
194      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
195      */
196     @Deprecated
197     public static final int DATA_X = 0;
198 
199     /**
200      * Index of the Y value in the array returned by
201      * {@link android.hardware.SensorListener#onSensorChanged}
202      *
203      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
204      */
205     @Deprecated
206     public static final int DATA_Y = 1;
207 
208     /**
209      * Index of the Z value in the array returned by
210      * {@link android.hardware.SensorListener#onSensorChanged}
211      *
212      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
213      */
214     @Deprecated
215     public static final int DATA_Z = 2;
216 
217     /**
218      * Offset to the untransformed values in the array returned by
219      * {@link android.hardware.SensorListener#onSensorChanged}
220      *
221      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
222      */
223     @Deprecated
224     public static final int RAW_DATA_INDEX = 3;
225 
226     /**
227      * Index of the untransformed X value in the array returned by
228      * {@link android.hardware.SensorListener#onSensorChanged}
229      *
230      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
231      */
232     @Deprecated
233     public static final int RAW_DATA_X = 3;
234 
235     /**
236      * Index of the untransformed Y value in the array returned by
237      * {@link android.hardware.SensorListener#onSensorChanged}
238      *
239      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
240      */
241     @Deprecated
242     public static final int RAW_DATA_Y = 4;
243 
244     /**
245      * Index of the untransformed Z value in the array returned by
246      * {@link android.hardware.SensorListener#onSensorChanged}
247      *
248      * @deprecated use {@link android.hardware.Sensor Sensor} instead.
249      */
250     @Deprecated
251     public static final int RAW_DATA_Z = 5;
252 
253     /** Standard gravity (g) on Earth. This value is equivalent to 1G */
254     public static final float STANDARD_GRAVITY = 9.80665f;
255 
256     /** Sun's gravity in SI units (m/s^2) */
257     public static final float GRAVITY_SUN             = 275.0f;
258     /** Mercury's gravity in SI units (m/s^2) */
259     public static final float GRAVITY_MERCURY         = 3.70f;
260     /** Venus' gravity in SI units (m/s^2) */
261     public static final float GRAVITY_VENUS           = 8.87f;
262     /** Earth's gravity in SI units (m/s^2) */
263     public static final float GRAVITY_EARTH           = 9.80665f;
264     /** The Moon's gravity in SI units (m/s^2) */
265     public static final float GRAVITY_MOON            = 1.6f;
266     /** Mars' gravity in SI units (m/s^2) */
267     public static final float GRAVITY_MARS            = 3.71f;
268     /** Jupiter's gravity in SI units (m/s^2) */
269     public static final float GRAVITY_JUPITER         = 23.12f;
270     /** Saturn's gravity in SI units (m/s^2) */
271     public static final float GRAVITY_SATURN          = 8.96f;
272     /** Uranus' gravity in SI units (m/s^2) */
273     public static final float GRAVITY_URANUS          = 8.69f;
274     /** Neptune's gravity in SI units (m/s^2) */
275     public static final float GRAVITY_NEPTUNE         = 11.0f;
276     /** Pluto's gravity in SI units (m/s^2) */
277     public static final float GRAVITY_PLUTO           = 0.6f;
278     /** Gravity (estimate) on the first Death Star in Empire units (m/s^2) */
279     public static final float GRAVITY_DEATH_STAR_I    = 0.000000353036145f;
280     /** Gravity on the island */
281     public static final float GRAVITY_THE_ISLAND      = 4.815162342f;
282 
283 
284     /** Maximum magnetic field on Earth's surface */
285     public static final float MAGNETIC_FIELD_EARTH_MAX = 60.0f;
286     /** Minimum magnetic field on Earth's surface */
287     public static final float MAGNETIC_FIELD_EARTH_MIN = 30.0f;
288 
289 
290     /** Standard atmosphere, or average sea-level pressure in hPa (millibar) */
291     public static final float PRESSURE_STANDARD_ATMOSPHERE = 1013.25f;
292 
293 
294     /** Maximum luminance of sunlight in lux */
295     public static final float LIGHT_SUNLIGHT_MAX = 120000.0f;
296     /** luminance of sunlight in lux */
297     public static final float LIGHT_SUNLIGHT     = 110000.0f;
298     /** luminance in shade in lux */
299     public static final float LIGHT_SHADE        = 20000.0f;
300     /** luminance under an overcast sky in lux */
301     public static final float LIGHT_OVERCAST     = 10000.0f;
302     /** luminance at sunrise in lux */
303     public static final float LIGHT_SUNRISE      = 400.0f;
304     /** luminance under a cloudy sky in lux */
305     public static final float LIGHT_CLOUDY       = 100.0f;
306     /** luminance at night with full moon in lux */
307     public static final float LIGHT_FULLMOON     = 0.25f;
308     /** luminance at night with no moon in lux*/
309     public static final float LIGHT_NO_MOON      = 0.001f;
310 
311 
312     /** get sensor data as fast as possible */
313     public static final int SENSOR_DELAY_FASTEST = 0;
314     /** rate suitable for games */
315     public static final int SENSOR_DELAY_GAME = 1;
316     /** rate suitable for the user interface  */
317     public static final int SENSOR_DELAY_UI = 2;
318     /** rate (default) suitable for screen orientation changes */
319     public static final int SENSOR_DELAY_NORMAL = 3;
320 
321 
322     /**
323      * The values returned by this sensor cannot be trusted, calibration is
324      * needed or the environment doesn't allow readings
325      */
326     public static final int SENSOR_STATUS_UNRELIABLE = 0;
327 
328     /**
329      * This sensor is reporting data with low accuracy, calibration with the
330      * environment is needed
331      */
332     public static final int SENSOR_STATUS_ACCURACY_LOW = 1;
333 
334     /**
335      * This sensor is reporting data with an average level of accuracy,
336      * calibration with the environment may improve the readings
337      */
338     public static final int SENSOR_STATUS_ACCURACY_MEDIUM = 2;
339 
340     /** This sensor is reporting data with maximum accuracy */
341     public static final int SENSOR_STATUS_ACCURACY_HIGH = 3;
342 
343     /** see {@link #remapCoordinateSystem} */
344     public static final int AXIS_X = 1;
345     /** see {@link #remapCoordinateSystem} */
346     public static final int AXIS_Y = 2;
347     /** see {@link #remapCoordinateSystem} */
348     public static final int AXIS_Z = 3;
349     /** see {@link #remapCoordinateSystem} */
350     public static final int AXIS_MINUS_X = AXIS_X | 0x80;
351     /** see {@link #remapCoordinateSystem} */
352     public static final int AXIS_MINUS_Y = AXIS_Y | 0x80;
353     /** see {@link #remapCoordinateSystem} */
354     public static final int AXIS_MINUS_Z = AXIS_Z | 0x80;
355 
356     /*-----------------------------------------------------------------------*/
357 
358     Looper mMainLooper;
359     @SuppressWarnings("deprecation")
360     private HashMap<SensorListener, LegacyListener> mLegacyListenersMap =
361         new HashMap<SensorListener, LegacyListener>();
362 
363     /*-----------------------------------------------------------------------*/
364 
365     private static final int SENSOR_DISABLE = -1;
366     private static boolean sSensorModuleInitialized = false;
367     private static ArrayList<Sensor> sFullSensorsList = new ArrayList<Sensor>();
368     private static SparseArray<List<Sensor>> sSensorListByType = new SparseArray<List<Sensor>>();
369     private static IWindowManager sWindowManager;
370     private static int sRotation = Surface.ROTATION_0;
371     /* The thread and the sensor list are global to the process
372      * but the actual thread is spawned on demand */
373     private static SensorThread sSensorThread;
374     private static int sQueue;
375 
376     // Used within this module from outside SensorManager, don't make private
377     static SparseArray<Sensor> sHandleToSensor = new SparseArray<Sensor>();
378     static final ArrayList<ListenerDelegate> sListeners =
379         new ArrayList<ListenerDelegate>();
380 
381     /*-----------------------------------------------------------------------*/
382 
383     static private class SensorThread {
384 
385         Thread mThread;
386         boolean mSensorsReady;
387 
SensorThread()388         SensorThread() {
389         }
390 
391         @Override
finalize()392         protected void finalize() {
393         }
394 
395         // must be called with sListeners lock
startLocked()396         boolean startLocked() {
397             try {
398                 if (mThread == null) {
399                     mSensorsReady = false;
400                     SensorThreadRunnable runnable = new SensorThreadRunnable();
401                     Thread thread = new Thread(runnable, SensorThread.class.getName());
402                     thread.start();
403                     synchronized (runnable) {
404                         while (mSensorsReady == false) {
405                             runnable.wait();
406                         }
407                     }
408                     mThread = thread;
409                 }
410             } catch (InterruptedException e) {
411             }
412             return mThread == null ? false : true;
413         }
414 
415         private class SensorThreadRunnable implements Runnable {
SensorThreadRunnable()416             SensorThreadRunnable() {
417             }
418 
open()419             private boolean open() {
420                 // NOTE: this cannot synchronize on sListeners, since
421                 // it's held in the main thread at least until we
422                 // return from here.
423                 sQueue = sensors_create_queue();
424                 return true;
425             }
426 
run()427             public void run() {
428                 //Log.d(TAG, "entering main sensor thread");
429                 final float[] values = new float[3];
430                 final int[] status = new int[1];
431                 final long timestamp[] = new long[1];
432                 Process.setThreadPriority(Process.THREAD_PRIORITY_URGENT_DISPLAY);
433 
434                 if (!open()) {
435                     return;
436                 }
437 
438                 synchronized (this) {
439                     // we've open the driver, we're ready to open the sensors
440                     mSensorsReady = true;
441                     this.notify();
442                 }
443 
444                 while (true) {
445                     // wait for an event
446                     final int sensor = sensors_data_poll(sQueue, values, status, timestamp);
447 
448                     int accuracy = status[0];
449                     synchronized (sListeners) {
450                         if (sensor == -1 || sListeners.isEmpty()) {
451                             // we lost the connection to the event stream. this happens
452                             // when the last listener is removed or if there is an error
453                             if (sensor == -1 && !sListeners.isEmpty()) {
454                                 // log a warning in case of abnormal termination
455                                 Log.e(TAG, "_sensors_data_poll() failed, we bail out: sensors=" + sensor);
456                             }
457                             // we have no more listeners or polling failed, terminate the thread
458                             sensors_destroy_queue(sQueue);
459                             sQueue = 0;
460                             mThread = null;
461                             break;
462                         }
463                         final Sensor sensorObject = sHandleToSensor.get(sensor);
464                         if (sensorObject != null) {
465                             // report the sensor event to all listeners that
466                             // care about it.
467                             final int size = sListeners.size();
468                             for (int i=0 ; i<size ; i++) {
469                                 ListenerDelegate listener = sListeners.get(i);
470                                 if (listener.hasSensor(sensorObject)) {
471                                     // this is asynchronous (okay to call
472                                     // with sListeners lock held).
473                                     listener.onSensorChangedLocked(sensorObject,
474                                             values, timestamp, accuracy);
475                                 }
476                             }
477                         }
478                     }
479                 }
480                 //Log.d(TAG, "exiting main sensor thread");
481             }
482         }
483     }
484 
485     /*-----------------------------------------------------------------------*/
486 
487     private class ListenerDelegate {
488         final SensorEventListener mSensorEventListener;
489         private final ArrayList<Sensor> mSensorList = new ArrayList<Sensor>();
490         private final Handler mHandler;
491         private SensorEvent mValuesPool;
492         public SparseBooleanArray mSensors = new SparseBooleanArray();
493         public SparseBooleanArray mFirstEvent = new SparseBooleanArray();
494         public SparseIntArray mSensorAccuracies = new SparseIntArray();
495 
ListenerDelegate(SensorEventListener listener, Sensor sensor, Handler handler)496         ListenerDelegate(SensorEventListener listener, Sensor sensor, Handler handler) {
497             mSensorEventListener = listener;
498             Looper looper = (handler != null) ? handler.getLooper() : mMainLooper;
499             // currently we create one Handler instance per listener, but we could
500             // have one per looper (we'd need to pass the ListenerDelegate
501             // instance to handleMessage and keep track of them separately).
502             mHandler = new Handler(looper) {
503                 @Override
504                 public void handleMessage(Message msg) {
505                     final SensorEvent t = (SensorEvent)msg.obj;
506                     final int handle = t.sensor.getHandle();
507 
508                     switch (t.sensor.getType()) {
509                         // Only report accuracy for sensors that support it.
510                         case Sensor.TYPE_MAGNETIC_FIELD:
511                         case Sensor.TYPE_ORIENTATION:
512                             // call onAccuracyChanged() only if the value changes
513                             final int accuracy = mSensorAccuracies.get(handle);
514                             if ((t.accuracy >= 0) && (accuracy != t.accuracy)) {
515                                 mSensorAccuracies.put(handle, t.accuracy);
516                                 mSensorEventListener.onAccuracyChanged(t.sensor, t.accuracy);
517                             }
518                             break;
519                         default:
520                             // For other sensors, just report the accuracy once
521                             if (mFirstEvent.get(handle) == false) {
522                                 mFirstEvent.put(handle, true);
523                                 mSensorEventListener.onAccuracyChanged(
524                                         t.sensor, SENSOR_STATUS_ACCURACY_HIGH);
525                             }
526                             break;
527                     }
528 
529                     mSensorEventListener.onSensorChanged(t);
530                     returnToPool(t);
531                 }
532             };
533             addSensor(sensor);
534         }
535 
createSensorEvent()536         protected SensorEvent createSensorEvent() {
537             // maximal size for all legacy events is 3
538             return new SensorEvent(3);
539         }
540 
getFromPool()541         protected SensorEvent getFromPool() {
542             SensorEvent t = null;
543             synchronized (this) {
544                 // remove the array from the pool
545                 t = mValuesPool;
546                 mValuesPool = null;
547             }
548             if (t == null) {
549                 // the pool was empty, we need a new one
550                 t = createSensorEvent();
551             }
552             return t;
553         }
554 
returnToPool(SensorEvent t)555         protected void returnToPool(SensorEvent t) {
556             synchronized (this) {
557                 // put back the array into the pool
558                 if (mValuesPool == null) {
559                     mValuesPool = t;
560                 }
561             }
562         }
563 
getListener()564         Object getListener() {
565             return mSensorEventListener;
566         }
567 
addSensor(Sensor sensor)568         void addSensor(Sensor sensor) {
569             mSensors.put(sensor.getHandle(), true);
570             mSensorList.add(sensor);
571         }
removeSensor(Sensor sensor)572         int removeSensor(Sensor sensor) {
573             mSensors.delete(sensor.getHandle());
574             mSensorList.remove(sensor);
575             return mSensors.size();
576         }
hasSensor(Sensor sensor)577         boolean hasSensor(Sensor sensor) {
578             return mSensors.get(sensor.getHandle());
579         }
getSensors()580         List<Sensor> getSensors() {
581             return mSensorList;
582         }
583 
onSensorChangedLocked(Sensor sensor, float[] values, long[] timestamp, int accuracy)584         void onSensorChangedLocked(Sensor sensor, float[] values, long[] timestamp, int accuracy) {
585             SensorEvent t = getFromPool();
586             final float[] v = t.values;
587             v[0] = values[0];
588             v[1] = values[1];
589             v[2] = values[2];
590             t.timestamp = timestamp[0];
591             t.accuracy = accuracy;
592             t.sensor = sensor;
593             Message msg = Message.obtain();
594             msg.what = 0;
595             msg.obj = t;
596             mHandler.sendMessage(msg);
597         }
598     }
599 
600     /**
601      * {@hide}
602      */
SensorManager(Looper mainLooper)603     public SensorManager(Looper mainLooper) {
604         mMainLooper = mainLooper;
605 
606 
607         synchronized(sListeners) {
608             if (!sSensorModuleInitialized) {
609                 sSensorModuleInitialized = true;
610 
611                 nativeClassInit();
612 
613                 sWindowManager = IWindowManager.Stub.asInterface(
614                         ServiceManager.getService("window"));
615                 if (sWindowManager != null) {
616                     // if it's null we're running in the system process
617                     // which won't get the rotated values
618                     try {
619                         sRotation = sWindowManager.watchRotation(
620                                 new IRotationWatcher.Stub() {
621                                     public void onRotationChanged(int rotation) {
622                                         SensorManager.this.onRotationChanged(rotation);
623                                     }
624                                 }
625                         );
626                     } catch (RemoteException e) {
627                     }
628                 }
629 
630                 // initialize the sensor list
631                 sensors_module_init();
632                 final ArrayList<Sensor> fullList = sFullSensorsList;
633                 int i = 0;
634                 do {
635                     Sensor sensor = new Sensor();
636                     i = sensors_module_get_next_sensor(sensor, i);
637 
638                     if (i>=0) {
639                         //Log.d(TAG, "found sensor: " + sensor.getName() +
640                         //        ", handle=" + sensor.getHandle());
641                         sensor.setLegacyType(getLegacySensorType(sensor.getType()));
642                         fullList.add(sensor);
643                         sHandleToSensor.append(sensor.getHandle(), sensor);
644                     }
645                 } while (i>0);
646 
647                 sSensorThread = new SensorThread();
648             }
649         }
650     }
651 
getLegacySensorType(int type)652     private int getLegacySensorType(int type) {
653         switch (type) {
654             case Sensor.TYPE_ACCELEROMETER:
655                 return SENSOR_ACCELEROMETER;
656             case Sensor.TYPE_MAGNETIC_FIELD:
657                 return SENSOR_MAGNETIC_FIELD;
658             case Sensor.TYPE_ORIENTATION:
659                 return SENSOR_ORIENTATION_RAW;
660             case Sensor.TYPE_TEMPERATURE:
661                 return SENSOR_TEMPERATURE;
662         }
663         return 0;
664     }
665 
666     /**
667      * @return available sensors.
668      * @deprecated This method is deprecated, use
669      *             {@link SensorManager#getSensorList(int)} instead
670      */
671     @Deprecated
getSensors()672     public int getSensors() {
673         int result = 0;
674         final ArrayList<Sensor> fullList = sFullSensorsList;
675         for (Sensor i : fullList) {
676             switch (i.getType()) {
677                 case Sensor.TYPE_ACCELEROMETER:
678                     result |= SensorManager.SENSOR_ACCELEROMETER;
679                     break;
680                 case Sensor.TYPE_MAGNETIC_FIELD:
681                     result |= SensorManager.SENSOR_MAGNETIC_FIELD;
682                     break;
683                 case Sensor.TYPE_ORIENTATION:
684                     result |= SensorManager.SENSOR_ORIENTATION |
685                     SensorManager.SENSOR_ORIENTATION_RAW;
686                     break;
687             }
688         }
689         return result;
690     }
691 
692     /**
693      * Use this method to get the list of available sensors of a certain type.
694      * Make multiple calls to get sensors of different types or use
695      * {@link android.hardware.Sensor#TYPE_ALL Sensor.TYPE_ALL} to get all the
696      * sensors.
697      *
698      * @param type
699      *        of sensors requested
700      *
701      * @return a list of sensors matching the asked type.
702      *
703      * @see #getDefaultSensor(int)
704      * @see Sensor
705      */
getSensorList(int type)706     public List<Sensor> getSensorList(int type) {
707         // cache the returned lists the first time
708         List<Sensor> list;
709         final ArrayList<Sensor> fullList = sFullSensorsList;
710         synchronized(fullList) {
711             list = sSensorListByType.get(type);
712             if (list == null) {
713                 if (type == Sensor.TYPE_ALL) {
714                     list = fullList;
715                 } else {
716                     list = new ArrayList<Sensor>();
717                     for (Sensor i : fullList) {
718                         if (i.getType() == type)
719                             list.add(i);
720                     }
721                 }
722                 list = Collections.unmodifiableList(list);
723                 sSensorListByType.append(type, list);
724             }
725         }
726         return list;
727     }
728 
729     /**
730      * Use this method to get the default sensor for a given type. Note that the
731      * returned sensor could be a composite sensor, and its data could be
732      * averaged or filtered. If you need to access the raw sensors use
733      * {@link SensorManager#getSensorList(int) getSensorList}.
734      *
735      * @param type
736      *        of sensors requested
737      *
738      * @return the default sensors matching the asked type.
739      *
740      * @see #getSensorList(int)
741      * @see Sensor
742      */
getDefaultSensor(int type)743     public Sensor getDefaultSensor(int type) {
744         // TODO: need to be smarter, for now, just return the 1st sensor
745         List<Sensor> l = getSensorList(type);
746         return l.isEmpty() ? null : l.get(0);
747     }
748 
749     /**
750      * Registers a listener for given sensors.
751      *
752      * @deprecated This method is deprecated, use
753      *             {@link SensorManager#registerListener(SensorEventListener, Sensor, int)}
754      *             instead.
755      *
756      * @param listener
757      *        sensor listener object
758      *
759      * @param sensors
760      *        a bit masks of the sensors to register to
761      *
762      * @return <code>true</code> if the sensor is supported and successfully
763      *         enabled
764      */
765     @Deprecated
registerListener(SensorListener listener, int sensors)766     public boolean registerListener(SensorListener listener, int sensors) {
767         return registerListener(listener, sensors, SENSOR_DELAY_NORMAL);
768     }
769 
770     /**
771      * Registers a SensorListener for given sensors.
772      *
773      * @deprecated This method is deprecated, use
774      *             {@link SensorManager#registerListener(SensorEventListener, Sensor, int)}
775      *             instead.
776      *
777      * @param listener
778      *        sensor listener object
779      *
780      * @param sensors
781      *        a bit masks of the sensors to register to
782      *
783      * @param rate
784      *        rate of events. This is only a hint to the system. events may be
785      *        received faster or slower than the specified rate. Usually events
786      *        are received faster. The value must be one of
787      *        {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
788      *        {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}.
789      *
790      * @return <code>true</code> if the sensor is supported and successfully
791      *         enabled
792      */
793     @Deprecated
registerListener(SensorListener listener, int sensors, int rate)794     public boolean registerListener(SensorListener listener, int sensors, int rate) {
795         if (listener == null) {
796             return false;
797         }
798         boolean result = false;
799         result = registerLegacyListener(SENSOR_ACCELEROMETER, Sensor.TYPE_ACCELEROMETER,
800                 listener, sensors, rate) || result;
801         result = registerLegacyListener(SENSOR_MAGNETIC_FIELD, Sensor.TYPE_MAGNETIC_FIELD,
802                 listener, sensors, rate) || result;
803         result = registerLegacyListener(SENSOR_ORIENTATION_RAW, Sensor.TYPE_ORIENTATION,
804                 listener, sensors, rate) || result;
805         result = registerLegacyListener(SENSOR_ORIENTATION, Sensor.TYPE_ORIENTATION,
806                 listener, sensors, rate) || result;
807         result = registerLegacyListener(SENSOR_TEMPERATURE, Sensor.TYPE_TEMPERATURE,
808                 listener, sensors, rate) || result;
809         return result;
810     }
811 
812     @SuppressWarnings("deprecation")
registerLegacyListener(int legacyType, int type, SensorListener listener, int sensors, int rate)813     private boolean registerLegacyListener(int legacyType, int type,
814             SensorListener listener, int sensors, int rate)
815     {
816         if (listener == null) {
817             return false;
818         }
819         boolean result = false;
820         // Are we activating this legacy sensor?
821         if ((sensors & legacyType) != 0) {
822             // if so, find a suitable Sensor
823             Sensor sensor = getDefaultSensor(type);
824             if (sensor != null) {
825                 // If we don't already have one, create a LegacyListener
826                 // to wrap this listener and process the events as
827                 // they are expected by legacy apps.
828                 LegacyListener legacyListener = null;
829                 synchronized (mLegacyListenersMap) {
830                     legacyListener = mLegacyListenersMap.get(listener);
831                     if (legacyListener == null) {
832                         // we didn't find a LegacyListener for this client,
833                         // create one, and put it in our list.
834                         legacyListener = new LegacyListener(listener);
835                         mLegacyListenersMap.put(listener, legacyListener);
836                     }
837                 }
838                 // register this legacy sensor with this legacy listener
839                 legacyListener.registerSensor(legacyType);
840                 // and finally, register the legacy listener with the new apis
841                 result = registerListener(legacyListener, sensor, rate);
842             }
843         }
844         return result;
845     }
846 
847     /**
848      * Unregisters a listener for the sensors with which it is registered.
849      *
850      * @deprecated This method is deprecated, use
851      *             {@link SensorManager#unregisterListener(SensorEventListener, Sensor)}
852      *             instead.
853      *
854      * @param listener
855      *        a SensorListener object
856      *
857      * @param sensors
858      *        a bit masks of the sensors to unregister from
859      */
860     @Deprecated
unregisterListener(SensorListener listener, int sensors)861     public void unregisterListener(SensorListener listener, int sensors) {
862         unregisterLegacyListener(SENSOR_ACCELEROMETER, Sensor.TYPE_ACCELEROMETER,
863                 listener, sensors);
864         unregisterLegacyListener(SENSOR_MAGNETIC_FIELD, Sensor.TYPE_MAGNETIC_FIELD,
865                 listener, sensors);
866         unregisterLegacyListener(SENSOR_ORIENTATION_RAW, Sensor.TYPE_ORIENTATION,
867                 listener, sensors);
868         unregisterLegacyListener(SENSOR_ORIENTATION, Sensor.TYPE_ORIENTATION,
869                 listener, sensors);
870         unregisterLegacyListener(SENSOR_TEMPERATURE, Sensor.TYPE_TEMPERATURE,
871                 listener, sensors);
872     }
873 
874     @SuppressWarnings("deprecation")
unregisterLegacyListener(int legacyType, int type, SensorListener listener, int sensors)875     private void unregisterLegacyListener(int legacyType, int type,
876             SensorListener listener, int sensors)
877     {
878         if (listener == null) {
879             return;
880         }
881         // do we know about this listener?
882         LegacyListener legacyListener = null;
883         synchronized (mLegacyListenersMap) {
884             legacyListener = mLegacyListenersMap.get(listener);
885         }
886         if (legacyListener != null) {
887             // Are we deactivating this legacy sensor?
888             if ((sensors & legacyType) != 0) {
889                 // if so, find the corresponding Sensor
890                 Sensor sensor = getDefaultSensor(type);
891                 if (sensor != null) {
892                     // unregister this legacy sensor and if we don't
893                     // need the corresponding Sensor, unregister it too
894                     if (legacyListener.unregisterSensor(legacyType)) {
895                         // corresponding sensor not needed, unregister
896                         unregisterListener(legacyListener, sensor);
897                         // finally check if we still need the legacyListener
898                         // in our mapping, if not, get rid of it too.
899                         synchronized(sListeners) {
900                             boolean found = false;
901                             for (ListenerDelegate i : sListeners) {
902                                 if (i.getListener() == legacyListener) {
903                                     found = true;
904                                     break;
905                                 }
906                             }
907                             if (!found) {
908                                 synchronized (mLegacyListenersMap) {
909                                     mLegacyListenersMap.remove(listener);
910                                 }
911                             }
912                         }
913                     }
914                 }
915             }
916         }
917     }
918 
919     /**
920      * Unregisters a listener for all sensors.
921      *
922      * @deprecated This method is deprecated, use
923      *             {@link SensorManager#unregisterListener(SensorEventListener)}
924      *             instead.
925      *
926      * @param listener
927      *        a SensorListener object
928      */
929     @Deprecated
unregisterListener(SensorListener listener)930     public void unregisterListener(SensorListener listener) {
931         unregisterListener(listener, SENSOR_ALL | SENSOR_ORIENTATION_RAW);
932     }
933 
934     /**
935      * Unregisters a listener for the sensors with which it is registered.
936      *
937      * @param listener
938      *        a SensorEventListener object
939      *
940      * @param sensor
941      *        the sensor to unregister from
942      *
943      * @see #unregisterListener(SensorEventListener)
944      * @see #registerListener(SensorEventListener, Sensor, int)
945      *
946      */
unregisterListener(SensorEventListener listener, Sensor sensor)947     public void unregisterListener(SensorEventListener listener, Sensor sensor) {
948         unregisterListener((Object)listener, sensor);
949     }
950 
951     /**
952      * Unregisters a listener for all sensors.
953      *
954      * @param listener
955      *        a SensorListener object
956      *
957      * @see #unregisterListener(SensorEventListener, Sensor)
958      * @see #registerListener(SensorEventListener, Sensor, int)
959      *
960      */
unregisterListener(SensorEventListener listener)961     public void unregisterListener(SensorEventListener listener) {
962         unregisterListener((Object)listener);
963     }
964 
965     /**
966      * Registers a {@link android.hardware.SensorEventListener
967      * SensorEventListener} for the given sensor.
968      *
969      * @param listener
970      *        A {@link android.hardware.SensorEventListener SensorEventListener}
971      *        object.
972      *
973      * @param sensor
974      *        The {@link android.hardware.Sensor Sensor} to register to.
975      *
976      * @param rate
977      *        The rate {@link android.hardware.SensorEvent sensor events} are
978      *        delivered at. This is only a hint to the system. Events may be
979      *        received faster or slower than the specified rate. Usually events
980      *        are received faster. The value must be one of
981      *        {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
982      *        {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}
983      *        or, the desired delay between events in microsecond.
984      *
985      * @return <code>true</code> if the sensor is supported and successfully
986      *         enabled.
987      *
988      * @see #registerListener(SensorEventListener, Sensor, int, Handler)
989      * @see #unregisterListener(SensorEventListener)
990      * @see #unregisterListener(SensorEventListener, Sensor)
991      *
992      */
registerListener(SensorEventListener listener, Sensor sensor, int rate)993     public boolean registerListener(SensorEventListener listener, Sensor sensor, int rate) {
994         return registerListener(listener, sensor, rate, null);
995     }
996 
enableSensorLocked(Sensor sensor, int delay)997     private boolean enableSensorLocked(Sensor sensor, int delay) {
998         boolean result = false;
999         for (ListenerDelegate i : sListeners) {
1000             if (i.hasSensor(sensor)) {
1001                 String name = sensor.getName();
1002                 int handle = sensor.getHandle();
1003                 result = sensors_enable_sensor(sQueue, name, handle, delay);
1004                 break;
1005             }
1006         }
1007         return result;
1008     }
1009 
disableSensorLocked(Sensor sensor)1010     private boolean disableSensorLocked(Sensor sensor) {
1011         for (ListenerDelegate i : sListeners) {
1012             if (i.hasSensor(sensor)) {
1013                 // not an error, it's just that this sensor is still in use
1014                 return true;
1015             }
1016         }
1017         String name = sensor.getName();
1018         int handle = sensor.getHandle();
1019         return sensors_enable_sensor(sQueue, name, handle, SENSOR_DISABLE);
1020     }
1021 
1022     /**
1023      * Registers a {@link android.hardware.SensorEventListener
1024      * SensorEventListener} for the given sensor.
1025      *
1026      * @param listener
1027      *        A {@link android.hardware.SensorEventListener SensorEventListener}
1028      *        object.
1029      *
1030      * @param sensor
1031      *        The {@link android.hardware.Sensor Sensor} to register to.
1032      *
1033      * @param rate
1034      *        The rate {@link android.hardware.SensorEvent sensor events} are
1035      *        delivered at. This is only a hint to the system. Events may be
1036      *        received faster or slower than the specified rate. Usually events
1037      *        are received faster. The value must be one of
1038      *        {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI},
1039      *        {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}.
1040      *        or, the desired delay between events in microsecond.
1041      *
1042      * @param handler
1043      *        The {@link android.os.Handler Handler} the
1044      *        {@link android.hardware.SensorEvent sensor events} will be
1045      *        delivered to.
1046      *
1047      * @return true if the sensor is supported and successfully enabled.
1048      *
1049      * @see #registerListener(SensorEventListener, Sensor, int)
1050      * @see #unregisterListener(SensorEventListener)
1051      * @see #unregisterListener(SensorEventListener, Sensor)
1052      *
1053      */
registerListener(SensorEventListener listener, Sensor sensor, int rate, Handler handler)1054     public boolean registerListener(SensorEventListener listener, Sensor sensor, int rate,
1055             Handler handler) {
1056         if (listener == null || sensor == null) {
1057             return false;
1058         }
1059         boolean result = true;
1060         int delay = -1;
1061         switch (rate) {
1062             case SENSOR_DELAY_FASTEST:
1063                 delay = 0;
1064                 break;
1065             case SENSOR_DELAY_GAME:
1066                 delay = 20000;
1067                 break;
1068             case SENSOR_DELAY_UI:
1069                 delay = 60000;
1070                 break;
1071             case SENSOR_DELAY_NORMAL:
1072                 delay = 200000;
1073                 break;
1074             default:
1075                 delay = rate;
1076                 break;
1077         }
1078 
1079         synchronized (sListeners) {
1080             // look for this listener in our list
1081             ListenerDelegate l = null;
1082             for (ListenerDelegate i : sListeners) {
1083                 if (i.getListener() == listener) {
1084                     l = i;
1085                     break;
1086                 }
1087             }
1088 
1089             // if we don't find it, add it to the list
1090             if (l == null) {
1091                 l = new ListenerDelegate(listener, sensor, handler);
1092                 sListeners.add(l);
1093                 // if the list is not empty, start our main thread
1094                 if (!sListeners.isEmpty()) {
1095                     if (sSensorThread.startLocked()) {
1096                         if (!enableSensorLocked(sensor, delay)) {
1097                             // oops. there was an error
1098                             sListeners.remove(l);
1099                             result = false;
1100                         }
1101                     } else {
1102                         // there was an error, remove the listener
1103                         sListeners.remove(l);
1104                         result = false;
1105                     }
1106                 } else {
1107                     // weird, we couldn't add the listener
1108                     result = false;
1109                 }
1110             } else {
1111                 l.addSensor(sensor);
1112                 if (!enableSensorLocked(sensor, delay)) {
1113                     // oops. there was an error
1114                     l.removeSensor(sensor);
1115                     result = false;
1116                 }
1117             }
1118         }
1119 
1120         return result;
1121     }
1122 
unregisterListener(Object listener, Sensor sensor)1123     private void unregisterListener(Object listener, Sensor sensor) {
1124         if (listener == null || sensor == null) {
1125             return;
1126         }
1127 
1128         synchronized (sListeners) {
1129             final int size = sListeners.size();
1130             for (int i=0 ; i<size ; i++) {
1131                 ListenerDelegate l = sListeners.get(i);
1132                 if (l.getListener() == listener) {
1133                     if (l.removeSensor(sensor) == 0) {
1134                         // if we have no more sensors enabled on this listener,
1135                         // take it off the list.
1136                         sListeners.remove(i);
1137                     }
1138                     break;
1139                 }
1140             }
1141             disableSensorLocked(sensor);
1142         }
1143     }
1144 
unregisterListener(Object listener)1145     private void unregisterListener(Object listener) {
1146         if (listener == null) {
1147             return;
1148         }
1149 
1150         synchronized (sListeners) {
1151             final int size = sListeners.size();
1152             for (int i=0 ; i<size ; i++) {
1153                 ListenerDelegate l = sListeners.get(i);
1154                 if (l.getListener() == listener) {
1155                     sListeners.remove(i);
1156                     // disable all sensors for this listener
1157                     for (Sensor sensor : l.getSensors()) {
1158                         disableSensorLocked(sensor);
1159                     }
1160                     break;
1161                 }
1162             }
1163         }
1164     }
1165 
1166     /**
1167      * <p>
1168      * Computes the inclination matrix <b>I</b> as well as the rotation matrix
1169      * <b>R</b> transforming a vector from the device coordinate system to the
1170      * world's coordinate system which is defined as a direct orthonormal basis,
1171      * where:
1172      * </p>
1173      *
1174      * <ul>
1175      * <li>X is defined as the vector product <b>Y.Z</b> (It is tangential to
1176      * the ground at the device's current location and roughly points East).</li>
1177      * <li>Y is tangential to the ground at the device's current location and
1178      * points towards the magnetic North Pole.</li>
1179      * <li>Z points towards the sky and is perpendicular to the ground.</li>
1180      * </ul>
1181      *
1182      * <p>
1183      * <center><img src="../../../images/axis_globe.png"
1184      * alt="World coordinate-system diagram." border="0" /></center>
1185      * </p>
1186      *
1187      * <p>
1188      * <hr>
1189      * <p>
1190      * By definition:
1191      * <p>
1192      * [0 0 g] = <b>R</b> * <b>gravity</b> (g = magnitude of gravity)
1193      * <p>
1194      * [0 m 0] = <b>I</b> * <b>R</b> * <b>geomagnetic</b> (m = magnitude of
1195      * geomagnetic field)
1196      * <p>
1197      * <b>R</b> is the identity matrix when the device is aligned with the
1198      * world's coordinate system, that is, when the device's X axis points
1199      * toward East, the Y axis points to the North Pole and the device is facing
1200      * the sky.
1201      *
1202      * <p>
1203      * <b>I</b> is a rotation matrix transforming the geomagnetic vector into
1204      * the same coordinate space as gravity (the world's coordinate space).
1205      * <b>I</b> is a simple rotation around the X axis. The inclination angle in
1206      * radians can be computed with {@link #getInclination}.
1207      * <hr>
1208      *
1209      * <p>
1210      * Each matrix is returned either as a 3x3 or 4x4 row-major matrix depending
1211      * on the length of the passed array:
1212      * <p>
1213      * <u>If the array length is 16:</u>
1214      *
1215      * <pre>
1216      *   /  M[ 0]   M[ 1]   M[ 2]   M[ 3]  \
1217      *   |  M[ 4]   M[ 5]   M[ 6]   M[ 7]  |
1218      *   |  M[ 8]   M[ 9]   M[10]   M[11]  |
1219      *   \  M[12]   M[13]   M[14]   M[15]  /
1220      *</pre>
1221      *
1222      * This matrix is ready to be used by OpenGL ES's
1223      * {@link javax.microedition.khronos.opengles.GL10#glLoadMatrixf(float[], int)
1224      * glLoadMatrixf(float[], int)}.
1225      * <p>
1226      * Note that because OpenGL matrices are column-major matrices you must
1227      * transpose the matrix before using it. However, since the matrix is a
1228      * rotation matrix, its transpose is also its inverse, conveniently, it is
1229      * often the inverse of the rotation that is needed for rendering; it can
1230      * therefore be used with OpenGL ES directly.
1231      * <p>
1232      * Also note that the returned matrices always have this form:
1233      *
1234      * <pre>
1235      *   /  M[ 0]   M[ 1]   M[ 2]   0  \
1236      *   |  M[ 4]   M[ 5]   M[ 6]   0  |
1237      *   |  M[ 8]   M[ 9]   M[10]   0  |
1238      *   \      0       0       0   1  /
1239      *</pre>
1240      *
1241      * <p>
1242      * <u>If the array length is 9:</u>
1243      *
1244      * <pre>
1245      *   /  M[ 0]   M[ 1]   M[ 2]  \
1246      *   |  M[ 3]   M[ 4]   M[ 5]  |
1247      *   \  M[ 6]   M[ 7]   M[ 8]  /
1248      *</pre>
1249      *
1250      * <hr>
1251      * <p>
1252      * The inverse of each matrix can be computed easily by taking its
1253      * transpose.
1254      *
1255      * <p>
1256      * The matrices returned by this function are meaningful only when the
1257      * device is not free-falling and it is not close to the magnetic north. If
1258      * the device is accelerating, or placed into a strong magnetic field, the
1259      * returned matrices may be inaccurate.
1260      *
1261      * @param R
1262      *        is an array of 9 floats holding the rotation matrix <b>R</b> when
1263      *        this function returns. R can be null.
1264      *        <p>
1265      *
1266      * @param I
1267      *        is an array of 9 floats holding the rotation matrix <b>I</b> when
1268      *        this function returns. I can be null.
1269      *        <p>
1270      *
1271      * @param gravity
1272      *        is an array of 3 floats containing the gravity vector expressed in
1273      *        the device's coordinate. You can simply use the
1274      *        {@link android.hardware.SensorEvent#values values} returned by a
1275      *        {@link android.hardware.SensorEvent SensorEvent} of a
1276      *        {@link android.hardware.Sensor Sensor} of type
1277      *        {@link android.hardware.Sensor#TYPE_ACCELEROMETER
1278      *        TYPE_ACCELEROMETER}.
1279      *        <p>
1280      *
1281      * @param geomagnetic
1282      *        is an array of 3 floats containing the geomagnetic vector
1283      *        expressed in the device's coordinate. You can simply use the
1284      *        {@link android.hardware.SensorEvent#values values} returned by a
1285      *        {@link android.hardware.SensorEvent SensorEvent} of a
1286      *        {@link android.hardware.Sensor Sensor} of type
1287      *        {@link android.hardware.Sensor#TYPE_MAGNETIC_FIELD
1288      *        TYPE_MAGNETIC_FIELD}.
1289      *
1290      * @return <code>true</code> on success, <code>false</code> on failure (for
1291      *         instance, if the device is in free fall). On failure the output
1292      *         matrices are not modified.
1293      *
1294      * @see #getInclination(float[])
1295      * @see #getOrientation(float[], float[])
1296      * @see #remapCoordinateSystem(float[], int, int, float[])
1297      */
1298 
getRotationMatrix(float[] R, float[] I, float[] gravity, float[] geomagnetic)1299     public static boolean getRotationMatrix(float[] R, float[] I,
1300             float[] gravity, float[] geomagnetic) {
1301         // TODO: move this to native code for efficiency
1302         float Ax = gravity[0];
1303         float Ay = gravity[1];
1304         float Az = gravity[2];
1305         final float Ex = geomagnetic[0];
1306         final float Ey = geomagnetic[1];
1307         final float Ez = geomagnetic[2];
1308         float Hx = Ey*Az - Ez*Ay;
1309         float Hy = Ez*Ax - Ex*Az;
1310         float Hz = Ex*Ay - Ey*Ax;
1311         final float normH = (float)Math.sqrt(Hx*Hx + Hy*Hy + Hz*Hz);
1312         if (normH < 0.1f) {
1313             // device is close to free fall (or in space?), or close to
1314             // magnetic north pole. Typical values are  > 100.
1315             return false;
1316         }
1317         final float invH = 1.0f / normH;
1318         Hx *= invH;
1319         Hy *= invH;
1320         Hz *= invH;
1321         final float invA = 1.0f / (float)Math.sqrt(Ax*Ax + Ay*Ay + Az*Az);
1322         Ax *= invA;
1323         Ay *= invA;
1324         Az *= invA;
1325         final float Mx = Ay*Hz - Az*Hy;
1326         final float My = Az*Hx - Ax*Hz;
1327         final float Mz = Ax*Hy - Ay*Hx;
1328         if (R != null) {
1329             if (R.length == 9) {
1330                 R[0] = Hx;     R[1] = Hy;     R[2] = Hz;
1331                 R[3] = Mx;     R[4] = My;     R[5] = Mz;
1332                 R[6] = Ax;     R[7] = Ay;     R[8] = Az;
1333             } else if (R.length == 16) {
1334                 R[0]  = Hx;    R[1]  = Hy;    R[2]  = Hz;   R[3]  = 0;
1335                 R[4]  = Mx;    R[5]  = My;    R[6]  = Mz;   R[7]  = 0;
1336                 R[8]  = Ax;    R[9]  = Ay;    R[10] = Az;   R[11] = 0;
1337                 R[12] = 0;     R[13] = 0;     R[14] = 0;    R[15] = 1;
1338             }
1339         }
1340         if (I != null) {
1341             // compute the inclination matrix by projecting the geomagnetic
1342             // vector onto the Z (gravity) and X (horizontal component
1343             // of geomagnetic vector) axes.
1344             final float invE = 1.0f / (float)Math.sqrt(Ex*Ex + Ey*Ey + Ez*Ez);
1345             final float c = (Ex*Mx + Ey*My + Ez*Mz) * invE;
1346             final float s = (Ex*Ax + Ey*Ay + Ez*Az) * invE;
1347             if (I.length == 9) {
1348                 I[0] = 1;     I[1] = 0;     I[2] = 0;
1349                 I[3] = 0;     I[4] = c;     I[5] = s;
1350                 I[6] = 0;     I[7] =-s;     I[8] = c;
1351             } else if (I.length == 16) {
1352                 I[0] = 1;     I[1] = 0;     I[2] = 0;
1353                 I[4] = 0;     I[5] = c;     I[6] = s;
1354                 I[8] = 0;     I[9] =-s;     I[10]= c;
1355                 I[3] = I[7] = I[11] = I[12] = I[13] = I[14] = 0;
1356                 I[15] = 1;
1357             }
1358         }
1359         return true;
1360     }
1361 
1362     /**
1363      * Computes the geomagnetic inclination angle in radians from the
1364      * inclination matrix <b>I</b> returned by {@link #getRotationMatrix}.
1365      *
1366      * @param I
1367      *        inclination matrix see {@link #getRotationMatrix}.
1368      *
1369      * @return The geomagnetic inclination angle in radians.
1370      *
1371      * @see #getRotationMatrix(float[], float[], float[], float[])
1372      * @see #getOrientation(float[], float[])
1373      * @see GeomagneticField
1374      *
1375      */
getInclination(float[] I)1376     public static float getInclination(float[] I) {
1377         if (I.length == 9) {
1378             return (float)Math.atan2(I[5], I[4]);
1379         } else {
1380             return (float)Math.atan2(I[6], I[5]);
1381         }
1382     }
1383 
1384     /**
1385      * <p>
1386      * Rotates the supplied rotation matrix so it is expressed in a different
1387      * coordinate system. This is typically used when an application needs to
1388      * compute the three orientation angles of the device (see
1389      * {@link #getOrientation}) in a different coordinate system.
1390      * </p>
1391      *
1392      * <p>
1393      * When the rotation matrix is used for drawing (for instance with OpenGL
1394      * ES), it usually <b>doesn't need</b> to be transformed by this function,
1395      * unless the screen is physically rotated, in which case you can use
1396      * {@link android.view.Display#getRotation() Display.getRotation()} to
1397      * retrieve the current rotation of the screen. Note that because the user
1398      * is generally free to rotate their screen, you often should consider the
1399      * rotation in deciding the parameters to use here.
1400      * </p>
1401      *
1402      * <p>
1403      * <u>Examples:</u>
1404      * <p>
1405      *
1406      * <ul>
1407      * <li>Using the camera (Y axis along the camera's axis) for an augmented
1408      * reality application where the rotation angles are needed:</li>
1409      *
1410      * <p>
1411      * <ul>
1412      * <code>remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR);</code>
1413      * </ul>
1414      * </p>
1415      *
1416      * <li>Using the device as a mechanical compass when rotation is
1417      * {@link android.view.Surface#ROTATION_90 Surface.ROTATION_90}:</li>
1418      *
1419      * <p>
1420      * <ul>
1421      * <code>remapCoordinateSystem(inR, AXIS_Y, AXIS_MINUS_X, outR);</code>
1422      * </ul>
1423      * </p>
1424      *
1425      * Beware of the above example. This call is needed only to account for a
1426      * rotation from its natural orientation when calculating the rotation
1427      * angles (see {@link #getOrientation}). If the rotation matrix is also used
1428      * for rendering, it may not need to be transformed, for instance if your
1429      * {@link android.app.Activity Activity} is running in landscape mode.
1430      * </ul>
1431      *
1432      * <p>
1433      * Since the resulting coordinate system is orthonormal, only two axes need
1434      * to be specified.
1435      *
1436      * @param inR
1437      *        the rotation matrix to be transformed. Usually it is the matrix
1438      *        returned by {@link #getRotationMatrix}.
1439      *
1440      * @param X
1441      *        defines on which world axis and direction the X axis of the device
1442      *        is mapped.
1443      *
1444      * @param Y
1445      *        defines on which world axis and direction the Y axis of the device
1446      *        is mapped.
1447      *
1448      * @param outR
1449      *        the transformed rotation matrix. inR and outR can be the same
1450      *        array, but it is not recommended for performance reason.
1451      *
1452      * @return <code>true</code> on success. <code>false</code> if the input
1453      *         parameters are incorrect, for instance if X and Y define the same
1454      *         axis. Or if inR and outR don't have the same length.
1455      *
1456      * @see #getRotationMatrix(float[], float[], float[], float[])
1457      */
1458 
remapCoordinateSystem(float[] inR, int X, int Y, float[] outR)1459     public static boolean remapCoordinateSystem(float[] inR, int X, int Y,
1460             float[] outR)
1461     {
1462         if (inR == outR) {
1463             final float[] temp = mTempMatrix;
1464             synchronized(temp) {
1465                 // we don't expect to have a lot of contention
1466                 if (remapCoordinateSystemImpl(inR, X, Y, temp)) {
1467                     final int size = outR.length;
1468                     for (int i=0 ; i<size ; i++)
1469                         outR[i] = temp[i];
1470                     return true;
1471                 }
1472             }
1473         }
1474         return remapCoordinateSystemImpl(inR, X, Y, outR);
1475     }
1476 
remapCoordinateSystemImpl(float[] inR, int X, int Y, float[] outR)1477     private static boolean remapCoordinateSystemImpl(float[] inR, int X, int Y,
1478             float[] outR)
1479     {
1480         /*
1481          * X and Y define a rotation matrix 'r':
1482          *
1483          *  (X==1)?((X&0x80)?-1:1):0    (X==2)?((X&0x80)?-1:1):0    (X==3)?((X&0x80)?-1:1):0
1484          *  (Y==1)?((Y&0x80)?-1:1):0    (Y==2)?((Y&0x80)?-1:1):0    (Y==3)?((X&0x80)?-1:1):0
1485          *                              r[0] ^ r[1]
1486          *
1487          * where the 3rd line is the vector product of the first 2 lines
1488          *
1489          */
1490 
1491         final int length = outR.length;
1492         if (inR.length != length)
1493             return false;   // invalid parameter
1494         if ((X & 0x7C)!=0 || (Y & 0x7C)!=0)
1495             return false;   // invalid parameter
1496         if (((X & 0x3)==0) || ((Y & 0x3)==0))
1497             return false;   // no axis specified
1498         if ((X & 0x3) == (Y & 0x3))
1499             return false;   // same axis specified
1500 
1501         // Z is "the other" axis, its sign is either +/- sign(X)*sign(Y)
1502         // this can be calculated by exclusive-or'ing X and Y; except for
1503         // the sign inversion (+/-) which is calculated below.
1504         int Z = X ^ Y;
1505 
1506         // extract the axis (remove the sign), offset in the range 0 to 2.
1507         final int x = (X & 0x3)-1;
1508         final int y = (Y & 0x3)-1;
1509         final int z = (Z & 0x3)-1;
1510 
1511         // compute the sign of Z (whether it needs to be inverted)
1512         final int axis_y = (z+1)%3;
1513         final int axis_z = (z+2)%3;
1514         if (((x^axis_y)|(y^axis_z)) != 0)
1515             Z ^= 0x80;
1516 
1517         final boolean sx = (X>=0x80);
1518         final boolean sy = (Y>=0x80);
1519         final boolean sz = (Z>=0x80);
1520 
1521         // Perform R * r, in avoiding actual muls and adds.
1522         final int rowLength = ((length==16)?4:3);
1523         for (int j=0 ; j<3 ; j++) {
1524             final int offset = j*rowLength;
1525             for (int i=0 ; i<3 ; i++) {
1526                 if (x==i)   outR[offset+i] = sx ? -inR[offset+0] : inR[offset+0];
1527                 if (y==i)   outR[offset+i] = sy ? -inR[offset+1] : inR[offset+1];
1528                 if (z==i)   outR[offset+i] = sz ? -inR[offset+2] : inR[offset+2];
1529             }
1530         }
1531         if (length == 16) {
1532             outR[3] = outR[7] = outR[11] = outR[12] = outR[13] = outR[14] = 0;
1533             outR[15] = 1;
1534         }
1535         return true;
1536     }
1537 
1538     /**
1539      * Computes the device's orientation based on the rotation matrix.
1540      * <p>
1541      * When it returns, the array values is filled with the result:
1542      * <ul>
1543      * <li>values[0]: <i>azimuth</i>, rotation around the Z axis.</li>
1544      * <li>values[1]: <i>pitch</i>, rotation around the X axis.</li>
1545      * <li>values[2]: <i>roll</i>, rotation around the Y axis.</li>
1546      * </ul>
1547      * <p>The reference coordinate-system used is different from the world
1548      * coordinate-system defined for the rotation matrix:</p>
1549      * <ul>
1550      * <li>X is defined as the vector product <b>Y.Z</b> (It is tangential to
1551      * the ground at the device's current location and roughly points West).</li>
1552      * <li>Y is tangential to the ground at the device's current location and
1553      * points towards the magnetic North Pole.</li>
1554      * <li>Z points towards the center of the Earth and is perpendicular to the ground.</li>
1555      * </ul>
1556      *
1557      * <p>
1558      * <center><img src="../../../images/axis_globe_inverted.png"
1559      * alt="Inverted world coordinate-system diagram." border="0" /></center>
1560      * </p>
1561      * <p>
1562      * All three angles above are in <b>radians</b> and <b>positive</b> in the
1563      * <b>counter-clockwise</b> direction.
1564      *
1565      * @param R
1566      *        rotation matrix see {@link #getRotationMatrix}.
1567      *
1568      * @param values
1569      *        an array of 3 floats to hold the result.
1570      *
1571      * @return The array values passed as argument.
1572      *
1573      * @see #getRotationMatrix(float[], float[], float[], float[])
1574      * @see GeomagneticField
1575      */
getOrientation(float[] R, float values[])1576     public static float[] getOrientation(float[] R, float values[]) {
1577         /*
1578          * 4x4 (length=16) case:
1579          *   /  R[ 0]   R[ 1]   R[ 2]   0  \
1580          *   |  R[ 4]   R[ 5]   R[ 6]   0  |
1581          *   |  R[ 8]   R[ 9]   R[10]   0  |
1582          *   \      0       0       0   1  /
1583          *
1584          * 3x3 (length=9) case:
1585          *   /  R[ 0]   R[ 1]   R[ 2]  \
1586          *   |  R[ 3]   R[ 4]   R[ 5]  |
1587          *   \  R[ 6]   R[ 7]   R[ 8]  /
1588          *
1589          */
1590         if (R.length == 9) {
1591             values[0] = (float)Math.atan2(R[1], R[4]);
1592             values[1] = (float)Math.asin(-R[7]);
1593             values[2] = (float)Math.atan2(-R[6], R[8]);
1594         } else {
1595             values[0] = (float)Math.atan2(R[1], R[5]);
1596             values[1] = (float)Math.asin(-R[9]);
1597             values[2] = (float)Math.atan2(-R[8], R[10]);
1598         }
1599         return values;
1600     }
1601 
1602     /**
1603      * Computes the Altitude in meters from the atmospheric pressure and the
1604      * pressure at sea level.
1605      * <p>
1606      * Typically the atmospheric pressure is read from a
1607      * {@link Sensor#TYPE_PRESSURE} sensor. The pressure at sea level must be
1608      * known, usually it can be retrieved from airport databases in the
1609      * vicinity. If unknown, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE}
1610      * as an approximation, but absolute altitudes won't be accurate.
1611      * </p>
1612      * <p>
1613      * To calculate altitude differences, you must calculate the difference
1614      * between the altitudes at both points. If you don't know the altitude
1615      * as sea level, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} instead,
1616      * which will give good results considering the range of pressure typically
1617      * involved.
1618      * </p>
1619      * <p>
1620      * <code><ul>
1621      *  float altitude_difference =
1622      *      getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point2)
1623      *      - getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point1);
1624      * </ul></code>
1625      * </p>
1626      *
1627      * @param p0 pressure at sea level
1628      * @param p atmospheric pressure
1629      * @return Altitude in meters
1630      */
getAltitude(float p0, float p)1631    public static float getAltitude(float p0, float p) {
1632         final float coef = 1.0f / 5.255f;
1633         return 44330.0f * (1.0f - (float)Math.pow(p/p0, coef));
1634     }
1635 
1636 
1637    /**
1638      * {@hide}
1639      */
onRotationChanged(int rotation)1640     public void onRotationChanged(int rotation) {
1641         synchronized(sListeners) {
1642             sRotation  = rotation;
1643         }
1644     }
1645 
getRotation()1646     static int getRotation() {
1647         synchronized(sListeners) {
1648             return sRotation;
1649         }
1650     }
1651 
1652     private class LegacyListener implements SensorEventListener {
1653         private float mValues[] = new float[6];
1654         @SuppressWarnings("deprecation")
1655         private SensorListener mTarget;
1656         private int mSensors;
1657         private final LmsFilter mYawfilter = new LmsFilter();
1658 
1659         @SuppressWarnings("deprecation")
LegacyListener(SensorListener target)1660         LegacyListener(SensorListener target) {
1661             mTarget = target;
1662             mSensors = 0;
1663         }
1664 
registerSensor(int legacyType)1665         void registerSensor(int legacyType) {
1666             mSensors |= legacyType;
1667         }
1668 
unregisterSensor(int legacyType)1669         boolean unregisterSensor(int legacyType) {
1670             mSensors &= ~legacyType;
1671             int mask = SENSOR_ORIENTATION|SENSOR_ORIENTATION_RAW;
1672             if (((legacyType&mask)!=0) && ((mSensors&mask)!=0)) {
1673                 return false;
1674             }
1675             return true;
1676         }
1677 
1678         @SuppressWarnings("deprecation")
onAccuracyChanged(Sensor sensor, int accuracy)1679         public void onAccuracyChanged(Sensor sensor, int accuracy) {
1680             try {
1681                 mTarget.onAccuracyChanged(sensor.getLegacyType(), accuracy);
1682             } catch (AbstractMethodError e) {
1683                 // old app that doesn't implement this method
1684                 // just ignore it.
1685             }
1686         }
1687 
1688         @SuppressWarnings("deprecation")
onSensorChanged(SensorEvent event)1689         public void onSensorChanged(SensorEvent event) {
1690             final float v[] = mValues;
1691             v[0] = event.values[0];
1692             v[1] = event.values[1];
1693             v[2] = event.values[2];
1694             int legacyType = event.sensor.getLegacyType();
1695             mapSensorDataToWindow(legacyType, v, SensorManager.getRotation());
1696             if (event.sensor.getType() == Sensor.TYPE_ORIENTATION) {
1697                 if ((mSensors & SENSOR_ORIENTATION_RAW)!=0) {
1698                     mTarget.onSensorChanged(SENSOR_ORIENTATION_RAW, v);
1699                 }
1700                 if ((mSensors & SENSOR_ORIENTATION)!=0) {
1701                     v[0] = mYawfilter.filter(event.timestamp, v[0]);
1702                     mTarget.onSensorChanged(SENSOR_ORIENTATION, v);
1703                 }
1704             } else {
1705                 mTarget.onSensorChanged(legacyType, v);
1706             }
1707         }
1708 
1709         /*
1710          * Helper function to convert the specified sensor's data to the windows's
1711          * coordinate space from the device's coordinate space.
1712          *
1713          * output: 3,4,5: values in the old API format
1714          *         0,1,2: transformed values in the old API format
1715          *
1716          */
mapSensorDataToWindow(int sensor, float[] values, int orientation)1717         private void mapSensorDataToWindow(int sensor,
1718                 float[] values, int orientation) {
1719             float x = values[0];
1720             float y = values[1];
1721             float z = values[2];
1722 
1723             switch (sensor) {
1724                 case SensorManager.SENSOR_ORIENTATION:
1725                 case SensorManager.SENSOR_ORIENTATION_RAW:
1726                     z = -z;
1727                     break;
1728                 case SensorManager.SENSOR_ACCELEROMETER:
1729                     x = -x;
1730                     y = -y;
1731                     z = -z;
1732                     break;
1733                 case SensorManager.SENSOR_MAGNETIC_FIELD:
1734                     x = -x;
1735                     y = -y;
1736                     break;
1737             }
1738             values[0] = x;
1739             values[1] = y;
1740             values[2] = z;
1741             values[3] = x;
1742             values[4] = y;
1743             values[5] = z;
1744 
1745             if ((orientation & Surface.ROTATION_90) != 0) {
1746                 // handles 90 and 270 rotation
1747                 switch (sensor) {
1748                     case SENSOR_ACCELEROMETER:
1749                     case SENSOR_MAGNETIC_FIELD:
1750                         values[0] =-y;
1751                         values[1] = x;
1752                         values[2] = z;
1753                         break;
1754                     case SENSOR_ORIENTATION:
1755                     case SENSOR_ORIENTATION_RAW:
1756                         values[0] = x + ((x < 270) ? 90 : -270);
1757                         values[1] = z;
1758                         values[2] = y;
1759                         break;
1760                 }
1761             }
1762             if ((orientation & Surface.ROTATION_180) != 0) {
1763                 x = values[0];
1764                 y = values[1];
1765                 z = values[2];
1766                 // handles 180 (flip) and 270 (flip + 90) rotation
1767                 switch (sensor) {
1768                     case SENSOR_ACCELEROMETER:
1769                     case SENSOR_MAGNETIC_FIELD:
1770                         values[0] =-x;
1771                         values[1] =-y;
1772                         values[2] = z;
1773                         break;
1774                     case SENSOR_ORIENTATION:
1775                     case SENSOR_ORIENTATION_RAW:
1776                         values[0] = (x >= 180) ? (x - 180) : (x + 180);
1777                         values[1] =-y;
1778                         values[2] =-z;
1779                         break;
1780                 }
1781             }
1782         }
1783     }
1784 
1785     class LmsFilter {
1786         private static final int SENSORS_RATE_MS = 20;
1787         private static final int COUNT = 12;
1788         private static final float PREDICTION_RATIO = 1.0f/3.0f;
1789         private static final float PREDICTION_TIME = (SENSORS_RATE_MS*COUNT/1000.0f)*PREDICTION_RATIO;
1790         private float mV[] = new float[COUNT*2];
1791         private float mT[] = new float[COUNT*2];
1792         private int mIndex;
1793 
LmsFilter()1794         public LmsFilter() {
1795             mIndex = COUNT;
1796         }
1797 
filter(long time, float in)1798         public float filter(long time, float in) {
1799             float v = in;
1800             final float ns = 1.0f / 1000000000.0f;
1801             final float t = time*ns;
1802             float v1 = mV[mIndex];
1803             if ((v-v1) > 180) {
1804                 v -= 360;
1805             } else if ((v1-v) > 180) {
1806                 v += 360;
1807             }
1808             /* Manage the circular buffer, we write the data twice spaced
1809              * by COUNT values, so that we don't have to copy the array
1810              * when it's full
1811              */
1812             mIndex++;
1813             if (mIndex >= COUNT*2)
1814                 mIndex = COUNT;
1815             mV[mIndex] = v;
1816             mT[mIndex] = t;
1817             mV[mIndex-COUNT] = v;
1818             mT[mIndex-COUNT] = t;
1819 
1820             float A, B, C, D, E;
1821             float a, b;
1822             int i;
1823 
1824             A = B = C = D = E = 0;
1825             for (i=0 ; i<COUNT-1 ; i++) {
1826                 final int j = mIndex - 1 - i;
1827                 final float Z = mV[j];
1828                 final float T = 0.5f*(mT[j] + mT[j+1]) - t;
1829                 float dT = mT[j] - mT[j+1];
1830                 dT *= dT;
1831                 A += Z*dT;
1832                 B += T*(T*dT);
1833                 C +=   (T*dT);
1834                 D += Z*(T*dT);
1835                 E += dT;
1836             }
1837             b = (A*B + C*D) / (E*B + C*C);
1838             a = (E*b - A) / C;
1839             float f = b + PREDICTION_TIME*a;
1840 
1841             // Normalize
1842             f *= (1.0f / 360.0f);
1843             if (((f>=0)?f:-f) >= 0.5f)
1844                 f = f - (float)Math.ceil(f + 0.5f) + 1.0f;
1845             if (f < 0)
1846                 f += 1.0f;
1847             f *= 360.0f;
1848             return f;
1849         }
1850     }
1851 
1852 
1853     /** Helper function to compute the angle change between two rotation matrices.
1854      *  Given a current rotation matrix (R) and a previous rotation matrix
1855      *  (prevR) computes the rotation around the x,y, and z axes which
1856      *  transforms prevR to R.
1857      *  outputs a 3 element vector containing the x,y, and z angle
1858      *  change at indexes 0, 1, and 2 respectively.
1859      * <p> Each input matrix is either as a 3x3 or 4x4 row-major matrix
1860      * depending on the length of the passed array:
1861      * <p>If the array length is 9, then the array elements represent this matrix
1862      * <pre>
1863      *   /  R[ 0]   R[ 1]   R[ 2]   \
1864      *   |  R[ 3]   R[ 4]   R[ 5]   |
1865      *   \  R[ 6]   R[ 7]   R[ 8]   /
1866      *</pre>
1867      * <p>If the array length is 16, then the array elements represent this matrix
1868      * <pre>
1869      *   /  R[ 0]   R[ 1]   R[ 2]   R[ 3]  \
1870      *   |  R[ 4]   R[ 5]   R[ 6]   R[ 7]  |
1871      *   |  R[ 8]   R[ 9]   R[10]   R[11]  |
1872      *   \  R[12]   R[13]   R[14]   R[15]  /
1873      *</pre>
1874      * @param R current rotation matrix
1875      * @param prevR previous rotation matrix
1876      * @param angleChange an array of floats in which the angle change is stored
1877      */
1878 
getAngleChange( float[] angleChange, float[] R, float[] prevR)1879     public static void getAngleChange( float[] angleChange, float[] R, float[] prevR) {
1880         float rd1=0,rd4=0, rd6=0,rd7=0, rd8=0;
1881         float ri0=0,ri1=0,ri2=0,ri3=0,ri4=0,ri5=0,ri6=0,ri7=0,ri8=0;
1882         float pri0=0, pri1=0, pri2=0, pri3=0, pri4=0, pri5=0, pri6=0, pri7=0, pri8=0;
1883         int i, j, k;
1884 
1885         if(R.length == 9) {
1886             ri0 = R[0];
1887             ri1 = R[1];
1888             ri2 = R[2];
1889             ri3 = R[3];
1890             ri4 = R[4];
1891             ri5 = R[5];
1892             ri6 = R[6];
1893             ri7 = R[7];
1894             ri8 = R[8];
1895         } else if(R.length == 16) {
1896             ri0 = R[0];
1897             ri1 = R[1];
1898             ri2 = R[2];
1899             ri3 = R[4];
1900             ri4 = R[5];
1901             ri5 = R[6];
1902             ri6 = R[8];
1903             ri7 = R[9];
1904             ri8 = R[10];
1905         }
1906 
1907         if(prevR.length == 9) {
1908             pri0 = prevR[0];
1909             pri1 = prevR[1];
1910             pri2 = prevR[2];
1911             pri3 = prevR[3];
1912             pri4 = prevR[4];
1913             pri5 = prevR[5];
1914             pri6 = prevR[6];
1915             pri7 = prevR[7];
1916             pri8 = prevR[8];
1917         } else if(prevR.length == 16) {
1918             pri0 = prevR[0];
1919             pri1 = prevR[1];
1920             pri2 = prevR[2];
1921             pri3 = prevR[4];
1922             pri4 = prevR[5];
1923             pri5 = prevR[6];
1924             pri6 = prevR[8];
1925             pri7 = prevR[9];
1926             pri8 = prevR[10];
1927         }
1928 
1929         // calculate the parts of the rotation difference matrix we need
1930         // rd[i][j] = pri[0][i] * ri[0][j] + pri[1][i] * ri[1][j] + pri[2][i] * ri[2][j];
1931 
1932         rd1 = pri0 * ri1 + pri3 * ri4 + pri6 * ri7; //rd[0][1]
1933         rd4 = pri1 * ri1 + pri4 * ri4 + pri7 * ri7; //rd[1][1]
1934         rd6 = pri2 * ri0 + pri5 * ri3 + pri8 * ri6; //rd[2][0]
1935         rd7 = pri2 * ri1 + pri5 * ri4 + pri8 * ri7; //rd[2][1]
1936         rd8 = pri2 * ri2 + pri5 * ri5 + pri8 * ri8; //rd[2][2]
1937 
1938         angleChange[0] = (float)Math.atan2(rd1, rd4);
1939         angleChange[1] = (float)Math.asin(-rd7);
1940         angleChange[2] = (float)Math.atan2(-rd6, rd8);
1941 
1942     }
1943 
1944     /** Helper function to convert a rotation vector to a rotation matrix.
1945      *  Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a
1946      *  9  or 16 element rotation matrix in the array R.  R must have length 9 or 16.
1947      *  If R.length == 9, the following matrix is returned:
1948      * <pre>
1949      *   /  R[ 0]   R[ 1]   R[ 2]   \
1950      *   |  R[ 3]   R[ 4]   R[ 5]   |
1951      *   \  R[ 6]   R[ 7]   R[ 8]   /
1952      *</pre>
1953      * If R.length == 16, the following matrix is returned:
1954      * <pre>
1955      *   /  R[ 0]   R[ 1]   R[ 2]   0  \
1956      *   |  R[ 4]   R[ 5]   R[ 6]   0  |
1957      *   |  R[ 8]   R[ 9]   R[10]   0  |
1958      *   \  0       0       0       1  /
1959      *</pre>
1960      *  @param rotationVector the rotation vector to convert
1961      *  @param R an array of floats in which to store the rotation matrix
1962      */
getRotationMatrixFromVector(float[] R, float[] rotationVector)1963     public static void getRotationMatrixFromVector(float[] R, float[] rotationVector) {
1964 
1965         float q0;
1966         float q1 = rotationVector[0];
1967         float q2 = rotationVector[1];
1968         float q3 = rotationVector[2];
1969 
1970         if (rotationVector.length == 4) {
1971             q0 = rotationVector[3];
1972         } else {
1973             q0 = 1 - q1*q1 - q2*q2 - q3*q3;
1974             q0 = (q0 > 0) ? (float)Math.sqrt(q0) : 0;
1975         }
1976 
1977         float sq_q1 = 2 * q1 * q1;
1978         float sq_q2 = 2 * q2 * q2;
1979         float sq_q3 = 2 * q3 * q3;
1980         float q1_q2 = 2 * q1 * q2;
1981         float q3_q0 = 2 * q3 * q0;
1982         float q1_q3 = 2 * q1 * q3;
1983         float q2_q0 = 2 * q2 * q0;
1984         float q2_q3 = 2 * q2 * q3;
1985         float q1_q0 = 2 * q1 * q0;
1986 
1987         if(R.length == 9) {
1988             R[0] = 1 - sq_q2 - sq_q3;
1989             R[1] = q1_q2 - q3_q0;
1990             R[2] = q1_q3 + q2_q0;
1991 
1992             R[3] = q1_q2 + q3_q0;
1993             R[4] = 1 - sq_q1 - sq_q3;
1994             R[5] = q2_q3 - q1_q0;
1995 
1996             R[6] = q1_q3 - q2_q0;
1997             R[7] = q2_q3 + q1_q0;
1998             R[8] = 1 - sq_q1 - sq_q2;
1999         } else if (R.length == 16) {
2000             R[0] = 1 - sq_q2 - sq_q3;
2001             R[1] = q1_q2 - q3_q0;
2002             R[2] = q1_q3 + q2_q0;
2003             R[3] = 0.0f;
2004 
2005             R[4] = q1_q2 + q3_q0;
2006             R[5] = 1 - sq_q1 - sq_q3;
2007             R[6] = q2_q3 - q1_q0;
2008             R[7] = 0.0f;
2009 
2010             R[8] = q1_q3 - q2_q0;
2011             R[9] = q2_q3 + q1_q0;
2012             R[10] = 1 - sq_q1 - sq_q2;
2013             R[11] = 0.0f;
2014 
2015             R[12] = R[13] = R[14] = 0.0f;
2016             R[15] = 1.0f;
2017         }
2018     }
2019 
2020     /** Helper function to convert a rotation vector to a normalized quaternion.
2021      *  Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a normalized
2022      *  quaternion in the array Q.  The quaternion is stored as [w, x, y, z]
2023      *  @param rv the rotation vector to convert
2024      *  @param Q an array of floats in which to store the computed quaternion
2025      */
getQuaternionFromVector(float[] Q, float[] rv)2026     public static void getQuaternionFromVector(float[] Q, float[] rv) {
2027         if (rv.length == 4) {
2028             Q[0] = rv[3];
2029         } else {
2030             Q[0] = 1 - rv[0]*rv[0] - rv[1]*rv[1] - rv[2]*rv[2];
2031             Q[0] = (Q[0] > 0) ? (float)Math.sqrt(Q[0]) : 0;
2032         }
2033         Q[1] = rv[0];
2034         Q[2] = rv[1];
2035         Q[3] = rv[2];
2036     }
2037 
nativeClassInit()2038     private static native void nativeClassInit();
2039 
sensors_module_init()2040     private static native int sensors_module_init();
sensors_module_get_next_sensor(Sensor sensor, int next)2041     private static native int sensors_module_get_next_sensor(Sensor sensor, int next);
2042 
2043     // Used within this module from outside SensorManager, don't make private
sensors_create_queue()2044     static native int sensors_create_queue();
sensors_destroy_queue(int queue)2045     static native void sensors_destroy_queue(int queue);
sensors_enable_sensor(int queue, String name, int sensor, int enable)2046     static native boolean sensors_enable_sensor(int queue, String name, int sensor, int enable);
sensors_data_poll(int queue, float[] values, int[] status, long[] timestamp)2047     static native int sensors_data_poll(int queue, float[] values, int[] status, long[] timestamp);
2048 }
2049