SensorManager.java revision 4481d9c10ceaf3b886fb5cab1d20941932af5b0f
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 17package android.hardware; 18 19import android.os.Handler; 20import android.util.Log; 21import android.util.SparseArray; 22 23import java.util.ArrayList; 24import java.util.Collections; 25import java.util.List; 26 27/** 28 * <p> 29 * SensorManager lets you access the device's {@link android.hardware.Sensor 30 * sensors}. Get an instance of this class by calling 31 * {@link android.content.Context#getSystemService(java.lang.String) 32 * Context.getSystemService()} with the argument 33 * {@link android.content.Context#SENSOR_SERVICE}. 34 * </p> 35 * <p> 36 * Always make sure to disable sensors you don't need, especially when your 37 * activity is paused. Failing to do so can drain the battery in just a few 38 * hours. Note that the system will <i>not</i> disable sensors automatically when 39 * the screen turns off. 40 * </p> 41 * 42 * <pre class="prettyprint"> 43 * public class SensorActivity extends Activity, implements SensorEventListener { 44 * private final SensorManager mSensorManager; 45 * private final Sensor mAccelerometer; 46 * 47 * public SensorActivity() { 48 * mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE); 49 * mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); 50 * } 51 * 52 * protected void onResume() { 53 * super.onResume(); 54 * mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL); 55 * } 56 * 57 * protected void onPause() { 58 * super.onPause(); 59 * mSensorManager.unregisterListener(this); 60 * } 61 * 62 * public void onAccuracyChanged(Sensor sensor, int accuracy) { 63 * } 64 * 65 * public void onSensorChanged(SensorEvent event) { 66 * } 67 * } 68 * </pre> 69 * 70 * @see SensorEventListener 71 * @see SensorEvent 72 * @see Sensor 73 * 74 */ 75public abstract class SensorManager { 76 /** @hide */ 77 protected static final String TAG = "SensorManager"; 78 79 private static final float[] mTempMatrix = new float[16]; 80 81 // Cached lists of sensors by type. Guarded by mSensorListByType. 82 private final SparseArray<List<Sensor>> mSensorListByType = 83 new SparseArray<List<Sensor>>(); 84 85 // Legacy sensor manager implementation. Guarded by mSensorListByType during initialization. 86 private LegacySensorManager mLegacySensorManager; 87 88 /* NOTE: sensor IDs must be a power of 2 */ 89 90 /** 91 * A constant describing an orientation sensor. See 92 * {@link android.hardware.SensorListener SensorListener} for more details. 93 * 94 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 95 */ 96 @Deprecated 97 public static final int SENSOR_ORIENTATION = 1 << 0; 98 99 /** 100 * A constant describing an accelerometer. See 101 * {@link android.hardware.SensorListener SensorListener} for more details. 102 * 103 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 104 */ 105 @Deprecated 106 public static final int SENSOR_ACCELEROMETER = 1 << 1; 107 108 /** 109 * A constant describing a temperature sensor See 110 * {@link android.hardware.SensorListener SensorListener} for more details. 111 * 112 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 113 */ 114 @Deprecated 115 public static final int SENSOR_TEMPERATURE = 1 << 2; 116 117 /** 118 * A constant describing a magnetic sensor See 119 * {@link android.hardware.SensorListener SensorListener} for more details. 120 * 121 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 122 */ 123 @Deprecated 124 public static final int SENSOR_MAGNETIC_FIELD = 1 << 3; 125 126 /** 127 * A constant describing an ambient light sensor See 128 * {@link android.hardware.SensorListener SensorListener} for more details. 129 * 130 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 131 */ 132 @Deprecated 133 public static final int SENSOR_LIGHT = 1 << 4; 134 135 /** 136 * A constant describing a proximity sensor See 137 * {@link android.hardware.SensorListener SensorListener} for more details. 138 * 139 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 140 */ 141 @Deprecated 142 public static final int SENSOR_PROXIMITY = 1 << 5; 143 144 /** 145 * A constant describing a Tricorder See 146 * {@link android.hardware.SensorListener SensorListener} for more details. 147 * 148 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 149 */ 150 @Deprecated 151 public static final int SENSOR_TRICORDER = 1 << 6; 152 153 /** 154 * A constant describing an orientation sensor. See 155 * {@link android.hardware.SensorListener SensorListener} for more details. 156 * 157 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 158 */ 159 @Deprecated 160 public static final int SENSOR_ORIENTATION_RAW = 1 << 7; 161 162 /** 163 * A constant that includes all sensors 164 * 165 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 166 */ 167 @Deprecated 168 public static final int SENSOR_ALL = 0x7F; 169 170 /** 171 * Smallest sensor ID 172 * 173 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 174 */ 175 @Deprecated 176 public static final int SENSOR_MIN = SENSOR_ORIENTATION; 177 178 /** 179 * Largest sensor ID 180 * 181 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 182 */ 183 @Deprecated 184 public static final int SENSOR_MAX = ((SENSOR_ALL + 1)>>1); 185 186 187 /** 188 * Index of the X value in the array returned by 189 * {@link android.hardware.SensorListener#onSensorChanged} 190 * 191 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 192 */ 193 @Deprecated 194 public static final int DATA_X = 0; 195 196 /** 197 * Index of the Y value in the array returned by 198 * {@link android.hardware.SensorListener#onSensorChanged} 199 * 200 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 201 */ 202 @Deprecated 203 public static final int DATA_Y = 1; 204 205 /** 206 * Index of the Z value in the array returned by 207 * {@link android.hardware.SensorListener#onSensorChanged} 208 * 209 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 210 */ 211 @Deprecated 212 public static final int DATA_Z = 2; 213 214 /** 215 * Offset to the untransformed values in the array returned by 216 * {@link android.hardware.SensorListener#onSensorChanged} 217 * 218 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 219 */ 220 @Deprecated 221 public static final int RAW_DATA_INDEX = 3; 222 223 /** 224 * Index of the untransformed X value in the array returned by 225 * {@link android.hardware.SensorListener#onSensorChanged} 226 * 227 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 228 */ 229 @Deprecated 230 public static final int RAW_DATA_X = 3; 231 232 /** 233 * Index of the untransformed Y value in the array returned by 234 * {@link android.hardware.SensorListener#onSensorChanged} 235 * 236 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 237 */ 238 @Deprecated 239 public static final int RAW_DATA_Y = 4; 240 241 /** 242 * Index of the untransformed Z value in the array returned by 243 * {@link android.hardware.SensorListener#onSensorChanged} 244 * 245 * @deprecated use {@link android.hardware.Sensor Sensor} instead. 246 */ 247 @Deprecated 248 public static final int RAW_DATA_Z = 5; 249 250 /** Standard gravity (g) on Earth. This value is equivalent to 1G */ 251 public static final float STANDARD_GRAVITY = 9.80665f; 252 253 /** Sun's gravity in SI units (m/s^2) */ 254 public static final float GRAVITY_SUN = 275.0f; 255 /** Mercury's gravity in SI units (m/s^2) */ 256 public static final float GRAVITY_MERCURY = 3.70f; 257 /** Venus' gravity in SI units (m/s^2) */ 258 public static final float GRAVITY_VENUS = 8.87f; 259 /** Earth's gravity in SI units (m/s^2) */ 260 public static final float GRAVITY_EARTH = 9.80665f; 261 /** The Moon's gravity in SI units (m/s^2) */ 262 public static final float GRAVITY_MOON = 1.6f; 263 /** Mars' gravity in SI units (m/s^2) */ 264 public static final float GRAVITY_MARS = 3.71f; 265 /** Jupiter's gravity in SI units (m/s^2) */ 266 public static final float GRAVITY_JUPITER = 23.12f; 267 /** Saturn's gravity in SI units (m/s^2) */ 268 public static final float GRAVITY_SATURN = 8.96f; 269 /** Uranus' gravity in SI units (m/s^2) */ 270 public static final float GRAVITY_URANUS = 8.69f; 271 /** Neptune's gravity in SI units (m/s^2) */ 272 public static final float GRAVITY_NEPTUNE = 11.0f; 273 /** Pluto's gravity in SI units (m/s^2) */ 274 public static final float GRAVITY_PLUTO = 0.6f; 275 /** Gravity (estimate) on the first Death Star in Empire units (m/s^2) */ 276 public static final float GRAVITY_DEATH_STAR_I = 0.000000353036145f; 277 /** Gravity on the island */ 278 public static final float GRAVITY_THE_ISLAND = 4.815162342f; 279 280 281 /** Maximum magnetic field on Earth's surface */ 282 public static final float MAGNETIC_FIELD_EARTH_MAX = 60.0f; 283 /** Minimum magnetic field on Earth's surface */ 284 public static final float MAGNETIC_FIELD_EARTH_MIN = 30.0f; 285 286 287 /** Standard atmosphere, or average sea-level pressure in hPa (millibar) */ 288 public static final float PRESSURE_STANDARD_ATMOSPHERE = 1013.25f; 289 290 291 /** Maximum luminance of sunlight in lux */ 292 public static final float LIGHT_SUNLIGHT_MAX = 120000.0f; 293 /** luminance of sunlight in lux */ 294 public static final float LIGHT_SUNLIGHT = 110000.0f; 295 /** luminance in shade in lux */ 296 public static final float LIGHT_SHADE = 20000.0f; 297 /** luminance under an overcast sky in lux */ 298 public static final float LIGHT_OVERCAST = 10000.0f; 299 /** luminance at sunrise in lux */ 300 public static final float LIGHT_SUNRISE = 400.0f; 301 /** luminance under a cloudy sky in lux */ 302 public static final float LIGHT_CLOUDY = 100.0f; 303 /** luminance at night with full moon in lux */ 304 public static final float LIGHT_FULLMOON = 0.25f; 305 /** luminance at night with no moon in lux*/ 306 public static final float LIGHT_NO_MOON = 0.001f; 307 308 309 /** get sensor data as fast as possible */ 310 public static final int SENSOR_DELAY_FASTEST = 0; 311 /** rate suitable for games */ 312 public static final int SENSOR_DELAY_GAME = 1; 313 /** rate suitable for the user interface */ 314 public static final int SENSOR_DELAY_UI = 2; 315 /** rate (default) suitable for screen orientation changes */ 316 public static final int SENSOR_DELAY_NORMAL = 3; 317 318 319 /** 320 * The values returned by this sensor cannot be trusted, calibration is 321 * needed or the environment doesn't allow readings 322 */ 323 public static final int SENSOR_STATUS_UNRELIABLE = 0; 324 325 /** 326 * This sensor is reporting data with low accuracy, calibration with the 327 * environment is needed 328 */ 329 public static final int SENSOR_STATUS_ACCURACY_LOW = 1; 330 331 /** 332 * This sensor is reporting data with an average level of accuracy, 333 * calibration with the environment may improve the readings 334 */ 335 public static final int SENSOR_STATUS_ACCURACY_MEDIUM = 2; 336 337 /** This sensor is reporting data with maximum accuracy */ 338 public static final int SENSOR_STATUS_ACCURACY_HIGH = 3; 339 340 /** see {@link #remapCoordinateSystem} */ 341 public static final int AXIS_X = 1; 342 /** see {@link #remapCoordinateSystem} */ 343 public static final int AXIS_Y = 2; 344 /** see {@link #remapCoordinateSystem} */ 345 public static final int AXIS_Z = 3; 346 /** see {@link #remapCoordinateSystem} */ 347 public static final int AXIS_MINUS_X = AXIS_X | 0x80; 348 /** see {@link #remapCoordinateSystem} */ 349 public static final int AXIS_MINUS_Y = AXIS_Y | 0x80; 350 /** see {@link #remapCoordinateSystem} */ 351 public static final int AXIS_MINUS_Z = AXIS_Z | 0x80; 352 353 354 /** 355 * {@hide} 356 */ 357 public SensorManager() { 358 } 359 360 /** 361 * Gets the full list of sensors that are available. 362 * @hide 363 */ 364 protected abstract List<Sensor> getFullSensorList(); 365 366 /** 367 * @return available sensors. 368 * @deprecated This method is deprecated, use 369 * {@link SensorManager#getSensorList(int)} instead 370 */ 371 @Deprecated 372 public int getSensors() { 373 return getLegacySensorManager().getSensors(); 374 } 375 376 /** 377 * Use this method to get the list of available sensors of a certain type. 378 * Make multiple calls to get sensors of different types or use 379 * {@link android.hardware.Sensor#TYPE_ALL Sensor.TYPE_ALL} to get all the 380 * sensors. 381 * 382 * @param type 383 * of sensors requested 384 * 385 * @return a list of sensors matching the asked type. 386 * 387 * @see #getDefaultSensor(int) 388 * @see Sensor 389 */ 390 public List<Sensor> getSensorList(int type) { 391 // cache the returned lists the first time 392 List<Sensor> list; 393 final List<Sensor> fullList = getFullSensorList(); 394 synchronized (mSensorListByType) { 395 list = mSensorListByType.get(type); 396 if (list == null) { 397 if (type == Sensor.TYPE_ALL) { 398 list = fullList; 399 } else { 400 list = new ArrayList<Sensor>(); 401 for (Sensor i : fullList) { 402 if (i.getType() == type) 403 list.add(i); 404 } 405 } 406 list = Collections.unmodifiableList(list); 407 mSensorListByType.append(type, list); 408 } 409 } 410 return list; 411 } 412 413 /** 414 * Use this method to get the default sensor for a given type. Note that the 415 * returned sensor could be a composite sensor, and its data could be 416 * averaged or filtered. If you need to access the raw sensors use 417 * {@link SensorManager#getSensorList(int) getSensorList}. 418 * 419 * @param type 420 * of sensors requested 421 * 422 * @return the default sensors matching the asked type. 423 * 424 * @see #getSensorList(int) 425 * @see Sensor 426 */ 427 public Sensor getDefaultSensor(int type) { 428 // TODO: need to be smarter, for now, just return the 1st sensor 429 List<Sensor> l = getSensorList(type); 430 return l.isEmpty() ? null : l.get(0); 431 } 432 433 /** 434 * Registers a listener for given sensors. 435 * 436 * @deprecated This method is deprecated, use 437 * {@link SensorManager#registerListener(SensorEventListener, Sensor, int)} 438 * instead. 439 * 440 * @param listener 441 * sensor listener object 442 * 443 * @param sensors 444 * a bit masks of the sensors to register to 445 * 446 * @return <code>true</code> if the sensor is supported and successfully 447 * enabled 448 */ 449 @Deprecated 450 public boolean registerListener(SensorListener listener, int sensors) { 451 return registerListener(listener, sensors, SENSOR_DELAY_NORMAL); 452 } 453 454 /** 455 * Registers a SensorListener for given sensors. 456 * 457 * @deprecated This method is deprecated, use 458 * {@link SensorManager#registerListener(SensorEventListener, Sensor, int)} 459 * instead. 460 * 461 * @param listener 462 * sensor listener object 463 * 464 * @param sensors 465 * a bit masks of the sensors to register to 466 * 467 * @param rate 468 * rate of events. This is only a hint to the system. events may be 469 * received faster or slower than the specified rate. Usually events 470 * are received faster. The value must be one of 471 * {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI}, 472 * {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}. 473 * 474 * @return <code>true</code> if the sensor is supported and successfully 475 * enabled 476 */ 477 @Deprecated 478 public boolean registerListener(SensorListener listener, int sensors, int rate) { 479 return getLegacySensorManager().registerListener(listener, sensors, rate); 480 } 481 482 /** 483 * Unregisters a listener for all sensors. 484 * 485 * @deprecated This method is deprecated, use 486 * {@link SensorManager#unregisterListener(SensorEventListener)} 487 * instead. 488 * 489 * @param listener 490 * a SensorListener object 491 */ 492 @Deprecated 493 public void unregisterListener(SensorListener listener) { 494 unregisterListener(listener, SENSOR_ALL | SENSOR_ORIENTATION_RAW); 495 } 496 497 /** 498 * Unregisters a listener for the sensors with which it is registered. 499 * 500 * @deprecated This method is deprecated, use 501 * {@link SensorManager#unregisterListener(SensorEventListener, Sensor)} 502 * instead. 503 * 504 * @param listener 505 * a SensorListener object 506 * 507 * @param sensors 508 * a bit masks of the sensors to unregister from 509 */ 510 @Deprecated 511 public void unregisterListener(SensorListener listener, int sensors) { 512 getLegacySensorManager().unregisterListener(listener, sensors); 513 } 514 515 /** 516 * Unregisters a listener for the sensors with which it is registered. 517 * 518 * @param listener 519 * a SensorEventListener object 520 * 521 * @param sensor 522 * the sensor to unregister from 523 * 524 * @see #unregisterListener(SensorEventListener) 525 * @see #registerListener(SensorEventListener, Sensor, int) 526 * 527 */ 528 public void unregisterListener(SensorEventListener listener, Sensor sensor) { 529 if (listener == null || sensor == null) { 530 return; 531 } 532 533 unregisterListenerImpl(listener, sensor); 534 } 535 536 /** 537 * Unregisters a listener for all sensors. 538 * 539 * @param listener 540 * a SensorListener object 541 * 542 * @see #unregisterListener(SensorEventListener, Sensor) 543 * @see #registerListener(SensorEventListener, Sensor, int) 544 * 545 */ 546 public void unregisterListener(SensorEventListener listener) { 547 if (listener == null) { 548 return; 549 } 550 551 unregisterListenerImpl(listener, null); 552 } 553 554 /** @hide */ 555 protected abstract void unregisterListenerImpl(SensorEventListener listener, Sensor sensor); 556 557 /** 558 * Registers a {@link android.hardware.SensorEventListener 559 * SensorEventListener} for the given sensor. 560 * 561 * @param listener 562 * A {@link android.hardware.SensorEventListener SensorEventListener} 563 * object. 564 * 565 * @param sensor 566 * The {@link android.hardware.Sensor Sensor} to register to. 567 * 568 * @param rate 569 * The rate {@link android.hardware.SensorEvent sensor events} are 570 * delivered at. This is only a hint to the system. Events may be 571 * received faster or slower than the specified rate. Usually events 572 * are received faster. The value must be one of 573 * {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI}, 574 * {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST} 575 * or, the desired delay between events in microsecond. 576 * 577 * @return <code>true</code> if the sensor is supported and successfully 578 * enabled. 579 * 580 * @see #registerListener(SensorEventListener, Sensor, int, Handler) 581 * @see #unregisterListener(SensorEventListener) 582 * @see #unregisterListener(SensorEventListener, Sensor) 583 * 584 */ 585 public boolean registerListener(SensorEventListener listener, Sensor sensor, int rate) { 586 return registerListener(listener, sensor, rate, null); 587 } 588 589 /** 590 * Registers a {@link android.hardware.SensorEventListener 591 * SensorEventListener} for the given sensor. 592 * 593 * @param listener 594 * A {@link android.hardware.SensorEventListener SensorEventListener} 595 * object. 596 * 597 * @param sensor 598 * The {@link android.hardware.Sensor Sensor} to register to. 599 * 600 * @param rate 601 * The rate {@link android.hardware.SensorEvent sensor events} are 602 * delivered at. This is only a hint to the system. Events may be 603 * received faster or slower than the specified rate. Usually events 604 * are received faster. The value must be one of 605 * {@link #SENSOR_DELAY_NORMAL}, {@link #SENSOR_DELAY_UI}, 606 * {@link #SENSOR_DELAY_GAME}, or {@link #SENSOR_DELAY_FASTEST}. 607 * or, the desired delay between events in microsecond. 608 * 609 * @param handler 610 * The {@link android.os.Handler Handler} the 611 * {@link android.hardware.SensorEvent sensor events} will be 612 * delivered to. 613 * 614 * @return true if the sensor is supported and successfully enabled. 615 * 616 * @see #registerListener(SensorEventListener, Sensor, int) 617 * @see #unregisterListener(SensorEventListener) 618 * @see #unregisterListener(SensorEventListener, Sensor) 619 * 620 */ 621 public boolean registerListener(SensorEventListener listener, Sensor sensor, int rate, 622 Handler handler) { 623 if (listener == null || sensor == null) { 624 return false; 625 } 626 627 int delay = -1; 628 switch (rate) { 629 case SENSOR_DELAY_FASTEST: 630 delay = 0; 631 break; 632 case SENSOR_DELAY_GAME: 633 delay = 20000; 634 break; 635 case SENSOR_DELAY_UI: 636 delay = 66667; 637 break; 638 case SENSOR_DELAY_NORMAL: 639 delay = 200000; 640 break; 641 default: 642 delay = rate; 643 break; 644 } 645 646 return registerListenerImpl(listener, sensor, delay, handler); 647 } 648 649 /** @hide */ 650 protected abstract boolean registerListenerImpl(SensorEventListener listener, Sensor sensor, 651 int delay, Handler handler); 652 653 /** 654 * <p> 655 * Computes the inclination matrix <b>I</b> as well as the rotation matrix 656 * <b>R</b> transforming a vector from the device coordinate system to the 657 * world's coordinate system which is defined as a direct orthonormal basis, 658 * where: 659 * </p> 660 * 661 * <ul> 662 * <li>X is defined as the vector product <b>Y.Z</b> (It is tangential to 663 * the ground at the device's current location and roughly points East).</li> 664 * <li>Y is tangential to the ground at the device's current location and 665 * points towards the magnetic North Pole.</li> 666 * <li>Z points towards the sky and is perpendicular to the ground.</li> 667 * </ul> 668 * 669 * <p> 670 * <center><img src="../../../images/axis_globe.png" 671 * alt="World coordinate-system diagram." border="0" /></center> 672 * </p> 673 * 674 * <p> 675 * <hr> 676 * <p> 677 * By definition: 678 * <p> 679 * [0 0 g] = <b>R</b> * <b>gravity</b> (g = magnitude of gravity) 680 * <p> 681 * [0 m 0] = <b>I</b> * <b>R</b> * <b>geomagnetic</b> (m = magnitude of 682 * geomagnetic field) 683 * <p> 684 * <b>R</b> is the identity matrix when the device is aligned with the 685 * world's coordinate system, that is, when the device's X axis points 686 * toward East, the Y axis points to the North Pole and the device is facing 687 * the sky. 688 * 689 * <p> 690 * <b>I</b> is a rotation matrix transforming the geomagnetic vector into 691 * the same coordinate space as gravity (the world's coordinate space). 692 * <b>I</b> is a simple rotation around the X axis. The inclination angle in 693 * radians can be computed with {@link #getInclination}. 694 * <hr> 695 * 696 * <p> 697 * Each matrix is returned either as a 3x3 or 4x4 row-major matrix depending 698 * on the length of the passed array: 699 * <p> 700 * <u>If the array length is 16:</u> 701 * 702 * <pre> 703 * / M[ 0] M[ 1] M[ 2] M[ 3] \ 704 * | M[ 4] M[ 5] M[ 6] M[ 7] | 705 * | M[ 8] M[ 9] M[10] M[11] | 706 * \ M[12] M[13] M[14] M[15] / 707 *</pre> 708 * 709 * This matrix is ready to be used by OpenGL ES's 710 * {@link javax.microedition.khronos.opengles.GL10#glLoadMatrixf(float[], int) 711 * glLoadMatrixf(float[], int)}. 712 * <p> 713 * Note that because OpenGL matrices are column-major matrices you must 714 * transpose the matrix before using it. However, since the matrix is a 715 * rotation matrix, its transpose is also its inverse, conveniently, it is 716 * often the inverse of the rotation that is needed for rendering; it can 717 * therefore be used with OpenGL ES directly. 718 * <p> 719 * Also note that the returned matrices always have this form: 720 * 721 * <pre> 722 * / M[ 0] M[ 1] M[ 2] 0 \ 723 * | M[ 4] M[ 5] M[ 6] 0 | 724 * | M[ 8] M[ 9] M[10] 0 | 725 * \ 0 0 0 1 / 726 *</pre> 727 * 728 * <p> 729 * <u>If the array length is 9:</u> 730 * 731 * <pre> 732 * / M[ 0] M[ 1] M[ 2] \ 733 * | M[ 3] M[ 4] M[ 5] | 734 * \ M[ 6] M[ 7] M[ 8] / 735 *</pre> 736 * 737 * <hr> 738 * <p> 739 * The inverse of each matrix can be computed easily by taking its 740 * transpose. 741 * 742 * <p> 743 * The matrices returned by this function are meaningful only when the 744 * device is not free-falling and it is not close to the magnetic north. If 745 * the device is accelerating, or placed into a strong magnetic field, the 746 * returned matrices may be inaccurate. 747 * 748 * @param R 749 * is an array of 9 floats holding the rotation matrix <b>R</b> when 750 * this function returns. R can be null. 751 * <p> 752 * 753 * @param I 754 * is an array of 9 floats holding the rotation matrix <b>I</b> when 755 * this function returns. I can be null. 756 * <p> 757 * 758 * @param gravity 759 * is an array of 3 floats containing the gravity vector expressed in 760 * the device's coordinate. You can simply use the 761 * {@link android.hardware.SensorEvent#values values} returned by a 762 * {@link android.hardware.SensorEvent SensorEvent} of a 763 * {@link android.hardware.Sensor Sensor} of type 764 * {@link android.hardware.Sensor#TYPE_ACCELEROMETER 765 * TYPE_ACCELEROMETER}. 766 * <p> 767 * 768 * @param geomagnetic 769 * is an array of 3 floats containing the geomagnetic vector 770 * expressed in the device's coordinate. You can simply use the 771 * {@link android.hardware.SensorEvent#values values} returned by a 772 * {@link android.hardware.SensorEvent SensorEvent} of a 773 * {@link android.hardware.Sensor Sensor} of type 774 * {@link android.hardware.Sensor#TYPE_MAGNETIC_FIELD 775 * TYPE_MAGNETIC_FIELD}. 776 * 777 * @return <code>true</code> on success, <code>false</code> on failure (for 778 * instance, if the device is in free fall). On failure the output 779 * matrices are not modified. 780 * 781 * @see #getInclination(float[]) 782 * @see #getOrientation(float[], float[]) 783 * @see #remapCoordinateSystem(float[], int, int, float[]) 784 */ 785 786 public static boolean getRotationMatrix(float[] R, float[] I, 787 float[] gravity, float[] geomagnetic) { 788 // TODO: move this to native code for efficiency 789 float Ax = gravity[0]; 790 float Ay = gravity[1]; 791 float Az = gravity[2]; 792 final float Ex = geomagnetic[0]; 793 final float Ey = geomagnetic[1]; 794 final float Ez = geomagnetic[2]; 795 float Hx = Ey*Az - Ez*Ay; 796 float Hy = Ez*Ax - Ex*Az; 797 float Hz = Ex*Ay - Ey*Ax; 798 final float normH = (float)Math.sqrt(Hx*Hx + Hy*Hy + Hz*Hz); 799 if (normH < 0.1f) { 800 // device is close to free fall (or in space?), or close to 801 // magnetic north pole. Typical values are > 100. 802 return false; 803 } 804 final float invH = 1.0f / normH; 805 Hx *= invH; 806 Hy *= invH; 807 Hz *= invH; 808 final float invA = 1.0f / (float)Math.sqrt(Ax*Ax + Ay*Ay + Az*Az); 809 Ax *= invA; 810 Ay *= invA; 811 Az *= invA; 812 final float Mx = Ay*Hz - Az*Hy; 813 final float My = Az*Hx - Ax*Hz; 814 final float Mz = Ax*Hy - Ay*Hx; 815 if (R != null) { 816 if (R.length == 9) { 817 R[0] = Hx; R[1] = Hy; R[2] = Hz; 818 R[3] = Mx; R[4] = My; R[5] = Mz; 819 R[6] = Ax; R[7] = Ay; R[8] = Az; 820 } else if (R.length == 16) { 821 R[0] = Hx; R[1] = Hy; R[2] = Hz; R[3] = 0; 822 R[4] = Mx; R[5] = My; R[6] = Mz; R[7] = 0; 823 R[8] = Ax; R[9] = Ay; R[10] = Az; R[11] = 0; 824 R[12] = 0; R[13] = 0; R[14] = 0; R[15] = 1; 825 } 826 } 827 if (I != null) { 828 // compute the inclination matrix by projecting the geomagnetic 829 // vector onto the Z (gravity) and X (horizontal component 830 // of geomagnetic vector) axes. 831 final float invE = 1.0f / (float)Math.sqrt(Ex*Ex + Ey*Ey + Ez*Ez); 832 final float c = (Ex*Mx + Ey*My + Ez*Mz) * invE; 833 final float s = (Ex*Ax + Ey*Ay + Ez*Az) * invE; 834 if (I.length == 9) { 835 I[0] = 1; I[1] = 0; I[2] = 0; 836 I[3] = 0; I[4] = c; I[5] = s; 837 I[6] = 0; I[7] =-s; I[8] = c; 838 } else if (I.length == 16) { 839 I[0] = 1; I[1] = 0; I[2] = 0; 840 I[4] = 0; I[5] = c; I[6] = s; 841 I[8] = 0; I[9] =-s; I[10]= c; 842 I[3] = I[7] = I[11] = I[12] = I[13] = I[14] = 0; 843 I[15] = 1; 844 } 845 } 846 return true; 847 } 848 849 /** 850 * Computes the geomagnetic inclination angle in radians from the 851 * inclination matrix <b>I</b> returned by {@link #getRotationMatrix}. 852 * 853 * @param I 854 * inclination matrix see {@link #getRotationMatrix}. 855 * 856 * @return The geomagnetic inclination angle in radians. 857 * 858 * @see #getRotationMatrix(float[], float[], float[], float[]) 859 * @see #getOrientation(float[], float[]) 860 * @see GeomagneticField 861 * 862 */ 863 public static float getInclination(float[] I) { 864 if (I.length == 9) { 865 return (float)Math.atan2(I[5], I[4]); 866 } else { 867 return (float)Math.atan2(I[6], I[5]); 868 } 869 } 870 871 /** 872 * <p> 873 * Rotates the supplied rotation matrix so it is expressed in a different 874 * coordinate system. This is typically used when an application needs to 875 * compute the three orientation angles of the device (see 876 * {@link #getOrientation}) in a different coordinate system. 877 * </p> 878 * 879 * <p> 880 * When the rotation matrix is used for drawing (for instance with OpenGL 881 * ES), it usually <b>doesn't need</b> to be transformed by this function, 882 * unless the screen is physically rotated, in which case you can use 883 * {@link android.view.Display#getRotation() Display.getRotation()} to 884 * retrieve the current rotation of the screen. Note that because the user 885 * is generally free to rotate their screen, you often should consider the 886 * rotation in deciding the parameters to use here. 887 * </p> 888 * 889 * <p> 890 * <u>Examples:</u> 891 * <p> 892 * 893 * <ul> 894 * <li>Using the camera (Y axis along the camera's axis) for an augmented 895 * reality application where the rotation angles are needed:</li> 896 * 897 * <p> 898 * <ul> 899 * <code>remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR);</code> 900 * </ul> 901 * </p> 902 * 903 * <li>Using the device as a mechanical compass when rotation is 904 * {@link android.view.Surface#ROTATION_90 Surface.ROTATION_90}:</li> 905 * 906 * <p> 907 * <ul> 908 * <code>remapCoordinateSystem(inR, AXIS_Y, AXIS_MINUS_X, outR);</code> 909 * </ul> 910 * </p> 911 * 912 * Beware of the above example. This call is needed only to account for a 913 * rotation from its natural orientation when calculating the rotation 914 * angles (see {@link #getOrientation}). If the rotation matrix is also used 915 * for rendering, it may not need to be transformed, for instance if your 916 * {@link android.app.Activity Activity} is running in landscape mode. 917 * </ul> 918 * 919 * <p> 920 * Since the resulting coordinate system is orthonormal, only two axes need 921 * to be specified. 922 * 923 * @param inR 924 * the rotation matrix to be transformed. Usually it is the matrix 925 * returned by {@link #getRotationMatrix}. 926 * 927 * @param X 928 * defines on which world axis and direction the X axis of the device 929 * is mapped. 930 * 931 * @param Y 932 * defines on which world axis and direction the Y axis of the device 933 * is mapped. 934 * 935 * @param outR 936 * the transformed rotation matrix. inR and outR can be the same 937 * array, but it is not recommended for performance reason. 938 * 939 * @return <code>true</code> on success. <code>false</code> if the input 940 * parameters are incorrect, for instance if X and Y define the same 941 * axis. Or if inR and outR don't have the same length. 942 * 943 * @see #getRotationMatrix(float[], float[], float[], float[]) 944 */ 945 946 public static boolean remapCoordinateSystem(float[] inR, int X, int Y, 947 float[] outR) 948 { 949 if (inR == outR) { 950 final float[] temp = mTempMatrix; 951 synchronized(temp) { 952 // we don't expect to have a lot of contention 953 if (remapCoordinateSystemImpl(inR, X, Y, temp)) { 954 final int size = outR.length; 955 for (int i=0 ; i<size ; i++) 956 outR[i] = temp[i]; 957 return true; 958 } 959 } 960 } 961 return remapCoordinateSystemImpl(inR, X, Y, outR); 962 } 963 964 private static boolean remapCoordinateSystemImpl(float[] inR, int X, int Y, 965 float[] outR) 966 { 967 /* 968 * X and Y define a rotation matrix 'r': 969 * 970 * (X==1)?((X&0x80)?-1:1):0 (X==2)?((X&0x80)?-1:1):0 (X==3)?((X&0x80)?-1:1):0 971 * (Y==1)?((Y&0x80)?-1:1):0 (Y==2)?((Y&0x80)?-1:1):0 (Y==3)?((X&0x80)?-1:1):0 972 * r[0] ^ r[1] 973 * 974 * where the 3rd line is the vector product of the first 2 lines 975 * 976 */ 977 978 final int length = outR.length; 979 if (inR.length != length) 980 return false; // invalid parameter 981 if ((X & 0x7C)!=0 || (Y & 0x7C)!=0) 982 return false; // invalid parameter 983 if (((X & 0x3)==0) || ((Y & 0x3)==0)) 984 return false; // no axis specified 985 if ((X & 0x3) == (Y & 0x3)) 986 return false; // same axis specified 987 988 // Z is "the other" axis, its sign is either +/- sign(X)*sign(Y) 989 // this can be calculated by exclusive-or'ing X and Y; except for 990 // the sign inversion (+/-) which is calculated below. 991 int Z = X ^ Y; 992 993 // extract the axis (remove the sign), offset in the range 0 to 2. 994 final int x = (X & 0x3)-1; 995 final int y = (Y & 0x3)-1; 996 final int z = (Z & 0x3)-1; 997 998 // compute the sign of Z (whether it needs to be inverted) 999 final int axis_y = (z+1)%3; 1000 final int axis_z = (z+2)%3; 1001 if (((x^axis_y)|(y^axis_z)) != 0) 1002 Z ^= 0x80; 1003 1004 final boolean sx = (X>=0x80); 1005 final boolean sy = (Y>=0x80); 1006 final boolean sz = (Z>=0x80); 1007 1008 // Perform R * r, in avoiding actual muls and adds. 1009 final int rowLength = ((length==16)?4:3); 1010 for (int j=0 ; j<3 ; j++) { 1011 final int offset = j*rowLength; 1012 for (int i=0 ; i<3 ; i++) { 1013 if (x==i) outR[offset+i] = sx ? -inR[offset+0] : inR[offset+0]; 1014 if (y==i) outR[offset+i] = sy ? -inR[offset+1] : inR[offset+1]; 1015 if (z==i) outR[offset+i] = sz ? -inR[offset+2] : inR[offset+2]; 1016 } 1017 } 1018 if (length == 16) { 1019 outR[3] = outR[7] = outR[11] = outR[12] = outR[13] = outR[14] = 0; 1020 outR[15] = 1; 1021 } 1022 return true; 1023 } 1024 1025 /** 1026 * Computes the device's orientation based on the rotation matrix. 1027 * <p> 1028 * When it returns, the array values is filled with the result: 1029 * <ul> 1030 * <li>values[0]: <i>azimuth</i>, rotation around the Z axis.</li> 1031 * <li>values[1]: <i>pitch</i>, rotation around the X axis.</li> 1032 * <li>values[2]: <i>roll</i>, rotation around the Y axis.</li> 1033 * </ul> 1034 * <p>The reference coordinate-system used is different from the world 1035 * coordinate-system defined for the rotation matrix:</p> 1036 * <ul> 1037 * <li>X is defined as the vector product <b>Y.Z</b> (It is tangential to 1038 * the ground at the device's current location and roughly points West).</li> 1039 * <li>Y is tangential to the ground at the device's current location and 1040 * points towards the magnetic North Pole.</li> 1041 * <li>Z points towards the center of the Earth and is perpendicular to the ground.</li> 1042 * </ul> 1043 * 1044 * <p> 1045 * <center><img src="../../../images/axis_globe_inverted.png" 1046 * alt="Inverted world coordinate-system diagram." border="0" /></center> 1047 * </p> 1048 * <p> 1049 * All three angles above are in <b>radians</b> and <b>positive</b> in the 1050 * <b>counter-clockwise</b> direction. 1051 * 1052 * @param R 1053 * rotation matrix see {@link #getRotationMatrix}. 1054 * 1055 * @param values 1056 * an array of 3 floats to hold the result. 1057 * 1058 * @return The array values passed as argument. 1059 * 1060 * @see #getRotationMatrix(float[], float[], float[], float[]) 1061 * @see GeomagneticField 1062 */ 1063 public static float[] getOrientation(float[] R, float values[]) { 1064 /* 1065 * 4x4 (length=16) case: 1066 * / R[ 0] R[ 1] R[ 2] 0 \ 1067 * | R[ 4] R[ 5] R[ 6] 0 | 1068 * | R[ 8] R[ 9] R[10] 0 | 1069 * \ 0 0 0 1 / 1070 * 1071 * 3x3 (length=9) case: 1072 * / R[ 0] R[ 1] R[ 2] \ 1073 * | R[ 3] R[ 4] R[ 5] | 1074 * \ R[ 6] R[ 7] R[ 8] / 1075 * 1076 */ 1077 if (R.length == 9) { 1078 values[0] = (float)Math.atan2(R[1], R[4]); 1079 values[1] = (float)Math.asin(-R[7]); 1080 values[2] = (float)Math.atan2(-R[6], R[8]); 1081 } else { 1082 values[0] = (float)Math.atan2(R[1], R[5]); 1083 values[1] = (float)Math.asin(-R[9]); 1084 values[2] = (float)Math.atan2(-R[8], R[10]); 1085 } 1086 return values; 1087 } 1088 1089 /** 1090 * Computes the Altitude in meters from the atmospheric pressure and the 1091 * pressure at sea level. 1092 * <p> 1093 * Typically the atmospheric pressure is read from a 1094 * {@link Sensor#TYPE_PRESSURE} sensor. The pressure at sea level must be 1095 * known, usually it can be retrieved from airport databases in the 1096 * vicinity. If unknown, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} 1097 * as an approximation, but absolute altitudes won't be accurate. 1098 * </p> 1099 * <p> 1100 * To calculate altitude differences, you must calculate the difference 1101 * between the altitudes at both points. If you don't know the altitude 1102 * as sea level, you can use {@link #PRESSURE_STANDARD_ATMOSPHERE} instead, 1103 * which will give good results considering the range of pressure typically 1104 * involved. 1105 * </p> 1106 * <p> 1107 * <code><ul> 1108 * float altitude_difference = 1109 * getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point2) 1110 * - getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point1); 1111 * </ul></code> 1112 * </p> 1113 * 1114 * @param p0 pressure at sea level 1115 * @param p atmospheric pressure 1116 * @return Altitude in meters 1117 */ 1118 public static float getAltitude(float p0, float p) { 1119 final float coef = 1.0f / 5.255f; 1120 return 44330.0f * (1.0f - (float)Math.pow(p/p0, coef)); 1121 } 1122 1123 /** Helper function to compute the angle change between two rotation matrices. 1124 * Given a current rotation matrix (R) and a previous rotation matrix 1125 * (prevR) computes the rotation around the x,y, and z axes which 1126 * transforms prevR to R. 1127 * outputs a 3 element vector containing the x,y, and z angle 1128 * change at indexes 0, 1, and 2 respectively. 1129 * <p> Each input matrix is either as a 3x3 or 4x4 row-major matrix 1130 * depending on the length of the passed array: 1131 * <p>If the array length is 9, then the array elements represent this matrix 1132 * <pre> 1133 * / R[ 0] R[ 1] R[ 2] \ 1134 * | R[ 3] R[ 4] R[ 5] | 1135 * \ R[ 6] R[ 7] R[ 8] / 1136 *</pre> 1137 * <p>If the array length is 16, then the array elements represent this matrix 1138 * <pre> 1139 * / R[ 0] R[ 1] R[ 2] R[ 3] \ 1140 * | R[ 4] R[ 5] R[ 6] R[ 7] | 1141 * | R[ 8] R[ 9] R[10] R[11] | 1142 * \ R[12] R[13] R[14] R[15] / 1143 *</pre> 1144 * @param R current rotation matrix 1145 * @param prevR previous rotation matrix 1146 * @param angleChange an array of floats in which the angle change is stored 1147 */ 1148 1149 public static void getAngleChange( float[] angleChange, float[] R, float[] prevR) { 1150 float rd1=0,rd4=0, rd6=0,rd7=0, rd8=0; 1151 float ri0=0,ri1=0,ri2=0,ri3=0,ri4=0,ri5=0,ri6=0,ri7=0,ri8=0; 1152 float pri0=0, pri1=0, pri2=0, pri3=0, pri4=0, pri5=0, pri6=0, pri7=0, pri8=0; 1153 int i, j, k; 1154 1155 if(R.length == 9) { 1156 ri0 = R[0]; 1157 ri1 = R[1]; 1158 ri2 = R[2]; 1159 ri3 = R[3]; 1160 ri4 = R[4]; 1161 ri5 = R[5]; 1162 ri6 = R[6]; 1163 ri7 = R[7]; 1164 ri8 = R[8]; 1165 } else if(R.length == 16) { 1166 ri0 = R[0]; 1167 ri1 = R[1]; 1168 ri2 = R[2]; 1169 ri3 = R[4]; 1170 ri4 = R[5]; 1171 ri5 = R[6]; 1172 ri6 = R[8]; 1173 ri7 = R[9]; 1174 ri8 = R[10]; 1175 } 1176 1177 if(prevR.length == 9) { 1178 pri0 = prevR[0]; 1179 pri1 = prevR[1]; 1180 pri2 = prevR[2]; 1181 pri3 = prevR[3]; 1182 pri4 = prevR[4]; 1183 pri5 = prevR[5]; 1184 pri6 = prevR[6]; 1185 pri7 = prevR[7]; 1186 pri8 = prevR[8]; 1187 } else if(prevR.length == 16) { 1188 pri0 = prevR[0]; 1189 pri1 = prevR[1]; 1190 pri2 = prevR[2]; 1191 pri3 = prevR[4]; 1192 pri4 = prevR[5]; 1193 pri5 = prevR[6]; 1194 pri6 = prevR[8]; 1195 pri7 = prevR[9]; 1196 pri8 = prevR[10]; 1197 } 1198 1199 // calculate the parts of the rotation difference matrix we need 1200 // rd[i][j] = pri[0][i] * ri[0][j] + pri[1][i] * ri[1][j] + pri[2][i] * ri[2][j]; 1201 1202 rd1 = pri0 * ri1 + pri3 * ri4 + pri6 * ri7; //rd[0][1] 1203 rd4 = pri1 * ri1 + pri4 * ri4 + pri7 * ri7; //rd[1][1] 1204 rd6 = pri2 * ri0 + pri5 * ri3 + pri8 * ri6; //rd[2][0] 1205 rd7 = pri2 * ri1 + pri5 * ri4 + pri8 * ri7; //rd[2][1] 1206 rd8 = pri2 * ri2 + pri5 * ri5 + pri8 * ri8; //rd[2][2] 1207 1208 angleChange[0] = (float)Math.atan2(rd1, rd4); 1209 angleChange[1] = (float)Math.asin(-rd7); 1210 angleChange[2] = (float)Math.atan2(-rd6, rd8); 1211 1212 } 1213 1214 /** Helper function to convert a rotation vector to a rotation matrix. 1215 * Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a 1216 * 9 or 16 element rotation matrix in the array R. R must have length 9 or 16. 1217 * If R.length == 9, the following matrix is returned: 1218 * <pre> 1219 * / R[ 0] R[ 1] R[ 2] \ 1220 * | R[ 3] R[ 4] R[ 5] | 1221 * \ R[ 6] R[ 7] R[ 8] / 1222 *</pre> 1223 * If R.length == 16, the following matrix is returned: 1224 * <pre> 1225 * / R[ 0] R[ 1] R[ 2] 0 \ 1226 * | R[ 4] R[ 5] R[ 6] 0 | 1227 * | R[ 8] R[ 9] R[10] 0 | 1228 * \ 0 0 0 1 / 1229 *</pre> 1230 * @param rotationVector the rotation vector to convert 1231 * @param R an array of floats in which to store the rotation matrix 1232 */ 1233 public static void getRotationMatrixFromVector(float[] R, float[] rotationVector) { 1234 1235 float q0; 1236 float q1 = rotationVector[0]; 1237 float q2 = rotationVector[1]; 1238 float q3 = rotationVector[2]; 1239 1240 if (rotationVector.length == 4) { 1241 q0 = rotationVector[3]; 1242 } else { 1243 q0 = 1 - q1*q1 - q2*q2 - q3*q3; 1244 q0 = (q0 > 0) ? (float)Math.sqrt(q0) : 0; 1245 } 1246 1247 float sq_q1 = 2 * q1 * q1; 1248 float sq_q2 = 2 * q2 * q2; 1249 float sq_q3 = 2 * q3 * q3; 1250 float q1_q2 = 2 * q1 * q2; 1251 float q3_q0 = 2 * q3 * q0; 1252 float q1_q3 = 2 * q1 * q3; 1253 float q2_q0 = 2 * q2 * q0; 1254 float q2_q3 = 2 * q2 * q3; 1255 float q1_q0 = 2 * q1 * q0; 1256 1257 if(R.length == 9) { 1258 R[0] = 1 - sq_q2 - sq_q3; 1259 R[1] = q1_q2 - q3_q0; 1260 R[2] = q1_q3 + q2_q0; 1261 1262 R[3] = q1_q2 + q3_q0; 1263 R[4] = 1 - sq_q1 - sq_q3; 1264 R[5] = q2_q3 - q1_q0; 1265 1266 R[6] = q1_q3 - q2_q0; 1267 R[7] = q2_q3 + q1_q0; 1268 R[8] = 1 - sq_q1 - sq_q2; 1269 } else if (R.length == 16) { 1270 R[0] = 1 - sq_q2 - sq_q3; 1271 R[1] = q1_q2 - q3_q0; 1272 R[2] = q1_q3 + q2_q0; 1273 R[3] = 0.0f; 1274 1275 R[4] = q1_q2 + q3_q0; 1276 R[5] = 1 - sq_q1 - sq_q3; 1277 R[6] = q2_q3 - q1_q0; 1278 R[7] = 0.0f; 1279 1280 R[8] = q1_q3 - q2_q0; 1281 R[9] = q2_q3 + q1_q0; 1282 R[10] = 1 - sq_q1 - sq_q2; 1283 R[11] = 0.0f; 1284 1285 R[12] = R[13] = R[14] = 0.0f; 1286 R[15] = 1.0f; 1287 } 1288 } 1289 1290 /** Helper function to convert a rotation vector to a normalized quaternion. 1291 * Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a normalized 1292 * quaternion in the array Q. The quaternion is stored as [w, x, y, z] 1293 * @param rv the rotation vector to convert 1294 * @param Q an array of floats in which to store the computed quaternion 1295 */ 1296 public static void getQuaternionFromVector(float[] Q, float[] rv) { 1297 if (rv.length == 4) { 1298 Q[0] = rv[3]; 1299 } else { 1300 Q[0] = 1 - rv[0]*rv[0] - rv[1]*rv[1] - rv[2]*rv[2]; 1301 Q[0] = (Q[0] > 0) ? (float)Math.sqrt(Q[0]) : 0; 1302 } 1303 Q[1] = rv[0]; 1304 Q[2] = rv[1]; 1305 Q[3] = rv[2]; 1306 } 1307 1308 private LegacySensorManager getLegacySensorManager() { 1309 synchronized (mSensorListByType) { 1310 if (mLegacySensorManager == null) { 1311 Log.i(TAG, "This application is using deprecated SensorManager API which will " 1312 + "be removed someday. Please consider switching to the new API."); 1313 mLegacySensorManager = new LegacySensorManager(this); 1314 } 1315 return mLegacySensorManager; 1316 } 1317 } 1318 1319 /** 1320 * Sensor event pool implementation. 1321 * @hide 1322 */ 1323 protected static final class SensorEventPool { 1324 private final int mPoolSize; 1325 private final SensorEvent mPool[]; 1326 private int mNumItemsInPool; 1327 1328 private SensorEvent createSensorEvent() { 1329 // maximal size for all legacy events is 3 1330 return new SensorEvent(3); 1331 } 1332 1333 SensorEventPool(int poolSize) { 1334 mPoolSize = poolSize; 1335 mNumItemsInPool = poolSize; 1336 mPool = new SensorEvent[poolSize]; 1337 } 1338 1339 SensorEvent getFromPool() { 1340 SensorEvent t = null; 1341 synchronized (this) { 1342 if (mNumItemsInPool > 0) { 1343 // remove the "top" item from the pool 1344 final int index = mPoolSize - mNumItemsInPool; 1345 t = mPool[index]; 1346 mPool[index] = null; 1347 mNumItemsInPool--; 1348 } 1349 } 1350 if (t == null) { 1351 // the pool was empty or this item was removed from the pool for 1352 // the first time. In any case, we need to create a new item. 1353 t = createSensorEvent(); 1354 } 1355 return t; 1356 } 1357 1358 void returnToPool(SensorEvent t) { 1359 synchronized (this) { 1360 // is there space left in the pool? 1361 if (mNumItemsInPool < mPoolSize) { 1362 // if so, return the item to the pool 1363 mNumItemsInPool++; 1364 final int index = mPoolSize - mNumItemsInPool; 1365 mPool[index] = t; 1366 } 1367 } 1368 } 1369 } 1370} 1371
