ardour/libs/temporal/tempo.cc

/*
    Copyright (C) 2017 Paul Davis

    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; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <algorithm>
#include <vector>

#include "pbd/error.h"
#include "pbd/i18n.h"
#include "pbd/compose.h"
#include "pbd/enumwriter.h"
#include "pbd/failed_constructor.h"
#include "pbd/stacktrace.h"

#include "temporal/debug.h"
#include "temporal/tempo.h"

using namespace PBD;
using namespace Temporal;
using std::cerr;
using std::cout;
using std::endl;
using Temporal::superclock_t;

std::string Tempo::xml_node_name = X_("Tempo");
std::string Meter::xml_node_name = X_("Meter");

SerializedRCUManager<TempoMap> TempoMap::_map_mgr (0);
thread_local TempoMap::SharedPtr TempoMap::_tempo_map_p;
PBD::Signal0<void> TempoMap::MapChanged;

void
Point::add_state (XMLNode & node) const
{
	node.set_property (X_("sclock"), _sclock);
	node.set_property (X_("quarters"), _quarters);
	node.set_property (X_("bbt"), _bbt);
}

Point::Point (TempoMap const & map, XMLNode const & node)
	: _map (&map)
{
	if (!node.get_property (X_("sclock"), _sclock)) {
		throw failed_constructor();
	}
	if (!node.get_property (X_("quarters"), _quarters)) {
		throw failed_constructor();
	}
	if (!node.get_property (X_("bbt"), _bbt)) {
		throw failed_constructor();
	}
}

#if 0
samplepos_t
Point::sample() const
{
	return superclock_to_samples (_sclock, _map->sample_rate());
}
#endif

timepos_t
Point::time() const
{
	if (_map->time_domain() == AudioTime) {
		return timepos_t::from_superclock (sclock());
	}

	return timepos_t (beats());
}

Tempo::Tempo (XMLNode const & node)
{
	assert (node.name() == xml_node_name);


	node.get_property (X_("npm"), _npm);
	node.get_property (X_("enpm"), _enpm);

	_superclocks_per_note_type = double_npm_to_scpn (_npm);
	_end_superclocks_per_note_type = double_npm_to_scpn (_enpm);
	_super_note_type_per_second = double_npm_to_snps (_npm);
	_end_super_note_type_per_second = double_npm_to_snps (_enpm);

	if (!node.get_property (X_("note-type"), _note_type)) {
		throw failed_constructor ();
	}
	if (!node.get_property (X_("type"), _type)) {
		throw failed_constructor ();
	}
	if (!node.get_property (X_("active"), _active)) {
		throw failed_constructor ();
	}
	if (!node.get_property (X_("locked-to-meter"), _locked_to_meter)) {
		_locked_to_meter = true;
	}
	if (!node.get_property (X_("clamped"), _clamped)) {
		_clamped = false;
	}
}

bool
Tempo::set_ramped (bool yn)
{
	_type = (yn ? Ramped : Constant);
	return true;
}

bool
Tempo::set_clamped (bool)
{
#warning implement Tempo::set_clamped
	return true;
}

XMLNode&
Tempo::get_state () const
{
	XMLNode* node = new XMLNode (xml_node_name);

	node->set_property (X_("npm"), note_types_per_minute());
	node->set_property (X_("enpm"), end_note_types_per_minute());
	node->set_property (X_("note-type"), note_type());
	node->set_property (X_("type"), type());
	node->set_property (X_("active"), active());
	node->set_property (X_("locked-to-meter"), _locked_to_meter);
	node->set_property (X_("clamped"), _clamped);

	return *node;
}

int
Tempo::set_state (XMLNode const & node, int /*version*/)
{
	if (node.name() != xml_node_name) {
		return -1;
	}

	node.get_property (X_("npm"), _npm);
	node.get_property (X_("enpm"), _enpm);

	_superclocks_per_note_type = double_npm_to_scpn (_npm);
	_end_superclocks_per_note_type = double_npm_to_scpn (_enpm);
	_super_note_type_per_second = double_npm_to_snps (_npm);
	_end_super_note_type_per_second = double_npm_to_snps (_enpm);

	node.get_property (X_("note-type"), _note_type);
	node.get_property (X_("type"), _type);
	node.get_property (X_("active"), _active);

	if (!node.get_property (X_("locked-to-meter"), _locked_to_meter)) {
		_locked_to_meter = true;
	}

	if (!node.get_property (X_("clamped"), _clamped)) {
		_clamped = false;
	}

	return 0;
}

Meter::Meter (XMLNode const & node)
{
	assert (node.name() == xml_node_name);
	if (!node.get_property (X_("note-value"), _note_value)) {
		throw failed_constructor ();
	}
	if (!node.get_property (X_("divisions-per-bar"), _divisions_per_bar)) {
		throw failed_constructor ();
	}
}

XMLNode&
Meter::get_state () const
{
	XMLNode* node = new XMLNode (xml_node_name);
	node->set_property (X_("note-value"), note_value());
	node->set_property (X_("divisions-per-bar"), divisions_per_bar());
	return *node;
}

int
Meter::set_state (XMLNode const & node, int /* version */)
{
	if (node.name() != xml_node_name) {
		return -1;
	}

	node.get_property (X_("note-value"), _note_value);
	node.get_property (X_("divisions-per-bar"), _divisions_per_bar);

	return 0;
}

Temporal::BBT_Time
Meter::bbt_add (Temporal::BBT_Time const & bbt, Temporal::BBT_Offset const & add) const
{
	int32_t bars = bbt.bars;
	int32_t beats = bbt.beats;
	int32_t ticks = bbt.ticks;

	if ((bars ^ add.bars) < 0) {
		/* signed-ness varies */
		if (abs(add.bars) >= abs(bars)) {
			/* addition will change which side of "zero" the answer is on;
			   adjust bbt.bars towards zero to deal with "unusual" BBT math
			*/
			if (bars < 0) {
				bars++;
			} else {
				bars--;
			}
		}
	}

	if ((beats ^ add.beats) < 0) {
		/* signed-ness varies */
		if (abs (add.beats) >= abs (beats)) {
			/* adjust bbt.beats towards zero to deal with "unusual" BBT math */
			if (beats < 0) {
				beats++;
			} else {
				beats--;
			}
		}
	}

	Temporal::BBT_Offset r (bars + add.bars, beats + add.beats, ticks + add.ticks);

	/* ticks-per-bar-division; PPQN is ticks-per-quarter note */

	const int32_t tpg = ticks_per_grid ();

	if (r.ticks >= tpg) {

		/* ticks per bar */
		const int32_t tpb = tpg * _divisions_per_bar;

		if (r.ticks >= tpb) {
			r.bars += r.ticks / tpb;
			r.ticks %= tpb;
		}

		if (r.ticks >= tpg) {
			r.beats += r.ticks / tpg;
			r.ticks %= tpg;
		}
	}

	if (r.beats > _divisions_per_bar) {

		/* adjust to zero-based math, since that's what C++ operators expect */

		r.beats -= 1;
		r.bars += r.beats / _divisions_per_bar;
		r.beats %= _divisions_per_bar;

		/* adjust back */

		r.beats += 1;
	}

	if (r.bars == 0) {
		r.bars = 1;
	}

	return Temporal::BBT_Time (r.bars, r.beats, r.ticks);
}

Temporal::BBT_Time
Meter::bbt_subtract (Temporal::BBT_Time const & bbt, Temporal::BBT_Offset const & sub) const
{
	int32_t bars = bbt.bars;
	int32_t beats = bbt.beats;
	int32_t ticks = bbt.ticks;

	if ((bars ^ sub.bars) < 0) {
		/* signed-ness varies */
		if (abs (sub.bars) >= abs (bars)) {
			/* adjust bbt.bars towards zero to deal with "unusual" BBT math */
			if (bars < 0) {
				bars++;
			} else {
				bars--;
			}
		}
	}

	if ((beats ^ sub.beats) < 0) {
		/* signed-ness varies */
		if (abs (sub.beats) >= abs (beats)) {
			/* adjust bbt.beats towards zero to deal with "unusual" BBT math */
			if (beats < 0) {
				beats++;
			} else {
				beats--;
			}
		}
	}

	Temporal::BBT_Offset r (bars - sub.bars, beats - sub.beats, ticks - sub.ticks);

	/* ticks-per-bar-division; PPQN is ticks-per-quarter note */

	const int32_t tpg = ticks_per_grid ();

	if (r.ticks < 0) {
		r.beats -= (r.ticks / tpg);
		r.ticks = tpg + (r.ticks % Temporal::Beats::PPQN);
	}

	if (r.beats < 0) {

		r.beats += 1;

		r.bars -= r.beats / _divisions_per_bar;
		r.beats = r.beats % _divisions_per_bar;

		r.beats -= 1;
	}

	if (r.bars <= 0) {
		r.bars -= 1;
	}

	return Temporal::BBT_Time (r.bars, r.beats, r.ticks);
}

Temporal::BBT_Time
Meter::round_to_bar (Temporal::BBT_Time const & bbt) const
{
	Beats b (bbt.beats, bbt.ticks);
	Beats half (Beats::ticks (Beats::PPQN + ((_divisions_per_bar * Beats::PPQN / 2))));

	if (b >= half) {
		return BBT_Time (bbt.bars+1, 1, 0);
	}

	return BBT_Time (bbt.bars, 1, 0);
}

Temporal::BBT_Time
Meter::round_up_to_bar (Temporal::BBT_Time const & bbt) const
{
	if (bbt.ticks == 0 && bbt.beats == 1) {
		return bbt;
	}
	BBT_Time b = bbt.round_up_to_beat ();
	if (b.beats > 1) {
		b.bars += 1;
		b.beats = 1;
	}
	return b;
}

Temporal::BBT_Time
Meter::round_down_to_bar (Temporal::BBT_Time const & bbt) const
{
	if (bbt.ticks == 0 && bbt.beats == 1) {
		return bbt;
	}
	BBT_Time b = bbt.round_down_to_beat ();
	if (b.beats > 1) {
		b.beats = 1;
	}
	return b;
}

Temporal::BBT_Time
Meter::round_up_to_beat (Temporal::BBT_Time const & bbt) const
{
	Temporal::BBT_Time b = bbt.round_up_to_beat ();
	if (b.beats > _divisions_per_bar) {
		b.bars++;
		b.beats = 1;
	}
	return b;
}

Temporal::Beats
Meter::to_quarters (Temporal::BBT_Offset const & offset) const
{
	int64_t ticks = 0;

	ticks += (Beats::PPQN * offset.bars * _divisions_per_bar * 4) / _note_value;
	ticks += (Beats::PPQN * offset.beats * 4) / _note_value;

	/* "parts per bar division" */

	const int tpg = ticks_per_grid ();

	if (offset.ticks > tpg) {
		ticks += Beats::PPQN * offset.ticks / tpg;
		ticks += offset.ticks % tpg;
	} else {
		ticks += offset.ticks;
	}

	return Beats (ticks/Beats::PPQN, ticks%Beats::PPQN);
}

int
TempoPoint::set_state (XMLNode const & node, int version)
{
	int ret;

	if ((ret = Tempo::set_state (node, version)) == 0) {
		node.get_property (X_("omega"), _omega);
	}

	return ret;
}

XMLNode&
TempoPoint::get_state () const
{
	XMLNode& base (Tempo::get_state());
	Point::add_state (base);
	base.set_property (X_("omega"), _omega);
	return base;
}

TempoPoint::TempoPoint (TempoMap const & map, XMLNode const & node)
	: Point (map, node)
	, Tempo (node)
	, _omega (0)
{
}

/* To understand the math(s) behind ramping, see the file doc/tempo.{pdf,tex}
 */

void
TempoPoint::compute_omega (samplecnt_t sr, superclock_t end_scpqn, Temporal::Beats const & quarter_duration)
{
	if ((superclocks_per_quarter_note () == end_scpqn) || (_type == Constant)) {
		_omega = 0.0;
		return;
	}

	_omega = ((1.0/end_scpqn) - (1.0/superclocks_per_quarter_note())) / DoubleableBeats (quarter_duration).to_double();

	DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("computed omega = %1%2 dur was %3\n", std::setprecision(12),_omega, DoubleableBeats (quarter_duration).to_double()));
}

superclock_t
TempoPoint::superclock_at (Temporal::Beats const & qn) const
{
	if (qn == _quarters) {
		return _sclock;
	}

	if (!actually_ramped()) {
		/* not ramped, use linear */
		const superclock_t spqn = superclocks_per_quarter_note ();
		return (spqn * qn.get_beats()) + int_div_round ((spqn * qn.get_ticks()), superclock_t (Temporal::ticks_per_beat));
	}

	return _sclock + llrint (log1p (superclocks_per_quarter_note() * _omega * DoubleableBeats (qn - _quarters).to_double()) / _omega);
}

superclock_t
TempoPoint::superclocks_per_note_type_at (timepos_t const &pos) const
{
	if (!actually_ramped()) {
		return _superclocks_per_note_type;
	}

	return _superclocks_per_note_type * exp (-_omega * pos.superclocks());
}

Temporal::Beats
TempoPoint::quarters_at_superclock (superclock_t sc) const
{
	/* catch a special case. The maximum superclock_t value cannot be
	   converted into a 32bit beat + 32 bit tick value for common tempos.
	   Obviously, values less than this can also cause overflow, but are
	   unlikely to be encountered.

	   A longer term/big picture solution for this is likely required in
	   order to deal with longer sessions. Still, even at 300bpm, a 32 bit
	   integer should cover 165 days. The problem is that a 62 bit (int62_t)
	   superclock counter can cover 105064 days, so the theoretical
	   potential for errors here is real.
	*/

	if (sc >= int62_t::max) {
		return std::numeric_limits<Beats>::max();
	}

	if (!actually_ramped()) {
		/* convert sc into superbeats, given that sc represents some number of seconds */
		const superclock_t whole_seconds = sc / superclock_ticks_per_second;
		const superclock_t remainder = sc - (whole_seconds * superclock_ticks_per_second);

		const int64_t supernotes = ((_super_note_type_per_second) * whole_seconds) + int_div_round (superclock_t ((_super_note_type_per_second) * remainder), superclock_ticks_per_second);
		/* multiply after divide to reduce overflow risk */
		const int64_t superbeats = int_div_round (supernotes, (superclock_t) _note_type) * 4;

		/* convert superbeats to beats:ticks */
		int32_t b;
		int32_t t;

		Tempo::superbeats_to_beats_ticks (superbeats, b, t);

		DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("%8 => \nsc %1 = %2 secs rem = %3 rem snotes %4 sbeats = %5 => %6 : %7\n", sc, whole_seconds, remainder, supernotes, superbeats, b , t, *this));

		return Beats (b, t);
	}

	const double b = (exp (_omega * (sc - _sclock)) - 1) / (superclocks_per_quarter_note() * _omega);
	return _quarters + Beats::from_double (b);
}

MeterPoint::MeterPoint (TempoMap const & map, XMLNode const & node)
	: Point (map, node)
	, Meter (node)
{
}

/* Given a time in BBT_Time, compute the equivalent Beat Time.
 *
 * Computation assumes that the Meter is in effect at the time specified as
 * BBT_Time (i.e. there is no other MeterPoint between this one and the specified
 * time.
 */
Temporal::Beats
MeterPoint::quarters_at (Temporal::BBT_Time const & bbt) const
{
	Temporal::BBT_Offset offset = bbt_delta (bbt, _bbt);
	return _quarters + to_quarters (offset);
}

/* Given a time in Beats, compute the equivalent BBT Time.
 *
 * Computation assumes that the Meter is in effect at the time specified in
 * Beats (i.e. there is no other MeterPoint between this one and the specified
 * time.
 */

Temporal::BBT_Time
MeterPoint::bbt_at (Temporal::Beats const & qn) const
{
	return bbt_add (_bbt, Temporal::BBT_Offset (0, 0,  (qn - _quarters).to_ticks()));
}

XMLNode&
MeterPoint::get_state () const
{
	XMLNode& base (Meter::get_state());
	Point::add_state (base);
	return base;
}

Temporal::BBT_Time
TempoMetric::bbt_at (superclock_t sc) const
{
	DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("qn @ %1 = %2, meter @ %3\n", sc, _tempo->quarters_at_superclock (sc), _meter->beats()));

	const Beats dq = _tempo->quarters_at_superclock (sc) - _meter->beats();

	/* dq is delta in quarters (beats). Convert to delta in note types of
	   the current meter, which we'll call "grid"
	*/

	const int64_t note_value_count = int_div_round (dq.get_beats() * _meter->note_value(), 4);

	/* now construct a BBT_Offset using the count in grid units */

	const BBT_Offset bbt_offset (0, note_value_count, dq.get_ticks());

	DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("BBT offset from meter @ %1: %2\n", _meter->bbt(), bbt_offset));
	return _meter->bbt_add (_meter->bbt(), bbt_offset);
}

superclock_t
TempoMetric::superclock_at (BBT_Time const & bbt) const
{
	DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("get quarters for %1 = %2\n", bbt, _meter->quarters_at (bbt)));
	return _tempo->superclock_at (_meter->quarters_at (bbt));
}

MusicTimePoint::MusicTimePoint (TempoMap const & map, XMLNode const & node)
	: Point (map, node)
	, TempoPoint (map, *node.child (Tempo::xml_node_name.c_str()))
	, MeterPoint (map, *node.child (Meter::xml_node_name.c_str()))
{
}

XMLNode&
MusicTimePoint::get_state () const
{
	XMLNode* node = new XMLNode (X_("MusicTime"));

	Point::add_state (*node);

	node->add_child_nocopy (Tempo::get_state());
	node->add_child_nocopy (Meter::get_state());

	return *node;
}

void
TempoMapPoint::start_float ()
{
	_floating = true;
}

void
TempoMapPoint::end_float ()
{
	_floating = false;
}

/* TEMPOMAP */

TempoMap::TempoMap (Tempo const & initial_tempo, Meter const & initial_meter)
	: _time_domain (AudioTime)
{
	TempoPoint* tp = new TempoPoint (*this, initial_tempo, 0, Beats(), BBT_Time());
	MeterPoint* mp = new MeterPoint (*this, initial_meter, 0, Beats(), BBT_Time());

	_tempos.push_back   (*tp);
	_meters.push_back   (*mp);

	_points.push_back (*tp);
	_points.push_back (*mp);
}

TempoMap::~TempoMap()
{
}

TempoMap::TempoMap (XMLNode const & node, int version)
{
	set_state (node, version);
}

TempoMap::TempoMap (TempoMap const & other)
	: _time_domain (other.time_domain())
{
	copy_points (other);
}

TempoMap&
TempoMap::operator= (TempoMap const & other)
{
	_time_domain = other.time_domain();
	copy_points (other);
	return *this;
}

void
TempoMap::copy_points (TempoMap const & other)
{
	std::vector<Point*> p;

	p.reserve (other._meters.size() + other._tempos.size() + other._bartimes.size());

	for (Meters::const_iterator m = other._meters.begin(); m != other._meters.end(); ++m) {
		MeterPoint* mp = new MeterPoint (*m);
		_meters.push_back (*mp);
		p.push_back (mp);
	}

	for (Tempos::const_iterator t = other._tempos.begin(); t != other._tempos.end(); ++t) {
		TempoPoint* tp = new TempoPoint (*t);
		_tempos.push_back (*tp);
		p.push_back (tp);
	}

	for (MusicTimes::const_iterator mt = other._bartimes.begin(); mt != other._bartimes.end(); ++mt) {
		MusicTimePoint* mtp = new MusicTimePoint (*mt);
		_bartimes.push_back (*mtp);
		p.push_back (mtp);
	}

	sort (p.begin(), p.end(), Point::ptr_sclock_comparator());

	for (std::vector<Point*>::iterator pi = p.begin(); pi != p.end(); ++pi) {
		_points.push_back (**pi);
	}
}

void
TempoMap::set_time_domain (TimeDomain td)
{
	if (td == time_domain()) {
		return;
	}

#warning paul tempo_map::set_time_domain needs implementing
#if 0
	switch (td) {
	case AudioTime:
		for (Tempos::iterator t = _tempos.begin(); t != _tempos.end(); ++t) {
			t->set_sclock (t->superclock_at (t->beats ()));
		}
		for (Meters::iterator m = _meters.begin(); m != _meters.end(); ++m) {
			m->set_sclock (m->superclock_at (m->beats ()));
		}
		break;

	default:
		for (Tempos::iterator t = _tempos.begin(); t != _tempos.end(); ++t) {
			t->set_beats (t->quarters_at_superclock (t->sclock()));
		}
		for (Meters::iterator m = _meters.begin(); m != _meters.end(); ++m) {
			m->set_beats (m->quarters_at_superclock (m->sclock()));
		}
	}
#endif

	_time_domain = td;
}

MeterPoint*
TempoMap::add_meter (MeterPoint* mp)
{
	/* CALLER MUST HOLD LOCK */

	Meters::iterator m;
	Points::iterator p;
	const superclock_t sclock_limit = mp->sclock();
	const Beats beats_limit = mp->beats ();

	switch (time_domain()) {
	case AudioTime:
		for (m = _meters.begin(); m != _meters.end() && m->sclock() < sclock_limit; ++m);
		for (p = _points.begin(); p != _points.end() && p->sclock() < sclock_limit; ++p);
		break;
	case BeatTime:
		for (m = _meters.begin(); m != _meters.end() && m->beats() < beats_limit; ++m);
		for (p = _points.begin(); p != _points.end() && p->beats() < beats_limit; ++p);
		break;
	}

	bool replaced = false;
	MeterPoint* ret = 0;

	if (m != _meters.end()) {
		if (m->sclock() == sclock_limit) {
			/* overwrite Meter part of this point */
			*((Meter*)&(*m)) = *mp;
			delete mp;
			ret = &(*m);
			replaced = true;
		}
	}

	if (!replaced) {
		ret = &(*(_meters.insert (m, *mp)));
		_points.insert (p, *mp);
	}

	reset_starting_at (sclock_limit);

	return ret;
}

void
TempoMap::change_tempo (TempoPoint & p, Tempo const & t)
{
	*((Tempo*)&p) = t;
}

TempoPoint &
TempoMap::set_tempo (Tempo const & t, BBT_Time const & bbt)
{
	return set_tempo (t, timepos_t (quarters_at (bbt)));
}

TempoPoint &
TempoMap::set_tempo (Tempo const & t, timepos_t const & time)
{
	TempoPoint * ret;

	DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("Set tempo @ %1 to %2\n", time, t));

	if (time.is_beats()) {


		/* tempo changes are required to be on-beat */

		Beats on_beat = time.beats().round_to_beat();
		superclock_t sc;
		BBT_Time bbt;

		TempoMetric metric (metric_at (on_beat, false));

		bbt = metric.bbt_at (on_beat);
		sc = metric.superclock_at (on_beat);

		TempoPoint* tp = new TempoPoint (*this, t, sc, on_beat, bbt);
		ret = add_tempo (tp);

	} else {

		Beats beats;
		BBT_Time bbt;
		superclock_t sc = time.superclocks();

		TempoMetric tm (metric_at (sc, false));

		/* tempo changes must be on beat */

		beats = tm.quarters_at_superclock (sc).round_to_beat ();
		bbt = tm.bbt_at (beats);

		/* recompute superclock position of rounded beat */
		sc = tm.superclock_at (beats);

		TempoPoint* tp = new TempoPoint (*this, t, sc, beats, bbt);
		ret = add_tempo (tp);

	}

	return *ret;
}

TempoPoint*
TempoMap::add_tempo (TempoPoint * tp)
{
	/* CALLER MUST HOLD LOCK */

	Tempos::iterator t;
	Points::iterator p;
	const superclock_t sclock_limit = tp->sclock();
	const Beats beats_limit = tp->beats ();

	switch (time_domain()) {
	case AudioTime:
		for (t = _tempos.begin(); t != _tempos.end() && t->sclock() < sclock_limit; ++t);
		for (p = _points.begin(); p != _points.end() && p->sclock() < sclock_limit; ++p);
		break;
	case BeatTime:
		for (t = _tempos.begin(); t != _tempos.end() && t->beats() < beats_limit; ++t);
		for (p = _points.begin(); p != _points.end() && p->beats() < beats_limit; ++p);
		break;
	}

	bool replaced = false;
	TempoPoint* ret = 0;

	if (t != _tempos.end()) {
		if (t->sclock() == sclock_limit) {
			/* overwrite Tempo part of this point */
			*((Tempo*)&(*t)) = *tp;
			delete tp;
			ret = &(*t);
			DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("overwrote old tempo with %1\n", tp));
			replaced = true;
		}
	}

	if (!replaced) {
		t = _tempos.insert (t, *tp);
		p = _points.insert (p, *tp);
		ret = &*t;
		DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("inserted tempo %1\n", tp));
	}

	/* t is guaranteed not to be _tempos.end() : it was either the
	 * TempoPoint we overwrote, or its the one we inserted.
	 */

	assert (t != _tempos.end());
	assert (p != _points.end());

	Tempos::iterator nxt = t;
	++nxt;

	if (t->ramped() && nxt != _tempos.end()) {
		DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("compute ramp over %1 .. %2 aka %3 .. %4\n", t->sclock(), nxt->sclock(), t->beats(), nxt->beats()));
		t->compute_omega (TEMPORAL_SAMPLE_RATE, nxt->superclocks_per_quarter_note (), nxt->beats() - t->beats());
	}

	reset_starting_at (sclock_limit);

	return ret;
}

void
TempoMap::remove_tempo (TempoPoint const & tp)
{
	superclock_t sc (tp.sclock());
	Tempos::iterator t;
	for (t = _tempos.begin(); t != _tempos.end() && t->sclock() < tp.sclock(); ++t);
	if (t->sclock() != tp.sclock()) {
		/* error ... no tempo point at the time of tp */
		return;
	}
	_tempos.erase (t);
	remove_point (tp);
	reset_starting_at (sc);
}

MusicTimePoint &
TempoMap::set_bartime (BBT_Time const & bbt, timepos_t const & pos)
{
	MusicTimePoint * ret;

	assert (pos.time_domain() == AudioTime);

	superclock_t sc (pos.superclocks());
	TempoMetric metric (metric_at (sc));
	MusicTimePoint* tp = new MusicTimePoint (*this, sc, metric.quarters_at_superclock (sc), bbt, metric.tempo(), metric.meter());

	ret = add_or_replace_bartime (*tp);

	return *ret;
}

MusicTimePoint*
TempoMap::add_or_replace_bartime (MusicTimePoint & tp)
{
	/* CALLER MUST HOLD LOCK */

	MusicTimes::iterator m;
	Points::iterator p;
	superclock_t sclock_limit = tp.sclock();

	for (m = _bartimes.begin(); m != _bartimes.end() && m->sclock() < sclock_limit; ++m);
	for (p = _points.begin(); p != _points.end() && p->sclock() < sclock_limit; ++p);

	bool replaced = false;
	MusicTimePoint* ret = 0;

	if (m != _bartimes.end()) {
		if (m->sclock() == tp.sclock()) {
			/* overwrite the point with */
			*m = tp;
			ret = &(*m);
			DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("overwrote old bartime with %1\n", tp));
			replaced = true;
		}
	}

	if (!replaced) {
		m = _bartimes.insert (m, tp);
		_points.insert (p, tp);

		ret = &*m;
		DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("inserted bartime %1\n", tp));
	}

	/* m is guaranteed not to be _bartimes.end() : it was either the
	 * TempoPoint we overwrote, or its the one we inserted.
	 */

	assert (m != _bartimes.end());

	reset_starting_at (tp.sclock());

	return ret;
}

void
TempoMap::remove_bartime (MusicTimePoint const & tp)
{
	superclock_t sc (tp.sclock());
	MusicTimes::iterator m;
	for (m = _bartimes.begin(); m != _bartimes.end() && m->sclock() < tp.sclock(); ++m);

	if (m->sclock() != tp.sclock()) {
		/* error ... no music time point at the time of tp */
		return;
	}

	_bartimes.erase (m);
	remove_point (tp);
	reset_starting_at (sc);
}

void
TempoMap::remove_point (Point const & point)
{
	Points::iterator p;
	Point const * tpp (&point);

	for (p = _points.begin(); p != _points.end(); ++p) {
		if (&(*p) == tpp) {
			// XXX need to fix this leak delete tpp;
			_points.erase (p);
			break;
		}
	}
}

void
TempoMap::reset_starting_at (superclock_t sc)
{
	/* CALLER MUST HOLD LOCK */

	Tempos::iterator t;
	Meters::iterator m;
	MusicTimes::iterator b;

	DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("reset starting at %1\n", sc));

	assert (!_tempos.empty());
	assert (!_meters.empty());

	TempoPoint* current_tempo = 0;
	MeterPoint* current_meter = 0;

	/* our task:

	   1) set t, m and b to the iterators for the tempo, meter and bartime
	   markers (if any) closest to but after @param sc.

	   2) set current_tempo and current_meter to point to the tempo and
	   meter in effect at @param sc
	*/

	if (sc) {
		for (t = _tempos.begin(); t != _tempos.end() && t->sclock() <= sc; ++t) {
			current_tempo = &*t;
		}
		for (m = _meters.begin(); m != _meters.end() && m->sclock() <= sc; ++m) {
			current_meter = &*m;
		}
		for (b = _bartimes.begin(); b != _bartimes.end() && b->sclock() <= sc; ++b);
	} else {
		t = _tempos.begin();
		m = _meters.begin();
		b = _bartimes.begin();

		current_meter = &*m;
		current_tempo = &*t;
	}

	Tempos::iterator nxt_tempo = _tempos.begin();

	while ((t != _tempos.end()) || (m != _meters.end()) || (b != _bartimes.end())) {

               /* UPDATE RAMP COEFFICIENTS WHEN NECESSARY */

		if (t->ramped() && (nxt_tempo != _tempos.begin()) && (nxt_tempo != _tempos.end())) {
		       t->compute_omega (TEMPORAL_SAMPLE_RATE, nxt_tempo->superclocks_per_quarter_note (), nxt_tempo->beats() - t->beats());
	       }

	       /* figure out which of the 1, 2 or 3 possible iterators defines the next explicit point (we want the earliest on the timeline,
                  but there may be more than 1 at the same location).
               */

	       Point* first_of_three = 0;
	       superclock_t limit = INT64_MAX;
	       bool is_bartime = false;

	       if (m != _meters.end() && m->sclock() < limit) {
                       first_of_three = &*m;
                       limit = m->sclock();
               }

	       if (t != _tempos.end() && t->sclock() < limit) {
                       first_of_three = &*t;
                       limit = t->sclock();
               }

               if (b != _bartimes.end() && b->sclock() < limit) {
                       first_of_three = &*b;
                       limit = b->sclock();
                       is_bartime = true;
               }

               assert (first_of_three);

               /* Determine whether a tempo or meter or bartime point (or any combination thereof) is defining this new point */

               bool advance_meter = false;
               bool advance_tempo = false;
               bool advance_bartime = false;

               TempoMetric metric (*current_tempo, *current_meter);

               if (m != _meters.end() && m->sclock() == first_of_three->sclock()) {
                       advance_meter = true;
                       current_meter = &*m;
                       DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("\tcurrent point defines meter %1\n", *current_meter));
               }

               if (t != _tempos.end() && t->sclock() == first_of_three->sclock()) {
                       advance_tempo = true;
                       current_tempo = &*t;
                       DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("\tcurrent point defines tempo %1\n", *current_tempo));
               }

               if ((b != _bartimes.end()) && (b->sclock() == first_of_three->sclock())) {
                       advance_bartime = true;
                       DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("\tcurrent point defines bartime %1\n", *b));
               }

               if (!is_bartime) {
	               superclock_t sc = metric.superclock_at (first_of_three->bbt());
	               DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("\tbased on %1 move to %2,%3\n", first_of_three->bbt(), sc, first_of_three->beats()));
	               first_of_three->set (sc, first_of_three->beats(), first_of_three->bbt());
               } else {


               }

               if (advance_meter && (m != _meters.end())) {
                       ++m;
               }
               if (advance_tempo && (t != _tempos.end())) {
                       ++t;
                       nxt_tempo = t;
                       ++nxt_tempo;
               }
               if (advance_bartime && (b != _bartimes.end())) {
                       ++b;
               }
	}

	DEBUG_TRACE (DEBUG::TemporalMap, "reset done\n");
#ifndef NDEBUG
	if (DEBUG_ENABLED (DEBUG::TemporalMap)) {
		dump (cerr);
	}
#endif
}

bool
TempoMap::move_meter (MeterPoint const & mp, timepos_t const & when, bool push)
{
	assert (!_tempos.empty());
	assert (!_meters.empty());

	if (_meters.size() < 2 || mp == _meters.front()) {
		/* not movable */
		return false;
	}

	superclock_t sc;
	Beats beats;
	BBT_Time bbt;
	TimeDomain td (time_domain());
	bool round_up;

	switch (td) {
	case AudioTime:
		sc = when.superclocks();
		if (sc > mp.sclock()) {
			round_up = true;
		} else {
			round_up = false;
		}
		break;
	case BeatTime:
		beats = when.beats ();
		if (beats > mp.beats ()) {
			round_up = true;
		} else {
			round_up = false;
		}
		break;
	}

	/* Do not allow moving a meter marker to the same position as
	 * an existing one.
	 */

	Tempos::iterator t, prev_t;
	Meters::iterator m, prev_m;

	switch (time_domain()) {
	case AudioTime: {

		/* Find TempoMetric *prior* to the intended new location, * using superclock position */

		for (t = _tempos.begin(), prev_t = _tempos.end(); t != _tempos.end() && t->sclock() < sc; ++t) { prev_t = t; }
		for (m = _meters.begin(), prev_m = _meters.end(); m != _meters.end() && m->sclock() < sc && *m != mp; ++m) { prev_m = m; }
		assert (prev_m != _meters.end());
		if (prev_t == _tempos.end()) { prev_t = _tempos.begin(); }
		TempoMetric metric (*prev_t, *prev_m);

		/* check the duration of 1 bar here. If we're not more than
		 * half-way to the next bar (in whatever the appropriate
		 * direction is), don't move
		 */

		const superclock_t one_bar = metric.superclocks_per_bar ();
		if (abs (sc - mp.sclock()) < one_bar / 2) {
			return false;
		}

		/* compute the BBT at the given superclock position, given the prior TempoMetric */

		bbt = metric.bbt_at (sc);

		/* meter changes must fall on a bar change */

		if (round_up) {
			bbt = metric.meter().round_up_to_bar (bbt);
		} else {
			bbt = metric.meter().round_down_to_bar (bbt);
		}

		/* Repeat using the computed (new) BBT location */

		for (m = _meters.begin(), prev_m = _meters.end(); m != _meters.end() && m->bbt() < bbt && *m != mp; ++m) {prev_m = m; }
		for (t = _tempos.begin(), prev_t = _tempos.end(); t != _tempos.end() && t->bbt() < bbt; ++t) { prev_t = t; }
		if (prev_m == _meters.end()) {
			/* given position is going to put us over the initial
			meter. Not allowed for a meter move.
			*/
			return false;
		}
		if (prev_t == _tempos.end()) { prev_t = _tempos.begin(); }
		metric = TempoMetric (*prev_t, *prev_m);

		/* recompute the superclock position of the new BBT position,
		 * since this is what we'll use to set the meter point.
		 */


		sc = metric.superclock_at (bbt);

		/* check to see if there's already a meter point at that location */

		for (m = _meters.begin(), prev_m = _meters.end(); m != _meters.end(); ++m) {
			if (&*m != &mp) {
				if (m->sclock() == sc) {
					return false;
				}
			}
		}
		beats = metric.quarters_at (bbt);
		break;
	}

	case BeatTime: {
		/* meter changes must be on bar */
		for (t = _tempos.begin(), prev_t = _tempos.end(); t != _tempos.end() && t->beats() < beats; ++t) { prev_t = t; }
		for (m = _meters.begin(), prev_m = _meters.end(); m != _meters.end() && m->beats() < beats && *m != mp; ++m) { prev_m = m; }
		assert (prev_m != _meters.end());
		if (prev_t == _tempos.end()) { prev_t = _tempos.begin(); }
		TempoMetric metric (*prev_t, *prev_m);
		bbt = metric.bbt_at (beats);
		if (round_up) {
			bbt = metric.meter().round_up_to_bar (bbt);
		} else {
			bbt = metric.meter().round_down_to_bar (bbt);
		}
		for (t = _tempos.begin(), prev_t = _tempos.end(); t != _tempos.end() && t->bbt() < bbt; ++t) { prev_t = t; }
		for (m = _meters.begin(), prev_m = _meters.end(); m != _meters.end() && m->bbt() < bbt && *m != mp; ++m) { prev_m = m; }
		assert (prev_m != _meters.end());
		if (prev_t == _tempos.end()) { prev_t = _tempos.begin(); }
		metric = TempoMetric (*prev_t, *prev_m);
		beats = metric.quarters_at (bbt);
		for (m = _meters.begin(), prev_m = _meters.end(); m != _meters.end(); ++m) {
			if (&*m != &mp) {
				if (m->beats() == beats) {
					return false;
				}
			}
		}
		sc = metric.superclock_at (bbt);
		break;
	}

	default:
		/* NOTREACHED */
		return false;
	}

	if (mp.sclock() == sc && mp.beats() == beats && mp.bbt() == bbt) {
		return false;
	}

	const superclock_t old_sc = mp.sclock();

	Meters::iterator current = _meters.end();
	Meters::iterator insert_before = _meters.end();

	for (Meters::iterator m = _meters.begin(); m != _meters.end(); ++m) {
		if (*m == mp) {
			current = m;
		}
		if (insert_before == _meters.end() && (m->sclock() > sc)) {
			insert_before = m;
		}
	}

	/* existing meter must have been found */
	assert (current != _meters.end());

	/* reset position of this meter */
	current->set (sc, beats, bbt);
	/* reposition in list */
	_meters.splice (insert_before, _meters, current);
	/* recompute 3 domain positions for everything after this */
	reset_starting_at (std::min (sc, old_sc));

	return true;
}

bool
TempoMap::move_tempo (TempoPoint const & tp, timepos_t const & when, bool push)
{
	assert (!_tempos.empty());
	assert (!_meters.empty());

	if (_tempos.size() < 2 || tp == _tempos.front()) {
		/* not movable */
		return false;
	}

	superclock_t sc;
	Beats beats;
	BBT_Time bbt;
	TimeDomain td (time_domain());

	switch (td) {
	case AudioTime:
		sc = when.superclocks();
		break;
	case BeatTime:
		beats = when.beats ();
		break;
	}

	/* Do not allow moving a tempo marker to the same position as
	 * an existing one.
	 */

	Tempos::iterator t, prev_t;
	Meters::iterator m, prev_m;

	switch (time_domain()) {
	case AudioTime: {
		for (t = _tempos.begin(), prev_t = _tempos.end(); t != _tempos.end() && t->sclock() < sc && *t != tp; ++t) { prev_t = t; }
		for (m = _meters.begin(), prev_m = _meters.end(); m != _meters.end() && m->sclock() < sc; ++m) { prev_m = m; }
		assert (prev_t != _tempos.end());
		if (prev_m == _meters.end()) { prev_m = _meters.begin(); }
		TempoMetric metric (*prev_t, *prev_m);
		beats = metric.quarters_at_superclock (sc);
		/* tempo changes must be on beat, so round and then
		 * recompute superclock and BBT with rounded result
		 */
		beats = beats.round_to_beat ();
		for (t = _tempos.begin(), prev_t = _tempos.end(); t != _tempos.end() && t->sclock() < sc && *t != tp; ++t) { prev_t = t; }
		for (m = _meters.begin(), prev_m = _meters.end(); m != _meters.end() && m->sclock() < sc; ++m) { prev_m = m; }
		assert (prev_t != _tempos.end());
		if (prev_m == _meters.end()) { prev_m = _meters.begin(); }
		metric = TempoMetric (*prev_t, *prev_m);
		sc = metric.superclock_at (beats);
		bbt = metric.bbt_at (beats);
		break;
	}

	case BeatTime: {
		/* tempo changes must be on beat */
		beats = beats.round_to_beat ();
		for (t = _tempos.begin(), prev_t = _tempos.end(); t != _tempos.end() && t->beats() < beats && *t != tp; ++t) { prev_t = t; }
		for (m = _meters.begin(), prev_m = _meters.end(); m != _meters.end() && m->beats() < beats; ++m) { prev_m = m; }
		assert (prev_t != _tempos.end());
		assert (prev_m != _meters.end());
		TempoMetric metric (*prev_t, *prev_m);
		sc = metric.superclock_at (beats);
		bbt = metric.bbt_at (beats);
		break;
	}

	default:
		/* NOTREACHED */
		return false;
	}

	if (tp.sclock() == sc && tp.beats() == beats && tp.bbt() == bbt) {
		return false;
	}

	const superclock_t old_sc = tp.sclock();

	Tempos::iterator current = _tempos.end();
	Tempos::iterator insert_before = _tempos.end();

	for (Tempos::iterator t = _tempos.begin(); t != _tempos.end(); ++t) {
		if (*t == tp) {
			current = t;
		}
		if (insert_before == _tempos.end() && (t->sclock() > sc)) {
			insert_before = t;
		}
	}

	/* existing tempo must have been found */
	assert (current != _tempos.end());

	/* reset position of this tempo */
	current->set (sc, beats, bbt);
	/* reposition in list */
	_tempos.splice (insert_before, _tempos, current);

	/* Update ramp coefficients when necessary */

	if (current->ramped() && insert_before != _tempos.end()) {
		current->compute_omega (TEMPORAL_SAMPLE_RATE, insert_before->superclocks_per_quarter_note (), insert_before->beats() - current->beats());
	}

	/* recompute 3 domain positions for everything after this */
	reset_starting_at (std::min (sc, old_sc));

	return true;
}

MeterPoint &
TempoMap::set_meter (Meter const & m, timepos_t const & time)
{
	MeterPoint * ret = 0;

	DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("Set meter @ %1 to %2\n", time, m));

	if (time.is_beats()) {

		Beats beats (time.beats());
		TempoMetric metric (metric_at (beats));

		/* meter changes are required to be on-bar */

		BBT_Time rounded_bbt = metric.bbt_at (beats);
		rounded_bbt = metric.round_to_bar (rounded_bbt);

		const Beats rounded_beats = metric.quarters_at (rounded_bbt);
		const superclock_t sc = metric.superclock_at (rounded_beats);

		MeterPoint* mp = new MeterPoint (*this, m, sc, rounded_beats, rounded_bbt);

		ret = add_meter (mp);

	} else {

		superclock_t sc (time.superclocks());
		Beats beats;
		BBT_Time bbt;

		TempoMetric metric (metric_at (sc));

		/* meter changes must be on bar */

		bbt = metric.bbt_at (sc);
		bbt = metric.round_to_bar (bbt);

		/* compute beat position */
		beats = metric.quarters_at (bbt);

		/* recompute superclock position of bar-rounded position */
		sc = metric.superclock_at (beats);

		MeterPoint* mp = new MeterPoint (*this, m, sc, beats, bbt);

		ret = add_meter (mp);
	}

	return *ret;
}

MeterPoint &
TempoMap::set_meter (Meter const & t, BBT_Time const & bbt)
{
	return set_meter (t, timepos_t (quarters_at (bbt)));
}

void
TempoMap::remove_meter (MeterPoint const & mp)
{
	superclock_t sc = mp.sclock();
	Meters::iterator m = std::upper_bound (_meters.begin(), _meters.end(), mp, Point::sclock_comparator());
	if (m->sclock() != mp.sclock()) {
		/* error ... no meter point at the time of mp */
		return;
	}
	_meters.erase (m);
	remove_point (mp);
	reset_starting_at (sc);
}

Temporal::BBT_Time
TempoMap::bbt_at (timepos_t const & pos) const
{
	if (pos.is_beats()) {
		return bbt_at (pos.beats());
	}
	return bbt_at (pos.superclocks());
}

Temporal::BBT_Time
TempoMap::bbt_at (superclock_t s) const
{
	return metric_at (s).bbt_at (s);
}

Temporal::BBT_Time
TempoMap::bbt_at (Temporal::Beats const & qn) const
{
	return metric_at (qn).bbt_at (qn);
}

#if 0
samplepos_t
TempoMap::sample_at (Temporal::Beats const & qn) const
{
	return superclock_to_samples (metric_at (qn).superclock_at (qn), TEMPORAL_SAMPLE_RATE);
}

samplepos_t
TempoMap::sample_at (Temporal::BBT_Time const & bbt) const
{
	return samples_to_superclock (metric_at (bbt).superclock_at (bbt), TEMPORAL_SAMPLE_RATE);
}

samplepos_t
TempoMap::sample_at (timepos_t const & pos) const
{
	if (pos.is_beat()) {
		return sample_at (pos.beats ());
	}

	/* somewhat nonsensical to call this under these conditions but ... */

	return pos.superclocks();
}
#endif

superclock_t
TempoMap::superclock_at (Temporal::Beats const & qn) const
{
	return metric_at (qn).superclock_at (qn);
}

superclock_t
TempoMap::superclock_at (Temporal::BBT_Time const & bbt) const
{
	return metric_at (bbt).superclock_at (bbt);
}

superclock_t
TempoMap::superclock_at (timepos_t const & pos) const
{
	if (pos.is_beats()) {
		return superclock_at (pos.beats ());
	}

	/* somewhat nonsensical to call this under these conditions but ... */

	return pos.superclocks();
}

#define S2Sc(s) (samples_to_superclock ((s), TEMPORAL_SAMPLE_RATE))
#define Sc2S(s) (superclock_to_samples ((s), TEMPORAL_SAMPLE_RATE))

/** Count the number of beats that are equivalent to distance when going forward,
    starting at pos.
*/
Temporal::Beats
TempoMap::scwalk_to_quarters (superclock_t pos, superclock_t distance) const
{
	TempoMetric first (metric_at (pos));
	TempoMetric last (metric_at (pos+distance));
	Temporal::Beats a = first.quarters_at_superclock (pos);
	Temporal::Beats b = last.quarters_at_superclock (pos+distance);
	return b - a;
}

Temporal::Beats
TempoMap::scwalk_to_quarters (Temporal::Beats const & pos, superclock_t distance) const
{
	/* XXX this converts from beats to superclock and back to beats... which is OK (reversible) */
	superclock_t s = metric_at (pos).superclock_at (pos);
	s += distance;
	return metric_at (s).quarters_at_superclock (s);

}

Temporal::Beats
TempoMap::bbtwalk_to_quarters (Beats const & pos, BBT_Offset const & distance) const
{
	return quarters_at (bbt_walk (bbt_at (pos), distance)) - pos;
}

void
TempoMap::sample_rate_changed (samplecnt_t new_sr)
{
	const double ratio = new_sr / (double) TEMPORAL_SAMPLE_RATE;

	for (Tempos::iterator t = _tempos.begin(); t != _tempos.end(); ++t) {
		t->map_reset_set_sclock_for_sr_change (llrint (ratio * t->sclock()));
	}

	for (Meters::iterator m = _meters.begin(); m != _meters.end(); ++m) {
		m->map_reset_set_sclock_for_sr_change (llrint (ratio * m->sclock()));
	}

	for (MusicTimes::iterator p = _bartimes.begin(); p != _bartimes.end(); ++p) {
		p->map_reset_set_sclock_for_sr_change (llrint (ratio * p->sclock()));
	}
}

void
TempoMap::dump (std::ostream& ostr) const
{
	ostr << "\n\nTEMPO MAP:\n";
	for (Tempos::const_iterator t = _tempos.begin(); t != _tempos.end(); ++t) {
		ostr << &*t << ' ' << *t << endl;
	}

	for (Meters::const_iterator m = _meters.begin(); m != _meters.end(); ++m) {
		ostr << &*m << ' ' << *m << endl;
	}

	for (MusicTimes::const_iterator m = _bartimes.begin(); m != _bartimes.end(); ++m) {
		ostr << &*m << ' ' << *m << endl;
	}
	ostr << "------------\n\n\n";
}

void
TempoMap::get_grid (TempoMapPoints& ret, superclock_t start, superclock_t end, uint32_t bar_mod)
{
	assert (!_tempos.empty());
	assert (!_meters.empty());
	assert (!_points.empty());

	DEBUG_TRACE (DEBUG::Grid, string_compose (">>> GRID START %1 .. %2 (barmod = %3)\n", start, end, bar_mod));

	TempoPoint* tp = 0;
	MeterPoint* mp = 0;
	Points::iterator p;

	/* initial values required, but will be reset before we begin */
	TempoMetric metric (_tempos.front(), _meters.front());

	/* first task: get to the right starting point for the requested
	 * grid. if bar_mod is zero, then we'll start on the next beat after
	 * @param start. if bar_mod is non-zero, we'll start on the first bar
	 * after @param start. This bar position may or may not be a part of the
	 * grid, depending on whether or not it is a multiple of bar_mod.
	 */

	for (tp = &_tempos.front(), mp = &_meters.front(), p = _points.begin(); p != _points.end() && p->sclock() < start; ++p) {

		TempoPoint* tpp;
		MeterPoint* mpp;

		if ((tpp = dynamic_cast<TempoPoint*> (&(*p))) != 0) {
			tp = tpp;
		}

		if ((mpp = dynamic_cast<MeterPoint*> (&(*p))) != 0) {
			mp = mpp;
		}

	}

	/* reset metric */

	metric = TempoMetric (*tp, *mp);
	DEBUG_TRACE (DEBUG::Grid, string_compose ("metric in effect at %1 = %2\n", start, metric));

	/* p now points to either the point *after* start, or the end of the
	 * _points list.
	 *
	 * metric is the TempoMetric that is in effect at start
	 */

	/* determine the BBT at start */

	BBT_Time bbt = metric.bbt_at (start);

	DEBUG_TRACE (DEBUG::Grid, string_compose ("start %1 is %2\n", start, bbt));

	if (bar_mod == 0) {

		/* round to next beat, then find the tempo/meter/bartime points
		 * in effect at that time.
		 */

		const BBT_Time new_bbt = metric.meter().round_up_to_beat (bbt);

		if (new_bbt != bbt) {

			bbt = new_bbt;

			/* rounded up, determine new starting superclock position */

			DEBUG_TRACE (DEBUG::Grid, string_compose ("new bbt for start (rounded up) = %1\n", bbt));

			for (tp = &_tempos.front(), mp = &_meters.front(), p = _points.begin(); p != _points.end() && p->sclock() < start; ++p) {

				TempoPoint* tpp;
				MeterPoint* mpp;

				if ((tpp = dynamic_cast<TempoPoint*> (&(*p))) != 0) {
					tp = tpp;
				}

				if ((mpp = dynamic_cast<MeterPoint*> (&(*p))) != 0) {
					mp = mpp;
				}

			}

			/* reset metric */

			metric = TempoMetric (*tp, *mp);

			/* recompute superclock position */

			superclock_t new_start = metric.superclock_at (bbt);

			DEBUG_TRACE (DEBUG::Grid, string_compose ("metric says that %1 is at %2\n", bbt, new_start));

			if (new_start < start) {
				abort ();
			}

			start = new_start;

		} else {
			DEBUG_TRACE (DEBUG::Grid, string_compose ("%1 was on a beat, no rounding up necessary\n", bbt));
		}

	} else {

		BBT_Time bar = bbt.round_down_to_bar ();

		/* adjust to match bar_mod (i.e. we only want every 4th bar)
		 */

		if (bar_mod != 1) {
			bar.bars -= bar.bars % bar_mod;
			++bar.bars;
		}

		/* the rounding we've just done cannot change the meter in
		   effect, because it remains within the bar. But it could
		   change the tempo (which are only quantized to grid positions
		   within a bar). So if it has generated a new BBT time,
		   recompute the metric.
		*/

		if (bar != bbt) {

			bbt = bar;

			for (tp = &_tempos.front(), mp = &_meters.front(), p = _points.begin(); p != _points.end() && p->sclock() < start; ++p) {

				TempoPoint* tpp;
				MeterPoint* mpp;

				if ((tpp = dynamic_cast<TempoPoint*> (&(*p))) != 0) {
					tp = tpp;
				}

				if ((mpp = dynamic_cast<MeterPoint*> (&(*p))) != 0) {
					mp = mpp;
				}

			}

			/* reset metric */

			metric = TempoMetric (*tp, *mp);

			start = metric.superclock_at (bbt);

		} else {
			DEBUG_TRACE (DEBUG::Grid, string_compose ("%1 was on a bar, no round down to bar necessary\n", bbt));
		}
	}

	/* at this point:
	 *
	 * - metric is a TempoMetric that describes the situation at start
	 * - p is an iterator pointin to either the end of the _points list, or
	 *   the next point in the list after start.
	 */

	DEBUG_TRACE (DEBUG::Grid, string_compose ("start filling points with start = %1 end = %2 with limit @ %3\n", start, end, *p));

	while (start < end) {

		Temporal::Beats beats = metric.quarters_at_superclock (start);

		DEBUG_TRACE (DEBUG::Grid, string_compose ("start %1 end %2 bbt %3 find first/limit with limit @ = %4\n", start, end, bbt, *p));

		while (start < p->sclock() && start < end) {

			/* add point to grid, perhaps */

			if (bar_mod != 0) {
				if (bbt.is_bar() && (bar_mod == 1 || ((bbt.bars % bar_mod == 0)))) {
					ret.push_back (TempoMapPoint (*this, metric, start, beats, bbt));
					DEBUG_TRACE (DEBUG::Grid, string_compose ("G %1\t       %2\n", metric, ret.back()));
				} else {
					DEBUG_TRACE (DEBUG::Grid, string_compose ("-- skip %1 not on bar_mod %2\n", bbt, bar_mod));
				}
			} else {
				ret.push_back (TempoMapPoint (*this, metric, start, beats, bbt));
				DEBUG_TRACE (DEBUG::Grid, string_compose ("G %1\t       %2\n", metric, ret.back()));
			}

			superclock_t step;

			if (bar_mod == 0) {

				/* Advance by the meter note value size */

				step = metric.superclocks_per_grid_at (start);
				start += step;
				bbt = metric.bbt_at (start);
				DEBUG_TRACE (DEBUG::Grid, string_compose ("step for note type was %1, now @ %2\n", step, start));

			} else {

				/* Advance by the number of bars specified by bar_mod */

				bbt.bars += bar_mod;
				start = metric.superclock_at (bbt);
				DEBUG_TRACE (DEBUG::Grid, string_compose ("bar mod %1 moved to %2 (start %3)\n", bar_mod, bbt, start))
			}
		}

		/* we might be finished ...*/

		if (start >= end) {
			break;
		}

		DEBUG_TRACE (DEBUG::Grid, string_compose ("stopped fill with start %1 and point at %2\n", start, (p == _points.end() ? -1 : p->sclock())));

		while ((p != _points.end()) && (start >= p->sclock())) {

			DEBUG_TRACE (DEBUG::Grid, string_compose ("pausing to deal with point => %1\n", *p));

			/* have just passed or arrived at the next
			 * point. Consider adding a grid point for this point.
			 */

			start = p->sclock();
			bbt = p->bbt();
			beats = p->beats();

			if (bar_mod != 0) {
				if (bbt.is_bar() && (bar_mod == 1 || ((bbt.bars % bar_mod == 0)))) {
					ret.push_back (TempoMapPoint (*this, metric, start, beats, bbt));
					DEBUG_TRACE (DEBUG::Grid, string_compose ("G %1\t       %2\n", metric, ret.back()));
				} else {
					DEBUG_TRACE (DEBUG::Grid, string_compose ("-- skip %1 not on bar_mod %2\n", bbt, bar_mod));
				}
			} else {
				ret.push_back (TempoMapPoint (*this, metric, start, beats, bbt));
				DEBUG_TRACE (DEBUG::Grid, string_compose ("G %1\t       %2\n", metric, ret.back()));
			}

			/* But there may be multiple points here, and we have
			 * to check them all (Tempo/Meter/MusicTime ... which
			 * is itself both a Tempo *and* Meter point) before
			 * proceeding.
			 */

			const superclock_t pos = p->sclock();

			Points::iterator nxt = p;
			++nxt;

			TempoPoint* tpp;
			MeterPoint* mpp;

			/* use this point */

			if ((tpp = dynamic_cast<TempoPoint*> (&(*p))) != 0) {
				tp = tpp;
			}

			if ((mpp = dynamic_cast<MeterPoint*> (&(*p))) != 0) {
				mp = mpp;
			}

			/* use any subsequent ones at the same location */

			while ((nxt != _points.end()) && (nxt->sclock() == pos)) {

				/* Set up the new metric given the new point */

				if ((tpp = dynamic_cast<TempoPoint*> (&(*nxt))) != 0) {
					tp = tpp;
				}

				if ((mpp = dynamic_cast<MeterPoint*> (&(*nxt))) != 0) {
					mp = mpp;
				}

				++nxt;
			}

			/* Build a new metric from the composite of all the
			 * points at this position.
			 */

			metric = TempoMetric (*tp, *mp);
			p = nxt;
		}

		if (p == _points.end()) {
			break;
		}
	}

	/* reached the end or no more points to consider, so just
	 * finish by filling the grid to the end, if necessary.
	 */

	if (start < end) {

		DEBUG_TRACE (DEBUG::Grid, string_compose ("reached end, no more map points, finish between %1 .. %2\n", start, end));

		/* note: if start < end, then p == _points.end(). This means there are
		 * no more Points beyond the current value of start.
		 *
		 * Since there are no more Points beyond start, the current metric
		 * cannot involve a ramp, so the step size per grid element is
		 * constant. metric will also remain constant until we finish.
		 */

		const superclock_t step  = metric.superclocks_per_grid_at (start);

		do {
			const Temporal::Beats beats = metric.quarters_at_superclock (start);

			if (bar_mod != 0) {
				if (bbt.is_bar() && (bar_mod == 1 || ((bbt.bars % bar_mod == 0)))) {
					ret.push_back (TempoMapPoint (*this, metric, start, beats, bbt));
					DEBUG_TRACE (DEBUG::Grid, string_compose ("Gend %1\t       %2\n", metric, ret.back()));
				}
			} else {
				ret.push_back (TempoMapPoint (*this, metric, start, beats, bbt));
				DEBUG_TRACE (DEBUG::Grid, string_compose ("Gend %1\t       %2\n", metric, ret.back()));
			}

			start += step;
			bbt = metric.bbt_at (start);

		} while (start < end);

		/* all done */
	} else {
		if (p == _points.end()) {
			DEBUG_TRACE (DEBUG::Grid, string_compose ("ended loop with start %1 end %2, p @ END\n", start, end));
		} else {
			DEBUG_TRACE (DEBUG::Grid, string_compose ("ended loop with start %1 end %2, p=> %3\n", start, end, *p));
		}
	}

	DEBUG_TRACE (DEBUG::Grid, "<<< GRID DONE\n");
}

std::ostream&
std::operator<<(std::ostream& str, Meter const & m)
{
	return str << m.divisions_per_bar() << '/' << m.note_value();
}

std::ostream&
std::operator<<(std::ostream& str, Tempo const & t)
{
	if (t.ramped()) {
		return str << t.note_types_per_minute() << " 1/" << t.note_type() << " RAMPED notes per minute [ " << t.super_note_type_per_second() << " => " << t.end_super_note_type_per_second() << " sntpm ] (" << t.superclocks_per_note_type() << " sc-per-1/" << t.note_type() << ')';
	} else {
		return str << t.note_types_per_minute() << " 1/" << t.note_type() << " notes per minute [" << t.super_note_type_per_second() << " sntpm] (" << t.superclocks_per_note_type() << " sc-per-1/" << t.note_type() << ')';
	}
}

std::ostream&
std::operator<<(std::ostream& str, Point const & p)
{
	return str << "P@" << p.sclock() << '/' << p.beats() << '/' << p.bbt();
}

std::ostream&
std::operator<<(std::ostream& str, MeterPoint const & m)
{
	return str << *((Meter const *) &m) << ' ' << *((Point const *) &m);
}

std::ostream&
std::operator<<(std::ostream& str, TempoPoint const & t)
{
	str << *((Tempo const *) &t) << ' '  << *((Point const *) &t);
	if (t.ramped()) {
		if (t.actually_ramped()) {
			str << ' ' << " ramp to " << t.end_note_types_per_minute();
		} else {
			str << ' ' << " !ramp to " << t.end_note_types_per_minute();
		}
		str << " omega = " << std::setprecision(12) << t.omega();
	}
	return str;
}

std::ostream&
std::operator<<(std::ostream& str, MusicTimePoint const & p)
{
	str << "MP@";
	str << *((Point const *) &p);
	str << *((Tempo const *) &p);
	str << *((Meter const *) &p);
	return str;
}

std::ostream&
std::operator<<(std::ostream& str, TempoMetric const & tm)
{
	return str << tm.tempo() << ' '  << tm.meter();
}

std::ostream&
std::operator<<(std::ostream& str, TempoMapPoint const & tmp)
{
	str << '@' << std::setw (12) << tmp.sclock() << ' ' << tmp.sclock() / (double) superclock_ticks_per_second
	    << " secs " << tmp.sample (TEMPORAL_SAMPLE_RATE) << " samples"
	    << (tmp.is_explicit_tempo() ? " EXP-T" : " imp-t")
	    << (tmp.is_explicit_meter() ? " EXP-M" : " imp-m")
	    << (tmp.is_explicit_position() ? " EXP-P" : " imp-p")
	    << " qn " << tmp.beats ()
	    << " bbt " << tmp.bbt()
		;

	if (tmp.is_explicit_tempo()) {
		str << " tempo " << tmp.tempo();
	}

	if (tmp.is_explicit_meter()) {
		str << " meter " << tmp.meter();
	}

	if (tmp.is_explicit_tempo() && tmp.tempo().ramped()) {
		str << " ramp omega = " << tmp.tempo().omega();
	}

	return str;
}

BBT_Time
TempoMap::bbt_walk (BBT_Time const & bbt, BBT_Offset const & o) const
{
	BBT_Offset offset (o);
	Tempos::const_iterator t, prev_t, next_t;
	Meters::const_iterator m, prev_m, next_m;

	assert (!_tempos.empty());
	assert (!_meters.empty());

	/* trivial (and common) case: single tempo, single meter */

	if (_tempos.size() == 1 && _meters.size() == 1) {
		return _meters.front().bbt_add (bbt, o);
	}

	/* Find tempo,meter pair for bbt, and also for the next tempo and meter
	 * after each (if any)
	 */

	/* Yes, linear search because the typical size of _tempos and _meters
	 * is 1, and extreme sizes are on the order of 10
	 */

	next_t = _tempos.end();
	next_m = _meters.end();

	for (t = _tempos.begin(), prev_t = t; t != _tempos.end() && t->bbt() < bbt;) {
		prev_t = t;
		++t;

		if (t != _tempos.end()) {
			next_t = t;
			++next_t;
		}
	}

	for (m = _meters.begin(), prev_m = m; m != _meters.end() && m->bbt() < bbt;) {
		prev_m = m;
		++m;

		if (m != _meters.end()) {
			next_m = m;
			++next_m;
		}
	}

	/* may have found tempo and/or meter precisely at the tiem given */

	if (t != _tempos.end() && t->bbt() == bbt) {
		prev_t = t;
	}

	if (m != _meters.end() && m->bbt() == bbt) {
		prev_m = m;
	}

	/* see ::metric_at() for comments about the use of const_cast here
	 */

	TempoMetric metric (*const_cast<TempoPoint*>(&*prev_t), *const_cast<MeterPoint*>(&*prev_m));
	superclock_t pos = metric.superclock_at (bbt);

	/* normalize possibly too-large ticks count */

	const int32_t tpg = metric.meter().ticks_per_grid ();

	if (offset.ticks > tpg) {
		/* normalize */
		offset.beats += offset.ticks / tpg;
		offset.ticks %= tpg;
	}

	/* add tick count, now guaranteed to be less than 1 grid unit */

	if (offset.ticks) {
		pos += metric.superclocks_per_ppqn () * offset.ticks;
	}

	/* add each beat, 1 by 1, rechecking to see if there's a new
	 * TempoMetric in effect after each addition
	 */

#define TEMPO_CHECK_FOR_NEW_METRIC                                      \
	if (((next_t != _tempos.end()) && (pos >= next_t->sclock())) || \
	    ((next_m != _meters.end()) && (pos >= next_m->sclock()))) { \
		/* need new metric */ \
		if (pos >= next_t->sclock()) { \
			if (pos >= next_m->sclock()) { \
				metric = TempoMetric (*const_cast<TempoPoint*>(&*next_t), *const_cast<MeterPoint*>(&*next_m)); \
				++next_t; \
				++next_m; \
			} else { \
				metric = TempoMetric (*const_cast<TempoPoint*>(&*next_t), metric.meter()); \
				++next_t; \
			} \
		} else if (pos >= next_m->sclock()) { \
			metric = TempoMetric (metric.tempo(), *const_cast<MeterPoint*>(&*next_m)); \
			++next_m; \
		} \
	}

	for (int32_t b = 0; b < offset.beats; ++b) {

		TEMPO_CHECK_FOR_NEW_METRIC;
		pos += metric.superclocks_per_grid ();
	}

	/* add each bar, 1 by 1, rechecking to see if there's a new
	 * TempoMetric in effect after each addition
	 */

	for (int32_t b = 0; b < offset.bars; ++b) {

		TEMPO_CHECK_FOR_NEW_METRIC;

		pos += metric.superclocks_per_bar ();
	}

	return metric.bbt_at (pos);
}

Temporal::Beats
TempoMap::quarters_at (timepos_t const & pos) const
{
	if (pos.is_beats()) {
		/* a bit redundant */
		return pos.beats();
	}
	return quarters_at_superclock (pos.superclocks());
}

Temporal::Beats
TempoMap::quarters_at (Temporal::BBT_Time const & bbt) const
{
	return metric_at (bbt).quarters_at (bbt);
}

Temporal::Beats
TempoMap::quarters_at_superclock (superclock_t pos) const
{
	return metric_at (pos).quarters_at_superclock (pos);
}

XMLNode&
TempoMap::get_state ()
{
	XMLNode* node = new XMLNode (X_("TempoMap"));

	node->set_property (X_("time-domain"), _time_domain);
	node->set_property (X_("superclocks-per-second"), superclock_ticks_per_second);

	XMLNode* children;

	children = new XMLNode (X_("Tempos"));
	node->add_child_nocopy (*children);
	for (Tempos::const_iterator t = _tempos.begin(); t != _tempos.end(); ++t) {
		children->add_child_nocopy (t->get_state());
	}

	children = new XMLNode (X_("Meters"));
	node->add_child_nocopy (*children);
	for (Meters::const_iterator m = _meters.begin(); m != _meters.end(); ++m) {
		children->add_child_nocopy (m->get_state());
	}

	children = new XMLNode (X_("MusicTimes"));
	node->add_child_nocopy (*children);
	for (MusicTimes::const_iterator b = _bartimes.begin(); b != _bartimes.end(); ++b) {
		children->add_child_nocopy (b->get_state());
	}

	return *node;
}

int
TempoMap::set_state (XMLNode const & node, int /*version*/)
{
	/* global map properties */

	/* XXX this should probably be at the global level in the session file because it affects a lot more than just the tempo map, potentially */
	node.get_property (X_("superclocks-per-second"), superclock_ticks_per_second);

	node.get_property (X_("time-domain"), _time_domain);

	XMLNodeList const & children (node.children());

	for (XMLNodeList::const_iterator c = children.begin(); c != children.end(); ++c) {
		if ((*c)->name() == X_("Tempos")) {
			if (set_tempos_from_state (**c)) {
				return -1;
			}
		}

		if ((*c)->name() == X_("Meters")) {
			if (set_meters_from_state (**c)) {
				return -1;
			}
		}

		if ((*c)->name() == X_("MusicTimes")) {
			if (set_music_times_from_state (**c)) {
				return -1;
			}
		}
	}

	return 0;
}

int
TempoMap::set_music_times_from_state (XMLNode const& mt_node)
{
	XMLNodeList const & children (mt_node.children());

	try {
		_bartimes.clear ();
		for (XMLNodeList::const_iterator c = children.begin(); c != children.end(); ++c) {
			MusicTimePoint* mp = new MusicTimePoint (*this, **c);
			_bartimes.push_back (*mp);
		}
	} catch (...) {
		_bartimes.clear (); /* remove any that were created */
		return -1;
	}

	return 0;
}

int
TempoMap::set_tempos_from_state (XMLNode const& tempos_node)
{
	XMLNodeList const & children (tempos_node.children());

	try {
		_tempos.clear ();
		for (XMLNodeList::const_iterator c = children.begin(); c != children.end(); ++c) {
			TempoPoint* tp = new TempoPoint (*this, **c);
			_tempos.push_back (*tp);
		}
	} catch (...) {
		_tempos.clear (); /* remove any that were created */
		return -1;
	}

	return 0;
}

int
TempoMap::set_meters_from_state (XMLNode const& meters_node)
{
	XMLNodeList const & children (meters_node.children());

	try {
		_meters.clear ();
		for (XMLNodeList::const_iterator c = children.begin(); c != children.end(); ++c) {
			MeterPoint* mp = new MeterPoint (*this, **c);
			_meters.push_back (*mp);
		}
	} catch (...) {
		_meters.clear (); /* remove any that were created */
		return -1;
	}

	return 0;
}

bool
TempoMap::can_remove (TempoPoint const & t) const
{
	return !is_initial (t);
}

bool
TempoMap::is_initial (TempoPoint const & t) const
{
	return t.sclock() == 0;
}

bool
TempoMap::is_initial (MeterPoint const & m) const
{
	return m.sclock() == 0;
}

bool
TempoMap::can_remove (MeterPoint const & m) const
{
	return !is_initial (m);
}

/** returns the duration (using the domain of @param pos) of the supplied BBT time at a specified sample position in the tempo map.
 * @param pos the frame position in the tempo map.
 * @param bbt the distance in BBT time from pos to calculate.
 * @param dir the rounding direction..
 * @return the timecnt_t that @param bbt represents when starting at @param pos, in
 * the time domain of @param pos
*/
timecnt_t
TempoMap::bbt_duration_at (timepos_t const & pos, BBT_Offset const & dur) const
{
	if (pos.time_domain() == AudioTime) {
		return timecnt_t::from_superclock (superclock_at (bbt_walk (bbt_at (pos), dur)) - pos.superclocks(), pos);
	}
	return timecnt_t (bbtwalk_to_quarters (pos.beats(), dur) - pos.beats(), pos);

}

/** Takes a position and distance (both in any time domain), and returns a timecnt_t
 * that describes that distance from that position in a specified time domain.
 *
 * This method is used when converting a (distance,pos) pair (a timecnt_t) into
 * (distance,pos') in a different time domain. For an english example: "given a
 * distance of N beats from position P, what is that same distance measured in
 * superclocks from P' ?"
 *
 * A different example: "given a distance N superclocks from position P, what
 * is that same distance measured in beats from P' ?"
 *
 * There is a trivial case in which the requested return domain is the same as
 * the domain for the distance. In english: "given a distance of N beats from
 * P, what is the same distance measured in beats from P' ?" In this case, we
 * can simply construct a new timecnt_t that uses P' instead of P, since the
 * distance component must necessarily be same. Notice that this true no matter
 * what domain is used.
 */

timecnt_t
TempoMap::convert_duration (timecnt_t const & duration, timepos_t const & new_position, TimeDomain return_domain) const
{
	timepos_t p (return_domain);
	Beats b;
	superclock_t s;

	if (return_domain == duration.time_domain()) {
		/* new timecnt_t: same distance, but new position */
		return timecnt_t (duration.distance(), new_position);
	}

	switch (return_domain) {
	case AudioTime:
		switch (duration.time_domain()) {
		case AudioTime:
			/*NOTREACHED*/
			break;
		case BeatTime:
			/* duration is in beats but we're asked to return superclocks */
			switch (new_position.time_domain()) {
			case BeatTime:
				/* new_position is already in beats */
				p = new_position;
				break;
			case AudioTime:
				/* Determine beats at sc pos, so that we can add beats */
				p = timepos_t (metric_at (new_position).quarters_at_superclock (new_position.superclocks()));
				break;
			}
			/* add beats */
			p += duration;
			/* determine superclocks */
			s = metric_at (p).superclock_at (p.beats());
			/* return duration in sc */
			return timecnt_t::from_superclock (s - new_position.superclocks(), new_position);
			break;
		}
		break;

	case BeatTime:
		switch (duration.time_domain()) {
		case AudioTime:
			/* duration is in superclocks but we're asked to return beats */
			switch (new_position.time_domain ()) {
			case AudioTime:
				/* pos is already in superclocks */
				p = new_position;
				break;
			case BeatTime:
				/* determined sc at beat position so we can add superclocks */
				p = timepos_t (metric_at (new_position).sample_at (new_position.beats()));
				break;
			}
			/* add superclocks */
			p += duration;
			/* determine beats */
			b = metric_at (p).quarters_at_superclock (p.superclocks());
			/* return duration in beats */
			return timecnt_t (b - new_position.beats(), new_position);
			break;
		case BeatTime:
			/*NOTREACHED*/
			break;
		}
		break;
	}

	/*NOTREACHED*/
	abort ();
	/*NOTREACHED*/

	return timecnt_t::from_superclock (0);

}

Tempo const *
TempoMap::next_tempo (Tempo const & t) const
{
	Tempos::const_iterator p = _tempos.begin();

	while (p != _tempos.end()) {
		if (&t == &*p) {
			break;
		}
		++p;
	}

	if (p != _tempos.end()) {
		++p;

		if (p != _tempos.end()) {
			return &*p;;
		}
	}

	return 0;
}

uint32_t
TempoMap::n_meters () const
{
	return _meters.size();
}

uint32_t
TempoMap::n_tempos () const
{
	return _tempos.size();
}

void
TempoMap::insert_time (timepos_t const & pos, timecnt_t const & duration)
{
	assert (!_tempos.empty());
	assert (!_meters.empty());

	if (pos == std::numeric_limits<timepos_t>::min()) {
		/* can't insert time at the front of the map: those entries are fixed */
		return;
	}

	Tempos::iterator     t (_tempos.begin());
	Meters::iterator     m (_meters.begin());
	MusicTimes::iterator b (_bartimes.begin());

	TempoPoint current_tempo = *t;
	MeterPoint current_meter = *m;
	MusicTimePoint current_time_point (*this, 0, Beats(), BBT_Time(), current_tempo, current_meter);

	if (_bartimes.size() > 0) {
		current_time_point = *b;
	}

	superclock_t sc;
	Beats beats;
	BBT_Time bbt;

	/* set these to true so that we set current_* on our first pass
	 * through the while loop(s)
	 */

	bool moved_tempo = true;
	bool moved_meter = true;
	bool moved_bartime = true;

	switch (duration.time_domain()) {
	case AudioTime:
		sc = pos.superclocks();

		/* handle a common case quickly */

		if ((_tempos.size() < 2 || sc > _tempos.back().sclock()) &&
		    (_meters.size() < 2 || sc > _meters.back().sclock()) &&
		    (_bartimes.size() < 2 || (_bartimes.empty() || sc > _bartimes.back().sclock()))) {

			/* only one tempo, plus one meter and zero or
			   one bartimes, or insertion point is after last
			   item. nothing to do here.
			*/

			return;
		}

		/* advance fundamental iterators to correct position */

		while (t != _tempos.end()   && t->sclock() < sc) ++t;
		while (m != _meters.end()   && m->sclock() < sc) ++m;
		while (b != _bartimes.end() && b->sclock() < sc) ++b;

		while (t != _tempos.end() && m != _meters.end() && b != _bartimes.end()) {

			if (moved_tempo && t != _tempos.end()) {
				current_tempo = *t;
				moved_tempo = false;
			}
			if (moved_meter && m != _meters.end()) {
				current_meter = *m;
				moved_meter = false;
			}
			if (moved_bartime && b != _bartimes.end()) {
				current_time_point = *b;
				moved_bartime = false;
			}

			/* for each of t, m and b:

			   if the point is earlier than the other two,
			   recompute the superclock, beat and bbt
			   positions, and reset the point.
			*/

			if (t->sclock() < m->sclock() && t->sclock() < b->sclock()) {

				sc = t->sclock() + duration.superclocks();
				beats = current_tempo.quarters_at_superclock (sc);
				/* round tempo to beats */
				beats = beats.round_to_beat ();
				sc = current_tempo.superclock_at (beats);
				bbt = current_meter.bbt_at (beats);

				t->set (sc, beats, bbt);
				++t;
				moved_tempo = true;
			}

			if (m->sclock() < t->sclock() && m->sclock() < b->sclock()) {

				sc = m->sclock() + duration.superclocks();
				beats = current_tempo.quarters_at_superclock (sc);
				/* round meter to bars */
				bbt = current_meter.bbt_at (beats);
				beats = current_meter.quarters_at (current_meter.round_to_bar(bbt));
				/* recompute */
				sc = current_tempo.superclock_at (beats);

				m->set (sc, beats, bbt);
				++m;
				moved_meter = true;
			}

			if (b->sclock() < t->sclock() && b->sclock() < m->sclock()) {

				sc = b->sclock() + duration.superclocks();
				beats = current_tempo.quarters_at_superclock (sc);
				/* round bartime to beats */
				beats = beats.round_to_beat();
				sc = current_tempo.superclock_at (beats);
				bbt = current_meter.bbt_at (beats);

				m->set (sc, beats, bbt);
				++m;
				moved_meter = true;
			}

		}
		break;

	case BeatTime:
		break;
	}
}

bool
TempoMap::remove_time (timepos_t const & pos, timecnt_t const & duration)
{
#warning NUTEMPO implement TempoMap::remove_time
	return false;
}

TempoPoint const *
TempoMap::previous_tempo (TempoPoint const & point) const
{
	Tempos::const_iterator t = _tempos.begin();
	Tempos::const_iterator prev = _tempos.end();

	while (t != _tempos.end()) {
		if (t->sclock() == point.sclock()) {
			if (prev != _tempos.end()) {
				return &*prev;
			}
		}
		prev = t;
		++t;
	}

	return 0;
}

TempoMetric
TempoMap::metric_at (timepos_t const & pos) const
{
	if (pos.is_beats()) {
		return metric_at (pos.beats());
	}

	return metric_at (pos.superclocks());
}

TempoMetric
TempoMap::metric_at (superclock_t sc, bool can_match) const
{
	assert (!_tempos.empty());
	assert (!_meters.empty());
	assert (!_points.empty());

	TempoPoint const * tpp = 0;
	MeterPoint const * mpp = 0;

	TempoPoint const * prev_t = &_tempos.front();
	MeterPoint const * prev_m = &_meters.front();

	/* Yes, linear search because the typical size of _points
	 * is 2, and extreme sizes are on the order of 10-100
	 */

	Points::const_iterator p;

	for (p = _points.begin(); p != _points.end() && p->sclock() < sc; ++p) {
		if ((tpp = dynamic_cast<TempoPoint const *> (&(*p)))) {
			prev_t = tpp;
		}
		if ((mpp = dynamic_cast<MeterPoint const *> (&(*p)))) {
			prev_m = mpp;
		}
	}

	if (can_match || sc == 0) {
		/* may have found tempo and/or meter precisely at @param sc */

		if (p != _points.end() && p->sclock() == sc) {

			if ((tpp = dynamic_cast<TempoPoint const *> (&(*p)))) {
				prev_t = tpp;
			}

			if ((mpp = dynamic_cast<MeterPoint const *> (&(*p)))) {
				prev_m = mpp;
			}
		}
	}

	/* I hate doing this const_cast<>, but making this method non-const
	 * propagates into everything that just calls metric_at(), and that's a
	 * bit ridiculous. Yes, the TempoMetric returned here can be used to
	 * change the map, and that's bad, but the non-const propagation is
	 * worse.
	 */

	return TempoMetric (*const_cast<TempoPoint*>(prev_t), *const_cast<MeterPoint*> (prev_m));
}

TempoMetric
TempoMap::metric_at (Beats const & b, bool can_match) const
{
	assert (!_tempos.empty());
	assert (!_meters.empty());
	assert (!_points.empty());

	TempoPoint const * tpp = 0;
	MeterPoint const * mpp = 0;

	TempoPoint const * prev_t = &_tempos.front();
	MeterPoint const * prev_m = &_meters.front();

	/* Yes, linear search because the typical size of _points
	 * is 2, and extreme sizes are on the order of 10-100
	 */

	Points::const_iterator p;

	for (p = _points.begin(); p != _points.end() && p->beats() < b; ++p) {
		if ((tpp = dynamic_cast<TempoPoint const *> (&(*p)))) {
			prev_t = tpp;
		}
		if ((mpp = dynamic_cast<MeterPoint const *> (&(*p)))) {
			prev_m = mpp;
		}
	}

	if (can_match || b == Beats()) {
		/* may have found tempo and/or meter precisely at @param sc */

		if (p != _points.end() && p->beats() == b) {

			if ((tpp = dynamic_cast<TempoPoint const *> (&(*p)))) {
				prev_t = tpp;
			}

			if ((mpp = dynamic_cast<MeterPoint const *> (&(*p)))) {
				prev_m = mpp;
			}
		}
	}

	/* I hate doing this const_cast<>, but making this method non-const
	 * propagates into everything that just calls metric_at(), and that's a
	 * bit ridiculous. Yes, the TempoMetric returned here can be used to
	 * change the map, and that's bad, but the non-const propagation is
	 * worse.
	 */

	return TempoMetric (*const_cast<TempoPoint*>(prev_t), *const_cast<MeterPoint*> (prev_m));
}

TempoMetric
TempoMap::metric_at (BBT_Time const & bbt, bool can_match) const
{
	assert (!_tempos.empty());
	assert (!_meters.empty());
	assert (!_points.empty());

	TempoPoint const * tpp = 0;
	MeterPoint const * mpp = 0;

	TempoPoint const * prev_t = &_tempos.front();
	MeterPoint const * prev_m = &_meters.front();

	/* Yes, linear search because the typical size of _points
	 * is 2, and extreme sizes are on the order of 10-100
	 */

	Points::const_iterator p;

	for (p = _points.begin(); p != _points.end() && p->bbt() < bbt; ++p) {
		if ((tpp = dynamic_cast<TempoPoint const *> (&(*p)))) {
			prev_t = tpp;
		}
		if ((mpp = dynamic_cast<MeterPoint const *> (&(*p)))) {
			prev_m = mpp;
		}
	}

	if (can_match || bbt == BBT_Time()) {
		/* may have found tempo and/or meter precisely at @param sc */

		if (p != _points.end() && p->bbt() == bbt) {

			if ((tpp = dynamic_cast<TempoPoint const *> (&(*p)))) {
				prev_t = tpp;
			}

			if ((mpp = dynamic_cast<MeterPoint const *> (&(*p)))) {
				prev_m = mpp;
			}
		}
	}

	/* I hate doing this const_cast<>, but making this method non-const
	 * propagates into everything that just calls metric_at(), and that's a
	 * bit ridiculous. Yes, the TempoMetric returned here can be used to
	 * change the map, and that's bad, but the non-const propagation is
	 * worse.
	 */

	return TempoMetric (*const_cast<TempoPoint*>(prev_t), *const_cast<MeterPoint*> (prev_m));
}

bool
TempoMap::set_ramped (TempoPoint & tp, bool yn)
{
	Rampable & r (tp);
	bool ret = r.set_ramped (yn);
	if (ret) {
		reset_starting_at (tp.sclock());
	}
	return ret;
}

#if 0
bool
TempoMap::twist_tempi (TempoSection* ts, const Tempo& bpm, const framepos_t frame, const framepos_t end_frame)
{
	TempoSection* next_t = 0;
	TempoSection* next_to_next_t = 0;
	Metrics future_map;
	bool can_solve = false;

	/* minimum allowed measurement distance in frames */
	framepos_t const min_dframe = 2;

	if (!ts) {
		return false;
	}

	TempoSection* tempo_copy = copy_metrics_and_point (_metrics, future_map, ts);
	TempoSection* prev_to_prev_t = 0;
	const frameoffset_t fr_off = end_frame - frame;

	if (!tempo_copy) {
		return false;
	}

	if (tempo_copy->pulse() > 0.0) {
		prev_to_prev_t = const_cast<TempoSection*>(&tempo_section_at_minute_locked (future_map, minute_at_frame (tempo_copy->frame() - 1)));
	}

	for (Metrics::const_iterator i = future_map.begin(); i != future_map.end(); ++i) {
		if ((*i)->is_tempo() && (*i)->minute() >  tempo_copy->minute()) {
			next_t = static_cast<TempoSection*> (*i);
			break;
		}
	}

	if (!next_t) {
		return false;
	}

	for (Metrics::const_iterator i = future_map.begin(); i != future_map.end(); ++i) {
		if ((*i)->is_tempo() && (*i)->minute() >  next_t->minute()) {
			next_to_next_t = static_cast<TempoSection*> (*i);
			break;
		}
	}

	if (!next_to_next_t) {
		return false;
	}

	double prev_contribution = 0.0;

	if (next_t && prev_to_prev_t && prev_to_prev_t->type() == TempoSection::Ramp) {
		prev_contribution = (tempo_copy->frame() - prev_to_prev_t->frame()) / (double) (next_t->frame() - prev_to_prev_t->frame());
	}

	const frameoffset_t tempo_copy_frame_contribution = fr_off - (prev_contribution * (double) fr_off);


	framepos_t old_tc_minute = tempo_copy->minute();
	double old_next_minute = next_t->minute();
	double old_next_to_next_minute = next_to_next_t->minute();

	double new_bpm;
	double new_next_bpm;
	double new_copy_end_bpm;

	if (frame > tempo_copy->frame() + min_dframe && (frame + tempo_copy_frame_contribution) > tempo_copy->frame() + min_dframe) {
		new_bpm = tempo_copy->note_types_per_minute() * ((frame - tempo_copy->frame())
		                                                 / (double) (end_frame - tempo_copy->frame()));
	} else {
		new_bpm = tempo_copy->note_types_per_minute();
	}

	/* don't clamp and proceed here.
	   testing has revealed that this can go negative,
	   which is an entirely different thing to just being too low.
	*/
	if (new_bpm < 0.5) {
		return false;
	}

	new_bpm = min (new_bpm, (double) 1000.0);

	tempo_copy->set_note_types_per_minute (new_bpm);
	if (tempo_copy->type() == TempoSection::Constant) {
		tempo_copy->set_end_note_types_per_minute (new_bpm);
	}

	recompute_tempi (future_map);

	if (check_solved (future_map)) {

		if (!next_t) {
			return false;
		}

		ts->set_note_types_per_minute (new_bpm);
		if (ts->type() == TempoSection::Constant) {
			ts->set_end_note_types_per_minute (new_bpm);
		}

		recompute_map (_metrics);

		can_solve = true;
	}

	if (next_t->type() == TempoSection::Constant || next_t->c() == 0.0) {
		if (frame > tempo_copy->frame() + min_dframe && end_frame > tempo_copy->frame() + min_dframe) {

			new_next_bpm = next_t->note_types_per_minute() * ((next_to_next_t->minute() - old_next_minute)
			                                                  / (double) ((old_next_to_next_minute) - old_next_minute));

		} else {
			new_next_bpm = next_t->note_types_per_minute();
		}

		next_t->set_note_types_per_minute (new_next_bpm);
		recompute_tempi (future_map);

		if (check_solved (future_map)) {
			for (Metrics::const_iterator i = _metrics.begin(); i != _metrics.end(); ++i) {
				if ((*i)->is_tempo() && (*i)->minute() >  ts->minute()) {
					next_t = static_cast<TempoSection*> (*i);
					break;
				}
			}

			if (!next_t) {
				return false;
			}
			next_t->set_note_types_per_minute (new_next_bpm);
			recompute_map (_metrics);
			can_solve = true;
		}
	} else {
		double next_frame_ratio = 1.0;
		double copy_frame_ratio = 1.0;

		if (next_to_next_t) {
			next_frame_ratio = (next_to_next_t->minute() - old_next_minute) / (old_next_to_next_minute -  old_next_minute);

			copy_frame_ratio = ((old_tc_minute - next_t->minute()) / (double) (old_tc_minute - old_next_minute));
		}

		new_next_bpm = next_t->note_types_per_minute() * next_frame_ratio;
		new_copy_end_bpm = tempo_copy->end_note_types_per_minute() * copy_frame_ratio;

		tempo_copy->set_end_note_types_per_minute (new_copy_end_bpm);

		if (next_t->clamped()) {
			next_t->set_note_types_per_minute (new_copy_end_bpm);
		} else {
			next_t->set_note_types_per_minute (new_next_bpm);
		}

		recompute_tempi (future_map);

		if (check_solved (future_map)) {
			for (Metrics::const_iterator i = _metrics.begin(); i != _metrics.end(); ++i) {
				if ((*i)->is_tempo() && (*i)->minute() >  ts->minute()) {
					next_t = static_cast<TempoSection*> (*i);
					break;
				}
			}

			if (!next_t) {
				return false;
			}

			if (next_t->clamped()) {
				next_t->set_note_types_per_minute (new_copy_end_bpm);
			} else {
				next_t->set_note_types_per_minute (new_next_bpm);
			}

			ts->set_end_note_types_per_minute (new_copy_end_bpm);
			recompute_map (_metrics);
			can_solve = true;
		}
	}

	Metrics::const_iterator d = future_map.begin();
	while (d != future_map.end()) {
		delete (*d);
		++d;
	}

	MetricPositionChanged (PropertyChange ()); // Emit Signal

	return can_solve;
}

#endif

void
TempoMap::MementoBinder::set_state (XMLNode const & node, int version) const
{
	/* fetch a writable copy of this thread's tempo map */
	TempoMap::SharedPtr map (write_copy());
	/* change the state of the copy */
	map->set_state (node, version);
	/* do the update step of RCU. This will also update this thread's map pointer */
	update (map);
}

void
TempoMap::init ()
{
	SharedPtr new_map (new TempoMap (Tempo (120, 4), Meter (4, 4)));
	_map_mgr.init (new_map);
	fetch ();
}

int
TempoMap::update (TempoMap::SharedPtr m)
{
	if (!_map_mgr.update (m)) {
		return -1;
	}

	/* update thread local map pointer in the calling thread */
	update_thread_tempo_map ();

	cerr << "New tempo map:\n";
	_tempo_map_p->dump (cerr);

	MapChanged (); /* EMIT SIGNAL */

	return 0;
}

void
TempoMap::abort_update ()
{
	/* drop lock taken by write_copy() */
	_map_mgr.abort ();
	/* update thread local map pointer in calling thread. Note that this
	   will reset _tempo_map_p, which is (almost guaranteed to be) the only
	   reference to the copy of the map made in ::write_copy(), so it will
	   be destroyed here.
	*/
	TempoMap::fetch ();
}