text: ////////////////////////////////////////////////////////////
  //
  // SFML - Simple and Fast Multimedia Library
  // Copyright (C) 2007-2015 Laurent Gomila (laurent@sfml-dev.org)
  //
  // This software is provided 'as-is', without any express or implied warranty.
  // In no event will the authors be held liable for any damages arising from the use of this software.
  //
  // Permission is granted to anyone to use this software for any purpose,
  // including commercial applications, and to alter it and redistribute it freely,
  // subject to the following restrictions:
  //
  // 1. The origin of this software must not be misrepresented;
  //    you must not claim that you wrote the original software.
  //    If you use this software in a product, an acknowledgment
  //    in the product documentation would be appreciated but is not required.
  //
  // 2. Altered source versions must be plainly marked as such,
  //    and must not be misrepresented as being the original software.
  //
  // 3. This notice may not be removed or altered from any source distribution.
  //
  ////////////////////////////////////////////////////////////
  
  #ifndef SFML_SENSOR_HPP
  #define SFML_SENSOR_HPP
  
  ////////////////////////////////////////////////////////////
  // Headers
  ////////////////////////////////////////////////////////////
  #include <array>
  
  namespace sf
  {
  ////////////////////////////////////////////////////////////
  /// \brief Give access to the real-time state of the sensors
  ///
  ////////////////////////////////////////////////////////////
  class Sensor
  {
  public:
  
      ////////////////////////////////////////////////////////////
      /// \brief Sensor type
      ///
      ////////////////////////////////////////////////////////////
      enum Type
      {
          Accelerometer,    ///< Measures the raw acceleration (m/s^2)
          Gyroscope,        ///< Measures the raw rotation rates (degrees/s)
          Magnetometer,     ///< Measures the ambient magnetic field (micro-teslas)
          Gravity,          ///< Measures the direction and intensity of gravity, independent of device acceleration (m/s^2)
          UserAcceleration, ///< Measures the direction and intensity of device acceleration, independent of the gravity (m/s^2)
          Orientation,      ///< Measures the absolute 3D orientation (degrees)
  
          Count             ///< Keep last -- the total number of sensor types
      };
  
      ////////////////////////////////////////////////////////////
      /// \brief Check if a sensor is available on the underlying platform
      ///
      /// \param sensor Sensor to check
      ///
      /// \return True if the sensor is available, false otherwise
      ///
      ////////////////////////////////////////////////////////////
      static bool isAvailable(Type sensor);
  
      ////////////////////////////////////////////////////////////
      /// \brief Enable or disable a sensor
      ///
      /// All sensors are disabled by default, to avoid consuming too
      /// much battery power. Once a sensor is enabled, it starts
      /// sending events of the corresponding type.
      ///
      /// This function does nothing if the sensor is unavailable.
      ///
      /// \param sensor  Sensor to enable
      /// \param enabled True to enable, false to disable
      ///
      ////////////////////////////////////////////////////////////
      static void setEnabled(Type sensor, bool enabled);
  
      ////////////////////////////////////////////////////////////
      /// \brief Get the current sensor value
      ///
      /// \param sensor Sensor to read
      ///
      /// \return The current sensor value
      ///
      ////////////////////////////////////////////////////////////
      static std::array<float, 3> getValue(Type sensor);
  };
  
  } // namespace sf
  
  
  #endif // SFML_SENSOR_HPP
  
  
  ////////////////////////////////////////////////////////////
  /// \class sf::Sensor
  /// \ingroup window
  ///
  /// sf::Sensor provides an interface to the state of the
  /// various sensors that a device provides. It only contains static
  /// functions, so it's not meant to be instantiated.
  ///
  /// This class allows users to query the sensors values at any
  /// time and directly, without having to deal with a window and
  /// its events. Compared to the SensorChanged event, sf::Sensor
  /// can retrieve the state of a sensor at any time (you don't need to
  /// store and update its current value on your side).
  ///
  /// Depending on the OS and hardware of the device (phone, tablet, ...),
  /// some sensor types may not be available. You should always check
  /// the availability of a sensor before trying to read it, with the
  /// sf::Sensor::isAvailable function.
  ///
  /// You may wonder why some sensor types look so similar, for example
  /// Accelerometer and Gravity / UserAcceleration. The first one
  /// is the raw measurement of the acceleration, and takes into account
  /// both the earth gravity and the user movement. The others are
  /// more precise: they provide these components separately, which is
  /// usually more useful. In fact they are not direct sensors, they
  /// are computed internally based on the raw acceleration and other sensors.
  /// This is exactly the same for Gyroscope vs Orientation.
  ///
  /// Because sensors consume a non-negligible amount of current, they are
  /// all disabled by default. You must call sf::Sensor::setEnabled for each
  /// sensor in which you are interested.
  ///
  /// Usage example:
  /// \code
  /// if (sf::Sensor::isAvailable(sf::Sensor::Gravity))
  /// {
  ///     // gravity sensor is available
  /// }
  ///
  /// // enable the gravity sensor
  /// sf::Sensor::setEnabled(sf::Sensor::Gravity, true);
  ///
  /// // get the current value of gravity
  /// std::array gravity = sf::Sensor::getValue(sf::Sensor::Gravity);
  /// \endcode
  ///
  ////////////////////////////////////////////////////////////
  