1 files changed, 49 insertions, 0 deletions
diff --git a/share/scripts/stop_at_marker.lua b/share/scripts/stop_at_marker.lua
new file mode 100644
index 0000000000..35de3510c4
--- /dev/null
+++ b/share/scripts/stop_at_marker.lua
@@ -0,0 +1,49 @@
+ardour {
+	["type"]    = "session",
+	name        = "Stop at Marker",
+	license     = "MIT",
+	author      = "Ardour Lua Task Force",
+	description = [[An example session script which stops the transport on every location marker when rolling forward.]]
+}
+
+function factory ()
+	return function (n_samples)
+		if (not Session:transport_rolling ()) then
+			-- not rolling, nothing to do.
+			return
+		end
+
+		local pos = Session:transport_sample () -- current playhead position
+		local loc = Session:locations () -- all marker locations
+
+		-- find first marker after the current playhead position, ignore loop + punch ranges
+		-- (this only works when rolling forward, to extend this example see
+		-- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:Locations )
+		--
+		local m = loc:first_mark_after (pos, false)
+
+		if (m == -1) then
+			-- no marker was found
+			return
+		end
+
+		-- due to `first_mark_after(pos)` "m" is always > "pos":
+		-- assert(pos < m)
+		--
+		-- This callback happens from within the process callback:
+		--
+		-- this cycle's end = next cycle start = pos + n_samples.
+		--
+		-- Note that if "m" is exactly at cycle's end, that marker
+		-- will be at "pos" in the next cycle. Since we ask for
+		-- "first_mark_after pos", the marker would not be found.
+		--
+		-- So even though "pos + n_samples" is barely reached,
+		-- we need to stop at "m" in the cycle that crosses or ends at "m".
+		if (pos + n_samples >= m) then
+			-- asking to locate to "m" ensures that playback continues at "m"
+			-- and the same marker will not be taken into account.
+			Session:request_locate (m, ARDOUR.LocateTransportDisposition.MustStop, ARDOUR.TransportRequestSource.TRS_Engine)
+		end
+	end
+end