Add Canvas::get_last_render_start_timestamp method

2 files changed, 7 insertions, 0 deletions

diff --git a/libs/canvas/canvas.cc b/libs/canvas/canvas.cc
index 7415478b60..a004d64ad3 100644
--- a/libs/canvas/canvas.cc
+++ b/libs/canvas/canvas.cc
@@ -58,6 +58,7 @@ uint32_t Canvas::tooltip_timeout_msecs = 750;
 Canvas::Canvas ()
 	: _root (this)
 	, _bg_color (rgba_to_color (0, 1.0, 0.0, 1.0))
+	, _last_render_start_timestamp(0)
 {
 	set_epoch ();
 }
@@ -103,6 +104,8 @@ Canvas::render (Rect const & area, Cairo::RefPtr<Cairo::Context> const & context
 {
 	PreRender (); // emit signal
 
+	_last_render_start_timestamp = g_get_monotonic_time();
+
 #ifdef CANVAS_DEBUG
 	if (DEBUG_ENABLED(PBD::DEBUG::CanvasRender)) {
 		cerr << this << " RENDER: " << area << endl;
diff --git a/libs/canvas/canvas/canvas.h b/libs/canvas/canvas/canvas.h
index cb4f6dd70c..70a44d2f80 100644
--- a/libs/canvas/canvas/canvas.h
+++ b/libs/canvas/canvas/canvas.h
@@ -89,6 +89,8 @@ public:
 
 	void prepare_for_render (Rect const &) const;
 
+	gint64 get_last_render_start_timestamp () const { return _last_render_start_timestamp; }
+
 	/** @return root group */
 	Item* root () {
 		return &_root;
@@ -169,6 +171,8 @@ protected:
 	Root  _root;
 	Color _bg_color;
 
+	mutable gint64 _last_render_start_timestamp;
+
 	static uint32_t tooltip_timeout_msecs;
 
 	void queue_draw_item_area (Item *, Rect);