Graph Editor: 'Ghost Curves' functionality from Apricot

This feature takes a 'snapshot' of the visible+selected F-Curves, and displays these in the background as 'ghosts curves' in the background. Such curves are drawn semi-transparent, slightly darker, and with dotted lines. 

To use, simply click the 'curve' button beside the Auto-Snapping selector. To clear, simply click that button again (with a different icon now). 

These 'ghost curves' are stored per Graph Editor instance, and are not saved to file (i.e. per session only). They are useful to be used as guides when refining the shape of existing curves.

1 files changed, 8 insertions, 1 deletions

diff --git a/source/blender/editors/space_graph/graph_intern.h b/source/blender/editors/space_graph/graph_intern.h
index a9d6cd125ca..a06cdddbec8 100644
--- a/source/blender/editors/space_graph/graph_intern.h
+++ b/source/blender/editors/space_graph/graph_intern.h
@@ -46,7 +46,9 @@ struct ARegion *graph_has_buttons_region(struct ScrArea *sa);
 /* ***************************************** */
 /* graph_draw.c */
 void graph_draw_channel_names(struct bAnimContext *ac, struct SpaceIpo *sipo, struct ARegion *ar);
-void graph_draw_curves(struct bAnimContext *ac, struct SpaceIpo *sipo, struct ARegion *ar, struct View2DGrid *grid);
+
+void graph_draw_curves(struct bAnimContext *ac, struct SpaceIpo *sipo, struct ARegion *ar, struct View2DGrid *grid, short sel);
+void graph_draw_ghost_curves(struct bAnimContext *ac, struct SpaceIpo *sipo, struct ARegion *ar, struct View2DGrid *grid);
 
 /* ***************************************** */
 /* graph_header.c */
@@ -127,6 +129,11 @@ enum {
 
 void GRAPHEDIT_OT_fmodifier_add(struct wmOperatorType *ot);
 
+/* ----------- */
+
+void GRAPHEDIT_OT_ghost_curves_create(struct wmOperatorType *ot);
+void GRAPHEDIT_OT_ghost_curves_clear(struct wmOperatorType *ot);
+
 /* ***************************************** */
 /* graph_buttons.c */
 void GRAPHEDIT_OT_properties(struct wmOperatorType *ot);