Use default minimum takeoff alt for guided takeoff

src/FirmwarePlugin/APM/APMFirmwarePlugin.cc

@@ -911,6 +911,18 @@ void APMFirmwarePlugin::guidedModeTakeoff(Vehicle* vehicle, double altitudeRel)
     _guidedModeTakeoff(vehicle, altitudeRel);
 }
 
+double APMFirmwarePlugin::minimumTakeoffAltitude(Vehicle* vehicle)
+{
+    QString takeoffAltParam(vehicle->vtol() ? QStringLiteral("Q_RTL_ALT") : QStringLiteral("PILOT_TKOFF_ALT"));
+    float paramDivisor = vehicle->vtol() ? 1.0 : 100.0; // PILOT_TAKEOFF_ALT is in centimeters
+
+    if (vehicle->parameterManager()->parameterExists(FactSystem::defaultComponentId, takeoffAltParam)) {
+        return vehicle->parameterManager()->getParameter(FactSystem::defaultComponentId, takeoffAltParam)->rawValue().toDouble() / paramDivisor;
+    } else {
+        return FirmwarePlugin::minimumTakeoffAltitude(vehicle);
+    }
+}
+
 bool APMFirmwarePlugin::_guidedModeTakeoff(Vehicle* vehicle, double altitudeRel)
 {
     if (!vehicle->multiRotor() && !vehicle->vtol()) {
@@ -924,20 +936,7 @@ bool APMFirmwarePlugin::_guidedModeTakeoff(Vehicle* vehicle, double altitudeRel)
         return false;
     }
 
-    QString takeoffAltParam(vehicle->vtol() ? QStringLiteral("Q_RTL_ALT") : QStringLiteral("PILOT_TKOFF_ALT"));
-    float paramDivisor = vehicle->vtol() ? 1.0 : 100.0; // PILOT_TAKEOFF_ALT is in centimeters
-
-    float takeoffAltRel = 0;
-    if (vehicle->parameterManager()->parameterExists(FactSystem::defaultComponentId, takeoffAltParam)) {
-        Fact* takeoffAltFact = vehicle->parameterManager()->getParameter(FactSystem::defaultComponentId, takeoffAltParam);
-        takeoffAltRel = takeoffAltFact->rawValue().toDouble();
-    }
-    if (takeoffAltRel <= 0) {
-        takeoffAltRel = 2.5;
-    } else {
-        takeoffAltRel /= paramDivisor;   // centimeters -> meters
-    }
-
+    double takeoffAltRel = minimumTakeoffAltitude(vehicle);
     if (!qIsNaN(altitudeRel) && altitudeRel > takeoffAltRel) {
         takeoffAltRel = altitudeRel;
     }

src/FirmwarePlugin/APM/APMFirmwarePlugin.h

@@ -78,6 +78,7 @@ public:
     void                setGuidedMode                   (Vehicle* vehicle, bool guidedMode) override;
     void                guidedModeTakeoff               (Vehicle* vehicle, double altitudeRel) override;
     void                guidedModeGotoLocation          (Vehicle* vehicle, const QGeoCoordinate& gotoCoord) override;
+    double              minimumTakeoffAltitude          (Vehicle* vehicle) override;
     void                startMission                    (Vehicle* vehicle) override;
     QStringList         flightModes                     (Vehicle* vehicle) override;
     QString             flightMode                      (uint8_t base_mode, uint32_t custom_mode) const override;

src/FirmwarePlugin/FirmwarePlugin.h

@@ -130,6 +130,9 @@ public:
     /// Command vehicle to takeoff from current location to a firmware specific height.
     virtual void guidedModeTakeoff(Vehicle* vehicle, double takeoffAltRel);
 
+    /// @return The minimum takeoff altitude (relative) for guided takeoff.
+    virtual double minimumTakeoffAltitude(Vehicle* vehicle) { Q_UNUSED(vehicle); return 10; }
+
     /// Command the vehicle to start the mission
     virtual void startMission(Vehicle* vehicle);
 

src/FirmwarePlugin/PX4/PX4FirmwarePlugin.cc

@@ -384,24 +384,30 @@ void PX4FirmwarePlugin::_mavCommandResult(int vehicleId, int component, int comm
     }
 }
 
-void PX4FirmwarePlugin::guidedModeTakeoff(Vehicle* vehicle, double takeoffAltRel)
+double PX4FirmwarePlugin::minimumTakeoffAltitude(Vehicle* vehicle)
 {
     QString takeoffAltParam("MIS_TAKEOFF_ALT");
 
+    if (vehicle->parameterManager()->parameterExists(FactSystem::defaultComponentId, takeoffAltParam)) {
+        return vehicle->parameterManager()->getParameter(FactSystem::defaultComponentId, takeoffAltParam)->rawValue().toDouble();
+    } else {
+        return FirmwarePlugin::minimumTakeoffAltitude(vehicle);
+    }
+}
+
+void PX4FirmwarePlugin::guidedModeTakeoff(Vehicle* vehicle, double takeoffAltRel)
+{
     double vehicleAltitudeAMSL = vehicle->altitudeAMSL()->rawValue().toDouble();
     if (qIsNaN(vehicleAltitudeAMSL)) {
         qgcApp()->showMessage(tr("Unable to takeoff, vehicle position not known."));
         return;
     }
 
-    if (!vehicle->parameterManager()->parameterExists(FactSystem::defaultComponentId, takeoffAltParam)) {
-        qgcApp()->showMessage(tr("Unable to takeoff, MIS_TAKEOFF_ALT parameter missing."));
-        return;
-    }
-
-    double takeoffAltRelFromVehicle = vehicle->parameterManager()->getParameter(FactSystem::defaultComponentId, takeoffAltParam)->rawValue().toDouble();
+    double takeoffAltRelFromVehicle = minimumTakeoffAltitude(vehicle);
     double takeoffAltAMSL = qMax(takeoffAltRel, takeoffAltRelFromVehicle) + vehicleAltitudeAMSL;
 
+    qDebug() << takeoffAltRel << takeoffAltRelFromVehicle << takeoffAltAMSL << vehicleAltitudeAMSL;
+
     connect(vehicle, &Vehicle::mavCommandResult, this, &PX4FirmwarePlugin::_mavCommandResult);
     vehicle->sendMavCommand(vehicle->defaultComponentId(),
                             MAV_CMD_NAV_TAKEOFF,

src/FirmwarePlugin/PX4/PX4FirmwarePlugin.h

@@ -49,6 +49,7 @@ public:
     void                guidedModeOrbit                 (Vehicle* vehicle, const QGeoCoordinate& centerCoord = QGeoCoordinate(), double radius = NAN, double velocity = NAN, double altitude = NAN) override;
     void                guidedModeGotoLocation          (Vehicle* vehicle, const QGeoCoordinate& gotoCoord) override;
     void                guidedModeChangeAltitude        (Vehicle* vehicle, double altitudeRel) override;
+    double              minimumTakeoffAltitude          (Vehicle* vehicle) override;
     void                startMission                    (Vehicle* vehicle) override;
     bool                isGuidedMode                    (const Vehicle* vehicle) const override;
     int                 manualControlReservedButtonCount(void) override;

src/FlightDisplay/GuidedActionsController.qml

@@ -213,7 +213,7 @@ Item {
             confirmDialog.title = takeoffTitle
             confirmDialog.message = takeoffMessage
             confirmDialog.hideTrigger = Qt.binding(function() { return !showTakeoff })
-            altitudeSlider.reset()
+            altitudeSlider.setToMinimumTakeoff()
             altitudeSlider.visible = true
             break;
         case actionStartMission:

src/FlightDisplay/GuidedAltitudeSlider.qml

@@ -32,6 +32,10 @@ Rectangle {
         altSlider.value = 0
     }
 
+    function setToMinimumTakeoff() {
+        altField.setToMinimumTakeoff()
+    }
+
     function getValue() {
         return altField.newAltitudeMeters - _vehicleAltitude
     }
@@ -70,6 +74,10 @@ Rectangle {
             property real   altLossGain:            altExp * (altSlider.value > 0 ? altGainRange : altLossRange)
             property real   newAltitudeMeters:      _vehicleAltitude + altLossGain
             property string newAltitudeAppUnits:    QGroundControl.metersToAppSettingsDistanceUnits(newAltitudeMeters).toFixed(1)
+
+            function setToMinimumTakeoff() {
+                altSlider.value = Math.pow(_activeVehicle.minimumTakeoffAltitude() / altGainRange, 1.0/3.0)
+            }
         }
     }
 

src/Vehicle/Vehicle.cc

@@ -2266,6 +2266,11 @@ void Vehicle::guidedModeTakeoff(double altitudeRelative)
     _firmwarePlugin->guidedModeTakeoff(this, altitudeRelative);
 }
 
+double Vehicle::minimumTakeoffAltitude(void)
+{
+    return _firmwarePlugin->minimumTakeoffAltitude(this);
+}
+
 void Vehicle::startMission(void)
 {
     _firmwarePlugin->startMission(this);

src/Vehicle/Vehicle.h

@@ -423,6 +423,9 @@ public:
     /// Command vehicle to takeoff from current location
     Q_INVOKABLE void guidedModeTakeoff(double altitudeRelative);
 
+    /// @return The minimum takeoff altitude (relative) for guided takeoff.
+    Q_INVOKABLE double minimumTakeoffAltitude(void);
+
     /// Command vehicle to move to specified location (altitude is included and relative)
     Q_INVOKABLE void guidedModeGotoLocation(const QGeoCoordinate& gotoCoord);