SpeedOfSound.h

Go to the documentation of this file.

//
//      ██╗██████╗     ██╗     ██╗██████╗ ███████╗
//      ██║██╔══██╗    ██║     ██║██╔══██╗██╔════╝      ** JPL Spatial **
//      ██║██████╔╝    ██║     ██║██████╔╝███████╗
// ██   ██║██╔═══╝     ██║     ██║██╔══██╗╚════██║      https://github.com/Jaytheway/JPLSpatial
// ╚█████╔╝██║         ███████╗██║██████╔╝███████║
//  ╚════╝ ╚═╝         ╚══════╝╚═╝╚═════╝ ╚══════╝
//
//   Copyright 2026 Jaroslav Pevno, JPL Spatial is offered under the terms of the ISC license:
//
//   Permission to use, copy, modify, and/or distribute this software for any purpose with or
//   without fee is hereby granted, provided that the above copyright notice and this permission
//   notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
//   WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
//   AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
//   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
//   WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
//   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
#pragma once
 
#include "Math/Math.h"
 
namespace JPL
{
    //==========================================================================
    class SpeedOfSound
    {
    public:
        // Speed of sound at reference temperature (20C)
        static constexpr float cReference = 343.2f;
        static constexpr float cInvReference = 1.0f / cReference;
 
        //======================================================================
        [[nodiscard]] static constexpr float ForTemperature(float temperatureC)
        {
            // ISO 9613-1, Equation A.5
            // Note: speed of sound changes with humidity up to 0.3%,
            // which is considered negligible.
 
            constexpr float zeroC_Kelvin = 273.15f;
            constexpr float invReferenceTemp = 1.0f / (20.0f + zeroC_Kelvin);
            return cReference * Math::Sqrt((zeroC_Kelvin + temperatureC) * invReferenceTemp);
        }
 
        // TODO: speed of sound in uncommon environments like liquids and space
    };
 
    // TODO: move JPL_SPEED_OF_SOUND here, or include this header in Math header where JPL_SPEED_OF_SOUND currently is
 
} // namespace JPL