Disable wheel button if lowering would be dangerous.

src/DynamicBody.cpp

@@ -110,6 +110,22 @@ void DynamicBody::SetFrame(Frame *f)
 	m_externalForce = m_gravityForce = m_atmosForce = vector3d(0.0);
 }
 
+double DynamicBody::CalcAtmosphericForce(double dragCoeff) const
+{
+	Body *body = GetFrame()->GetBody();
+	if (!body || !GetFrame()->IsRotFrame() || !body->IsType(Object::PLANET))
+		return 0.0;
+	Planet *planet = static_cast<Planet*>(body);
+	double dist = GetPosition().Length();
+	double speed = m_vel.Length();
+	double pressure, density;
+	planet->GetAtmosphericState(dist, &pressure, &density);
+	const double radius = GetClipRadius();		// bogus, preserving behaviour
+	const double area = radius;
+	// ^^^ yes that is as stupid as it looks
+	return 0.5*density*speed*speed*area*dragCoeff;
+}
+
 void DynamicBody::CalcExternalForce()
 {
 	// gravity
@@ -128,16 +144,8 @@ void DynamicBody::CalcExternalForce()
 	// atmospheric drag
 	if (body && GetFrame()->IsRotFrame() && body->IsType(Object::PLANET))
 	{
-		Planet *planet = static_cast<Planet*>(body);
-		double dist = GetPosition().Length();
-		double speed = m_vel.Length();
-		double pressure, density;
-		planet->GetAtmosphericState(dist, &pressure, &density);
-		const double radius = GetClipRadius();		// bogus, preserving behaviour
-		const double AREA = radius;
-		// ^^^ yes that is as stupid as it looks
 		vector3d dragDir = -m_vel.NormalizedSafe();
-		vector3d fDrag = 0.5*density*speed*speed*AREA*m_dragCoeff*dragDir;
+		vector3d fDrag = CalcAtmosphericForce(m_dragCoeff)*dragDir;
 
 		// make this a bit less daft at high time accel
 		// only allow atmosForce to increase by .1g per frame

src/DynamicBody.h

@@ -29,6 +29,7 @@ public:
 	bool IsMoving() const { return m_isMoving; }
 	virtual double GetMass() const { return m_mass; }	// XXX don't override this
 	virtual void TimeStepUpdate(const float timeStep);
+	double CalcAtmosphericForce(double dragCoeff) const;
 	void CalcExternalForce();
 	void UndoTimestep();
 

src/Ship.cpp

@@ -876,6 +876,13 @@ void Ship::FireWeapon(int num)
 	LuaEvent::Queue("onShipFiring", this);
 }
 
+double Ship::ExtrapolateHullTemperature() const
+{
+	const double dragCoeff = DynamicBody::DEFAULT_DRAG_COEFF * 1.25;
+	const double dragGs = CalcAtmosphericForce(dragCoeff) / (GetMass() * 9.81);
+	return dragGs / 5.0;
+}
+
 double Ship::GetHullTemperature() const
 {
 	double dragGs = GetAtmosForce().Length() / (GetMass() * 9.81);

src/Ship.h

@@ -152,6 +152,8 @@ public:
 
 	// 0 to 1.0 is alive, > 1.0 = death
 	double GetHullTemperature() const;
+	// Calculate temperature we would have with wheels down
+	double ExtrapolateHullTemperature() const;
 
 	enum ECMResult {
 		ECM_NOT_INSTALLED,

src/WorldView.cpp

@@ -567,6 +567,10 @@ void WorldView::RefreshButtonStateAndVisibility()
 		m_game->GetCpan()->SetOverlayToolTip(ShipCpanel::OVERLAY_BOTTOM_RIGHT, Lang::SHIP_ALTITUDE_ABOVE_TERRAIN);
 	}
 
+	if (is_equal_exact(Pi::player->GetWheelState(), 0.0f) && Pi::player->ExtrapolateHullTemperature() > 0.7)
+		m_wheelsButton->Hide();
+	else
+		m_wheelsButton->Show();
 	m_wheelsButton->SetActiveState(int(Pi::player->GetWheelState()) || Pi::player->GetWheelTransition() == 1);
 
 	RefreshHyperspaceButton();