db.inl

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
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 *  Copyright (C) 2004-2011 the Initial Developer.
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 *
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 *  GNU General Public License Version 2 or later (the GPL), in which case the 
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 *  *** END LICENSE INFORMATION ***
 */
 
#ifndef LASS_GUARDIAN_OF_INCLUSION_NUM_DB_INL
#define LASS_GUARDIAN_OF_INCLUSION_NUM_DB_INL
 
#include "num_traits.h"
 
namespace lass
{
    namespace num
    {
        #define LASS_NUM_REFERENCE_PRESSURE_P0      20.e-6
        #define LASS_NUM_REFERENCE_INTENSITY_I0     1.e-12
        #define LASS_NUM_REFERENCE_POWER_W0         1.e-12
 
        template< typename T >  T   p2dB( const T& pressure )
        {
            if (pressure < T(0))
            {
                LASS_THROW( "Negative argument '" << pressure << "'" );
            }
            if (isNaN(pressure))
            {
                return pressure; // nan
            }
            return T(LASS_NUM_DB_20_OVER_LN10) * num::log(pressure / T(LASS_NUM_REFERENCE_PRESSURE_P0));
        }
 
        template< typename T >  T   W2dB( const T& power )
        {
            if (power < T(0))
            {
                LASS_THROW( "Negative argument '" << power << "'" );
            }
            if (isNaN(power))
            {
                return power; // nan
            }
            return T(LASS_NUM_DB_10_OVER_LN10) * num::log(power / T(LASS_NUM_REFERENCE_POWER_W0));
        }
 
        template< typename T >  T   I2dB( const T& intensity )
        {
            if (intensity < T(0))
            {
                LASS_THROW( "Negative argument '" << intensity << "'" );
            }
            if (isNaN(intensity))
            {
                return intensity; // nan
            }
            return T(LASS_NUM_DB_10_OVER_LN10) * num::log(intensity / T(LASS_NUM_REFERENCE_INTENSITY_I0));
        }
 
        template< typename T >  T   dB2p( const T& decibels )
        {
            return decibels == -NumTraits<T>::infinity ?
                NumTraits<T>::zero :
                T(LASS_NUM_REFERENCE_PRESSURE_P0) * num::exp(decibels * T(LASS_NUM_DB_LN10_OVER_20));
        }
 
        template< typename T >  T   dB2W( const T& decibels )
        {
            return decibels == -NumTraits<T>::infinity ?
                NumTraits<T>::zero :
                T(LASS_NUM_REFERENCE_POWER_W0) * num::exp(decibels * T(LASS_NUM_DB_LN10_OVER_10));
        }
 
        template< typename T >  T   dB2I( const T& decibels )
        {
            return decibels == -NumTraits<T>::infinity ?
                NumTraits<T>::zero :
                T(LASS_NUM_REFERENCE_INTENSITY_I0) * num::exp(decibels * T(LASS_NUM_DB_LN10_OVER_10));
        }
    }
}
 
#endif
 
// EOF