vmount: refactor architecture & use C++

This splits vmount into inputs and outputs modules with a small API in
between. It allows for greater flexibility, as any input method can be
combined with any output method. At the same time it is easy to add a new
input or output module.

src/drivers/vmount/output.cpp

@@ -0,0 +1,205 @@
+/****************************************************************************
+*
+*   Copyright (c) 2016 PX4 Development Team. All rights reserved.
+*
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions
+* are met:
+*
+* 1. Redistributions of source code must retain the above copyright
+*    notice, this list of conditions and the following disclaimer.
+* 2. Redistributions in binary form must reproduce the above copyright
+*    notice, this list of conditions and the following disclaimer in
+*    the documentation and/or other materials provided with the
+*    distribution.
+* 3. Neither the name PX4 nor the names of its contributors may be
+*    used to endorse or promote products derived from this software
+*    without specific prior written permission.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+* POSSIBILITY OF SUCH DAMAGE.
+*
+****************************************************************************/
+
+/**
+ * @file output.cpp
+ * @author Leon Müller (thedevleon)
+ * @author Beat Küng <beat-kueng@gmx.net>
+ *
+ */
+
+#include "output.h"
+#include <errno.h>
+
+#include <uORB/topics/vehicle_attitude.h>
+#include <uORB/topics/vehicle_global_position.h>
+#include <px4_defines.h>
+#include <geo/geo.h>
+#include <math.h>
+
+#define LATLON_TO_M  0.01113195
+
+namespace vmount
+{
+
+OutputBase::OutputBase(const OutputConfig &output_config)
+	: _config(output_config)
+{
+	_last_update = hrt_absolute_time();
+}
+
+OutputBase::~OutputBase()
+{
+	if (_vehicle_attitude_sub >= 0) {
+		orb_unsubscribe(_vehicle_attitude_sub);
+	}
+
+	if (_vehicle_global_position_sub >= 0) {
+		orb_unsubscribe(_vehicle_global_position_sub);
+	}
+}
+
+int OutputBase::initialize()
+{
+	if ((_vehicle_attitude_sub = orb_subscribe(ORB_ID(vehicle_attitude))) < 0) {
+		return -errno;
+	}
+
+	if ((_vehicle_global_position_sub = orb_subscribe(ORB_ID(vehicle_global_position))) < 0) {
+		return -errno;
+	}
+
+	return 0;
+}
+
+float OutputBase::_calculate_pitch(double lon, double lat, float altitude,
+				   const vehicle_global_position_s &global_position)
+{
+	double scale = cos(M_DEG_TO_RAD * ((global_position.lat + lat) * 0.00000005));
+	float x = (float)((lon - global_position.lon) * scale * LATLON_TO_M);
+	float y = (float)((lat - global_position.lat) * LATLON_TO_M);
+	float z = altitude - global_position.alt;
+	float target_distance = sqrtf(x * x + y * y);
+
+	return atan2f(z, target_distance) * (float)M_RAD_TO_DEG;
+}
+
+void OutputBase::_set_angle_setpoints(const ControlData *control_data)
+{
+	_cur_control_data = control_data;
+
+	for (int i = 0; i < 3; ++i) {
+		_stabilize[i] = control_data->stabilize_axis[i];
+		_angle_speeds[i] = 0.f;
+	}
+
+	switch (control_data->type) {
+	case ControlData::Type::Angle:
+		for (int i = 0; i < 3; ++i) {
+			if (control_data->type_data.angle.is_speed[i]) {
+				_angle_speeds[i] = control_data->type_data.angle.angles[i];
+
+			} else {
+				_angle_setpoints[i] = control_data->type_data.angle.angles[i];
+			}
+		}
+
+		break;
+
+	case ControlData::Type::LonLat:
+		_handle_position_update(true);
+		break;
+
+	case ControlData::Type::Neutral:
+		_angle_setpoints[0] = 0.f;
+		_angle_setpoints[1] = 0.f;
+		_angle_setpoints[2] = 0.f;
+		break;
+	}
+}
+
+void OutputBase::_handle_position_update(bool force_update)
+{
+	bool need_update = force_update;
+
+	if (!_cur_control_data || _cur_control_data->type != ControlData::Type::LonLat) {
+		return;
+	}
+
+	if (!force_update) {
+		orb_check(_vehicle_global_position_sub, &need_update);
+	}
+
+	if (!need_update) {
+		return;
+	}
+
+	vehicle_global_position_s vehicle_global_position;
+	orb_copy(ORB_ID(vehicle_global_position), _vehicle_global_position_sub, &vehicle_global_position);
+
+	float pitch;
+	const double &lon = _cur_control_data->type_data.lonlat.lon;
+	const double &lat = _cur_control_data->type_data.lonlat.lat;
+	const float &alt = _cur_control_data->type_data.lonlat.altitude;
+
+	if (_cur_control_data->type_data.lonlat.pitch_fixed_angle >= -M_PI_F) {
+		pitch = _cur_control_data->type_data.lonlat.pitch_fixed_angle;
+
+	} else {
+		pitch = _calculate_pitch(lon, lat, alt, vehicle_global_position);
+	}
+
+	float roll = _cur_control_data->type_data.lonlat.roll_angle;
+	float yaw = get_bearing_to_next_waypoint(vehicle_global_position.lat, vehicle_global_position.lon,
+			lat, lon) * (float)M_RAD_TO_DEG;
+
+	_angle_setpoints[0] = roll;
+	_angle_setpoints[1] = pitch;
+	_angle_setpoints[2] = yaw;
+}
+
+void OutputBase::_calculate_output_angles(const hrt_abstime &t)
+{
+	//take speed into account
+	float dt = (t - _last_update) / 1.e6f;
+
+	for (int i = 0; i < 3; ++i) {
+		_angle_setpoints[i] += dt * _angle_speeds[i];
+	}
+
+	//get the output angles and stabilize if necessary
+	vehicle_attitude_s vehicle_attitude;
+
+	if (_stabilize[0] || _stabilize[1] || _stabilize[2]) {
+		orb_copy(ORB_ID(vehicle_attitude), _vehicle_attitude_sub, &vehicle_attitude);
+	}
+
+	float att[3] = { vehicle_attitude.roll, vehicle_attitude.pitch, vehicle_attitude.yaw };
+
+	for (int i = 0; i < 3; ++i) {
+		if (_stabilize[i]) {
+			_angle_outputs[i] = _angle_setpoints[i] - att[i];
+
+		} else {
+			_angle_outputs[i] = _angle_setpoints[i];
+		}
+
+		//bring angles into proper range [-pi, pi]
+		while (_angle_outputs[i] > M_PI_F) { _angle_outputs[i] -= 2.f * M_PI_F; }
+
+		while (_angle_outputs[i] < -M_PI_F) { _angle_outputs[i] += 2.f * M_PI_F; }
+	}
+}
+
+} /* namespace vmount */
+