Pressure.h

/***************************************************************************
 *   Copyright (C) 2023 by Stefan Kebekus                                  *
 *   stefan.kebekus@gmail.com                                              *
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 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 3 of the License, or     *
 *   (at your option) any later version.                                   *
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 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
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 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
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 ***************************************************************************/
 
#pragma once
 
#include <QObject>
#include <QQmlEngine>
#include <QtMath>
 
 
namespace Units {

    class Pressure {
        Q_GADGET
        QML_VALUE_TYPE(pressure)
 
    public:
        static constexpr auto fromHPa(double pressureInHPa) -> Pressure
        {
            Pressure result;
            result.m_pressureInPa = 100.0*pressureInHPa;
            return result;
        }

        static constexpr auto fromInHg(double pressureInInHg) -> Pressure
        {
            Pressure result;
            result.m_pressureInPa = PascalPerInHg*pressureInInHg;
            return result;
        }

        static constexpr auto fromPa(double pressureInPa) -> Pressure
        {
            Pressure result;
            result.m_pressureInPa = pressureInPa;
            return result;
        }

        [[nodiscard]] Q_INVOKABLE bool isFinite() const
        {
            return std::isfinite(m_pressureInPa);
        }

        Q_INVOKABLE Units::Pressure& operator+=(Units::Pressure other)
        {
            m_pressureInPa += other.m_pressureInPa;
            return *this;
        }

        [[nodiscard]] Q_INVOKABLE std::partial_ordering operator<=>(const Units::Pressure& rhs) const = default;

        [[nodiscard]] Q_INVOKABLE double toHPa() const
        {
            return m_pressureInPa/100.0;
        }

        [[nodiscard]] Q_INVOKABLE double toInHg() const
        {
            return m_pressureInPa/PascalPerInHg;
        }

        [[nodiscard]] Q_INVOKABLE double toPa() const
        {
            return m_pressureInPa;
        }
 
    private:
        static constexpr double PascalPerInHg = 3386.39;
 
        // Pressure in Pascal
        double m_pressureInPa{ NAN };
    };
} // namespace Units
 

auto operator<<(QDataStream &out, Units::Pressure pressure) -> QDataStream &;
 

auto operator>>(QDataStream &in, Units::Pressure &pressure) -> QDataStream &;
 
 
// Declare meta types
Q_DECLARE_METATYPE(Units::Pressure)