Mercurial > hg > sonic-visualiser
view audioio/PlaySpeedRangeMapper.cpp @ 183:3fdaf3157eea
* add overlooked solo icon
author | Chris Cannam |
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date | Sat, 29 Sep 2007 10:58:31 +0000 |
parents | bedc7517b6e8 |
children |
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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 "PlaySpeedRangeMapper.h" #include <iostream> #include <cmath> PlaySpeedRangeMapper::PlaySpeedRangeMapper(int minpos, int maxpos) : m_minpos(minpos), m_maxpos(maxpos) { } int PlaySpeedRangeMapper::getPositionForValue(float value) const { // value is percent float factor = getFactorForValue(value); int position = getPositionForFactor(factor); return position; } int PlaySpeedRangeMapper::getPositionForFactor(float factor) const { bool slow = (factor > 1.0); if (!slow) factor = 1.0 / factor; int half = (m_maxpos + m_minpos) / 2; factor = sqrtf((factor - 1.0) * 1000.f); int position = lrintf(((factor * (half - m_minpos)) / 100.0) + m_minpos); if (slow) { position = half - position; } else { position = position + half; } // std::cerr << "value = " << value << " slow = " << slow << " factor = " << factor << " position = " << position << std::endl; return position; } float PlaySpeedRangeMapper::getValueForPosition(int position) const { float factor = getFactorForPosition(position); float pc = getValueForFactor(factor); return pc; } float PlaySpeedRangeMapper::getValueForFactor(float factor) const { float pc; if (factor < 1.0) pc = ((1.0 / factor) - 1.0) * 100.0; else pc = (1.0 - factor) * 100.0; // std::cerr << "position = " << position << " percent = " << pc << std::endl; return pc; } float PlaySpeedRangeMapper::getFactorForValue(float value) const { // value is percent float factor; if (value <= 0) { factor = 1.0 - (value / 100.0); } else { factor = 1.0 / (1.0 + (value / 100.0)); } // std::cerr << "value = " << value << " factor = " << factor << std::endl; return factor; } float PlaySpeedRangeMapper::getFactorForPosition(int position) const { bool slow = false; if (position < m_minpos) position = m_minpos; if (position > m_maxpos) position = m_maxpos; int half = (m_maxpos + m_minpos) / 2; if (position < half) { slow = true; position = half - position; } else { position = position - half; } // position is between min and half (inclusive) float factor; if (position == m_minpos) { factor = 1.0; } else { factor = ((position - m_minpos) * 100.0) / (half - m_minpos); factor = 1.0 + (factor * factor) / 1000.f; } if (!slow) factor = 1.0 / factor; // std::cerr << "position = " << position << " slow = " << slow << " factor = " << factor << std::endl; return factor; } QString PlaySpeedRangeMapper::getUnit() const { return "%"; }