MidiExport.h

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/*
 * MidiExport.h - support for Exporting MIDI-files
 *
 * Copyright (c) 2015 Mohamed Abdel Maksoud <mohamed at amaksoud.com>
 * Copyright (c) 2017 Hyunjin Song <tteu.ingog/at/gmail.com>
 *
 * This file is part of LMMS - https://lmms.io
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 */
 
#ifndef _MIDI_EXPORT_H
#define _MIDI_EXPORT_H
 
 
#include "ExportFilter.h"
#include "MidiFile.hpp"
#include "Note.h"
 
class QDomNode;
 
namespace lmms
{
 
 
const int BUFFER_SIZE = 50*1024;
using MTrack = MidiFile::MIDITrack<BUFFER_SIZE>;
 
struct MidiNote
{
        int time;
        uint8_t pitch;
        int duration;
        uint8_t volume;
        Note::Type type;
 
        inline bool operator<(const MidiNote &b) const
        {
                return this->time < b.time;
        }
} ;
 
using MidiNoteVector = std::vector<MidiNote>;
using MidiNoteIterator = std::vector<MidiNote>::iterator;
 
class MidiExport: public ExportFilter
{
//      Q_OBJECT
public:
        MidiExport();
        ~MidiExport() override = default;
 
        // Default Beat Length in ticks for step notes
        // TODO: The beat length actually varies per note, however the method that
        // calculates it (InstrumentTrack::beatLen) requires a NotePlayHandle to do
        // so. While we don't figure out a way to hold the beat length of each note
        // on its member variables, we will use a default value as a beat length that
        // will be used as an upper limit of the midi note length. This doesn't worsen
        // the current logic used for MidiExport because right now the beat length is
        // not even considered during the generation of the MIDI.
        static constexpr int DefaultBeatLength = 1500;
 
        gui::PluginView* instantiateView(QWidget *) override
        {
                return nullptr;
        }
 
        bool tryExport(const TrackContainer::TrackList &tracks,
                                const TrackContainer::TrackList &patternTracks,
                                int tempo, int masterPitch, const QString &filename) override;
        
private:
        void writeMidiClip(MidiNoteVector &midiClip, const QDomNode& n,
                                int base_pitch, double base_volume, int base_time);
        void writeMidiClipToTrack(MTrack &mtrack, MidiNoteVector &nv);
        void writePatternClip(MidiNoteVector &src, MidiNoteVector &dst,
                                int len, int base, int start, int end);
        void processPatternNotes(MidiNoteVector &nv, int cutPos);
 
        void error();
 
 
} ;
 
 
} // namespace lmms
 
#endif