annotate base/LogRange.h @ 249:d3ac9f953ebf

* Fix #1672407 confused by plugin-named files in cwd (or home?)
* Fix #1491848 crash when loading new file while transform plugin runs
* Fix #1502287 Background remains black after spectrogram layer deleted
* Fix #1604477 Replacing the main audio file silences secondary audio file
* Fix failure to initialise property box layout to last preference on startup
* Fix resample/wrong-rate display in Pane, ensure that right rate is chosen
  if all current models have an acceptable rate even if previous main model
  had a different one
* Fix "global zoom" broken in previous commit
* Some fixes to spectrogram cache area updating (makes spectrogram appear
  more quickly, previously it had a tendency to refresh with empty space)
* Fixes to colour 3d plot normalization

/* -*- 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 Chris Cannam.
    
    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.
*/

#ifndef _LOG_RANGE_H_
#define _LOG_RANGE_H_

class LogRange
{
public:
    /**
     * Map a linear range onto a logarithmic range.  min and max are
     * passed as the extents of the linear range and returned as the
     * extents of the logarithmic range.  thresh is the minimum value
     * for the log range, to be used if the linear range spans zero.
     */
    static void mapRange(float &min, float &max, float thresh = -10);

    /**
     * Map a value onto a logarithmic range.  This just means taking
     * the base-10 log of the absolute value, or using the threshold
     * value if the absolute value is zero.
     */
    static float map(float value, float thresh = -10);
};

#endif