SITL: Add missing const in member functions

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

libraries/SITL/SIM_Aircraft.h

@@ -50,7 +50,7 @@ public:
       set simulation speedup
      */
     void set_speedup(float speedup);
-    float get_speedup() { return target_speedup; }
+    float get_speedup() const { return target_speedup; }
 
     /*
       set instance number

libraries/SITL/SIM_BalanceBot.cpp

@@ -34,7 +34,7 @@ BalanceBot::BalanceBot(const char *frame_str) :
 /*
    return yaw rate in degrees/second given steering_angle
 */
-float BalanceBot::calc_yaw_rate(float steering)
+float BalanceBot::calc_yaw_rate(float steering) const
 {
     float wheel_base_length = 0.15f;
     return steering * degrees( skid_turn_rate/wheel_base_length );

libraries/SITL/SIM_BalanceBot.h

@@ -40,7 +40,7 @@ private:
 
     float skid_turn_rate;
 
-    float calc_yaw_rate(float steering);
+    float calc_yaw_rate(float steering) const;
 };
 
 } // namespace SITL

libraries/SITL/SIM_Battery.cpp

@@ -71,7 +71,7 @@ static const struct {
 /*
   use table to get resting voltage from remaining capacity
  */
-float Battery::get_resting_voltage(float charge_pct)
+float Battery::get_resting_voltage(float charge_pct) const
 {
     const float max_cell_voltage = soc_table[0].volt_per_cell;
     for (uint8_t i=1; i<ARRAY_SIZE(soc_table); i++) {

libraries/SITL/SIM_Battery.h

@@ -45,7 +45,7 @@ private:
     // 10Hz filter for battery voltage
     LowPassFilterFloat voltage_filter{10};
 
-    float get_resting_voltage(float charge_pct);
+    float get_resting_voltage(float charge_pct) const;
     void set_initial_SoC(float voltage);
 };
 }

libraries/SITL/SIM_Gripper_EPM.cpp

@@ -101,7 +101,7 @@ void Gripper_EPM::update(const struct sitl_input &input)
 }
 
 
-bool Gripper_EPM::should_report()
+bool Gripper_EPM::should_report() const
 {
     if (AP_HAL::micros64() - last_report_us < report_interval) {
         return false;
@@ -114,7 +114,7 @@ bool Gripper_EPM::should_report()
     return false;
 }
 
-float Gripper_EPM::tesla()
+float Gripper_EPM::tesla() const
 {
     // https://en.wikipedia.org/wiki/Orders_of_magnitude_(magnetic_field)
     // 200N lifting capacity ~= 2.5T

libraries/SITL/SIM_Gripper_EPM.h

@@ -58,12 +58,12 @@ private:
 
     uint64_t last_update_us;
 
-    bool should_report();
+    bool should_report() const;
 
     void update_from_demand();
     void update_servobased(int16_t gripper_pwm);
 
-    float tesla();
+    float tesla() const;
 
     float demand;
 };

libraries/SITL/SIM_Gripper_Servo.cpp

@@ -114,7 +114,7 @@ void Gripper_Servo::update(const struct sitl_input &input)
     last_update_us = now;
 }
 
-bool Gripper_Servo::should_report()
+bool Gripper_Servo::should_report() const
 {
     if (AP_HAL::micros64() - last_report_us < report_interval) {
         return false;

libraries/SITL/SIM_Gripper_Servo.h

@@ -58,7 +58,7 @@ private:
 
     uint64_t last_update_us;
 
-    bool should_report();
+    bool should_report() const;
 
     // dangle load from a string:
     const float string_length = 2.0f; // metres

libraries/SITL/SIM_JSBSim.cpp

@@ -255,7 +255,7 @@ bool JSBSim::start_JSBSim(void)
 /*
   check for stdout from JSBSim
  */
-void JSBSim::check_stdout(void)
+void JSBSim::check_stdout(void) const
 {
     char line[100];
     ssize_t ret = ::read(jsbsim_stdout, line, sizeof(line));
@@ -269,7 +269,7 @@ void JSBSim::check_stdout(void)
 /*
   a simple function to wait for a string on jsbsim_stdout
  */
-bool JSBSim::expect(const char *str)
+bool JSBSim::expect(const char *str) const
 {
     const char *basestr = str;
     while (*str) {

libraries/SITL/SIM_JSBSim.h

@@ -74,8 +74,8 @@ private:
     bool open_fdm_socket(void);
     void send_servos(const struct sitl_input &input);
     void recv_fdm(const struct sitl_input &input);
-    void check_stdout(void);
-    bool expect(const char *str);
+    void check_stdout(void) const;
+    bool expect(const char *str) const;
 
     void drain_control_socket();
 };

libraries/SITL/SIM_Motor.cpp

@@ -121,7 +121,7 @@ void Motor::calculate_forces(const struct sitl_input &input,
 /*
   update and return current value of a servo. Calculated as 1000..2000
  */
-uint16_t Motor::update_servo(uint16_t demand, uint64_t time_usec, float &last_value)
+uint16_t Motor::update_servo(uint16_t demand, uint64_t time_usec, float &last_value) const
 {
     if (servo_rate <= 0) {
         return demand;

libraries/SITL/SIM_Motor.h

@@ -79,7 +79,7 @@ public:
                           float effective_prop_area,
                           float voltage);
 
-    uint16_t update_servo(uint16_t demand, uint64_t time_usec, float &last_value);
+    uint16_t update_servo(uint16_t demand, uint64_t time_usec, float &last_value) const;
 
     // get current
     float get_current(void) const;

libraries/SITL/SIM_Parachute.cpp

@@ -60,7 +60,7 @@ void Parachute::update(const struct sitl_input &input)
     last_update_us = now;
 }
 
-bool Parachute::should_report()
+bool Parachute::should_report() const
 {
     if (AP_HAL::micros64() - last_report_us < report_interval) {
         return false;

libraries/SITL/SIM_Parachute.h

@@ -51,7 +51,7 @@ public:
 
     uint64_t last_update_us;
 
-    bool should_report();
+    bool should_report() const;
     bool zero_report_done = false;
 };
 

libraries/SITL/SIM_Rover.cpp

@@ -42,7 +42,7 @@ SimRover::SimRover(const char *frame_str) :
 /*
   return turning circle (diameter) in meters for steering angle proportion in degrees
 */
-float SimRover::turn_circle(float steering)
+float SimRover::turn_circle(float steering) const
 {
     if (fabsf(steering) < 1.0e-6) {
         return 0;

libraries/SITL/SIM_Rover.h

@@ -45,7 +45,7 @@ private:
     float skid_turn_rate = 140.0f;
     bool skid_steering;
 
-    float turn_circle(float steering);
+    float turn_circle(float steering) const;
     float calc_yaw_rate(float steering, float speed);
     float calc_lat_accel(float steering_angle, float speed);
 };

libraries/SITL/SIM_SerialDevice.cpp

@@ -75,7 +75,7 @@ bool SerialDevice::init_sitl_pointer()
 }
 
 
-ssize_t SerialDevice::read_from_autopilot(char *buffer, const size_t size)
+ssize_t SerialDevice::read_from_autopilot(char *buffer, const size_t size) const
 {
     const ssize_t ret = ::read(read_fd_my_end, buffer, size);
     // if (ret > 0) {
@@ -93,7 +93,7 @@ ssize_t SerialDevice::read_from_autopilot(char *buffer, const size_t size)
     return ret;
 }
 
-ssize_t SerialDevice::write_to_autopilot(const char *buffer, const size_t size)
+ssize_t SerialDevice::write_to_autopilot(const char *buffer, const size_t size) const
 {
     const ssize_t ret = write(fd_my_end, buffer, size);
     // ::fprintf(stderr, "write to autopilot: (");

libraries/SITL/SIM_SerialDevice.h

@@ -29,12 +29,12 @@ public:
 
     // return fd on which data from the device can be read
     // to the device can be written
-    int fd() { return fd_their_end; }
+    int fd() const { return fd_their_end; }
     // return fd on which data to the device can be written
-    int write_fd() { return read_fd_their_end; }
+    int write_fd() const { return read_fd_their_end; }
 
-    ssize_t read_from_autopilot(char *buffer, size_t size);
-    ssize_t write_to_autopilot(const char *buffer, size_t size);
+    ssize_t read_from_autopilot(char *buffer, size_t size) const;
+    ssize_t write_to_autopilot(const char *buffer, size_t size) const;
 
 protected:
 

libraries/SITL/SIM_Submarine.cpp

@@ -151,7 +151,7 @@ float Submarine::calculate_sea_floor_depth(const Vector3f &/*position*/)
  * $ F_D = rho * v^2 * A * C_D / 2 $
  * rho = water density (kg/m^3), V = velocity (m/s), A = area (m^2), C_D = drag_coefficient
  */
-void Submarine::calculate_drag_force(const Vector3f &velocity, const Vector3f &drag_coefficient, Vector3f &force)
+void Submarine::calculate_drag_force(const Vector3f &velocity, const Vector3f &drag_coefficient, Vector3f &force) const
 {
     /**
      * @brief It's necessary to keep the velocity orientation from the body frame.
@@ -182,7 +182,7 @@ void Submarine::calculate_drag_force(const Vector3f &velocity, const Vector3f &d
  * @param angular_velocity Body frame velocity of fluid
  * @param drag_coefficient Rotational drag coefficient of body
  */
-void Submarine::calculate_angular_drag_torque(const Vector3f &angular_velocity, const Vector3f &drag_coefficient, Vector3f &torque)
+void Submarine::calculate_angular_drag_torque(const Vector3f &angular_velocity, const Vector3f &drag_coefficient, Vector3f &torque) const
 {
      /**
      * @brief It's necessary to keep the velocity orientation from the body frame.

libraries/SITL/SIM_Submarine.h

@@ -96,9 +96,9 @@ protected:
     // calculate buoyancy
     float calculate_buoyancy_acceleration();
     // calculate drag from velocity and drag coefficient
-    void calculate_drag_force(const Vector3f &velocity, const Vector3f &drag_coefficient, Vector3f &force);
+    void calculate_drag_force(const Vector3f &velocity, const Vector3f &drag_coefficient, Vector3f &force) const;
     // calculate torque water resistance
-    void calculate_angular_drag_torque(const Vector3f &angular_velocity, const Vector3f &drag_coefficient, Vector3f &torque);
+    void calculate_angular_drag_torque(const Vector3f &angular_velocity, const Vector3f &drag_coefficient, Vector3f &torque) const;
     // calculate torque induced by buoyancy foams
     void calculate_buoyancy_torque(Vector3f &torque);
 

libraries/SITL/SIM_Tracker.cpp

@@ -25,7 +25,7 @@ namespace SITL {
 /*
   update function for position (normal) servos.
 */
-void Tracker::update_position_servos(float delta_time, float &yaw_rate, float &pitch_rate)
+void Tracker::update_position_servos(float delta_time, float &yaw_rate, float &pitch_rate) const
 {
     float pitch_target = pitch_input*pitch_range;
     float yaw_target = yaw_input*yaw_range;
@@ -39,7 +39,7 @@ void Tracker::update_position_servos(float delta_time, float &yaw_rate, float &p
   These servos either move at a constant rate or are still
   Returns (yaw_rate,pitch_rate) tuple
 */
-void Tracker::update_onoff_servos(float &yaw_rate, float &pitch_rate)
+void Tracker::update_onoff_servos(float &yaw_rate, float &pitch_rate) const
 {
     if (fabsf(yaw_input) < 0.1) {
         yaw_rate = 0;

libraries/SITL/SIM_Tracker.h

@@ -52,8 +52,8 @@ private:
     float yaw_current_relative;
     float pitch_current_relative;
 
-    void update_position_servos(float delta_time, float &yaw_rate, float &pitch_rate);
-    void update_onoff_servos(float &yaw_rate, float &pitch_rate);
+    void update_position_servos(float delta_time, float &yaw_rate, float &pitch_rate) const;
+    void update_onoff_servos(float &yaw_rate, float &pitch_rate) const;
 };
 
 } // namespace SITL

libraries/SITL/SITL.cpp

@@ -396,7 +396,7 @@ const AP_Param::GroupInfo SITL::var_ins[] = {
 };
     
 /* report SITL state via MAVLink SIMSTATE*/
-void SITL::simstate_send(mavlink_channel_t chan)
+void SITL::simstate_send(mavlink_channel_t chan) const
 {
     float yaw;
 
@@ -421,7 +421,7 @@ void SITL::simstate_send(mavlink_channel_t chan)
 }
 
 /* report SITL state via MAVLink SIM_STATE */
-void SITL::sim_state_send(mavlink_channel_t chan)
+void SITL::sim_state_send(mavlink_channel_t chan) const
 {
     // convert to same conventions as DCM
     float yaw = state.yawDeg;

libraries/SITL/SITL.h

@@ -376,8 +376,8 @@ public:
 
     time_t start_time_UTC;
 
-    void simstate_send(mavlink_channel_t chan);
-    void sim_state_send(mavlink_channel_t chan);
+    void simstate_send(mavlink_channel_t chan) const;
+    void sim_state_send(mavlink_channel_t chan) const;
 
     void Log_Write_SIMSTATE();
 
@@ -434,8 +434,8 @@ public:
     float get_rangefinder(uint8_t instance);
 
     // get the apparent wind speed and direction as set by external physics backend
-    float get_apparent_wind_dir(){return state.wind_vane_apparent.direction;}
-    float get_apparent_wind_spd(){return state.wind_vane_apparent.speed;}
+    float get_apparent_wind_dir() const{return state.wind_vane_apparent.direction;}
+    float get_apparent_wind_spd() const{return state.wind_vane_apparent.speed;}
 
     // IMU temperature calibration params
     AP_Float imu_temp_start;