AP_Compass: remove unused setup_earth_field

libraries/AP_Compass/AP_Compass.cpp

@@ -1856,21 +1856,6 @@ bool Compass::configured(char *failure_msg, uint8_t failure_msg_len)
     return all_configured;
 }
 
-#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
-// setup _Bearth
-void Compass::_setup_earth_field(void)
-{
-    // assume a earth field strength of 400
-    _sitl.Bearth = {400, 0, 0};
-
-    // rotate _Bearth for inclination and declination. -66 degrees
-    // is the inclination in Canberra, Australia
-    Matrix3f R;
-    R.from_euler(0, ToRad(66), get_declination());
-    _sitl.Bearth = R * _sitl.Bearth;
-}
-#endif
-
 /*
   set the type of motor compensation to use
  */

libraries/AP_Compass/AP_Compass.h

@@ -289,10 +289,6 @@ public:
     bool configured(uint8_t i);
     bool configured(char *failure_msg, uint8_t failure_msg_len);
 
-#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
-    void        _setup_earth_field();
-#endif
-
     // return last update time in microseconds
     uint32_t last_update_usec(void) const { return last_update_usec(_first_usable); }
     uint32_t last_update_usec(uint8_t i) const { return _get_state(Priority(i)).last_update_usec; }
@@ -302,14 +298,6 @@ public:
 
     static const struct AP_Param::GroupInfo var_info[];
 
-    // HIL variables
-    struct {
-        Vector3f Bearth;
-        // float last_declination;
-        // bool healthy[COMPASS_MAX_INSTANCES];
-        // Vector3f field[COMPASS_MAX_INSTANCES];
-    } _sitl;
-
     enum LearnType {
         LEARN_NONE=0,
         LEARN_INTERNAL=1,

libraries/AP_Compass/AP_Compass_SITL.cpp

@@ -9,7 +9,6 @@ AP_Compass_SITL::AP_Compass_SITL()
     : _sitl(AP::sitl())
 {
     if (_sitl != nullptr) {
-        _compass._setup_earth_field();
         for (uint8_t i=0; i<MAX_CONNECTED_MAGS; i++) {
             uint32_t dev_id = _sitl->mag_devid[i];
             if (dev_id == 0) {