Sequencer display overlay option, this can show a border area from another time to help compare for color grading.

- Okey sets the border in the display.
- Okey resets the frame offset in the sequencer timeline.
- ghost icon in the header can enable/disable.
- frame offset can be relative or absolute (lock icon)

Not very happy that this commit adds a call to BKE_animsys_evaluate_animdata(scene, ...) in do_build_seq_array_recursively()
without this the offset frames dont have fcurves applied.
Though we will need something like this for prefetch frames to work too.

1 files changed, 15 insertions, 1 deletions

diff --git a/source/blender/editors/space_sequencer/space_sequencer.c b/source/blender/editors/space_sequencer/space_sequencer.c
index 8b7670a55bc..586b76268e4 100644
--- a/source/blender/editors/space_sequencer/space_sequencer.c
+++ b/source/blender/editors/space_sequencer/space_sequencer.c
@@ -396,7 +396,21 @@ static void sequencer_preview_area_draw(const bContext *C, ARegion *ar)
 	
 	/* XXX temp fix for wrong setting in sseq->mainb */
 	if (sseq->mainb == SEQ_DRAW_SEQUENCE) sseq->mainb = SEQ_DRAW_IMG_IMBUF;
-	draw_image_seq(C, scene, ar, sseq);
+
+	draw_image_seq(C, scene, ar, sseq, scene->r.cfra, 0);
+
+	if(scene->ed && scene->ed->over_flag & SEQ_EDIT_OVERLAY_SHOW && sseq->mainb == SEQ_DRAW_IMG_IMBUF) {
+		int over_cfra;
+
+		if(scene->ed->over_flag & SEQ_EDIT_OVERLAY_ABS)
+			over_cfra= scene->ed->over_cfra;
+		else
+			over_cfra= scene->r.cfra + scene->ed->over_ofs;
+
+		if(over_cfra != scene->r.cfra)
+			draw_image_seq(C, scene, ar, sseq, scene->r.cfra, over_cfra - scene->r.cfra);
+	}
+
 }
 
 static void sequencer_preview_area_listener(ARegion *ar, wmNotifier *wmn)