| /* |
| * Copyright (C) 2008 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.hardware; |
| |
| import android.os.Handler; |
| import android.util.Log; |
| import android.util.SparseArray; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| |
| /** |
| * <p> |
| * SensorManager lets you access the device's {@link android.hardware.Sensor |
| * sensors}. Get an instance of this class by calling |
| * {@link android.content.Context#getSystemService(java.lang.String) |
| * Context.getSystemService()} with the argument |
| * {@link android.content.Context#SENSOR_SERVICE}. |
| * </p> |
| * <p> |
| * Always make sure to disable sensors you don't need, especially when your |
| * activity is paused. Failing to do so can drain the battery in just a few |
| * hours. Note that the system will <i>not</i> disable sensors automatically when |
| * the screen turns off. |
| * </p> |
| * |
| * <pre class="prettyprint"> |
| * public class SensorActivity extends Activity, implements SensorEventListener { |
| * private final SensorManager mSensorManager; |
| * private final Sensor mAccelerometer; |
| * |
| * public SensorActivity() { |
| * mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE); |
| * mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); |
| * } |
| * |
| * protected void onResume() { |
| * super.onResume(); |
| * mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL); |
| * } |
| * |
| * protected void onPause() { |
| * super.onPause(); |
| * mSensorManager.unregisterListener(this); |
| * } |
| * |
| * public void onAccuracyChanged(Sensor sensor, int accuracy) { |
| * } |
| * |
| * public void onSensorChanged(SensorEvent event) { |
| * } |
| * } |
| * </pre> |
| * |
| * @see SensorEventListener |
| * @see SensorEvent |
| * @see Sensor |
| * |
| */ |
| public abstract class SensorManager { |
| /** @hide */ |
| protected static final String TAG = "SensorManager"; |
| |
| private static final float[] mTempMatrix = new float[16]; |
| |
| // Cached lists of sensors by type. Guarded by mSensorListByType. |
| private final SparseArray<List<Sensor>> mSensorListByType = |
| new SparseArray<List<Sensor>>(); |
| |
| // Legacy sensor manager implementation. Guarded by mSensorListByType during initialization. |
| private LegacySensorManager mLegacySensorManager; |
| |
| /* NOTE: sensor IDs must be a power of 2 */ |
| |
| /** |
| * A constant describing an orientation sensor. See |
| * {@link android.hardware.SensorListener SensorListener} for more details. |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_ORIENTATION = 1 << 0; |
| |
| /** |
| * A constant describing an accelerometer. See |
| * {@link android.hardware.SensorListener SensorListener} for more details. |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_ACCELEROMETER = 1 << 1; |
| |
| /** |
| * A constant describing a temperature sensor See |
| * {@link android.hardware.SensorListener SensorListener} for more details. |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_TEMPERATURE = 1 << 2; |
| |
| /** |
| * A constant describing a magnetic sensor See |
| * {@link android.hardware.SensorListener SensorListener} for more details. |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_MAGNETIC_FIELD = 1 << 3; |
| |
| /** |
| * A constant describing an ambient light sensor See |
| * {@link android.hardware.SensorListener SensorListener} for more details. |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_LIGHT = 1 << 4; |
| |
| /** |
| * A constant describing a proximity sensor See |
| * {@link android.hardware.SensorListener SensorListener} for more details. |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_PROXIMITY = 1 << 5; |
| |
| /** |
| * A constant describing a Tricorder See |
| * {@link android.hardware.SensorListener SensorListener} for more details. |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_TRICORDER = 1 << 6; |
| |
| /** |
| * A constant describing an orientation sensor. See |
| * {@link android.hardware.SensorListener SensorListener} for more details. |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_ORIENTATION_RAW = 1 << 7; |
| |
| /** |
| * A constant that includes all sensors |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_ALL = 0x7F; |
| |
| /** |
| * Smallest sensor ID |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_MIN = SENSOR_ORIENTATION; |
| |
| /** |
| * Largest sensor ID |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int SENSOR_MAX = ((SENSOR_ALL + 1)>>1); |
| |
| |
| /** |
| * Index of the X value in the array returned by |
| * {@link android.hardware.SensorListener#onSensorChanged} |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int DATA_X = 0; |
| |
| /** |
| * Index of the Y value in the array returned by |
| * {@link android.hardware.SensorListener#onSensorChanged} |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int DATA_Y = 1; |
| |
| /** |
| * Index of the Z value in the array returned by |
| * {@link android.hardware.SensorListener#onSensorChanged} |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int DATA_Z = 2; |
| |
| /** |
| * Offset to the untransformed values in the array returned by |
| * {@link android.hardware.SensorListener#onSensorChanged} |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int RAW_DATA_INDEX = 3; |
| |
| /** |
| * Index of the untransformed X value in the array returned by |
| * {@link android.hardware.SensorListener#onSensorChanged} |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int RAW_DATA_X = 3; |
| |
| /** |
| * Index of the untransformed Y value in the array returned by |
| * {@link android.hardware.SensorListener#onSensorChanged} |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int RAW_DATA_Y = 4; |
| |
| /** |
| * Index of the untransformed Z value in the array returned by |
| * {@link android.hardware.SensorListener#onSensorChanged} |
| * |
| * @deprecated use {@link android.hardware.Sensor Sensor} instead. |
| */ |
| @Deprecated |
| public static final int RAW_DATA_Z = 5; |
| |
| /** Standard gravity (g) on Earth. This value is equivalent to 1G */ |
| public static final float STANDARD_GRAVITY = 9.80665f; |
| |
| /** Sun's gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_SUN = 275.0f; |
| /** Mercury's gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_MERCURY = 3.70f; |
| /** Venus' gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_VENUS = 8.87f; |
| /** Earth's gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_EARTH = 9.80665f; |
| /** The Moon's gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_MOON = 1.6f; |
| /** Mars' gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_MARS = 3.71f; |
| /** Jupiter's gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_JUPITER = 23.12f; |
| /** Saturn's gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_SATURN = 8.96f; |
| /** Uranus' gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_URANUS = 8.69f; |
| /** Neptune's gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_NEPTUNE = 11.0f; |
| /** Pluto's gravity in SI units (m/s^2) */ |
| public static final float GRAVITY_PLUTO = 0.6f; |
| /** Gravity (estimate) on the first Death Star in Empire units (m/s^2) */ |
| public static final float GRAVITY_DEATH_STAR_I = 0.000000353036145f; |
| /** Gravity on the island */ |
| public static final float GRAVITY_THE_ISLAND = 4.815162342f; |
| |
| |
| /** Maximum magnetic field on Earth's surface */ |
| public static final float MAGNETIC_FIELD_EARTH_MAX = 60.0f; |
| /** Minimum magnetic field on Earth's surface */ |
| public static final float MAGNETIC_FIELD_EARTH_MIN = 30.0f; |
| |
| |
| /** Standard atmosphere, or average sea-level pressure in hPa (millibar) */ |
| public static final float PRESSURE_STANDARD_ATMOSPHERE = 1013.25f; |
| |
| |
| /** Maximum luminance of sunlight in lux */ |
| public static final float LIGHT_SUNLIGHT_MAX = 120000.0f; |
| /** luminance of sunlight in lux */ |
| public static final float LIGHT_SUNLIGHT = 110000.0f; |
| /** luminance in shade in lux */ |
| public static final float LIGHT_SHADE = 20000.0f; |
| /** luminance under an overcast sky in lux */ |
| public static final float LIGHT_OVERCAST = 10000.0f; |
| /** luminance at sunrise in lux */ |
| public static final float LIGHT_SUNRISE = 400.0f; |
| /** luminance under a cloudy sky in lux */ |
| public static final float LIGHT_CLOUDY = 100.0f; |
| /** luminance at night with full moon in lux */ |
| public static final float LIGHT_FULLMOON = 0.25f; |
| /** luminance at night with no moon in lux*/ |
| public static final float LIGHT_NO_MOON = 0.001f; |
| |
| |
| /** get sensor data as fast as possible */ |
| public static final int SENSOR_DELAY_FASTEST = 0; |
| /** rate suitable for games */ |
| public static final int SENSOR_DELAY_GAME = 1; |
| /** rate suitable for the user interface */ |
| public static final int SENSOR_DELAY_UI = 2; |
| /** rate (default) suitable for screen orientation changes */ |
| public static final int SENSOR_DELAY_NORMAL = 3; |
| |
| |
| /** |
| * The values returned by this sensor cannot be trusted, calibration is |
| * needed or the environment doesn't allow readings |
| */ |
| public static final int SENSOR_STATUS_UNRELIABLE = 0; |
| |
| /** |
| * This sensor is reporting data with low accuracy, calibration with the |
| * environment is needed |
| */ |
| public static final int SENSOR_STATUS_ACCURACY_LOW = 1; |
| |
| /** |
| * This sensor is reporting data with an average level of accuracy, |
| * calibration with the environment may improve the readings |
| */ |
| public static final int SENSOR_STATUS_ACCURACY_MEDIUM = 2; |
| |
| /** This sensor is reporting data with maximum accuracy */ |
| public static final int SENSOR_STATUS_ACCURACY_HIGH = 3; |
| |
| /** see {@link #remapCoordinateSystem} */ |
| public static final int AXIS_X = 1; |
| /** see {@link #remapCoordinateSystem} */ |
| public static final int AXIS_Y = 2; |
| /** see {@link #remapCoordinateSystem} */ |
| public static final int AXIS_Z = 3; |
| /** see {@link #remapCoordinateSystem} */ |
| public static final int AXIS_MINUS_X = AXIS_X | 0x80; |
| /** see {@link #remapCoordinateSystem} */ |
| public static final int AXIS_MINUS_Y = AXIS_Y | 0x80; |
| /** see {@link #remapCoordinateSystem} */ |
| public static final int AXIS_MINUS_Z = AXIS_Z | 0x80; |
| |
| |
| /** |
| * {@hide} |
| */ |
| public SensorManager() { |
| } |
| |
| /** |
| * Gets the full list of sensors that are available. |
| * @hide |
| */ |
| protected abstract List<Sensor> getFullSensorList(); |
| |
| /** |
| * @return available sensors. |
| * @deprecated This method is deprecated, use |
| * {@link SensorManager#getSensorList(int)} instead |
| */ |
| @Deprecated |
| public int getSensors() { |
| return getLegacySensorManager().getSensors(); |
| } |
| |
| /** |
| * Use this method to get the list of available sensors of a certain type. |
| * Make multiple calls to get sensors of different types or use |
| * {@link android.hardware.Sensor#TYPE_ALL Sensor.TYPE_ALL} to get all the |
| * sensors. |
| * |
| * @param type |
| * of sensors requested |
| * |
| * @return a list of sensors matching the asked type. |
| * |
| * @see #getDefaultSensor(int) |
| * @see Sensor |
| */ |
| public List<Sensor> getSensorList(int type) { |
| // cache the returned lists the first time |
| List<Sensor> list; |
| final List<Sensor> fullList = getFullSensorList(); |
| synchronized (mSensorListByType) { |
| list = mSensorListByType.get(type); |
| if (list == null) { |
| if (type == Sensor.TYPE_ALL) { |
| list = fullList; |
| } else { |
| list = new ArrayList<Sensor>(); |
| for (Sensor i : fullList) { |
| if (i.getType() == type) |
| list.add(i); |
| } |
| } |
| list = Collections.unmodifiableList(list); |
| mSensorListByType.append(type, list); |
| } |
| } |
| return list; |
| } |
| |
| /** |
| * Use this method to get the default sensor for a given type. Note that the |
| * returned sensor could be a composite sensor, and its data could be |
| * averaged or filtered. If you need to access the raw sensors use |
| * {@link SensorManager#getSensorList(int) getSensorList}. |
| * |
| * @param type |
| * of sensors requested |
| * |
| * @return the default sensors matching the asked type. |
| * |
| * @see #getSensorList(int) |
| * @see Sensor |
| */ |
| public Sensor getDefaultSensor(int type) { |
| // TODO: need to be smarter, for now, just return the 1st sensor |
| List<Sensor> l = getSensorList(type); |
| return l.isEmpty() ? null : l.get(0); |
| } |
| |
| /** |
| * Registers a listener for given sensors. |
| * |
| * @deprecated This method is deprecated, use |
| * {@link SensorManager#registerListener(SensorEventListener, Sensor, int)} |
| * instead. |
| * |
| * @param listener |
| * sensor listener object |
| * |
| * @param sensors |
| * a bit masks of the sensors to register to |
| * |
| * @return <code>true</code> if the sensor is supported and successfully |
| * enabled |
| */ |
| @Deprecated |
| public boolean registerListener(SensorListener listener, int sensors) { |
| return registerListener(listener, sensors, SENSOR_DELAY_NORMAL); |
| } |
| |
| /** |
| * Registers a SensorListener for given sensors. |
| * |
| * @deprecated This method is deprecated, use |
| * {@link SensorManager#registerListener(SensorEventListener, Sensor, int)} |
| * instead. |
| * |
| * @param listener |
| * sensor listener object |
| * |
| * @param sensors |
| * a bit masks of the sensors to register to |
| * |
| * @param rate |
| * rate of events. This is only a hint to the system. events may be |
| * received faster or slower than the specified rate. Usually events |
| * are received faster. The value must be one of |
| * {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI}, |
| * {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}. |
| * |
| * @return <code>true</code> if the sensor is supported and successfully |
| * enabled |
| */ |
| @Deprecated |
| public boolean registerListener(SensorListener listener, int sensors, int rate) { |
| return getLegacySensorManager().registerListener(listener, sensors, rate); |
| } |
| |
| /** |
| * Unregisters a listener for all sensors. |
| * |
| * @deprecated This method is deprecated, use |
| * {@link SensorManager#unregisterListener(SensorEventListener)} |
| * instead. |
| * |
| * @param listener |
| * a SensorListener object |
| */ |
| @Deprecated |
| public void unregisterListener(SensorListener listener) { |
| unregisterListener(listener, SENSOR_ALL | SENSOR_ORIENTATION_RAW); |
| } |
| |
| /** |
| * Unregisters a listener for the sensors with which it is registered. |
| * |
| * @deprecated This method is deprecated, use |
| * {@link SensorManager#unregisterListener(SensorEventListener, Sensor)} |
| * instead. |
| * |
| * @param listener |
| * a SensorListener object |
| * |
| * @param sensors |
| * a bit masks of the sensors to unregister from |
| */ |
| @Deprecated |
| public void unregisterListener(SensorListener listener, int sensors) { |
| getLegacySensorManager().unregisterListener(listener, sensors); |
| } |
| |
| /** |
| * Unregisters a listener for the sensors with which it is registered. |
| * |
| * @param listener |
| * a SensorEventListener object |
| * |
| * @param sensor |
| * the sensor to unregister from |
| * |
| * @see #unregisterListener(SensorEventListener) |
| * @see #registerListener(SensorEventListener, Sensor, int) |
| * |
| */ |
| public void unregisterListener(SensorEventListener listener, Sensor sensor) { |
| if (listener == null || sensor == null) { |
| return; |
| } |
| |
| unregisterListenerImpl(listener, sensor); |
| } |
| |
| /** |
| * Unregisters a listener for all sensors. |
| * |
| * @param listener |
| * a SensorListener object |
| * |
| * @see #unregisterListener(SensorEventListener, Sensor) |
| * @see #registerListener(SensorEventListener, Sensor, int) |
| * |
| */ |
| public void unregisterListener(SensorEventListener listener) { |
| if (listener == null) { |
| return; |
| } |
| |
| unregisterListenerImpl(listener, null); |
| } |
| |
| /** @hide */ |
| protected abstract void unregisterListenerImpl(SensorEventListener listener, Sensor sensor); |
| |
| /** |
| * Registers a {@link android.hardware.SensorEventListener |
| * SensorEventListener} for the given sensor. |
| * |
| * @param listener |
| * A {@link android.hardware.SensorEventListener SensorEventListener} |
| * object. |
| * |
| * @param sensor |
| * The {@link android.hardware.Sensor Sensor} to register to. |
| * |
| * @param rate |
| * The rate {@link android.hardware.SensorEvent sensor events} are |
| * delivered at. This is only a hint to the system. Events may be |
| * received faster or slower than the specified rate. Usually events |
| * are received faster. The value must be one of |
| * {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI}, |
| * {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST} |
| * or, the desired delay between events in microsecond. |
| * |
| * @return <code>true</code> if the sensor is supported and successfully |
| * enabled. |
| * |
| * @see #registerListener(SensorEventListener, Sensor, int, Handler) |
| * @see #unregisterListener(SensorEventListener) |
| * @see #unregisterListener(SensorEventListener, Sensor) |
| * |
| */ |
| public boolean registerListener(SensorEventListener listener, Sensor sensor, int rate) { |
| return registerListener(listener, sensor, rate, null); |
| } |
| |
| /** |
| * Registers a {@link android.hardware.SensorEventListener |
| * SensorEventListener} for the given sensor. |
| * |
| * @param listener |
| * A {@link android.hardware.SensorEventListener SensorEventListener} |
| * object. |
| * |
| * @param sensor |
| * The {@link android.hardware.Sensor Sensor} to register to. |
| * |
| * @param rate |
| * The rate {@link android.hardware.SensorEvent sensor events} are |
| * delivered at. This is only a hint to the system. Events may be |
| * received faster or slower than the specified rate. Usually events |
| * are received faster. The value must be one of |
| * {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI}, |
| * {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}. |
| * or, the desired delay between events in microsecond. |
| * |
| * @param handler |
| * The {@link android.os.Handler Handler} the |
| * {@link android.hardware.SensorEvent sensor events} will be |
| * delivered to. |
| * |
| * @return true if the sensor is supported and successfully enabled. |
| * |
| * @see #registerListener(SensorEventListener, Sensor, int) |
| * @see #unregisterListener(SensorEventListener) |
| * @see #unregisterListener(SensorEventListener, Sensor) |
| * |
| */ |
| public boolean registerListener(SensorEventListener listener, Sensor sensor, int rate, |
| Handler handler) { |
| if (listener == null || sensor == null) { |
| return false; |
| } |
| |
| int delay = -1; |
| switch (rate) { |
| case SENSOR_DELAY_FASTEST: |
| delay = 0; |
| break; |
| case SENSOR_DELAY_GAME: |
| delay = 20000; |
| break; |
| case SENSOR_DELAY_UI: |
| delay = 66667; |
| break; |
| case SENSOR_DELAY_NORMAL: |
| delay = 200000; |
| break; |
| default: |
| delay = rate; |
| break; |
| } |
| |
| return registerListenerImpl(listener, sensor, delay, handler); |
| } |
| |
| /** @hide */ |
| protected abstract boolean registerListenerImpl(SensorEventListener listener, Sensor sensor, |
| int delay, Handler handler); |
| |
| /** |
| * <p> |
| * Computes the inclination matrix <b>I</b> as well as the rotation matrix |
| * <b>R</b> transforming a vector from the device coordinate system to the |
| * world's coordinate system which is defined as a direct orthonormal basis, |
| * where: |
| * </p> |
| * |
| * <ul> |
| * <li>X is defined as the vector product <b>Y.Z</b> (It is tangential to |
| * the ground at the device's current location and roughly points East).</li> |
| * <li>Y is tangential to the ground at the device's current location and |
| * points towards the magnetic North Pole.</li> |
| * <li>Z points towards the sky and is perpendicular to the ground.</li> |
| * </ul> |
| * |
| * <p> |
| * <center><img src="../../../images/axis_globe.png" |
| * alt="World coordinate-system diagram." border="0" /></center> |
| * </p> |
| * |
| * <p> |
| * <hr> |
| * <p> |
| * By definition: |
| * <p> |
| * [0 0 g] = <b>R</b> * <b>gravity</b> (g = magnitude of gravity) |
| * <p> |
| * [0 m 0] = <b>I</b> * <b>R</b> * <b>geomagnetic</b> (m = magnitude of |
| * geomagnetic field) |
| * <p> |
| * <b>R</b> is the identity matrix when the device is aligned with the |
| * world's coordinate system, that is, when the device's X axis points |
| * toward East, the Y axis points to the North Pole and the device is facing |
| * the sky. |
| * |
| * <p> |
| * <b>I</b> is a rotation matrix transforming the geomagnetic vector into |
| * the same coordinate space as gravity (the world's coordinate space). |
| * <b>I</b> is a simple rotation around the X axis. The inclination angle in |
| * radians can be computed with {@link #getInclination}. |
| * <hr> |
| * |
| * <p> |
| * Each matrix is returned either as a 3x3 or 4x4 row-major matrix depending |
| * on the length of the passed array: |
| * <p> |
| * <u>If the array length is 16:</u> |
| * |
| * <pre> |
| * / M[ 0] M[ 1] M[ 2] M[ 3] \ |
| * | M[ 4] M[ 5] M[ 6] M[ 7] | |
| * | M[ 8] M[ 9] M[10] M[11] | |
| * \ M[12] M[13] M[14] M[15] / |
| *</pre> |
| * |
| * This matrix is ready to be used by OpenGL ES's |
| * {@link javax.microedition.khronos.opengles.GL10#glLoadMatrixf(float[], int) |
| * glLoadMatrixf(float[], int)}. |
| * <p> |
| * Note that because OpenGL matrices are column-major matrices you must |
| * transpose the matrix before using it. However, since the matrix is a |
| * rotation matrix, its transpose is also its inverse, conveniently, it is |
| * often the inverse of the rotation that is needed for rendering; it can |
| * therefore be used with OpenGL ES directly. |
| * <p> |
| * Also note that the returned matrices always have this form: |
| * |
| * <pre> |
| * / M[ 0] M[ 1] M[ 2] 0 \ |
| * | M[ 4] M[ 5] M[ 6] 0 | |
| * | M[ 8] M[ 9] M[10] 0 | |
| * \ 0 0 0 1 / |
| *</pre> |
| * |
| * <p> |
| * <u>If the array length is 9:</u> |
| * |
| * <pre> |
| * / M[ 0] M[ 1] M[ 2] \ |
| * | M[ 3] M[ 4] M[ 5] | |
| * \ M[ 6] M[ 7] M[ 8] / |
| *</pre> |
| * |
| * <hr> |
| * <p> |
| * The inverse of each matrix can be computed easily by taking its |
| * transpose. |
| * |
| * <p> |
| * The matrices returned by this function are meaningful only when the |
| * device is not free-falling and it is not close to the magnetic north. If |
| * the device is accelerating, or placed into a strong magnetic field, the |
| * returned matrices may be inaccurate. |
| * |
| * @param R |
| * is an array of 9 floats holding the rotation matrix <b>R</b> when |
| * this function returns. R can be null. |
| * <p> |
| * |
| * @param I |
| * is an array of 9 floats holding the rotation matrix <b>I</b> when |
| * this function returns. I can be null. |
| * <p> |
| * |
| * @param gravity |
| * is an array of 3 floats containing the gravity vector expressed in |
| * the device's coordinate. You can simply use the |
| * {@link android.hardware.SensorEvent#values values} returned by a |
| * {@link android.hardware.SensorEvent SensorEvent} of a |
| * {@link android.hardware.Sensor Sensor} of type |
| * {@link android.hardware.Sensor#TYPE_ACCELEROMETER |
| * TYPE_ACCELEROMETER}. |
| * <p> |
| * |
| * @param geomagnetic |
| * is an array of 3 floats containing the geomagnetic vector |
| * expressed in the device's coordinate. You can simply use the |
| * {@link android.hardware.SensorEvent#values values} returned by a |
| * {@link android.hardware.SensorEvent SensorEvent} of a |
| * {@link android.hardware.Sensor Sensor} of type |
| * {@link android.hardware.Sensor#TYPE_MAGNETIC_FIELD |
| * TYPE_MAGNETIC_FIELD}. |
| * |
| * @return <code>true</code> on success, <code>false</code> on failure (for |
| * instance, if the device is in free fall). On failure the output |
| * matrices are not modified. |
| * |
| * @see #getInclination(float[]) |
| * @see #getOrientation(float[], float[]) |
| * @see #remapCoordinateSystem(float[], int, int, float[]) |
| */ |
| |
| public static boolean getRotationMatrix(float[] R, float[] I, |
| float[] gravity, float[] geomagnetic) { |
| // TODO: move this to native code for efficiency |
| float Ax = gravity[0]; |
| float Ay = gravity[1]; |
| float Az = gravity[2]; |
| final float Ex = geomagnetic[0]; |
| final float Ey = geomagnetic[1]; |
| final float Ez = geomagnetic[2]; |
| float Hx = Ey*Az - Ez*Ay; |
| float Hy = Ez*Ax - Ex*Az; |
| float Hz = Ex*Ay - Ey*Ax; |
| final float normH = (float)Math.sqrt(Hx*Hx + Hy*Hy + Hz*Hz); |
| if (normH < 0.1f) { |
| // device is close to free fall (or in space?), or close to |
| // magnetic north pole. Typical values are > 100. |
| return false; |
| } |
| final float invH = 1.0f / normH; |
| Hx *= invH; |
| Hy *= invH; |
| Hz *= invH; |
| final float invA = 1.0f / (float)Math.sqrt(Ax*Ax + Ay*Ay + Az*Az); |
| Ax *= invA; |
| Ay *= invA; |
| Az *= invA; |
| final float Mx = Ay*Hz - Az*Hy; |
| final float My = Az*Hx - Ax*Hz; |
| final float Mz = Ax*Hy - Ay*Hx; |
| if (R != null) { |
| if (R.length == 9) { |
| R[0] = Hx; R[1] = Hy; R[2] = Hz; |
| R[3] = Mx; R[4] = My; R[5] = Mz; |
| R[6] = Ax; R[7] = Ay; R[8] = Az; |
| } else if (R.length == 16) { |
| R[0] = Hx; R[1] = Hy; R[2] = Hz; R[3] = 0; |
| R[4] = Mx; R[5] = My; R[6] = Mz; R[7] = 0; |
| R[8] = Ax; R[9] = Ay; R[10] = Az; R[11] = 0; |
| R[12] = 0; R[13] = 0; R[14] = 0; R[15] = 1; |
| } |
| } |
| if (I != null) { |
| // compute the inclination matrix by projecting the geomagnetic |
| // vector onto the Z (gravity) and X (horizontal component |
| // of geomagnetic vector) axes. |
| final float invE = 1.0f / (float)Math.sqrt(Ex*Ex + Ey*Ey + Ez*Ez); |
| final float c = (Ex*Mx + Ey*My + Ez*Mz) * invE; |
| final float s = (Ex*Ax + Ey*Ay + Ez*Az) * invE; |
| if (I.length == 9) { |
| I[0] = 1; I[1] = 0; I[2] = 0; |
| I[3] = 0; I[4] = c; I[5] = s; |
| I[6] = 0; I[7] =-s; I[8] = c; |
| } else if (I.length == 16) { |
| I[0] = 1; I[1] = 0; I[2] = 0; |
| I[4] = 0; I[5] = c; I[6] = s; |
| I[8] = 0; I[9] =-s; I[10]= c; |
| I[3] = I[7] = I[11] = I[12] = I[13] = I[14] = 0; |
| I[15] = 1; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Computes the geomagnetic inclination angle in radians from the |
| * inclination matrix <b>I</b> returned by {@link #getRotationMatrix}. |
| * |
| * @param I |
| * inclination matrix see {@link #getRotationMatrix}. |
| * |
| * @return The geomagnetic inclination angle in radians. |
| * |
| * @see #getRotationMatrix(float[], float[], float[], float[]) |
| * @see #getOrientation(float[], float[]) |
| * @see GeomagneticField |
| * |
| */ |
| public static float getInclination(float[] I) { |
| if (I.length == 9) { |
| return (float)Math.atan2(I[5], I[4]); |
| } else { |
| return (float)Math.atan2(I[6], I[5]); |
| } |
| } |
| |
| /** |
| * <p> |
| * Rotates the supplied rotation matrix so it is expressed in a different |
| * coordinate system. This is typically used when an application needs to |
| * compute the three orientation angles of the device (see |
| * {@link #getOrientation}) in a different coordinate system. |
| * </p> |
| * |
| * <p> |
| * When the rotation matrix is used for drawing (for instance with OpenGL |
| * ES), it usually <b>doesn't need</b> to be transformed by this function, |
| * unless the screen is physically rotated, in which case you can use |
| * {@link android.view.Display#getRotation() Display.getRotation()} to |
| * retrieve the current rotation of the screen. Note that because the user |
| * is generally free to rotate their screen, you often should consider the |
| * rotation in deciding the parameters to use here. |
| * </p> |
| * |
| * <p> |
| * <u>Examples:</u> |
| * <p> |
| * |
| * <ul> |
| * <li>Using the camera (Y axis along the camera's axis) for an augmented |
| * reality application where the rotation angles are needed:</li> |
| * |
| * <p> |
| * <ul> |
| * <code>remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR);</code> |
| * </ul> |
| * </p> |
| * |
| * <li>Using the device as a mechanical compass when rotation is |
| * {@link android.view.Surface#ROTATION_90 Surface.ROTATION_90}:</li> |
| * |
| * <p> |
| * <ul> |
| * <code>remapCoordinateSystem(inR, AXIS_Y, AXIS_MINUS_X, outR);</code> |
| * </ul> |
| * </p> |
| * |
| * Beware of the above example. This call is needed only to account for a |
| * rotation from its natural orientation when calculating the rotation |
| * angles (see {@link #getOrientation}). If the rotation matrix is also used |
| * for rendering, it may not need to be transformed, for instance if your |
| * {@link android.app.Activity Activity} is running in landscape mode. |
| * </ul> |
| * |
| * <p> |
| * Since the resulting coordinate system is orthonormal, only two axes need |
| * to be specified. |
| * |
| * @param inR |
| * the rotation matrix to be transformed. Usually it is the matrix |
| * returned by {@link #getRotationMatrix}. |
| * |
| * @param X |
| * defines on which world axis and direction the X axis of the device |
| * is mapped. |
| * |
| * @param Y |
| * defines on which world axis and direction the Y axis of the device |
| * is mapped. |
| * |
| * @param outR |
| * the transformed rotation matrix. inR and outR can be the same |
| * array, but it is not recommended for performance reason. |
| * |
| * @return <code>true</code> on success. <code>false</code> if the input |
| * parameters are incorrect, for instance if X and Y define the same |
| * axis. Or if inR and outR don't have the same length. |
| * |
| * @see #getRotationMatrix(float[], float[], float[], float[]) |
| */ |
| |
| public static boolean remapCoordinateSystem(float[] inR, int X, int Y, |
| float[] outR) |
| { |
| if (inR == outR) { |
| final float[] temp = mTempMatrix; |
| synchronized(temp) { |
| // we don't expect to have a lot of contention |
| if (remapCoordinateSystemImpl(inR, X, Y, temp)) { |
| final int size = outR.length; |
| for (int i=0 ; i<size ; i++) |
| outR[i] = temp[i]; |
| return true; |
| } |
| } |
| } |
| return remapCoordinateSystemImpl(inR, X, Y, outR); |
| } |
| |
| private static boolean remapCoordinateSystemImpl(float[] inR, int X, int Y, |
| float[] outR) |
| { |
| /* |
| * X and Y define a rotation matrix 'r': |
| * |
| * (X==1)?((X&0x80)?-1:1):0 (X==2)?((X&0x80)?-1:1):0 (X==3)?((X&0x80)?-1:1):0 |
| * (Y==1)?((Y&0x80)?-1:1):0 (Y==2)?((Y&0x80)?-1:1):0 (Y==3)?((X&0x80)?-1:1):0 |
| * r[0] ^ r[1] |
| * |
| * where the 3rd line is the vector product of the first 2 lines |
| * |
| */ |
| |
| final int length = outR.length; |
| if (inR.length != length) |
| return false; // invalid parameter |
| if ((X & 0x7C)!=0 || (Y & 0x7C)!=0) |
| return false; // invalid parameter |
| if (((X & 0x3)==0) || ((Y & 0x3)==0)) |
| return false; // no axis specified |
| if ((X & 0x3) == (Y & 0x3)) |
| return false; // same axis specified |
| |
| // Z is "the other" axis, its sign is either +/- sign(X)*sign(Y) |
| // this can be calculated by exclusive-or'ing X and Y; except for |
| // the sign inversion (+/-) which is calculated below. |
| int Z = X ^ Y; |
| |
| // extract the axis (remove the sign), offset in the range 0 to 2. |
| final int x = (X & 0x3)-1; |
| final int y = (Y & 0x3)-1; |
| final int z = (Z & 0x3)-1; |
| |
| // compute the sign of Z (whether it needs to be inverted) |
| final int axis_y = (z+1)%3; |
| final int axis_z = (z+2)%3; |
| if (((x^axis_y)|(y^axis_z)) != 0) |
| Z ^= 0x80; |
| |
| final boolean sx = (X>=0x80); |
| final boolean sy = (Y>=0x80); |
| final boolean sz = (Z>=0x80); |
| |
| // Perform R * r, in avoiding actual muls and adds. |
| final int rowLength = ((length==16)?4:3); |
| for (int j=0 ; j<3 ; j++) { |
| final int offset = j*rowLength; |
| for (int i=0 ; i<3 ; i++) { |
| if (x==i) outR[offset+i] = sx ? -inR[offset+0] : inR[offset+0]; |
| if (y==i) outR[offset+i] = sy ? -inR[offset+1] : inR[offset+1]; |
| if (z==i) outR[offset+i] = sz ? -inR[offset+2] : inR[offset+2]; |
| } |
| } |
| if (length == 16) { |
| outR[3] = outR[7] = outR[11] = outR[12] = outR[13] = outR[14] = 0; |
| outR[15] = 1; |
| } |
| return true; |
| } |
| |
| /** |
| * Computes the device's orientation based on the rotation matrix. |
| * <p> |
| * When it returns, the array values is filled with the result: |
| * <ul> |
| * <li>values[0]: <i>azimuth</i>, rotation around the Z axis.</li> |
| * <li>values[1]: <i>pitch</i>, rotation around the X axis.</li> |
| * <li>values[2]: <i>roll</i>, rotation around the Y axis.</li> |
| * </ul> |
| * <p>The reference coordinate-system used is different from the world |
| * coordinate-system defined for the rotation matrix:</p> |
| * <ul> |
| * <li>X is defined as the vector product <b>Y.Z</b> (It is tangential to |
| * the ground at the device's current location and roughly points West).</li> |
| * <li>Y is tangential to the ground at the device's current location and |
| * points towards the magnetic North Pole.</li> |
| * <li>Z points towards the center of the Earth and is perpendicular to the ground.</li> |
| * </ul> |
| * |
| * <p> |
| * <center><img src="../../../images/axis_globe_inverted.png" |
| * alt="Inverted world coordinate-system diagram." border="0" /></center> |
| * </p> |
| * <p> |
| * All three angles above are in <b>radians</b> and <b>positive</b> in the |
| * <b>counter-clockwise</b> direction. |
| * |
| * @param R |
| * rotation matrix see {@link #getRotationMatrix}. |
| * |
| * @param values |
| * an array of 3 floats to hold the result. |
| * |
| * @return The array values passed as argument. |
| * |
| * @see #getRotationMatrix(float[], float[], float[], float[]) |
| * @see GeomagneticField |
| */ |
| public static float[] getOrientation(float[] R, float values[]) { |
| /* |
| * 4x4 (length=16) case: |
| * / R[ 0] R[ 1] R[ 2] 0 \ |
| * | R[ 4] R[ 5] R[ 6] 0 | |
| * | R[ 8] R[ 9] R[10] 0 | |
| * \ 0 0 0 1 / |
| * |
| * 3x3 (length=9) case: |
| * / R[ 0] R[ 1] R[ 2] \ |
| * | R[ 3] R[ 4] R[ 5] | |
| * \ R[ 6] R[ 7] R[ 8] / |
| * |
| */ |
| if (R.length == 9) { |
| values[0] = (float)Math.atan2(R[1], R[4]); |
| values[1] = (float)Math.asin(-R[7]); |
| values[2] = (float)Math.atan2(-R[6], R[8]); |
| } else { |
| values[0] = (float)Math.atan2(R[1], R[5]); |
| values[1] = (float)Math.asin(-R[9]); |
| values[2] = (float)Math.atan2(-R[8], R[10]); |
| } |
| return values; |
| } |
| |
| /** |
| * Computes the Altitude in meters from the atmospheric pressure and the |
| * pressure at sea level. |
| * <p> |
| * Typically the atmospheric pressure is read from a |
| * {@link Sensor#TYPE_PRESSURE} sensor. The pressure at sea level must be |
| * known, usually it can be retrieved from airport databases in the |
| * vicinity. If unknown, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} |
| * as an approximation, but absolute altitudes won't be accurate. |
| * </p> |
| * <p> |
| * To calculate altitude differences, you must calculate the difference |
| * between the altitudes at both points. If you don't know the altitude |
| * as sea level, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} instead, |
| * which will give good results considering the range of pressure typically |
| * involved. |
| * </p> |
| * <p> |
| * <code><ul> |
| * float altitude_difference = |
| * getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point2) |
| * - getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point1); |
| * </ul></code> |
| * </p> |
| * |
| * @param p0 pressure at sea level |
| * @param p atmospheric pressure |
| * @return Altitude in meters |
| */ |
| public static float getAltitude(float p0, float p) { |
| final float coef = 1.0f / 5.255f; |
| return 44330.0f * (1.0f - (float)Math.pow(p/p0, coef)); |
| } |
| |
| /** Helper function to compute the angle change between two rotation matrices. |
| * Given a current rotation matrix (R) and a previous rotation matrix |
| * (prevR) computes the rotation around the z,x, and y axes which |
| * transforms prevR to R. |
| * outputs a 3 element vector containing the z,x, and y angle |
| * change at indexes 0, 1, and 2 respectively. |
| * <p> Each input matrix is either as a 3x3 or 4x4 row-major matrix |
| * depending on the length of the passed array: |
| * <p>If the array length is 9, then the array elements represent this matrix |
| * <pre> |
| * / R[ 0] R[ 1] R[ 2] \ |
| * | R[ 3] R[ 4] R[ 5] | |
| * \ R[ 6] R[ 7] R[ 8] / |
| *</pre> |
| * <p>If the array length is 16, then the array elements represent this matrix |
| * <pre> |
| * / R[ 0] R[ 1] R[ 2] R[ 3] \ |
| * | R[ 4] R[ 5] R[ 6] R[ 7] | |
| * | R[ 8] R[ 9] R[10] R[11] | |
| * \ R[12] R[13] R[14] R[15] / |
| *</pre> |
| * @param R current rotation matrix |
| * @param prevR previous rotation matrix |
| * @param angleChange an an array of floats (z, x, and y) in which the angle change is stored |
| */ |
| |
| public static void getAngleChange( float[] angleChange, float[] R, float[] prevR) { |
| float rd1=0,rd4=0, rd6=0,rd7=0, rd8=0; |
| float ri0=0,ri1=0,ri2=0,ri3=0,ri4=0,ri5=0,ri6=0,ri7=0,ri8=0; |
| float pri0=0, pri1=0, pri2=0, pri3=0, pri4=0, pri5=0, pri6=0, pri7=0, pri8=0; |
| |
| if(R.length == 9) { |
| ri0 = R[0]; |
| ri1 = R[1]; |
| ri2 = R[2]; |
| ri3 = R[3]; |
| ri4 = R[4]; |
| ri5 = R[5]; |
| ri6 = R[6]; |
| ri7 = R[7]; |
| ri8 = R[8]; |
| } else if(R.length == 16) { |
| ri0 = R[0]; |
| ri1 = R[1]; |
| ri2 = R[2]; |
| ri3 = R[4]; |
| ri4 = R[5]; |
| ri5 = R[6]; |
| ri6 = R[8]; |
| ri7 = R[9]; |
| ri8 = R[10]; |
| } |
| |
| if(prevR.length == 9) { |
| pri0 = prevR[0]; |
| pri1 = prevR[1]; |
| pri2 = prevR[2]; |
| pri3 = prevR[3]; |
| pri4 = prevR[4]; |
| pri5 = prevR[5]; |
| pri6 = prevR[6]; |
| pri7 = prevR[7]; |
| pri8 = prevR[8]; |
| } else if(prevR.length == 16) { |
| pri0 = prevR[0]; |
| pri1 = prevR[1]; |
| pri2 = prevR[2]; |
| pri3 = prevR[4]; |
| pri4 = prevR[5]; |
| pri5 = prevR[6]; |
| pri6 = prevR[8]; |
| pri7 = prevR[9]; |
| pri8 = prevR[10]; |
| } |
| |
| // calculate the parts of the rotation difference matrix we need |
| // rd[i][j] = pri[0][i] * ri[0][j] + pri[1][i] * ri[1][j] + pri[2][i] * ri[2][j]; |
| |
| rd1 = pri0 * ri1 + pri3 * ri4 + pri6 * ri7; //rd[0][1] |
| rd4 = pri1 * ri1 + pri4 * ri4 + pri7 * ri7; //rd[1][1] |
| rd6 = pri2 * ri0 + pri5 * ri3 + pri8 * ri6; //rd[2][0] |
| rd7 = pri2 * ri1 + pri5 * ri4 + pri8 * ri7; //rd[2][1] |
| rd8 = pri2 * ri2 + pri5 * ri5 + pri8 * ri8; //rd[2][2] |
| |
| angleChange[0] = (float)Math.atan2(rd1, rd4); |
| angleChange[1] = (float)Math.asin(-rd7); |
| angleChange[2] = (float)Math.atan2(-rd6, rd8); |
| |
| } |
| |
| /** Helper function to convert a rotation vector to a rotation matrix. |
| * Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a |
| * 9 or 16 element rotation matrix in the array R. R must have length 9 or 16. |
| * If R.length == 9, the following matrix is returned: |
| * <pre> |
| * / R[ 0] R[ 1] R[ 2] \ |
| * | R[ 3] R[ 4] R[ 5] | |
| * \ R[ 6] R[ 7] R[ 8] / |
| *</pre> |
| * If R.length == 16, the following matrix is returned: |
| * <pre> |
| * / R[ 0] R[ 1] R[ 2] 0 \ |
| * | R[ 4] R[ 5] R[ 6] 0 | |
| * | R[ 8] R[ 9] R[10] 0 | |
| * \ 0 0 0 1 / |
| *</pre> |
| * @param rotationVector the rotation vector to convert |
| * @param R an array of floats in which to store the rotation matrix |
| */ |
| public static void getRotationMatrixFromVector(float[] R, float[] rotationVector) { |
| |
| float q0; |
| float q1 = rotationVector[0]; |
| float q2 = rotationVector[1]; |
| float q3 = rotationVector[2]; |
| |
| if (rotationVector.length == 4) { |
| q0 = rotationVector[3]; |
| } else { |
| q0 = 1 - q1*q1 - q2*q2 - q3*q3; |
| q0 = (q0 > 0) ? (float)Math.sqrt(q0) : 0; |
| } |
| |
| float sq_q1 = 2 * q1 * q1; |
| float sq_q2 = 2 * q2 * q2; |
| float sq_q3 = 2 * q3 * q3; |
| float q1_q2 = 2 * q1 * q2; |
| float q3_q0 = 2 * q3 * q0; |
| float q1_q3 = 2 * q1 * q3; |
| float q2_q0 = 2 * q2 * q0; |
| float q2_q3 = 2 * q2 * q3; |
| float q1_q0 = 2 * q1 * q0; |
| |
| if(R.length == 9) { |
| R[0] = 1 - sq_q2 - sq_q3; |
| R[1] = q1_q2 - q3_q0; |
| R[2] = q1_q3 + q2_q0; |
| |
| R[3] = q1_q2 + q3_q0; |
| R[4] = 1 - sq_q1 - sq_q3; |
| R[5] = q2_q3 - q1_q0; |
| |
| R[6] = q1_q3 - q2_q0; |
| R[7] = q2_q3 + q1_q0; |
| R[8] = 1 - sq_q1 - sq_q2; |
| } else if (R.length == 16) { |
| R[0] = 1 - sq_q2 - sq_q3; |
| R[1] = q1_q2 - q3_q0; |
| R[2] = q1_q3 + q2_q0; |
| R[3] = 0.0f; |
| |
| R[4] = q1_q2 + q3_q0; |
| R[5] = 1 - sq_q1 - sq_q3; |
| R[6] = q2_q3 - q1_q0; |
| R[7] = 0.0f; |
| |
| R[8] = q1_q3 - q2_q0; |
| R[9] = q2_q3 + q1_q0; |
| R[10] = 1 - sq_q1 - sq_q2; |
| R[11] = 0.0f; |
| |
| R[12] = R[13] = R[14] = 0.0f; |
| R[15] = 1.0f; |
| } |
| } |
| |
| /** Helper function to convert a rotation vector to a normalized quaternion. |
| * Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a normalized |
| * quaternion in the array Q. The quaternion is stored as [w, x, y, z] |
| * @param rv the rotation vector to convert |
| * @param Q an array of floats in which to store the computed quaternion |
| */ |
| public static void getQuaternionFromVector(float[] Q, float[] rv) { |
| if (rv.length == 4) { |
| Q[0] = rv[3]; |
| } else { |
| Q[0] = 1 - rv[0]*rv[0] - rv[1]*rv[1] - rv[2]*rv[2]; |
| Q[0] = (Q[0] > 0) ? (float)Math.sqrt(Q[0]) : 0; |
| } |
| Q[1] = rv[0]; |
| Q[2] = rv[1]; |
| Q[3] = rv[2]; |
| } |
| |
| private LegacySensorManager getLegacySensorManager() { |
| synchronized (mSensorListByType) { |
| if (mLegacySensorManager == null) { |
| Log.i(TAG, "This application is using deprecated SensorManager API which will " |
| + "be removed someday. Please consider switching to the new API."); |
| mLegacySensorManager = new LegacySensorManager(this); |
| } |
| return mLegacySensorManager; |
| } |
| } |
| } |