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lmms/include/RmsHelper.h
2024-07-21 22:34:34 +01:00

102 lines
2.0 KiB
C++

/*
* RmsHelper.h - helper class for calculating RMS
*
* Copyright (c) 2014 Vesa Kivimäki <contact/dot/diizy/at/nbl/dot/fi>
* Copyright (c) 2008 Tobias Doerffel <tobydox/at/users.sourceforge.net>
*
* This file is part of LMMS - https://lmms.io
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public
* License along with this program (see COPYING); if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA.
*
*/
#ifndef LMMS_RMS_HELPER_H
#define LMMS_RMS_HELPER_H
#include "lmms_math.h"
namespace lmms
{
class RmsHelper
{
public:
RmsHelper(std::size_t size) :
m_buffer( nullptr )
{
setSize( size );
}
virtual ~RmsHelper()
{
if( m_buffer ) delete[] m_buffer;
}
void setSize(std::size_t size)
{
if( m_buffer )
{
if( m_size < size )
{
delete m_buffer;
m_buffer = new float[ size ];
m_size = size;
reset();
}
else
{
m_size = size;
reset();
}
}
else
{
m_buffer = new float[ size ];
m_size = size;
reset();
}
}
inline void reset()
{
m_sizef = 1.0f / (float) m_size;
m_pos = 0;
m_sum = 0.0f;
memset( m_buffer, 0, m_size * sizeof( float ) );
}
inline float update( const float in )
{
m_sum -= m_buffer[ m_pos ];
m_sum += m_buffer[ m_pos ] = in * in;
++m_pos %= m_size;
return sqrtf( m_sum * m_sizef );
}
private:
float * m_buffer;
float m_sum;
std::size_t m_pos;
std::size_t m_size;
float m_sizef;
};
} // namespace lmms
#endif // LMMS_RMS_HELPER_H