AP_Common: add get_alt - 100 times better than get_alt_cm

Author: peterbarker

libraries/AP_Common/Location.cpp

@@ -209,6 +209,15 @@ bool Location::get_alt_cm(AltFrame desired_frame, int32_t &ret_alt_cm) const
     }
     return false;  // LCOV_EXCL_LINE  - not reachable
 }
+bool Location::get_alt(AltFrame desired_frame, float &ret_alt) const
+{
+    int32_t ret_alt_cm;
+    if (!get_alt_cm(desired_frame, ret_alt_cm)) {
+        return false;
+    }
+    ret_alt = ret_alt_cm * 0.01;
+    return true;
+}
 
 #if AP_AHRS_ENABLED
 bool Location::get_vector_xy_from_origin_NE(Vector2f &vec_ne) const

libraries/AP_Common/Location.h

@@ -42,6 +42,8 @@ class Location
     // - above-home and home is not set
     // - above-origin and origin is not set
     bool get_alt_cm(AltFrame desired_frame, int32_t &ret_alt_cm) const WARN_IF_UNUSED;
+    // same as get_alt_cm but in metres:
+    bool get_alt(AltFrame desired_frame, float &ret_alt) const WARN_IF_UNUSED;
 
     // get altitude frame
     AltFrame get_alt_frame() const;