view base/RangeMapper.cpp @ 458:f60360209e5c

* Fix race condition in FFTFileCache when reading from the same FFT model from multiple threads (e.g. when applying more than one plugin at once)
author Chris Cannam
date Wed, 15 Oct 2008 12:08:02 +0000
parents ca3b91119482
children 9525c9d7e54d
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 QMUL.
    
    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.  See the file
    COPYING included with this distribution for more information.
*/

#include "RangeMapper.h"

#include <cassert>
#include <cmath>

#include <iostream>

LinearRangeMapper::LinearRangeMapper(int minpos, int maxpos,
				     float minval, float maxval,
                                     QString unit) :
    m_minpos(minpos),
    m_maxpos(maxpos),
    m_minval(minval),
    m_maxval(maxval),
    m_unit(unit)
{
    assert(m_maxval != m_minval);
    assert(m_maxpos != m_minpos);
}

int
LinearRangeMapper::getPositionForValue(float value) const
{
    int position = m_minpos +
        lrintf(((value - m_minval) / (m_maxval - m_minval))
               * (m_maxpos - m_minpos));
    if (position < m_minpos) position = m_minpos;
    if (position > m_maxpos) position = m_maxpos;
//    std::cerr << "LinearRangeMapper::getPositionForValue: " << value << " -> "
//              << position << " (minpos " << m_minpos << ", maxpos " << m_maxpos << ", minval " << m_minval << ", maxval " << m_maxval << ")" << std::endl;
    return position;
}

float
LinearRangeMapper::getValueForPosition(int position) const
{
    float value = m_minval +
        ((float(position - m_minpos) / float(m_maxpos - m_minpos))
         * (m_maxval - m_minval));
    if (value < m_minval) value = m_minval;
    if (value > m_maxval) value = m_maxval;
//    std::cerr << "LinearRangeMapper::getValueForPosition: " << position << " -> "
//              << value << " (minpos " << m_minpos << ", maxpos " << m_maxpos << ", minval " << m_minval << ", maxval " << m_maxval << ")" << std::endl;
    return value;
}

LogRangeMapper::LogRangeMapper(int minpos, int maxpos,
                               float minval, float maxval,
                               QString unit) :
    m_minpos(minpos),
    m_maxpos(maxpos),
    m_unit(unit)
{
    convertMinMax(minpos, maxpos, minval, maxval, m_minlog, m_ratio);

    std::cerr << "LogRangeMapper: minpos " << minpos << ", maxpos "
              << maxpos << ", minval " << minval << ", maxval "
              << maxval << ", minlog " << m_minlog << ", ratio " << m_ratio
              << ", unit " << unit.toStdString() << std::endl;

    assert(m_maxpos != m_minpos);

    m_maxlog = (m_maxpos - m_minpos) / m_ratio + m_minlog;
}

void
LogRangeMapper::convertMinMax(int minpos, int maxpos,
                              float minval, float maxval,
                              float &minlog, float &ratio)
{
    static float thresh = powf(10, -10);
    if (minval < thresh) minval = thresh;
    minlog = log10f(minval);
    ratio = (maxpos - minpos) / (log10f(maxval) - minlog);
}

void
LogRangeMapper::convertRatioMinLog(float ratio, float minlog,
                                   int minpos, int maxpos,
                                   float &minval, float &maxval)
{
    minval = powf(10, minlog);
    maxval = powf(10, (maxpos - minpos) / ratio + minlog);
}

int
LogRangeMapper::getPositionForValue(float value) const
{
    int position = (log10(value) - m_minlog) * m_ratio + m_minpos;
    if (position < m_minpos) position = m_minpos;
    if (position > m_maxpos) position = m_maxpos;
    std::cerr << "LogRangeMapper::getPositionForValue: " << value << " -> "
              << position << " (minpos " << m_minpos << ", maxpos " << m_maxpos << ", ratio " << m_ratio << ", minlog " << m_minlog << ")" << std::endl;
    return position;
}

float
LogRangeMapper::getValueForPosition(int position) const
{
    float value = powf(10, (position - m_minpos) / m_ratio + m_minlog);
    std::cerr << "LogRangeMapper::getValueForPosition: " << position << " -> "
              << value << " (minpos " << m_minpos << ", maxpos " << m_maxpos << ", ratio " << m_ratio << ", minlog " << m_minlog << ")" << std::endl;
    return value;
}