am 04d7e83e: Added SensorManager.getAltitude()

Merge commit '04d7e83e65e246e154b5b346e3eb0081b741ae88' into gingerbread-plus-aosp

* commit '04d7e83e65e246e154b5b346e3eb0081b741ae88':
  Added SensorManager.getAltitude()

api/current.xml

@@ -77870,6 +77870,21 @@
  deprecated="not deprecated"
  visibility="public"
 >
+<method name="getAltitude"
+ return="float"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="true"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+<parameter name="p0" type="float">
+</parameter>
+<parameter name="p" type="float">
+</parameter>
+</method>
 <method name="getDefaultSensor"
  return="android.hardware.Sensor"
  abstract="false"
@@ -78449,6 +78464,17 @@
  visibility="public"
 >
 </field>
+<field name="PRESSURE_STANDARD_ATMOSPHERE"
+ type="float"
+ transient="false"
+ volatile="false"
+ value="1013.25f"
+ static="true"
+ final="true"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</field>
 <field name="RAW_DATA_INDEX"
  type="int"
  transient="false"

core/java/android/hardware/SensorManager.java

@@ -268,6 +268,10 @@ public class SensorManager
     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 */
@@ -1514,6 +1518,25 @@ public class SensorManager
         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.
+     * </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));
+    }
+
 
    /**
      * {@hide}