GPencil: Interpolate Tools refactor

Following with the changes included to interpolate strokes of different number of points, a full review has been done in the interpolation tools.

* Interpolate now is a tool and not an operator. It was not logic to have this tool as a button.
* Interpolate tool parameters have been moved to topbar.
* Interpolate popover has been removed from topbar and interpolate `Sequence` operator has been moved to grease pencil menu.
* Interpolate Sequence now include a Redo panel.
* Interpolate tool now allows to select the strokes by pairs. This allows to interpolate any stroke with any stroke and not as before that it was only possible by drawing order. If no stroke is selected, the interpolation is done as before.
* Now is possible interpolate again if a previous keyframe exist. Before, it was impossible to interpolate two times in same frame and this made impossible to do the interpolation by groups of frames.
* New automatic option to `Flip strokes` if the stroke and end are not in the right position. Also the flip can be set manually for corner cases.
* Cleanup of menus related to interpolate.
* Fixed some bugs and removed parameters from scene because now all are tool or operator contained.
* Some code cleanup and function renames.

This commit also includes the some codebase to future implementation of the concept `Vertex Active` that now does not exist in grease pencil.

1 files changed, 10 insertions, 2 deletions

diff --git a/source/blender/editors/gpencil/gpencil_edit.c b/source/blender/editors/gpencil/gpencil_edit.c
index bf1aff5a34a..aec593b97ea 100644
--- a/source/blender/editors/gpencil/gpencil_edit.c
+++ b/source/blender/editors/gpencil/gpencil_edit.c
@@ -214,7 +214,7 @@ static int gpencil_editmode_toggle_exec(bContext *C, wmOperator *op)
       if (gpc->flag & GP_CURVE_NEEDS_STROKE_UPDATE) {
         BKE_gpencil_stroke_editcurve_update(gpd, gpl, gps);
         /* Update the selection from the stroke to the curve. */
-        BKE_gpencil_editcurve_stroke_sync_selection(gps, gps->editcurve);
+        BKE_gpencil_editcurve_stroke_sync_selection(gpd, gps, gps->editcurve);
 
         gps->flag |= GP_STROKE_NEEDS_CURVE_UPDATE;
         BKE_gpencil_stroke_geometry_update(gpd, gps);
@@ -992,6 +992,7 @@ static int gpencil_duplicate_exec(bContext *C, wmOperator *op)
             pt->flag &= ~GP_SPOINT_SELECT;
           }
           gps->flag &= ~GP_STROKE_SELECT;
+          BKE_gpencil_stroke_select_index_set(NULL, gps, true);
 
           changed = true;
         }
@@ -1193,6 +1194,7 @@ static void gpencil_add_move_points(bGPdata *gpd, bGPDframe *gpf, bGPDstroke *gp
   /* if the stroke is not reused, deselect */
   if (!do_stroke) {
     gps->flag &= ~GP_STROKE_SELECT;
+    BKE_gpencil_stroke_select_index_set(NULL, gps, true);
   }
 }
 
@@ -1709,6 +1711,7 @@ static int gpencil_strokes_paste_exec(bContext *C, wmOperator *op)
     }
 
     gps->flag &= ~GP_STROKE_SELECT;
+    BKE_gpencil_stroke_select_index_set(NULL, gps, true);
   }
   CTX_DATA_END;
 
@@ -2548,6 +2551,7 @@ static bool gpencil_dissolve_selected_stroke_points(bContext *C,
 
         /* deselect the stroke, since none of its selected points will still be selected */
         gps->flag &= ~GP_STROKE_SELECT;
+        BKE_gpencil_stroke_select_index_set(NULL, gps, true);
         for (i = 0, pt = gps->points; i < gps->totpoints; i++, pt++) {
           pt->flag &= ~GP_SPOINT_SELECT;
         }
@@ -2620,6 +2624,7 @@ static int gpencil_delete_selected_points(bContext *C)
           if (gps->flag & GP_STROKE_SELECT) {
             /* deselect old stroke, since it will be used as template for the new strokes */
             gps->flag &= ~GP_STROKE_SELECT;
+            BKE_gpencil_stroke_select_index_set(NULL, gps, true);
 
             if (is_curve_edit) {
               bGPDcurve *gpc = gps->editcurve;
@@ -3790,7 +3795,7 @@ static int gpencil_strokes_reproject_exec(bContext *C, wmOperator *op)
       if (is_curve_edit && gps->editcurve != NULL) {
         BKE_gpencil_stroke_editcurve_update(gpd, gpl, gps);
         /* Update the selection from the stroke to the curve. */
-        BKE_gpencil_editcurve_stroke_sync_selection(gps, gps->editcurve);
+        BKE_gpencil_editcurve_stroke_sync_selection(gpd, gps, gps->editcurve);
 
         gps->flag |= GP_STROKE_NEEDS_CURVE_UPDATE;
         BKE_gpencil_stroke_geometry_update(gpd, gps);
@@ -4574,6 +4579,7 @@ static int gpencil_stroke_separate_exec(bContext *C, wmOperator *op)
               else if (mode == GP_SEPARATE_STROKE) {
                 /* deselect old stroke */
                 gps->flag &= ~GP_STROKE_SELECT;
+                BKE_gpencil_stroke_select_index_set(NULL, gps, true);
                 /* unlink from source frame */
                 BLI_remlink(&gpf->strokes, gps);
                 gps->prev = gps->next = NULL;
@@ -4982,6 +4988,7 @@ static int gpencil_cutter_lasso_select(bContext *C,
     }
 
     gps->flag &= ~GP_STROKE_SELECT;
+    BKE_gpencil_stroke_select_index_set(NULL, gps, true);
   }
   CTX_DATA_END;
 
@@ -5022,6 +5029,7 @@ static int gpencil_cutter_lasso_select(bContext *C,
               changed = true;
               pt->flag |= GP_SPOINT_SELECT;
               gps->flag |= GP_STROKE_SELECT;
+              BKE_gpencil_stroke_select_index_set(gpd, gps, false);
               float r_hita[3], r_hitb[3];
               if (gps->totpoints > 1) {
                 ED_gpencil_select_stroke_segment(