Fix T63125: Gpencil: bones cannot be selected in weightpaint mode

Some underlying functionality was not ready for greasepencil:
- BKE_modifiers_get_virtual_modifierlist (now introduce dedicated BKE_gpencil_modifiers_get_virtual_modifierlist)
- BKE_modifiers_is_deformed_by_armature
- checks in drawing code
- checks in (pose) selection code

A couple of changes to make this work:
- `eGpencilModifierType_Armature` has to be respected (not only `eModifierType_Armature`)
- `OB_MODE_WEIGHT_GPENCIL` has to be respected (not only `OB_MODE_WEIGHT_PAINT`) --  (now use new `OB_MODE_ALL_WEIGHT_PAINT`)
- `gpencil_weightmode_toggle_exec` now shares functionality from `wpaint_mode_toggle_exec` -- moved to new `ED_object_posemode_set_for_weight_paint`

This patch will also set the context member "weight_paint_object" for greasepencil (otherwise some appropriate pose operators wont work when in weightpaint mode)

Reviewed By: campbellbarton

Maniphest Tasks: T63125

Differential Revision: https://developer.blender.org/D8483

1 files changed, 2 insertions, 2 deletions

diff --git a/source/blender/editors/space_view3d/view3d_select.c b/source/blender/editors/space_view3d/view3d_select.c
index f99301371d4..03c1ecae317 100644
--- a/source/blender/editors/space_view3d/view3d_select.c
+++ b/source/blender/editors/space_view3d/view3d_select.c
@@ -2208,7 +2208,7 @@ static bool ed_object_select_pick(bContext *C,
 
           /* In weight-paint, we use selected bone to select vertex-group,
            * so don't switch to new active object. */
-          if (oldbasact && (oldbasact->object->mode & OB_MODE_WEIGHT_PAINT)) {
+          if (oldbasact && (oldbasact->object->mode & OB_MODE_ALL_WEIGHT_PAINT)) {
             /* Prevent activating.
              * Selection causes this to be considered the 'active' pose in weight-paint mode.
              * Eventually this limitation may be removed.
@@ -2382,7 +2382,7 @@ static int view3d_select_exec(bContext *C, wmOperator *op)
   bool object = (RNA_boolean_get(op->ptr, "object") &&
                  (obedit || BKE_paint_select_elem_test(obact) ||
                   /* so its possible to select bones in weight-paint mode (LMB select) */
-                  (obact && (obact->mode & OB_MODE_WEIGHT_PAINT) &&
+                  (obact && (obact->mode & OB_MODE_ALL_WEIGHT_PAINT) &&
                    BKE_object_pose_armature_get(obact))));
 
   bool retval = false;