src/Atmosphere/Temperature.hpp

   1 /*
   2 Copyright_License {
   3
   4   XCSoar Glide Computer - http://www.xcsoar.org/
   5   Copyright (C) 2000-2013 The XCSoar Project
   6   A detailed list of copyright holders can be found in the file "AUTHORS".
   7
   8   This program is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU General Public License
  10   as published by the Free Software Foundation; either version 2
  11   of the License, or (at your option) any later version.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with this program; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 }
  22 */
  23
  24 #ifndef XCSOAR_ATMOSPHERE_TEMPERATURE_HPP
  25 #define XCSOAR_ATMOSPHERE_TEMPERATURE_HPP
  26
  27 #include "Math/fixed.hpp"
  28
  29 /**
  30  * The offset between 0 Kelvin and 0 degrees Celsius [K].
  31  */
  32 static constexpr fixed CELSIUS_OFFSET(273.15);
  33
  34 /**
  35  * Convert a temperature from Kelvin to degrees Celsius.
  36  */
  37 constexpr
  38 static inline fixed
  39 KelvinToCelsius(fixed kelvin)
  40 {
  41   return kelvin - CELSIUS_OFFSET;
  42 }
  43
  44 /**
  45  * Convert a temperature from degrees Celsius to Kelvin.
  46  */
  47 constexpr
  48 static inline fixed
  49 CelsiusToKelvin(fixed celsius)
  50 {
  51   return celsius + CELSIUS_OFFSET;
  52 }
  53
  54 #endif