scripts/startup/bl_ui/properties_material_gpencil.py

@@ -27,6 +27,13 @@ class GPENCIL_MT_material_context_menu(Menu):
             layout.operator("grease_pencil.material_unlock_all", icon='UNLOCKED', text="Unlock All")
             layout.operator("grease_pencil.material_lock_unselected", text="Lock Unselected")
             layout.operator("grease_pencil.material_lock_unused", text="Lock Unused")
+
+            layout.separator()
+
+            layout.operator("grease_pencil.material_copy_to_object", text="Copy Material to Selected").only_active = True
+            layout.operator("grease_pencil.material_copy_to_object",
+                            text="Copy All Materials to Selected").only_active = False
+
         else:
             layout.operator("gpencil.material_reveal", icon='RESTRICT_VIEW_OFF', text="Show All")
             layout.operator("gpencil.material_hide", icon='RESTRICT_VIEW_ON', text="Hide Others").unselected = True

source/blender/blenkernel/BKE_grease_pencil.hh

@@ -813,7 +813,6 @@ void BKE_grease_pencil_data_update(Depsgraph *depsgraph, Scene *scene, Object *o
 void BKE_grease_pencil_duplicate_drawing_array(const GreasePencil *grease_pencil_src,
                                                GreasePencil *grease_pencil_dst);
 
-int BKE_grease_pencil_object_material_index_get(Object *ob, Material *ma);
 int BKE_grease_pencil_object_material_index_get_by_name(Object *ob, const char *name);
 Material *BKE_grease_pencil_object_material_new(Main *bmain,
                                                 Object *ob,

source/blender/blenkernel/BKE_material.h

@@ -114,6 +114,9 @@ bool BKE_object_material_slot_add(struct Main *bmain, struct Object *ob);
 bool BKE_object_material_slot_remove(struct Main *bmain, struct Object *ob);
 bool BKE_object_material_slot_used(struct Object *object, short actcol);
 
+int BKE_object_material_index_get(Object *ob, Material *ma);
+int BKE_object_material_ensure(Main *bmain, Object *ob, Material *material);
+
 struct Material *BKE_gpencil_material(struct Object *ob, short act);
 struct MaterialGPencilStyle *BKE_gpencil_material_settings(struct Object *ob, short act);
 

source/blender/blenkernel/intern/grease_pencil.cc

@@ -1216,19 +1216,6 @@ void BKE_grease_pencil_duplicate_drawing_array(const GreasePencil *grease_pencil
 /** \name Grease Pencil material functions
  * \{ */
 
-int BKE_grease_pencil_object_material_index_get(Object *ob, Material *ma)
-{
-  short *totcol = BKE_object_material_len_p(ob);
-  Material *read_ma = nullptr;
-  for (short i = 0; i < *totcol; i++) {
-    read_ma = BKE_object_material_get(ob, i + 1);
-    if (ma == read_ma) {
-      return i;
-    }
-  }
-  return -1;
-}
-
 int BKE_grease_pencil_object_material_index_get_by_name(Object *ob, const char *name)
 {
   short *totcol = BKE_object_material_len_p(ob);
@@ -1304,7 +1291,7 @@ Material *BKE_grease_pencil_object_material_ensure_from_brush(Main *bmain,
     Material *ma = BKE_grease_pencil_brush_material_get(brush);
 
     /* check if the material is already on object material slots and add it if missing */
-    if (ma && BKE_grease_pencil_object_material_index_get(ob, ma) < 0) {
+    if (ma && BKE_object_material_index_get(ob, ma) < 0) {
       BKE_object_material_slot_add(bmain, ob);
       BKE_object_material_assign(bmain, ob, ma, ob->totcol, BKE_MAT_ASSIGN_USERPREF);
     }

source/blender/blenkernel/intern/material.cc

@@ -825,6 +825,33 @@ void BKE_id_material_eval_ensure_default_slot(ID *id)
   }
 }
 
+int BKE_object_material_index_get(Object *ob, Material *ma)
+{
+  short *totcol = BKE_object_material_len_p(ob);
+  Material *read_ma = nullptr;
+  for (short i = 0; i < *totcol; i++) {
+    read_ma = BKE_object_material_get(ob, i + 1);
+    if (ma == read_ma) {
+      return i;
+    }
+  }
+  return -1;
+}
+
+int BKE_object_material_ensure(Main *bmain, Object *ob, Material *material)
+{
+  if (!material) {
+    return -1;
+  }
+  int index = BKE_object_material_index_get(ob, material);
+  if (index < 0) {
+    BKE_object_material_slot_add(bmain, ob);
+    BKE_object_material_assign(bmain, ob, material, ob->totcol, BKE_MAT_ASSIGN_USERPREF);
+    return ob->totcol - 1;
+  }
+  return index;
+}
+
 Material *BKE_gpencil_material(Object *ob, short act)
 {
   Material *ma = BKE_object_material_get(ob, act);

source/blender/editors/grease_pencil/intern/grease_pencil_material.cc

@@ -333,6 +333,76 @@ static void GREASE_PENCIL_OT_material_lock_unselected(wmOperatorType *ot)
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name Copy Materials to Selected Objects
+ * \{ */
+
+static int grease_pencil_material_copy_to_object_exec(bContext *C, wmOperator *op)
+{
+  using namespace blender;
+  using namespace blender::bke;
+
+  Main *bmain = CTX_data_main(C);
+  const bool only_active = RNA_boolean_get(op->ptr, "only_active");
+  Object *ob_src = CTX_data_active_object(C);
+  Material *ma_active = BKE_object_material_get(ob_src, ob_src->actcol);
+  if (ma_active == nullptr) {
+    return OPERATOR_CANCELLED;
+  }
+
+  CTX_DATA_BEGIN (C, Object *, ob, selected_objects) {
+    if ((ob == ob_src) || (ob->type != OB_GREASE_PENCIL)) {
+      continue;
+    }
+    /* Duplicate materials. */
+    for (const int i : IndexRange(ob_src->totcol)) {
+      Material *ma_src = BKE_object_material_get(ob_src, i + 1);
+      if (only_active && ma_src != ma_active) {
+        continue;
+      }
+
+      if (ma_src == nullptr) {
+        continue;
+      }
+
+      BKE_object_material_ensure(bmain, ob, ma_src);
+    }
+
+    DEG_id_tag_update(&ob->id, ID_RECALC_COPY_ON_WRITE);
+  }
+  CTX_DATA_END;
+
+  WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, nullptr);
+
+  return OPERATOR_FINISHED;
+}
+
+static void GREASE_PENCIL_OT_material_copy_to_object(wmOperatorType *ot)
+{
+  PropertyRNA *prop;
+
+  /* Identifiers. */
+  ot->name = "Copy Materials to Selected Object";
+  ot->idname = "GREASE_PENCIL_OT_material_copy_to_object";
+  ot->description = "Append Materials of the active Grease Pencil to other object";
+
+  /* Callbacks. */
+  ot->exec = grease_pencil_material_copy_to_object_exec;
+  ot->poll = active_grease_pencil_poll;
+
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+  prop = RNA_def_boolean(ot->srna,
+                         "only_active",
+                         true,
+                         "Only Active",
+                         "Append only active material, uncheck to append all materials");
+
+  RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
+}
+
+/** \} */
+
 }  // namespace blender::ed::greasepencil
 
 void ED_operatortypes_grease_pencil_material()
@@ -344,4 +414,5 @@ void ED_operatortypes_grease_pencil_material()
   WM_operatortype_append(GREASE_PENCIL_OT_material_unlock_all);
   WM_operatortype_append(GREASE_PENCIL_OT_material_lock_unused);
   WM_operatortype_append(GREASE_PENCIL_OT_material_lock_unselected);
+  WM_operatortype_append(GREASE_PENCIL_OT_material_copy_to_object);
 }

source/blender/editors/sculpt_paint/grease_pencil_paint.cc

@@ -475,7 +475,7 @@ void PaintOperation::on_stroke_begin(const bContext &C, const InputSample &start
 
   Material *material = BKE_grease_pencil_object_material_ensure_from_active_input_brush(
       CTX_data_main(&C), object, brush);
-  const int material_index = BKE_grease_pencil_object_material_index_get(object, material);
+  const int material_index = BKE_object_material_index_get(object, material);
 
   PaintOperationExecutor executor{C};
   executor.process_start_sample(*this, C, start_sample, material_index);