Android传感器API之：方向SensorOrientation传感器功能实现与源码分享，,继续明确一下空间坐标系的

Android传感器API之：方向SensorOrientation传感器功能实现与源码分享，,继续明确一下空间坐标系的

继续明确一下空间坐标系的三个方向：x 方向就是手机的水平方向，右为正；y 方向就是手机的水平垂直方向，前为正；z方向就是手机的空间垂直方向，天空的方向为正，地球的方向为负。方向角的定义是手机y轴 水平面上的投影 与 正北方向的夹角。 （值得范围是 0 ~ 359其中0=North, 90=East, 180=South, 270=West）倾斜角的定义是手机y轴 与水平面的夹角 （手机z轴向y轴方向移动为正,值得范围是 -180 ~ 180）旋转角的定义是手机x轴 与水平面的夹角 （手机x轴离开z轴方向为正， 值得范围是 -90 ~ 90）也就是说，当你把手机水平放置在桌面上(屏幕向上)且手机指向正北(Y轴方向)，此时传感器获得的xyz三个值应该都为0。如下是Rexsee实现的方向传感器功能源码。我会把Rexsee扩展的全部传感器源码都陆续贴出来，感兴趣的也可以直接去Rexsee社区查阅，反正都是开源的：http://www.rexsee.com。但是首先需要知道，并不是所有的Android手机都支持方向传感器。比如说乐Phone，好像就是加速度、重力和光线，方向和磁场貌似都不支持。

/* * Copyright (C) 2011 The Rexsee Open Source Project * * Licensed under the Rexsee License, Version 1.0 (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.rexsee.com/CN/legal/license.html * * 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 cn.outofmemory.rexsee.sensor;  import rexsee.core.browser.JavascriptInterface;  import rexsee.core.browser.RexseeBrowser;  import android.content.Context;  import android.hardware.Sensor;  import android.hardware.SensorEvent;  import android.hardware.SensorEventListener;  import android.hardware.SensorManager;  public class RexseeSensorOrientation implements JavascriptInterface {         public static final String INTERFACE_NAME = "Orientation";         @Override         public String getInterfaceName() {                 return mBrowser.application.resources.prefix + INTERFACE_NAME;         }         @Override         public JavascriptInterface getInheritInterface(RexseeBrowser childBrowser) {                 return this;         }         @Override         public JavascriptInterface getNewInterface(RexseeBrowser childBrowser) {                 return new RexseeSensorOrientation(childBrowser);         }         public static final String EVENT_ONORIENTATIONCHANGED = "onOrientationChanged";         private final Context mContext;         private final RexseeBrowser mBrowser;         private final SensorManager mSensorManager;         private SensorEventListener mSensorListener;         private final Sensor mSensor;         private int mRate = SensorManager.SENSOR_DELAY_NORMAL;         private int mCycle = 100; //milliseconds         private int mEventCycle = 100; //milliseconds         private float mAccuracyX = 0;         private float mAccuracyY = 0;         private float mAccuracyZ = 0;         private long lastUpdate = -1;         private long lastEvent = -1;         private float x = -999f;         private float y = -999f;         private float z = -999f;         public RexseeSensorOrientation(RexseeBrowser browser) {                 mContext = browser.getContext();                 mBrowser = browser;                 browser.eventList.add(EVENT_ONORIENTATIONCHANGED);                 mSensorManager = (SensorManager) mContext.getSystemService(Context.SENSOR_SERVICE);                 mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION);                 mSensorListener = new SensorEventListener() {                         @Override                         public void onAccuracyChanged(Sensor sensor, int accuracy) {                         }                         @Override                         public void onSensorChanged(SensorEvent event) {                                 if (event.sensor.getType() != Sensor.TYPE_ORIENTATION) return;                                 long curTime = System.currentTimeMillis();                                 if (lastUpdate == -1 || (curTime - lastUpdate) > mCycle) {                                         lastUpdate = curTime;                                         float lastX = x;                                         float lastY = y;                                         float lastZ = z;                                         x = event.values[SensorManager.DATA_X];                                         y = event.values[SensorManager.DATA_Y];                                         z = event.values[SensorManager.DATA_Z];                                         if (lastEvent == -1 || (curTime - lastEvent) > mEventCycle) {                                                 if (                                                                 (mAccuracyX >= 0 && Math.abs(x - lastX) > mAccuracyX)                                                                                 || (mAccuracyY >= 0 && Math.abs(y - lastY) > mAccuracyY)                                                                                 || (mAccuracyZ >= 0 && Math.abs(z - lastZ) > mAccuracyZ)                                                         ) {                                                                 lastEvent = curTime;                                                                 mBrowser.eventList.run(EVENT_ONORIENTATIONCHANGED);                                                         }                                                 }                                         }                                 }                 };         }         public String getLastKnownX() {                 return (x == -999) ? "null" : String.valueOf(x);         }         public String getLastKnownY() {                 return (y == -999) ? "null" : String.valueOf(y);         }         public String getLastKnownZ() {                 return (z == -999) ? "null" : String.valueOf(z);         }         public void setRate(String rate) {                 mRate = SensorRate.getInt(rate);         }         public String getRate() {                 return SensorRate.getString(mRate);         }         public void setCycle(int milliseconds) {                 mCycle = milliseconds;         }         public int getCycle() {                 return mCycle;         }         public void setEventCycle(int milliseconds) {                 mEventCycle = milliseconds;         }         public int getEventCycle() {                 return mEventCycle;         }         public void setAccuracy(float x, float y, float z) {                 mAccuracyX = x;                 mAccuracyY = y;                 mAccuracyZ = z;         }         public float getAccuracyX() {                 return mAccuracyX;         }         public float getAccuracyY() {                 return mAccuracyY;         }         public float getAccuracyZ() {                 return mAccuracyZ;         }         public boolean isReady() {                 return (mSensor == null) ? false : true;         }         public void start() {                 if (isReady()) {                         mSensorManager.registerListener(mSensorListener, mSensor, mRate);                 } else {                         mBrowser.exception(getInterfaceName(), "Orientation sensor is not found.");                 }         }         public void stop() {                 if (isReady()) {                         mSensorManager.unregisterListener(mSensorListener);                 }         }  }