[mutter/tintou/clutter-stage-capture] clutter-stage: Add annotations to clutter_stage_capture

[Corentin Noël <corentinnoel src gnome org>]

commit da765fcab8249b396c7b623dd16aa475353a6654
Author: Corentin Noël <corentin elementary io>
Date:   Tue Mar 17 13:37:49 2020 +0100

    clutter-stage: Add annotations to clutter_stage_capture
    
    Especially document that out_captures is an array that is given as output.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1131

 clutter/clutter/clutter-stage.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
---
diff --git a/clutter/clutter/clutter-stage.c b/clutter/clutter/clutter-stage.c
index 80061bba7..2bd056d9c 100644
--- a/clutter/clutter/clutter-stage.c
+++ b/clutter/clutter/clutter-stage.c
@@ -4349,6 +4349,20 @@ capture_view (ClutterStage          *stage,
   cairo_surface_mark_dirty (capture->image);
 }
 
+/**
+ * clutter_stage_capture:
+ * @stage: a #ClutterStage
+ * @paint: whether to pain the frame
+ * @rect: a #cairo_rectangle_int_t
+ * @out_captures: (out) (array length=out_n_captures): an array of
+ *   #ClutterCapture
+ * @out_n_captures: (out): the number of captures in @out_captures
+ *
+ * Enables capturing the screen and turn the framebuffers into a #ClutterCapture
+ * array allowing to access the pixels.
+ *
+ * Returns: %TRUE if a #ClutterCapture has been created, %FALSE otherwise
+ */
 gboolean
 clutter_stage_capture (ClutterStage          *stage,
                        gboolean               paint,