Curves: Implement Handles for selected points only

When editing a complex curve is very annoying to have all handles at a time. Also, this is a requirement for the current GSoC Edit Grease Pencil using curves.
I have seen that this improvement can be used in any other area of blender, so I have decided to publish the option in the overlay panel..

Reviewed By: fclem, #user_interface, billreynish, Severin

Differential Revision: https://developer.blender.org/D7754

4 files changed, 19 insertions, 7 deletions

diff --git a/source/blender/editors/curve/editcurve.c b/source/blender/editors/curve/editcurve.c
index d6256f67066..3cd24caa137 100644
--- a/source/blender/editors/curve/editcurve.c
+++ b/source/blender/editors/curve/editcurve.c
@@ -4923,7 +4923,7 @@ bool ED_curve_editnurb_select_pick(
       }
     }
     else {
-      BKE_nurbList_flag_set(editnurb, 0);
+      BKE_nurbList_flag_set(editnurb, SELECT, false);
 
       if (bezt) {
 
diff --git a/source/blender/editors/curve/editcurve_add.c b/source/blender/editors/curve/editcurve_add.c
index 91d5ea58361..499f621ab47 100644
--- a/source/blender/editors/curve/editcurve_add.c
+++ b/source/blender/editors/curve/editcurve_add.c
@@ -138,7 +138,7 @@ Nurb *ED_curve_add_nurbs_primitive(
     copy_v3_v3(zvec, rv3d->viewinv[2]);
   }
 
-  BKE_nurbList_flag_set(editnurb, 0);
+  BKE_nurbList_flag_set(editnurb, SELECT, false);
 
   /* these types call this function to return a Nurb */
   if (stype != CU_PRIM_TUBE && stype != CU_PRIM_DONUT) {
diff --git a/source/blender/editors/curve/editcurve_query.c b/source/blender/editors/curve/editcurve_query.c
index 0b15d9e55b9..e0f161ca0cf 100644
--- a/source/blender/editors/curve/editcurve_query.c
+++ b/source/blender/editors/curve/editcurve_query.c
@@ -44,8 +44,13 @@
 /** \name Cursor Picking API
  * \{ */
 
-static void ED_curve_pick_vert__do_closest(
-    void *userData, Nurb *nu, BPoint *bp, BezTriple *bezt, int beztindex, const float screen_co[2])
+static void ED_curve_pick_vert__do_closest(void *userData,
+                                           Nurb *nu,
+                                           BPoint *bp,
+                                           BezTriple *bezt,
+                                           int beztindex,
+                                           bool handles_visible,
+                                           const float screen_co[2])
 {
   struct {
     BPoint *bp;
@@ -64,6 +69,8 @@ static void ED_curve_pick_vert__do_closest(
     flag = bp->f1;
   }
   else {
+    BLI_assert(handles_visible || beztindex == 1);
+
     if (beztindex == 0) {
       flag = bezt->f1;
     }
diff --git a/source/blender/editors/curve/editcurve_select.c b/source/blender/editors/curve/editcurve_select.c
index 9cf61d02677..9294bc6e91b 100644
--- a/source/blender/editors/curve/editcurve_select.c
+++ b/source/blender/editors/curve/editcurve_select.c
@@ -590,8 +590,8 @@ static int de_select_all_exec(bContext *C, wmOperator *op)
         changed = ED_curve_deselect_all(cu->editnurb);
         break;
       case SEL_INVERT:
-        changed = ED_curve_select_swap(
-            cu->editnurb, (v3d->overlay.edit_flag & V3D_OVERLAY_EDIT_CU_HANDLES) == 0);
+        changed = ED_curve_select_swap(cu->editnurb,
+                                       v3d->overlay.handle_display == CURVE_HANDLE_NONE);
         break;
     }
 
@@ -772,7 +772,7 @@ static int select_row_exec(bContext *C, wmOperator *UNUSED(op))
 
   if (last == bp) {
     direction = 1 - direction;
-    BKE_nurbList_flag_set(editnurb, 0);
+    BKE_nurbList_flag_set(editnurb, SELECT, false);
   }
   last = bp;
 
@@ -826,8 +826,10 @@ static int select_next_exec(bContext *C, wmOperator *UNUSED(op))
 
   for (uint ob_index = 0; ob_index < objects_len; ob_index++) {
     Object *obedit = objects[ob_index];
+
     ListBase *editnurb = object_editcurve_get(obedit);
     select_adjacent_cp(editnurb, 1, 0, SELECT);
+
     DEG_id_tag_update(obedit->data, ID_RECALC_SELECT);
     WM_event_add_notifier(C, NC_GEOM | ND_SELECT, obedit->data);
   }
@@ -861,8 +863,10 @@ static int select_previous_exec(bContext *C, wmOperator *UNUSED(op))
 
   for (uint ob_index = 0; ob_index < objects_len; ob_index++) {
     Object *obedit = objects[ob_index];
+
     ListBase *editnurb = object_editcurve_get(obedit);
     select_adjacent_cp(editnurb, -1, 0, SELECT);
+
     DEG_id_tag_update(obedit->data, ID_RECALC_SELECT);
     WM_event_add_notifier(C, NC_GEOM | ND_SELECT, obedit->data);
   }
@@ -1392,6 +1396,7 @@ static int select_nth_exec(bContext *C, wmOperator *op)
 
     if (ed_curve_select_nth(obedit->data, &op_params) == true) {
       changed = true;
+
       DEG_id_tag_update(obedit->data, ID_RECALC_SELECT);
       WM_event_add_notifier(C, NC_GEOM | ND_SELECT, obedit->data);
     }