Chris@189: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@189: 
Chris@189: /*
Chris@189:     Sonic Visualiser
Chris@189:     An audio file viewer and annotation editor.
Chris@189:     Centre for Digital Music, Queen Mary, University of London.
Chris@202:     This file copyright 2006 QMUL.
Chris@189:     
Chris@189:     This program is free software; you can redistribute it and/or
Chris@189:     modify it under the terms of the GNU General Public License as
Chris@189:     published by the Free Software Foundation; either version 2 of the
Chris@189:     License, or (at your option) any later version.  See the file
Chris@189:     COPYING included with this distribution for more information.
Chris@189: */
Chris@189: 
Chris@189: #include "RangeMapper.h"
Chris@573: #include "system/System.h"
Chris@189: 
Chris@189: #include <cassert>
Chris@189: #include <cmath>
Chris@189: 
Chris@189: #include <iostream>
Chris@189: 
Chris@189: LinearRangeMapper::LinearRangeMapper(int minpos, int maxpos,
Chris@1038: 				     double minval, double maxval,
Chris@464:                                      QString unit, bool inverted) :
Chris@189:     m_minpos(minpos),
Chris@189:     m_maxpos(maxpos),
Chris@189:     m_minval(minval),
Chris@189:     m_maxval(maxval),
Chris@464:     m_unit(unit),
Chris@464:     m_inverted(inverted)
Chris@189: {
Chris@189:     assert(m_maxval != m_minval);
Chris@189:     assert(m_maxpos != m_minpos);
Chris@189: }
Chris@189: 
Chris@189: int
Chris@1038: LinearRangeMapper::getPositionForValue(double value) const
Chris@189: {
Chris@885:     int position = getPositionForValueUnclamped(value);
Chris@885:     if (position < m_minpos) position = m_minpos;
Chris@885:     if (position > m_maxpos) position = m_maxpos;
Chris@885:     return position;
Chris@885: }
Chris@885: 
Chris@885: int
Chris@1038: LinearRangeMapper::getPositionForValueUnclamped(double value) const
Chris@885: {
Chris@190:     int position = m_minpos +
Chris@1038:         int(lrint(((value - m_minval) / (m_maxval - m_minval))
Chris@1038:                   * (m_maxpos - m_minpos)));
Chris@879:     if (m_inverted) return m_maxpos - (position - m_minpos);
Chris@464:     else return position;
Chris@189: }
Chris@189: 
Chris@1038: double
Chris@189: LinearRangeMapper::getValueForPosition(int position) const
Chris@189: {
Chris@879:     if (position < m_minpos) position = m_minpos;
Chris@879:     if (position > m_maxpos) position = m_maxpos;
Chris@1038:     double value = getValueForPositionUnclamped(position);
Chris@885:     return value;
Chris@885: }
Chris@885: 
Chris@1038: double
Chris@885: LinearRangeMapper::getValueForPositionUnclamped(int position) const
Chris@885: {
Chris@885:     if (m_inverted) position = m_maxpos - (position - m_minpos);
Chris@1038:     double value = m_minval +
Chris@1038:         ((double(position - m_minpos) / double(m_maxpos - m_minpos))
Chris@190:          * (m_maxval - m_minval));
Chris@1201: //    cerr << "getValueForPositionUnclamped(" << position << "): minval " << m_minval << ", maxval " << m_maxval << ", value " << value << endl;
Chris@189:     return value;
Chris@189: }
Chris@189: 
Chris@189: LogRangeMapper::LogRangeMapper(int minpos, int maxpos,
Chris@1038:                                double minval, double maxval,
Chris@464:                                QString unit, bool inverted) :
Chris@189:     m_minpos(minpos),
Chris@189:     m_maxpos(maxpos),
Chris@464:     m_unit(unit),
Chris@464:     m_inverted(inverted)
Chris@189: {
Chris@356:     convertMinMax(minpos, maxpos, minval, maxval, m_minlog, m_ratio);
Chris@356: 
Chris@879: //    cerr << "LogRangeMapper: minpos " << minpos << ", maxpos "
Chris@879: //              << maxpos << ", minval " << minval << ", maxval "
Chris@879: //              << maxval << ", minlog " << m_minlog << ", ratio " << m_ratio
Chris@879: //              << ", unit " << unit << endl;
Chris@356: 
Chris@189:     assert(m_maxpos != m_minpos);
Chris@189: 
Chris@189:     m_maxlog = (m_maxpos - m_minpos) / m_ratio + m_minlog;
Chris@879: 
Chris@879: //    cerr << "LogRangeMapper: maxlog = " << m_maxlog << endl;
Chris@189: }
Chris@189: 
Chris@356: void
Chris@356: LogRangeMapper::convertMinMax(int minpos, int maxpos,
Chris@1038:                               double minval, double maxval,
Chris@1038:                               double &minlog, double &ratio)
Chris@356: {
Chris@1038:     static double thresh = powf(10, -10);
Chris@356:     if (minval < thresh) minval = thresh;
Chris@1038:     minlog = log10(minval);
Chris@1038:     ratio = (maxpos - minpos) / (log10(maxval) - minlog);
Chris@356: }
Chris@356: 
Chris@356: void
Chris@1038: LogRangeMapper::convertRatioMinLog(double ratio, double minlog,
Chris@356:                                    int minpos, int maxpos,
Chris@1038:                                    double &minval, double &maxval)
Chris@356: {
Chris@1038:     minval = pow(10, minlog);
Chris@1038:     maxval = pow(10, (maxpos - minpos) / ratio + minlog);
Chris@356: }
Chris@356: 
Chris@189: int
Chris@1038: LogRangeMapper::getPositionForValue(double value) const
Chris@189: {
Chris@885:     int position = getPositionForValueUnclamped(value);
Chris@189:     if (position < m_minpos) position = m_minpos;
Chris@189:     if (position > m_maxpos) position = m_maxpos;
Chris@885:     return position;
Chris@885: }
Chris@885: 
Chris@885: int
Chris@1038: LogRangeMapper::getPositionForValueUnclamped(double value) const
Chris@885: {
Chris@1038:     static double thresh = pow(10, -10);
Chris@885:     if (value < thresh) value = thresh;
Chris@1038:     int position = int(lrint((log10(value) - m_minlog) * m_ratio)) + m_minpos;
Chris@879:     if (m_inverted) return m_maxpos - (position - m_minpos);
Chris@464:     else return position;
Chris@189: }
Chris@189: 
Chris@1038: double
Chris@189: LogRangeMapper::getValueForPosition(int position) const
Chris@189: {
Chris@879:     if (position < m_minpos) position = m_minpos;
Chris@879:     if (position > m_maxpos) position = m_maxpos;
Chris@1038:     double value = getValueForPositionUnclamped(position);
Chris@885:     return value;
Chris@885: }
Chris@885: 
Chris@1038: double
Chris@885: LogRangeMapper::getValueForPositionUnclamped(int position) const
Chris@885: {
Chris@885:     if (m_inverted) position = m_maxpos - (position - m_minpos);
Chris@1038:     double value = pow(10, (position - m_minpos) / m_ratio + m_minlog);
Chris@189:     return value;
Chris@189: }
Chris@189: 
Chris@880: InterpolatingRangeMapper::InterpolatingRangeMapper(CoordMap pointMappings,
Chris@880:                                                    QString unit) :
Chris@880:     m_mappings(pointMappings),
Chris@880:     m_unit(unit)
Chris@880: {
Chris@880:     for (CoordMap::const_iterator i = m_mappings.begin(); 
Chris@880:          i != m_mappings.end(); ++i) {
Chris@880:         m_reverse[i->second] = i->first;
Chris@880:     }
Chris@880: }
Chris@880: 
Chris@880: int
Chris@1038: InterpolatingRangeMapper::getPositionForValue(double value) const
Chris@880: {
Chris@885:     int pos = getPositionForValueUnclamped(value);
Chris@885:     CoordMap::const_iterator i = m_mappings.begin();
Chris@885:     if (pos < i->second) pos = i->second;
Chris@885:     i = m_mappings.end(); --i;
Chris@885:     if (pos > i->second) pos = i->second;
Chris@885:     return pos;
Chris@885: }
Chris@880: 
Chris@885: int
Chris@1038: InterpolatingRangeMapper::getPositionForValueUnclamped(double value) const
Chris@885: {
Chris@1038:     double p = interpolate(&m_mappings, value);
Chris@1038:     return int(lrint(p));
Chris@880: }
Chris@880: 
Chris@1038: double
Chris@880: InterpolatingRangeMapper::getValueForPosition(int position) const
Chris@880: {
Chris@1038:     double val = getValueForPositionUnclamped(position);
Chris@885:     CoordMap::const_iterator i = m_mappings.begin();
Chris@885:     if (val < i->first) val = i->first;
Chris@885:     i = m_mappings.end(); --i;
Chris@885:     if (val > i->first) val = i->first;
Chris@885:     return val;
Chris@885: }
Chris@885: 
Chris@1038: double
Chris@885: InterpolatingRangeMapper::getValueForPositionUnclamped(int position) const
Chris@885: {
Chris@885:     return interpolate(&m_reverse, position);
Chris@885: }
Chris@885: 
Chris@885: template <typename T>
Chris@1038: double
Chris@1038: InterpolatingRangeMapper::interpolate(T *mapping, double value) const
Chris@885: {
Chris@885:     // lower_bound: first element which does not compare less than value
Chris@1038:     typename T::const_iterator i =
Chris@1038:         mapping->lower_bound(typename T::key_type(value));
Chris@885: 
Chris@885:     if (i == mapping->begin()) {
Chris@885:         // value is less than or equal to first element, so use the
Chris@885:         // gradient from first to second and extend it
Chris@885:         ++i;
Chris@885:     }
Chris@885: 
Chris@885:     if (i == mapping->end()) {
Chris@885:         // value is off the end, so use the gradient from penultimate
Chris@885:         // to ultimate and extend it
Chris@885:         --i;
Chris@885:     }
Chris@885: 
Chris@885:     typename T::const_iterator j = i;
Chris@880:     --j;
Chris@880: 
Chris@1038:     double gradient = double(i->second - j->second) / double(i->first - j->first);
Chris@880: 
Chris@885:     return j->second + (value - j->first) * gradient;
Chris@880: }
Chris@880: 
Chris@880: AutoRangeMapper::AutoRangeMapper(CoordMap pointMappings,
Chris@880:                                  QString unit) :
Chris@880:     m_mappings(pointMappings),
Chris@880:     m_unit(unit)
Chris@880: {
Chris@880:     m_type = chooseMappingTypeFor(m_mappings);
Chris@880: 
Chris@880:     CoordMap::const_iterator first = m_mappings.begin();
Chris@880:     CoordMap::const_iterator last = m_mappings.end();
Chris@880:     --last;
Chris@880: 
Chris@880:     switch (m_type) {
Chris@880:     case StraightLine:
Chris@880:         m_mapper = new LinearRangeMapper(first->second, last->second,
Chris@880:                                          first->first, last->first,
Chris@880:                                          unit, false);
Chris@880:         break;
Chris@880:     case Logarithmic:
Chris@880:         m_mapper = new LogRangeMapper(first->second, last->second,
Chris@880:                                       first->first, last->first,
Chris@880:                                       unit, false);
Chris@880:         break;
Chris@880:     case Interpolating:
Chris@880:         m_mapper = new InterpolatingRangeMapper(m_mappings, unit);
Chris@880:         break;
Chris@880:     }
Chris@880: }
Chris@880: 
Chris@880: AutoRangeMapper::~AutoRangeMapper()
Chris@880: {
Chris@880:     delete m_mapper;
Chris@880: }
Chris@880: 
Chris@880: AutoRangeMapper::MappingType
Chris@880: AutoRangeMapper::chooseMappingTypeFor(const CoordMap &mappings)
Chris@880: {
Chris@880:     // how do we work out whether a linear/log mapping is "close enough"?
Chris@880: 
Chris@880:     CoordMap::const_iterator first = mappings.begin();
Chris@880:     CoordMap::const_iterator last = mappings.end();
Chris@880:     --last;
Chris@880: 
Chris@880:     LinearRangeMapper linm(first->second, last->second,
Chris@880:                            first->first, last->first,
Chris@880:                            "", false);
Chris@880: 
Chris@880:     bool inadequate = false;
Chris@880: 
Chris@880:     for (CoordMap::const_iterator i = mappings.begin();
Chris@880:          i != mappings.end(); ++i) {
Chris@880:         int candidate = linm.getPositionForValue(i->first);
Chris@880:         int diff = candidate - i->second;
Chris@880:         if (diff < 0) diff = -diff;
Chris@880:         if (diff > 1) {
Chris@885: //            cerr << "AutoRangeMapper::chooseMappingTypeFor: diff = " << diff
Chris@885: //                 << ", straight-line mapping inadequate" << endl;
Chris@880:             inadequate = true;
Chris@880:             break;
Chris@880:         }
Chris@880:     }
Chris@880: 
Chris@880:     if (!inadequate) {
Chris@880:         return StraightLine;
Chris@880:     }
Chris@880: 
Chris@880:     LogRangeMapper logm(first->second, last->second,
Chris@880:                         first->first, last->first,
Chris@880:                         "", false);
Chris@880: 
Chris@880:     inadequate = false;
Chris@880: 
Chris@880:     for (CoordMap::const_iterator i = mappings.begin();
Chris@880:          i != mappings.end(); ++i) {
Chris@880:         int candidate = logm.getPositionForValue(i->first);
Chris@880:         int diff = candidate - i->second;
Chris@880:         if (diff < 0) diff = -diff;
Chris@880:         if (diff > 1) {
Chris@885: //            cerr << "AutoRangeMapper::chooseMappingTypeFor: diff = " << diff
Chris@885: //                 << ", log mapping inadequate" << endl;
Chris@880:             inadequate = true;
Chris@880:             break;
Chris@880:         }
Chris@880:     }
Chris@880: 
Chris@880:     if (!inadequate) {
Chris@880:         return Logarithmic;
Chris@880:     }
Chris@880: 
Chris@880:     return Interpolating;
Chris@880: }
Chris@880: 
Chris@880: int
Chris@1038: AutoRangeMapper::getPositionForValue(double value) const
Chris@880: {
Chris@880:     return m_mapper->getPositionForValue(value);
Chris@880: }
Chris@880: 
Chris@1038: double
Chris@880: AutoRangeMapper::getValueForPosition(int position) const
Chris@880: {
Chris@880:     return m_mapper->getValueForPosition(position);
Chris@880: }
Chris@885: 
Chris@885: int
Chris@1038: AutoRangeMapper::getPositionForValueUnclamped(double value) const
Chris@885: {
Chris@885:     return m_mapper->getPositionForValueUnclamped(value);
Chris@885: }
Chris@885: 
Chris@1038: double
Chris@885: AutoRangeMapper::getValueForPositionUnclamped(int position) const
Chris@885: {
Chris@885:     return m_mapper->getValueForPositionUnclamped(position);
Chris@885: }