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, 9 insertions, 0 deletions

diff --git a/source/blender/editors/gpencil/gpencil_edit.c b/source/blender/editors/gpencil/gpencil_edit.c
index 1bbba6c4b8a..37338ec4592 100644
--- a/source/blender/editors/gpencil/gpencil_edit.c
+++ b/source/blender/editors/gpencil/gpencil_edit.c
@@ -39,6 +39,7 @@
 
 #include "BLT_translation.h"
 
+#include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
@@ -52,7 +53,9 @@
 #include "BKE_global.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_geom.h"
+#include "BKE_layer.h"
 #include "BKE_lib_id.h"
+#include "BKE_library.h"
 #include "BKE_main.h"
 #include "BKE_material.h"
 #include "BKE_object.h"
@@ -75,6 +78,7 @@
 
 #include "UI_view2d.h"
 
+#include "ED_armature.h"
 #include "ED_gpencil.h"
 #include "ED_object.h"
 #include "ED_outliner.h"
@@ -571,6 +575,8 @@ static int gpencil_weightmode_toggle_exec(bContext *C, wmOperator *op)
     gpd = ob->data;
     is_object = true;
   }
+  const int mode_flag = OB_MODE_WEIGHT_GPENCIL;
+  const bool is_mode_set = (ob->mode & mode_flag) != 0;
 
   if (gpd == NULL) {
     return OPERATOR_CANCELLED;
@@ -593,6 +599,9 @@ static int gpencil_weightmode_toggle_exec(bContext *C, wmOperator *op)
     }
     ob->restore_mode = ob->mode;
     ob->mode = mode;
+
+    /* Prepare armature posemode. */
+    ED_object_posemode_set_for_weight_paint(C, bmain, ob, is_mode_set);
   }
 
   if (mode == OB_MODE_WEIGHT_GPENCIL) {