From db8b054543649e5942a5e4c0c7e034255f635f0d Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Fri, 2 Oct 2020 21:25:57 -0600
Subject: [PATCH] add required methods for region-relative time conversion

---
 libs/ardour/ardour/region.h | 29 +++++++++++++++++++++
 libs/ardour/region.cc       | 51 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 79 insertions(+), 1 deletion(-)

diff --git a/libs/ardour/ardour/region.h b/libs/ardour/ardour/region.h
index 378db8c5c7..e22d7c17b4 100644
--- a/libs/ardour/ardour/region.h
+++ b/libs/ardour/ardour/region.h
@@ -278,6 +278,35 @@ public:
 	void set_video_locked (bool yn);
 	void set_position_locked (bool yn);
 
+	Temporal::timepos_t region_beats_to_absolute_time(Temporal::Beats beats) const;
+	/** Convert a timestamp in beats into timepos_t (both relative to region position) */
+	Temporal::timepos_t region_beats_to_region_time (Temporal::Beats beats) const {
+		return timepos_t (nt_position().distance (region_beats_to_absolute_time (beats)));
+	}
+	/** Convert a timestamp in beats relative to region position into beats relative to source start */
+	Temporal::Beats region_beats_to_source_beats (Temporal::Beats beats) const {
+		return nt_position().distance (region_beats_to_absolute_time (beats)).beats ();
+	}
+	/** Convert a distance within a region to beats relative to region position */
+	Temporal::Beats region_distance_to_region_beats (Temporal::timecnt_t const &) const;
+
+	/** Convert a timestamp in beats measured from source start into absolute beats */
+	Temporal::Beats source_beats_to_absolute_beats(Temporal::Beats beats) const;
+
+	/** Convert a timestamp in beats measured from source start into absolute samples */
+	Temporal::timepos_t source_beats_to_absolute_time(Temporal::Beats beats) const;
+
+	/** Convert a timestamp in beats measured from source start into region-relative samples */
+	Temporal::timepos_t source_beats_to_region_time(Temporal::Beats beats) const {
+		return timepos_t (nt_position().distance (source_beats_to_absolute_time (beats)));
+	}
+	/** Convert a timestamp in absolute time to beats measured from source start*/
+	Temporal::Beats absolute_time_to_source_beats(Temporal::timepos_t const &) const;
+
+	Temporal::Beats absolute_time_to_region_beats (Temporal::timepos_t const & b) const {
+		return b.distance (nt_position()).beats ();
+	}
+
 	int apply (Filter &, Progress* progress = 0);
 
 	boost::shared_ptr<ARDOUR::Playlist> playlist () const { return _playlist.lock(); }
diff --git a/libs/ardour/region.cc b/libs/ardour/region.cc
index 877655a3c7..25b9fa9164 100644
--- a/libs/ardour/region.cc
+++ b/libs/ardour/region.cc
@@ -1973,6 +1973,56 @@ Region::latest_possible_sample () const
 	return position_sample() + (minlen - start_sample()) - 1;
 }
 
+Temporal::TimeDomain
+Region::position_time_domain() const
+{
+	return _position.val().time_domain();
+}
+
+timepos_t
+Region::nt_end() const
+{
+	return _position.val() + _length.val();
+}
+
+Temporal::Beats
+Region::region_distance_to_region_beats (timecnt_t const & region_relative_offset) const
+{
+	return timecnt_t (region_relative_offset, nt_position()).beats ();
+}
+
+Temporal::Beats
+Region::source_beats_to_absolute_beats (Temporal::Beats beats) const
+{
+	return source_position().beats() + beats;
+}
+
+Temporal::timepos_t
+Region::region_beats_to_absolute_time (Temporal::Beats beats) const
+{
+	/* beats is an additional offset to the start point of the region, from
+	   the effective start of the source on the timeline.
+	*/
+	return source_position() + nt_start () + beats;
+}
+
+Temporal::timepos_t
+Region::source_beats_to_absolute_time (Temporal::Beats beats) const
+{
+	/* return the time corresponding to `beats' relative to the start of
+	   the source. The start of the source is an implied position given by
+	   region->position - region->start
+	*/
+	return source_position() + beats;
+}
+
+Temporal::Beats
+Region::absolute_time_to_source_beats(timepos_t const & time) const
+{
+	const timepos_t s (source_position());
+	return time.earlier (timecnt_t (s, s)).beats();
+}
+
 timepos_t
 Region::source_position () const
 {
@@ -1990,4 +2040,3 @@ Region::region_relative_position (timepos_t const & p) const
 {
 	return p.earlier (_position.val());
 }
-