view base/LogRange.h @ 1671:82d03c9661f9 single-point

Rework isReady()/getCompletion() on models. Previously the new overhauled models were implementing getCompletion() but inheriting a version of isReady() (from the Model base) that didn't call it, referring only to isOK(). So they were reporting completion as soon as they had begun. Instead hoist getCompletion() to abstract base and call it from Model::isReady().

/* -*- 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 SV_LOG_RANGE_H
#define SV_LOG_RANGE_H

#include <vector>
#include "Debug.h"

class LogRange
{
public:
    /**
     * 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 double map(double value, double thresh = -10);

    /**
     * Map a value from the logarithmic range back again.  This just
     * means taking the value'th power of ten.
     */
    static double unmap(double value);

    /**
     * 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(double &min, double &max, double thresh = -10);

    /**
     * Estimate whether a set of values would be more properly shown
     * using a logarithmic than a linear scale.  This is only ever
     * going to be a rough guess.
     */
    static bool shouldUseLogScale(std::vector<double> values);

};

#endif