From 5d49d29c273fbead6dc91d386edc7600a862eeae Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Tue, 17 Aug 2021 12:34:15 +1000
Subject: [PATCH] AP_AHRS: move wind-estimation-enabled state to frontend

---
 libraries/AP_AHRS/AP_AHRS.cpp       |  2 +-
 libraries/AP_AHRS/AP_AHRS.h         | 20 ++++++++++++++++++++
 libraries/AP_AHRS/AP_AHRS_Backend.h |  9 ---------
 libraries/AP_AHRS/AP_AHRS_DCM.cpp   |  4 ++--
 4 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/libraries/AP_AHRS/AP_AHRS.cpp b/libraries/AP_AHRS/AP_AHRS.cpp
index 868445d2b5..6d8e4f8148 100644
--- a/libraries/AP_AHRS/AP_AHRS.cpp
+++ b/libraries/AP_AHRS/AP_AHRS.cpp
@@ -808,7 +808,7 @@ bool AP_AHRS::airspeed_estimate(float &airspeed_ret) const
         return true;
     }
 
-    if (!_flags.wind_estimation) {
+    if (!get_wind_estimation_enabled()) {
         return false;
     }
 
diff --git a/libraries/AP_AHRS/AP_AHRS.h b/libraries/AP_AHRS/AP_AHRS.h
index fd5517de59..a59371b18d 100644
--- a/libraries/AP_AHRS/AP_AHRS.h
+++ b/libraries/AP_AHRS/AP_AHRS.h
@@ -103,9 +103,24 @@ public:
     float           get_error_rp() const override;
     float           get_error_yaw() const override;
 
+    /*
+     * wind estimation support
+     */
+
+    // enable wind estimation
+    void set_wind_estimation_enabled(bool b) { wind_estimation_enabled = b; }
+
+    // wind_estimation_enabled returns true if wind estimation is enabled
+    bool get_wind_estimation_enabled() const { return wind_estimation_enabled; }
+
     // return a wind estimation vector, in m/s
     Vector3f wind_estimate() const override;
 
+
+    /*
+     * airspeed support
+     */
+
     // return an airspeed estimate if available. return true
     // if we have an estimate
     bool airspeed_estimate(float &airspeed_ret) const override;
@@ -567,6 +582,11 @@ private:
     bool touchdown_expected;    // true if the vehicle is in a state that touchdown might be expected.  Ground effect may be in play.
     uint32_t touchdown_expected_start_ms;
 
+    /*
+     * wind estimation support
+     */
+    bool wind_estimation_enabled;
+
     /*
      * fly_forward is set by the vehicles to indicate the vehicle
      * should generally be moving in the direction of its heading.
diff --git a/libraries/AP_AHRS/AP_AHRS_Backend.h b/libraries/AP_AHRS/AP_AHRS_Backend.h
index be8a52da7b..aeb6a7ffa5 100644
--- a/libraries/AP_AHRS/AP_AHRS_Backend.h
+++ b/libraries/AP_AHRS/AP_AHRS_Backend.h
@@ -46,10 +46,6 @@ public:
     // init sets up INS board orientation
     virtual void init();
 
-    void set_wind_estimation(bool b) {
-        _flags.wind_estimation = b;
-    }
-
     // return the index of the primary core or -1 if no primary core selected
     virtual int8_t get_primary_core_index() const { return -1; }
 
@@ -472,11 +468,6 @@ protected:
 
     Matrix3f _custom_rotation;
 
-    // flags structure
-    struct ahrs_flags {
-        uint8_t wind_estimation         : 1;    // 1 if we should do wind estimation
-    } _flags;
-
     // calculate sin/cos of roll/pitch/yaw from rotation
     void calc_trig(const Matrix3f &rot,
                    float &cr, float &cp, float &cy,
diff --git a/libraries/AP_AHRS/AP_AHRS_DCM.cpp b/libraries/AP_AHRS/AP_AHRS_DCM.cpp
index f0517c666b..8b81f3e66d 100644
--- a/libraries/AP_AHRS/AP_AHRS_DCM.cpp
+++ b/libraries/AP_AHRS/AP_AHRS_DCM.cpp
@@ -957,7 +957,7 @@ AP_AHRS_DCM::drift_correction(float deltat)
 // update our wind speed estimate
 void AP_AHRS_DCM::estimate_wind(void)
 {
-    if (!_flags.wind_estimation) {
+    if (!AP::ahrs().get_wind_estimation_enabled()) {
         return;
     }
     const Vector3f &velocity = _last_velocity;
@@ -1074,7 +1074,7 @@ bool AP_AHRS_DCM::airspeed_estimate(uint8_t airspeed_index, float &airspeed_ret)
 {
     if (airspeed_sensor_enabled(airspeed_index)) {
         airspeed_ret = AP::airspeed()->get_airspeed(airspeed_index);
-    } else if (_flags.wind_estimation && have_gps()) {
+    } else if (AP::ahrs().get_wind_estimation_enabled() && have_gps()) {
         // estimate it via GPS speed and wind
         airspeed_ret = _last_airspeed;
     } else {