170 lines
6.0 KiB
C++
170 lines
6.0 KiB
C++
/**********************************************************************
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Audacity: A Digital Audio Editor
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Audacity(R) is copyright (c) 1999-2012 Audacity Team.
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License: GPL v2. See License.txt.
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PitchName.cpp
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Vaughan Johnson and Dominic Mazzoni.
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******************************************************************//**
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\file PitchName.cpp
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\brief Utilities for converting from frequency to pitch
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and from pitch to absolute (e.g., C4 for middle C)
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or nominal (A through G#) pitch name.
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*//*******************************************************************/
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#include "PitchName.h"
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#include <math.h>
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#include <stdio.h>
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#include "Internat.h"
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double FreqToMIDInote(const double freq)
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{
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// Make the calculation relative to A440 (A4), note number 69.
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return (69.0 + (12.0 * (log(freq / 440.0) / log(2.0))));
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}
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double MIDInoteToFreq(const double dMIDInote)
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{
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return (440.0 * pow(2.0, (dMIDInote - 69.0) / 12.0));
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}
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unsigned int PitchIndex(const double dMIDInote)
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{
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// MIDI numbers can be negative. Round in the right direction.
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double dRound = (dMIDInote < 0.0) ? -0.5 : 0.5;
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int nPitchIndex = ((int)(dMIDInote + dRound) % 12);
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// Because of the modulo, we know we're within 12 of positive, if dMIDInote is negative.
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if (nPitchIndex < 0)
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nPitchIndex += 12;
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return nPitchIndex;
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}
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int PitchOctave(const double dMIDInote)
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{
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double dRound = (dMIDInote < 0.0) ? -0.5 : 0.5;
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return ((int)((dMIDInote + dRound) / 12.0) - 1);
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}
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TranslatableString PitchName(const double dMIDInote, const PitchNameChoice choice)
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{
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static const TranslatableString sharpnames[12] = {
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("C"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("C\u266f"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("D"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("D\u266f"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("E"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("F"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("F\u266f"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("G"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("G\u266f"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("A"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("A\u266f"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("B"),
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};
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static const TranslatableString flatnames[12] = {
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("C"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("D\u266d"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("D"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("E\u266d"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("E"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("F"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("G\u266d"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("G"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("A\u266d"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("A"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("B\u266d"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("B"),
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};
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static const TranslatableString bothnames[12] = {
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("C"),
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/* i18n-hint: Two, alternate names of a musical note in the 12-tone chromatic scale */
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XO("C\u266f/D\u266d"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("D"),
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/* i18n-hint: Two, alternate names of a musical note in the 12-tone chromatic scale */
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XO("D\u266f/E\u266d"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("E"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("F"),
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/* i18n-hint: Two, alternate names of a musical note in the 12-tone chromatic scale */
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XO("F\u266f/G\u266d"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("G"),
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/* i18n-hint: Two, alternate names of a musical note in the 12-tone chromatic scale */
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XO("G\u266f/A\u266d"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("A"),
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/* i18n-hint: Two, alternate names of a musical note in the 12-tone chromatic scale */
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XO("A\u266f/B\u266d"),
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/* i18n-hint: Name of a musical note in the 12-tone chromatic scale */
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XO("B"),
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};
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const TranslatableString *table = nullptr;
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switch ( choice ) {
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case PitchNameChoice::Sharps: table = sharpnames; break;
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case PitchNameChoice::Flats: table = flatnames; break;
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case PitchNameChoice::Both: table = bothnames; break;
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default: wxASSERT(false); break;
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}
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return table[PitchIndex(dMIDInote)];
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}
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TranslatableString PitchName_Absolute(const double dMIDInote, const PitchNameChoice choice)
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{
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// The format string is not localized. Should it be?
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return Verbatim( wxT("%s%d") )
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.Format( PitchName(dMIDInote, choice), PitchOctave(dMIDInote) );
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}
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double PitchToMIDInote(const unsigned int nPitchIndex, const int nPitchOctave)
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{
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return ((double)nPitchIndex + (((double)nPitchOctave + 1.0) * 12.0));
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}
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double PitchToFreq(const unsigned int nPitchIndex, const int nPitchOctave)
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{
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return MIDInoteToFreq(PitchToMIDInote(nPitchIndex, nPitchOctave));
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}
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