Added plane stalling if going too slow.

src/main.cpp

@@ -216,6 +216,10 @@ int main(int argc, char** args)
                                         glm::sin(-rot.x ), 
                                         glm::cos(rot.y)*glm::cos(rot.x));
         ImGui::Text("Plane speed: %f", Input::m_planeSpeed);     // Print to GUI.
+        if (Input::m_planeSpeed < Input::m_planeMaxSpeed / 4);
+        {
+            pos.y += glm::clamp(1 - (Input::m_planeSpeed) / (Input::m_planeMaxSpeed / 4), -0.1f, 0.0f) * 0.1;
+        }
         plane-> setPosition(pos);
         plane-> setRotation(glm::degrees(rot));