//
// Programmer:    Craig Stuart Sapp <craig@ccrma.stanford.edu>
// Creation Date: Sat Feb 14 21:55:38 PST 2015
// Last Modified: Sat Apr 21 10:52:19 PDT 2018 Removed using namespace std;
// Filename:      midifile/src/MidiEventList.cpp
// Website:       http://midifile.sapp.org
// Syntax:        C++11
// vim:           ts=3 noexpandtab
//
// Description:   A class which stores a MidiEvents for a MidiFile track.
//

#include "MidiEventList.h"

#include <algorithm>
#include <cstdlib>
#include <iterator>
#include <list>
#include <stdexcept>
#include <utility>
#include <vector>



namespace smf {

//////////////////////////////
//
// MidiEventList::MidiEventList -- Constructor.
//

MidiEventList::MidiEventList(void) {
	reserve(1000);
}



//////////////////////////////
//
// MidiEventList::MidiEventList(MidiEventList&) -- Copy constructor.
//

MidiEventList::MidiEventList(const MidiEventList& other) {
	list.reserve(other.list.size());
	auto it = other.list.begin();
	std::generate_n(std::back_inserter(list), other.list.size(), [&]() -> MidiEvent* {
		return new MidiEvent(**it++);
	});
}



//////////////////////////////
//
// MidiEventList::MidiEventList(MidiEventList&&) -- Move constructor.
//

MidiEventList::MidiEventList(MidiEventList&& other) {
	list = std::move(other.list);
	other.list.clear();
}



//////////////////////////////
//
// MidiEventList::~MidiEventList -- Deconstructor.  Deallocate all stored
//   data.
//

MidiEventList::~MidiEventList() {
	clear();
}



//////////////////////////////
//
// MidiEventList::operator[] --
//

MidiEvent&  MidiEventList::operator[](int index) {
	return *list[index];
}


const MidiEvent&  MidiEventList::operator[](int index) const {
	return *list[index];
}



//////////////////////////////
//
// MidiEventList::at -- Similar to vector::at, checking validity of index.
//

MidiEvent& MidiEventList::at(int index) {
	if (index < 0 || static_cast<size_t>(index) >= list.size()) {
		throw std::out_of_range("Index out of bounds: " + std::to_string(index));
	}
	return *list[index];
}


const MidiEvent& MidiEventList::at(int index) const {
	if (index < 0 || static_cast<size_t>(index) >= list.size()) {
		throw std::out_of_range("Index out of bounds: " + std::to_string(index));
	}
	return *list[index];
}



//////////////////////////////
//
// MidiEventList::back -- Return the last element in the list.
//

MidiEvent& MidiEventList::back(void) {
	return *list.back();
}


const MidiEvent& MidiEventList::back(void) const {
	return *list.back();
}

//
// MidiEventList::last -- Alias for MidiEventList::back().
//

MidiEvent& MidiEventList::last(void) {
	return back();
}


const MidiEvent& MidiEventList::last(void) const {
	return back();
}



//////////////////////////////
//
// MidiEventList::getEvent -- The same thing as operator[], for
//      internal use when operator[] would look more messy.
//

MidiEvent& MidiEventList::getEvent(int index) {
	return *list[index];
}


const MidiEvent& MidiEventList::getEvent(int index) const {
	return *list[index];
}



//////////////////////////////
//
// MidiEventList::clear -- De-allocate any MidiEvents present in the list
//    and set the size of the list to 0.
//

void MidiEventList::clear(void) {
	for (auto& item : list) {
		if (item != NULL) {
			delete item;
			item = NULL;
		}
	}
	list.resize(0);
}



//////////////////////////////
//
// MidiEventList::data -- Return the low-level array of MidiMessage
//     pointers.  This is useful for applying your own sorting
//     function to the list.
//

MidiEvent** MidiEventList::data(void) {
	return list.data();
}



//////////////////////////////
//
// MidiEventList::reserve --  Pre-allocate space in the list for storing
//     elements.
//

void MidiEventList::reserve(int rsize) {
	if (rsize > (int)list.size()) {
		list.reserve(rsize);
	}
}


//////////////////////////////
//
// MidiEventList::getSize -- Return the number of MidiEvents stored
//     in the list.
//

int MidiEventList::getSize(void) const {
	return (int)list.size();
}

//
// MidiEventList::size -- Alias for MidiEventList::getSize().
//

int MidiEventList::size(void) const {
	return getSize();
}

//
// MidiEventList::getEventCount -- Alias for MidiEventList::getSize().
//

int MidiEventList::getEventCount(void) const {
	return getSize();
}



//////////////////////////////
//
// MidiEventList::append -- add a MidiEvent at the end of the list.  Returns
//     the index of the appended event.
//

int MidiEventList::append(MidiEvent& event) {
	MidiEvent* ptr = new MidiEvent(event);
	list.push_back(ptr);
	return (int)list.size()-1;
}

//
// MidiEventList::push -- Alias for MidiEventList::append().
//

int MidiEventList::push(MidiEvent& event) {
	return append(event);
}

//
// MidiEventList::push_back -- Alias for MidiEventList::append().
//

int MidiEventList::push_back(MidiEvent& event) {
	return append(event);
}



//////////////////////////////
//
// MidiEventList::removeEmpties -- Remove any MIDI message which contain no
//    bytes.  This function first deallocates any empty MIDI events, and then
//    removes them from the list of events.
//

void MidiEventList::removeEmpties(void) {
	int count = 0;
	for (auto& item : list) {
		if (item->empty()) {
			delete item;
			item = NULL;
			count++;
		}
	}
	if (count == 0) {
		return;
	}
	std::vector<MidiEvent*> newlist;
	newlist.reserve(list.size() - count);
	for (auto& item : list) {
		if (item) {
			newlist.push_back(item);
		}
	}
	list.swap(newlist);
}



//////////////////////////////
//
// MidiEventList::linkNotePairs -- Match note-ones and note-offs together
//   There are two models that can be done if two notes are overlapping
//   on the same pitch: the first note-off affects the last note-on,
//   or the first note-off affects the first note-on.  Currently  the
//   first note-off affects the last note-on, but both methods could
//   be implemented with user selectability.  The current state of the
//   track is assumed to be in time-sorted order.  Returns the number
//   of linked notes (note-on/note-off pairs).
//

int MidiEventList::linkEventPairs(void) {
	return linkNotePairsFIFO();
}


int MidiEventList::linkNotePairsFIFO(void) {
	// Note-on states:
	// dimension 1: MIDI channel (0-15)
	// dimension 2: MIDI key     (0-127)  (but 0 not used for note-ons)
	// dimension 3: List of active note-ons or note-offs (FIFO behavior).
	std::vector<std::vector<std::list<MidiEvent*>>> noteons;
	noteons.resize(16);
	for (auto& noteon : noteons) {
		noteon.resize(128);
	}

	// Controller linking: The following General MIDI controller numbers are
	// also monitored for linking within the track (but not between tracks).
	// hex dec  name                                    range
	// 40  64   Hold pedal (Sustain) on/off             0..63=off  64..127=on
	// 41  65   Portamento on/off                       0..63=off  64..127=on
	// 42  66   Sustenuto Pedal on/off                  0..63=off  64..127=on
	// 43  67   Soft Pedal on/off                       0..63=off  64..127=on
	// 44  68   Legato Pedal on/off                     0..63=off  64..127=on
	// 45  69   Hold Pedal 2 on/off                     0..63=off  64..127=on
	// 50  80   General Purpose Button                  0..63=off  64..127=on
	// 51  81   General Purpose Button                  0..63=off  64..127=on
	// 52  82   General Purpose Button                  0..63=off  64..127=on
	// 53  83   General Purpose Button                  0..63=off  64..127=on
	// 54  84   Undefined on/off                        0..63=off  64..127=on
	// 55  85   Undefined on/off                        0..63=off  64..127=on
	// 56  86   Undefined on/off                        0..63=off  64..127=on
	// 57  87   Undefined on/off                        0..63=off  64..127=on
	// 58  88   Undefined on/off                        0..63=off  64..127=on
	// 59  89   Undefined on/off                        0..63=off  64..127=on
	// 5A  90   Undefined on/off                        0..63=off  64..127=on
	// 7A 122   Local Keyboard On/Off                   0..63=off  64..127=on

	// first keep track of whether the controller is an on/off switch:
	std::vector<std::pair<int, int>> contmap(128, {0, 0});
	contmap[64] = {1, 0}; contmap[65] = {1, 1}; contmap[66] = {1, 2}; 
	contmap[67] = {1, 3}; contmap[68] = {1, 4}; contmap[69] = {1, 5};
	contmap[80] = {1, 6}; contmap[81] = {1, 7}; contmap[82] = {1, 8}; 
	contmap[83] = {1, 9}; contmap[84] = {1, 10}; contmap[85] = {1, 11};
	contmap[86] = {1, 12}; contmap[87] = {1, 13}; contmap[88] = {1, 14}; 
	contmap[89] = {1, 15}; contmap[90] = {1, 16}; contmap[122] = {1, 17};

	std::vector<std::vector<MidiEvent*>> contevents(18, std::vector<MidiEvent*>(16, nullptr));
	std::vector<std::vector<int>> oldstates(18, std::vector<int>(16, -1));

	int counter = 0;
	for (int i = 0; i < getSize(); i++) {
		MidiEvent* mev = &getEvent(i);
		mev->unlinkEvent();

		if (mev->isNoteOn()) {
			int key = mev->getKeyNumber();
			int channel = mev->getChannel();
			noteons[channel][key].push_back(mev);  // Enqueue (FIFO)
		} else if (mev->isNoteOff()) {
			int key = mev->getKeyNumber();
			int channel = mev->getChannel();
			if (!noteons[channel][key].empty()) {  // **Check before accessing**
				MidiEvent* noteon = noteons[channel][key].front(); // Safely access first event
				noteons[channel][key].pop_front(); // Remove first event (FIFO)
				noteon->linkEvent(mev);
				counter++;
			}
		} else if (mev->isController()) {
			int contnum = mev->getP1();
			if (contmap[contnum].first) {
				int conti = contmap[contnum].second;
				int channel = mev->getChannel();
				int contval = mev->getP2();
				int contstate = contval < 64 ? 0 : 1;

				if ((oldstates[conti][channel] == -1) && contstate) {
					contevents[conti][channel] = mev;
					oldstates[conti][channel] = contstate;
				} else if (oldstates[conti][channel] == contstate) {
					// Redundant controller state, ignore.
				} else if ((oldstates[conti][channel] == 0) && contstate) {
					contevents[conti][channel] = mev;
					oldstates[conti][channel] = contstate;
				} else if ((oldstates[conti][channel] == 1) && (contstate == 0)) {
					contevents[conti][channel]->linkEvent(mev);
					oldstates[conti][channel] = contstate;
					contevents[conti][channel] = mev;
				}
			}
		}
	}
	return counter;
}



int MidiEventList::linkNotePairsLIFO(void) {

	// Note-on states:
	// dimension 1: MIDI channel (0-15)
	// dimension 2: MIDI key     (0-127)  (but 0 not used for note-ons)
	// dimension 3: List of active note-ons or note-offs.
	std::vector<std::vector<std::vector<MidiEvent*>>> noteons;
	noteons.resize(16);
	for (auto& noteon : noteons) {
		noteon.resize(128);
	}

	// Controller linking: The following General MIDI controller numbers are
	// also monitored for linking within the track (but not between tracks).
	// hex dec  name                                    range
	// 40  64   Hold pedal (Sustain) on/off             0..63=off  64..127=on
	// 41  65   Portamento on/off                       0..63=off  64..127=on
	// 42  66   Sustenuto Pedal on/off                  0..63=off  64..127=on
	// 43  67   Soft Pedal on/off                       0..63=off  64..127=on
	// 44  68   Legato Pedal on/off                     0..63=off  64..127=on
	// 45  69   Hold Pedal 2 on/off                     0..63=off  64..127=on
	// 50  80   General Purpose Button                  0..63=off  64..127=on
	// 51  81   General Purpose Button                  0..63=off  64..127=on
	// 52  82   General Purpose Button                  0..63=off  64..127=on
	// 53  83   General Purpose Button                  0..63=off  64..127=on
	// 54  84   Undefined on/off                        0..63=off  64..127=on
	// 55  85   Undefined on/off                        0..63=off  64..127=on
	// 56  86   Undefined on/off                        0..63=off  64..127=on
	// 57  87   Undefined on/off                        0..63=off  64..127=on
	// 58  88   Undefined on/off                        0..63=off  64..127=on
	// 59  89   Undefined on/off                        0..63=off  64..127=on
	// 5A  90   Undefined on/off                        0..63=off  64..127=on
	// 7A 122   Local Keyboard On/Off                   0..63=off  64..127=on

	// first keep track of whether the controller is an on/off switch:
	std::vector<std::pair<int, int>> contmap;
	contmap.resize(128);
	std::pair<int, int> zero(0, 0);
	std::fill(contmap.begin(), contmap.end(), zero);
	contmap[64].first  = 1;   contmap[64].second = 0;
	contmap[65].first  = 1;   contmap[65].second = 1;
	contmap[66].first  = 1;   contmap[66].second = 2;
	contmap[67].first  = 1;   contmap[67].second = 3;
	contmap[68].first  = 1;   contmap[68].second = 4;
	contmap[69].first  = 1;   contmap[69].second = 5;
	contmap[80].first  = 1;   contmap[80].second = 6;
	contmap[81].first  = 1;   contmap[81].second = 7;
	contmap[82].first  = 1;   contmap[82].second = 8;
	contmap[83].first  = 1;   contmap[83].second = 9;
	contmap[84].first  = 1;   contmap[84].second = 10;
	contmap[85].first  = 1;   contmap[85].second = 11;
	contmap[86].first  = 1;   contmap[86].second = 12;
	contmap[87].first  = 1;   contmap[87].second = 13;
	contmap[88].first  = 1;   contmap[88].second = 14;
	contmap[89].first  = 1;   contmap[89].second = 15;
	contmap[90].first  = 1;   contmap[90].second = 16;
	contmap[122].first = 1;   contmap[122].second = 17;

	// dimensions:
	// 1: mapped controller (0 to 17)
	// 2: channel (0 to 15)
	std::vector<std::vector<MidiEvent*>> contevents;
	contevents.resize(18);
	std::vector<std::vector<int>> oldstates;
	oldstates.resize(18);
	for (int i=0; i<18; i++) {
		contevents[i].resize(16);
		std::fill(contevents[i].begin(), contevents[i].end(), nullptr);
		oldstates[i].resize(16);
		std::fill(oldstates[i].begin(), oldstates[i].end(), -1);
	}

	// Now iterate through the MidiEventList keeping track of note and
	// select controller states and linking notes/controllers as needed.
	int channel;
	int key;
	int contnum;
	int contval;
	int conti;
	int contstate;
	int counter = 0;
	MidiEvent* mev;
	MidiEvent* noteon;
	for (int i=0; i<getSize(); i++) {
		mev = &getEvent(i);
		mev->unlinkEvent();
		if (mev->isNoteOn()) {
			// store the note-on to pair later with a note-off message.
			key = mev->getKeyNumber();
			channel = mev->getChannel();
			noteons[channel][key].push_back(mev);
		} else if (mev->isNoteOff()) {
			key = mev->getKeyNumber();
			channel = mev->getChannel();
			if (noteons[channel][key].size() > 0) {
				noteon = noteons[channel][key].back();
				noteons[channel][key].pop_back();
				noteon->linkEvent(mev);
				counter++;
			}
		} else if (mev->isController()) {
			contnum = mev->getP1();
			if (contmap[contnum].first) {
				conti     = contmap[contnum].second;
				channel   = mev->getChannel();
				contval   = mev->getP2();
				contstate = contval < 64 ? 0 : 1;
				if ((oldstates[conti][channel] == -1) && contstate) {
					// a newly initialized onstate was detected, so store for
					// later linking to an off state.
					contevents[conti][channel] = mev;
					oldstates[conti][channel] = contstate;
				} else if (oldstates[conti][channel] == contstate) {
					// the controller state is redundant and will be ignored.
				} else if ((oldstates[conti][channel] == 0) && contstate) {
					// controller is currently off, so store on-state for next link
					contevents[conti][channel] = mev;
					oldstates[conti][channel] = contstate;
				} else if ((oldstates[conti][channel] == 1) && (contstate == 0)) {
					// controller has just been turned off, so link to
					// stored on-message.
					contevents[conti][channel]->linkEvent(mev);
					oldstates[conti][channel] = contstate;
					// not necessary, but maybe use for something later:
					contevents[conti][channel] = mev;
				}
			}
		}
	}
	return counter;
}



//////////////////////////////
//
// MidiEventList::clearLinks -- remove all note-on/note-off links.
//

void MidiEventList::clearLinks(void) {
	for (int i=0; i<(int)getSize(); i++) {
		getEvent(i).unlinkEvent();
	}
}



//////////////////////////////
//
// MidiEventList::clearSequence -- Remove any sequence serial numbers from
//   MidiEvents in the list.  This will cause the default ordering by
//   sortTracks() to be used, in which case the ordering of MidiEvents
//   occurring at the same tick may switch their ordering.
//

void MidiEventList::clearSequence(void) {
	for (int i=0; i<getEventCount(); i++) {
		getEvent(i).seq = 0;
	}
}



//////////////////////////////
//
// MidiEventList::markSequence -- Assign a sequence serial number to
//   every MidiEvent in the event list.  This is useful if you want
//   to preseve the order of MIDI messages in a track when they occur
//   at the same tick time.  Particularly for use with joinTracks()
//   or sortTracks().  markSequence will be done automatically when
//   a MIDI file is read, in case the ordering of events occurring at
//   the same time is important.  Use clearSequence() to use the
//   default sorting behavior of sortTracks() when events occur at the
//   same time.  Returns the next serial number that has not yet been
//   used.
//   default value: sequence = 1.
//

int MidiEventList::markSequence(int sequence) {
	for (int i=0; i<getEventCount(); i++) {
		getEvent(i).seq = sequence++;
	}
	return sequence;
}


///////////////////////////////////////////////////////////////////////////
//
// protected functions --
//


//////////////////////////////
//
// MidiEventList::detach -- De-allocate any MidiEvents present in the list
//    and set the size of the list to 0.
//


void MidiEventList::detach(void) {
	list.resize(0);
}



//////////////////////////////
//
// MidiEventList::push_back_no_copy -- add a MidiEvent at the end of
//     the list.  The event is not copied, but memory from the
//     remote location is used.  Returns the index of the appended event.
//

int MidiEventList::push_back_no_copy(MidiEvent* event) {
	list.push_back(event);
	return (int)list.size()-1;
}



//////////////////////////////
//
// MidiEventList::operator=(MidiEventList) -- Assignment.
//

MidiEventList& MidiEventList::operator=(MidiEventList& other) {
	list.swap(other.list);
	return *this;
}


///////////////////////////////////////////////////////////////////////////
//
// private functions
//

//////////////////////////////
//
// MidiEventList::sort -- Private because the MidiFile class keeps
//    track of delta versus absolute tick states of the MidiEventList,
//    and sorting is only allowed in absolute tick state (The MidiEventList
//    does not know about delta/absolute tick states of its contents).
//

void MidiEventList::sortNoteOnsBeforeOffs(void) {
	qsort(data(), getEventCount(), sizeof(MidiEvent*), MidiEventList::eventCompareNoteOnsBeforeOffs);
}

void MidiEventList::sortNoteOffsBeforeOns(void) {
	qsort(data(), getEventCount(), sizeof(MidiEvent*), MidiEventList::eventCompareNoteOnsBeforeOffs);
}



///////////////////////////////////////////////////////////////////////////
//
// external functions
//

//////////////////////////////
//
// MidiEventList::eventCompare -- Event comparison function for sorting tracks.
//
// Sorting rules:
//    (1) sort by (absolute) tick value; otherwise, if tick values are the same:
//    (2) end-of-track meta message is always last.
//    (3) other meta-messages come before regular MIDI messages.
//    (4) note-offs come after all other regular MIDI messages except note-ons.
//    (5) note-ons come after all other regular MIDI messages.
//
// Note: If you load a MIDI file from a file, MidiMessage.seq numbers
// will automatically be added, and sorting will follow the sequence
// numbers.  Use MidiFile::clearSequence() if you want to sort the
// MIDI events (occuring at the same time) using the rest of the sorting
// algorithm (such as to place note-offs before note-ons when they
// occur at the same time).
//

int MidiEventList::eventCompareNoteOnsBeforeOffs(const void* a, const void* b) {
	MidiEvent& aevent = **((MidiEvent**)a);
	MidiEvent& bevent = **((MidiEvent**)b);

	if (aevent.tick < bevent.tick) {
		// aevent occurs before bevent
		return -1;
	} else if (aevent.tick > bevent.tick) {
		// aevent occurs after bevent
		return +1;
	} else if ((aevent.seq != 0) && (bevent.seq != 0) && (aevent.seq < bevent.seq)) {
		// aevent sequencing state occurs before bevent
		// see MidiEventList::markSequence()
		return -1;
	} else if ((aevent.seq != 0) && (bevent.seq != 0) && (aevent.seq > bevent.seq)) {
		// aevent sequencing state occurs after bevent
		// see MidiEventList::markSequence()
		return +1;
	} else if ((aevent.getP0() == 0xff) && (aevent.getP1() == 0x2f)) {
		// end-of-track meta-message should always be last (but this won't really
		// matter since the writing function ignores all end-of-track messages
		// and writes its own.
		return +1;
	} else if ((bevent.getP0() == 0xff) && (bevent.getP1() == 0x2f)) {
		// end-of-track meta-message should always be last (but won't really
		// matter since the writing function ignores all end-of-track messages
		// and writes its own.
		return -1;
	} else if (aevent.getP0() == 0xff && bevent.getP0() != 0xff) {
		// other meta-messages are placed before real MIDI messages
		return -1;
	} else if ((aevent.getP0() != 0xff) && (bevent.getP0() == 0xff)) {
		// other meta-messages are placed before real MIDI messages
		return +1;
	} else if ((aevent.getP0() == 0xff) && (bevent.getP0() == 0xff)) {
		// could sort by meta-message number here
		return 0;
	} else if (aevent.isNote() && !bevent.isNote()) {
		// notes come after all other message types
		return +1;
	} else if (!aevent.isNote() && bevent.isNote()) {
		// notes come after all other message types
		return -1;
	} else if (aevent.isNoteOff() && bevent.isNoteOn()) {
		// note-offs come after note-ons
		return +1;
	} else if (aevent.isNoteOn() && bevent.isNoteOff()) {
		// note-ons come before all other types of MIDI messages
		return -1;
	} else if (aevent.isNoteOn() && bevent.isNoteOn()) {
		// sorted further by key number
		if (aevent.getP1() < bevent.getP1()) {
			return -1;
		} else if (aevent.getP1() > bevent.getP1()) {
			return +1;
		} else {
			return 0;
		}
		return 0;
	} else if (aevent.isNoteOff() && bevent.isNoteOff()) {
		// sorted further by key number
		if (aevent.getP1() < bevent.getP1()) {
			return -1;
		} else if (aevent.getP1() > bevent.getP1()) {
			return +1;
		} else {
			return 0;
		}
		// could be sorted further by key number.
		return 0;
	} else if (((aevent.getP0() & 0xf0) == 0xb0) && ((bevent.getP0() & 0xf0) == 0xb0)) {
		// both events are continuous controllers.  Sort them by controller number and value if equal
		if (aevent.getP1() > bevent.getP1()) {
			return +1;
		} if (aevent.getP1() < bevent.getP1()) {
			return -1;
		} else {
			// same controller number, so sort by data value
			// useful for sustain pedalling, for example.
			if (aevent.getP2() > bevent.getP2()) {
				return +1;
			} if (aevent.getP2() < bevent.getP2()) {
				return -1;
			} else {
				return 0;
			}
		}
	} else {
		return 0;
	}
}

int MidiEventList::eventCompareNoteOffsBeforeOns(const void* a, const void* b) {
	MidiEvent& aevent = **((MidiEvent**)a);
	MidiEvent& bevent = **((MidiEvent**)b);

	if (aevent.tick < bevent.tick) {
		// aevent occurs before bevent
		return -1;
	} else if (aevent.tick > bevent.tick) {
		// aevent occurs after bevent
		return +1;
	} else if ((aevent.seq != 0) && (bevent.seq != 0) && (aevent.seq < bevent.seq)) {
		// aevent sequencing state occurs before bevent
		// see MidiEventList::markSequence()
		return -1;
	} else if ((aevent.seq != 0) && (bevent.seq != 0) && (aevent.seq > bevent.seq)) {
		// aevent sequencing state occurs after bevent
		// see MidiEventList::markSequence()
		return +1;
	} else if ((aevent.getP0() == 0xff) && (aevent.getP1() == 0x2f)) {
		// end-of-track meta-message should always be last (but this won't really
		// matter since the writing function ignores all end-of-track messages
		// and writes its own.
		return +1;
	} else if ((bevent.getP0() == 0xff) && (bevent.getP1() == 0x2f)) {
		// end-of-track meta-message should always be last (but won't really
		// matter since the writing function ignores all end-of-track messages
		// and writes its own.
		return -1;
	} else if (aevent.getP0() == 0xff && bevent.getP0() != 0xff) {
		// other meta-messages are placed before real MIDI messages
		return -1;
	} else if ((aevent.getP0() != 0xff) && (bevent.getP0() == 0xff)) {
		// other meta-messages are placed before real MIDI messages
		return +1;
	} else if ((aevent.getP0() == 0xff) && (bevent.getP0() == 0xff)) {
		// could sort by meta-message number here
		return 0;
	} else if (aevent.isNote() && !bevent.isNote()) {
		// notes come after all other message types
		return +1;
	} else if (!aevent.isNote() && bevent.isNote()) {
		// notes come after all other message types
		return -1;
	} else if (aevent.isNoteOff() && bevent.isNoteOn()) {
		// note-offs come before note-ons
		return -1;
	} else if (aevent.isNoteOn() && bevent.isNoteOff()) {
		// note-ons come after all other types of MIDI messages
		return +1;
	} else if (aevent.isNoteOn() && bevent.isNoteOn()) {
		// sorted further by key number
		if (aevent.getP1() < bevent.getP1()) {
			return -1;
		} else if (aevent.getP1() > bevent.getP1()) {
			return +1;
		} else {
			return 0;
		}
		return 0;
	} else if (aevent.isNoteOff() && bevent.isNoteOff()) {
		// sorted further by key number
		if (aevent.getP1() < bevent.getP1()) {
			return -1;
		} else if (aevent.getP1() > bevent.getP1()) {
			return +1;
		} else {
			return 0;
		}
		// could be sorted further by key number.
		return 0;
	} else if (((aevent.getP0() & 0xf0) == 0xb0) && ((bevent.getP0() & 0xf0) == 0xb0)) {
		// both events are continuous controllers.  Sort them by controller number and value if equal
		if (aevent.getP1() > bevent.getP1()) {
			return +1;
		} if (aevent.getP1() < bevent.getP1()) {
			return -1;
		} else {
			// same controller number, so sort by data value
			// useful for sustain pedalling, for example.
			if (aevent.getP2() > bevent.getP2()) {
				return +1;
			} if (aevent.getP2() < bevent.getP2()) {
				return -1;
			} else {
				return 0;
			}
		}
	} else {
		return 0;
	}
}


} // end namespace smf



