Factor out more duplicated code.

git-svn-id: svn://localhost/ardour2/branches/3.0@5819 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 45 insertions, 0 deletions

diff --git a/libs/ardour/diskstream.cc b/libs/ardour/diskstream.cc
index 0b4c98eaa3..aaeb15a995 100644
--- a/libs/ardour/diskstream.cc
+++ b/libs/ardour/diskstream.cc
@@ -594,3 +594,48 @@ Diskstream::route_going_away ()
 {
 	_io.reset ();
 }
+
+void
+Diskstream::calculate_record_range(OverlapType ot, sframes_t transport_frame, nframes_t nframes,
+		nframes_t& rec_nframes, nframes_t& rec_offset)
+{
+	switch (ot) {
+	case OverlapNone:
+		rec_nframes = 0;
+		break;
+
+	case OverlapInternal:
+		/*     ----------    recrange
+		         |---|       transrange
+		*/
+		rec_nframes = nframes;
+		rec_offset = 0;
+		break;
+
+	case OverlapStart:
+		/*    |--------|    recrange
+	        -----|          transrange
+		*/
+		rec_nframes = transport_frame + nframes - first_recordable_frame;
+		if (rec_nframes) {
+			rec_offset = first_recordable_frame - transport_frame;
+		}
+		break;
+
+	case OverlapEnd:
+		/*    |--------|    recrange
+		         |--------  transrange
+		*/
+		rec_nframes = last_recordable_frame - transport_frame;
+		rec_offset = 0;
+		break;
+
+	case OverlapExternal:
+		/*    |--------|    recrange
+		    --------------  transrange
+		*/
+		rec_nframes = last_recordable_frame - first_recordable_frame;
+		rec_offset = first_recordable_frame - transport_frame;
+		break;
+	}
+}