Copter: reduce args passed to get_surface_tracking_climb_rate

The same arguments are always passed in

ArduCopter/Attitude.cpp

@@ -121,7 +121,7 @@ float Copter::get_non_takeoff_throttle()
 
 // get_surface_tracking_climb_rate - hold copter at the desired distance above the ground
 //      returns climb rate (in cm/s) which should be passed to the position controller
-float Copter::get_surface_tracking_climb_rate(int16_t target_rate, float current_alt_target, float dt)
+float Copter::get_surface_tracking_climb_rate(int16_t target_rate)
 {
 #if RANGEFINDER_ENABLED == ENABLED
     if (!copter.rangefinder_alt_ok()) {
@@ -130,9 +130,10 @@ float Copter::get_surface_tracking_climb_rate(int16_t target_rate, float current
     }
 
     static uint32_t last_call_ms = 0;
+    const float current_alt = inertial_nav.get_altitude();
+    const float current_alt_target = pos_control->get_alt_target();
     float distance_error;
     float velocity_correction;
-    float current_alt = inertial_nav.get_altitude();
 
     uint32_t now = millis();
 
@@ -146,7 +147,7 @@ float Copter::get_surface_tracking_climb_rate(int16_t target_rate, float current
 
     // adjust rangefinder target alt if motors have not hit their limits
     if ((target_rate<0 && !motors->limit.throttle_lower) || (target_rate>0 && !motors->limit.throttle_upper)) {
-        target_rangefinder_alt += target_rate * dt;
+        target_rangefinder_alt += target_rate * G_Dt;
     }
 
     /*

ArduCopter/Copter.h

@@ -617,7 +617,7 @@ private:
     void set_throttle_takeoff();
     float get_pilot_desired_climb_rate(float throttle_control);
     float get_non_takeoff_throttle();
-    float get_surface_tracking_climb_rate(int16_t target_rate, float current_alt_target, float dt);
+    float get_surface_tracking_climb_rate(int16_t target_rate);
     float get_avoidance_adjusted_climbrate(float target_rate);
     void set_accel_throttle_I_from_pilot_throttle();
     void rotate_body_frame_to_NE(float &x, float &y);

ArduCopter/mode.cpp

@@ -688,9 +688,9 @@ Copter::Mode::AltHoldModeState Copter::Mode::get_alt_hold_state(float target_cli
 // these are candidates for moving into the Mode base
 // class.
 
-float Copter::Mode::get_surface_tracking_climb_rate(int16_t target_rate, float current_alt_target, float dt)
+float Copter::Mode::get_surface_tracking_climb_rate(int16_t target_rate)
 {
-    return copter.get_surface_tracking_climb_rate(target_rate, current_alt_target, dt);
+    return copter.get_surface_tracking_climb_rate(target_rate);
 }
 
 float Copter::Mode::get_pilot_desired_yaw_rate(int16_t stick_angle)

ArduCopter/mode.h

@@ -197,7 +197,7 @@ protected:
     // pass-through functions to reduce code churn on conversion;
     // these are candidates for moving into the Mode base
     // class.
-    float get_surface_tracking_climb_rate(int16_t target_rate, float current_alt_target, float dt);
+    float get_surface_tracking_climb_rate(int16_t target_rate);
     float get_pilot_desired_yaw_rate(int16_t stick_angle);
     float get_pilot_desired_climb_rate(float throttle_control);
     float get_pilot_desired_throttle() const;

ArduCopter/mode_althold.cpp

@@ -96,7 +96,7 @@ void Copter::ModeAltHold::run()
 #endif
 
         // adjust climb rate using rangefinder
-        target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate, pos_control->get_alt_target(), G_Dt);
+        target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate);
 
         // get avoidance adjusted climb rate
         target_climb_rate = get_avoidance_adjusted_climbrate(target_climb_rate);

ArduCopter/mode_circle.cpp

@@ -44,7 +44,7 @@ void Copter::ModeCircle::run()
     // adjust climb rate using rangefinder
     if (copter.rangefinder_alt_ok()) {
         // if rangefinder is ok, use surface tracking
-        target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate, pos_control->get_alt_target(), G_Dt);
+        target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate);
     }
 
     // if not armed set throttle to zero and exit immediately

ArduCopter/mode_flowhold.cpp

@@ -300,7 +300,7 @@ void Copter::ModeFlowHold::run()
         copter.motors->set_desired_spool_state(AP_Motors::DesiredSpoolState::THROTTLE_UNLIMITED);
 
         // adjust climb rate using rangefinder
-        target_climb_rate = copter.get_surface_tracking_climb_rate(target_climb_rate, copter.pos_control->get_alt_target(), copter.G_Dt);
+        target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate);
 
         // get avoidance adjusted climb rate
         target_climb_rate = copter.get_avoidance_adjusted_climbrate(target_climb_rate);

ArduCopter/mode_loiter.cpp

@@ -187,7 +187,7 @@ void Copter::ModeLoiter::run()
         attitude_control->input_euler_angle_roll_pitch_euler_rate_yaw(loiter_nav->get_roll(), loiter_nav->get_pitch(), target_yaw_rate);
 
         // adjust climb rate using rangefinder
-        target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate, pos_control->get_alt_target(), G_Dt);
+        target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate);
 
         // get avoidance adjusted climb rate
         target_climb_rate = get_avoidance_adjusted_climbrate(target_climb_rate);

ArduCopter/mode_poshold.cpp

@@ -234,7 +234,7 @@ void Copter::ModePosHold::run()
         // adjust climb rate using rangefinder
         if (copter.rangefinder_alt_ok()) {
             // if rangefinder is ok, use surface tracking
-            target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate, pos_control->get_alt_target(), G_Dt);
+            target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate);
         }
 
         // get avoidance adjusted climb rate

ArduCopter/mode_sport.cpp

@@ -121,7 +121,7 @@ void Copter::ModeSport::run()
         motors->set_desired_spool_state(AP_Motors::DesiredSpoolState::THROTTLE_UNLIMITED);
 
         // adjust climb rate using rangefinder
-        target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate, pos_control->get_alt_target(), G_Dt);
+        target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate);
 
         // get avoidance adjusted climb rate
         target_climb_rate = get_avoidance_adjusted_climbrate(target_climb_rate);

ArduCopter/mode_zigzag.cpp

@@ -192,7 +192,7 @@ void Copter::ModeZigZag::manual_control()
     attitude_control->input_euler_angle_roll_pitch_euler_rate_yaw(loiter_nav->get_roll(), loiter_nav->get_pitch(), target_yaw_rate);
 
     // adjust climb rate using rangefinder
-    target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate, pos_control->get_alt_target(), G_Dt);
+    target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate);
 
     // get avoidance adjusted climb rate
     target_climb_rate = get_avoidance_adjusted_climbrate(target_climb_rate);