RangeMapper.h

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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.
*/

#ifndef _RANGE_MAPPER_H_
#define _RANGE_MAPPER_H_

#include <QString>

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

class RangeMapper 
{
public:
    virtual ~RangeMapper() { }

    virtual int getPositionForValue(float value) const = 0;

    virtual int getPositionForValueUnclamped(float value) const = 0;

    virtual float getValueForPosition(int position) const = 0;

    virtual float getValueForPositionUnclamped(int position) const = 0;

    virtual QString getUnit() const { return ""; }
};


class LinearRangeMapper : public RangeMapper
{
public:
    LinearRangeMapper(int minpos, int maxpos,
                      float minval, float maxval,
                      QString unit = "", bool inverted = false);
    
    virtual int getPositionForValue(float value) const;
    virtual int getPositionForValueUnclamped(float value) const;

    virtual float getValueForPosition(int position) const;
    virtual float getValueForPositionUnclamped(int position) const;

    virtual QString getUnit() const { return m_unit; }

protected:
    int m_minpos;
    int m_maxpos;
    float m_minval;
    float m_maxval;
    QString m_unit;
    bool m_inverted;
};

class LogRangeMapper : public RangeMapper
{
public:
    LogRangeMapper(int minpos, int maxpos,
                   float minval, float maxval,
                   QString m_unit = "", bool inverted = false);

    static void convertRatioMinLog(float ratio, float minlog,
                                   int minpos, int maxpos,
                                   float &minval, float &maxval);

    static void convertMinMax(int minpos, int maxpos,
                              float minval, float maxval,
                              float &ratio, float &minlog);

    virtual int getPositionForValue(float value) const;
    virtual int getPositionForValueUnclamped(float value) const;

    virtual float getValueForPosition(int position) const;
    virtual float getValueForPositionUnclamped(int position) const;

    virtual QString getUnit() const { return m_unit; }

protected:
    int m_minpos;
    int m_maxpos;
    float m_ratio;
    float m_minlog;
    float m_maxlog;
    QString m_unit;
    bool m_inverted;
};

class InterpolatingRangeMapper : public RangeMapper
{
public:
    typedef std::map<float, int> CoordMap;

    InterpolatingRangeMapper(CoordMap pointMappings,
                             QString unit);

    virtual int getPositionForValue(float value) const;
    virtual int getPositionForValueUnclamped(float value) const;

    virtual float getValueForPosition(int position) const;
    virtual float getValueForPositionUnclamped(int position) const;

    virtual QString getUnit() const { return m_unit; }

protected:
    CoordMap m_mappings;
    std::map<int, float> m_reverse;
    QString m_unit;

    template <typename T>
    float interpolate(T *mapping, float v) const;
};

class AutoRangeMapper : public RangeMapper
{
public:
    enum MappingType {
        Interpolating,
        StraightLine,
        Logarithmic,
    };

    typedef std::map<float, int> CoordMap;

    AutoRangeMapper(CoordMap pointMappings,
                    QString unit);

    ~AutoRangeMapper();

    MappingType getType() const { return m_type; }

    virtual int getPositionForValue(float value) const;
    virtual int getPositionForValueUnclamped(float value) const;

    virtual float getValueForPosition(int position) const;
    virtual float getValueForPositionUnclamped(int position) const;

    virtual QString getUnit() const { return m_unit; }

protected:
    MappingType m_type;
    CoordMap m_mappings;
    QString m_unit;
    RangeMapper *m_mapper;

    MappingType chooseMappingTypeFor(const CoordMap &);
};

#endif