Render: Add operators to add all used or remove all unused lightgroups

These operators build a list of all lightgroups that are used by the view layer's
scene and either add all used lightgroups that are not part of the view layer yet
or remove all lightgroups in the view layer that are not being used.

Differential Revision: https://developer.blender.org/D14596

3 files changed, 112 insertions, 0 deletions

diff --git a/source/blender/editors/render/render_intern.hh b/source/blender/editors/render/render_intern.hh
index 85d917ae8e8..a4056f3dab3 100644
--- a/source/blender/editors/render/render_intern.hh
+++ b/source/blender/editors/render/render_intern.hh
@@ -35,6 +35,8 @@ void SCENE_OT_view_layer_add_aov(struct wmOperatorType *ot);
 void SCENE_OT_view_layer_remove_aov(struct wmOperatorType *ot);
 void SCENE_OT_view_layer_add_lightgroup(struct wmOperatorType *ot);
 void SCENE_OT_view_layer_remove_lightgroup(struct wmOperatorType *ot);
+void SCENE_OT_view_layer_add_used_lightgroups(struct wmOperatorType *ot);
+void SCENE_OT_view_layer_remove_unused_lightgroups(struct wmOperatorType *ot);
 
 void SCENE_OT_light_cache_bake(struct wmOperatorType *ot);
 void SCENE_OT_light_cache_free(struct wmOperatorType *ot);
diff --git a/source/blender/editors/render/render_ops.cc b/source/blender/editors/render/render_ops.cc
index f671b2f950d..def220fb4fc 100644
--- a/source/blender/editors/render/render_ops.cc
+++ b/source/blender/editors/render/render_ops.cc
@@ -41,6 +41,8 @@ void ED_operatortypes_render()
   WM_operatortype_append(SCENE_OT_view_layer_remove_aov);
   WM_operatortype_append(SCENE_OT_view_layer_add_lightgroup);
   WM_operatortype_append(SCENE_OT_view_layer_remove_lightgroup);
+  WM_operatortype_append(SCENE_OT_view_layer_add_used_lightgroups);
+  WM_operatortype_append(SCENE_OT_view_layer_remove_unused_lightgroups);
 
   WM_operatortype_append(SCENE_OT_render_view_add);
   WM_operatortype_append(SCENE_OT_render_view_remove);
diff --git a/source/blender/editors/render/render_shading.cc b/source/blender/editors/render/render_shading.cc
index 4c885d50b4c..1bd6b87f1a7 100644
--- a/source/blender/editors/render/render_shading.cc
+++ b/source/blender/editors/render/render_shading.cc
@@ -1217,6 +1217,114 @@ void SCENE_OT_view_layer_remove_lightgroup(wmOperatorType *ot)
 /** \} */
 
 /* -------------------------------------------------------------------- */
+/** \name View Layer Add Used Lightgroups Operator
+ * \{ */
+
+static GSet *get_used_lightgroups(Scene *scene)
+{
+  GSet *used_lightgroups = BLI_gset_str_new(__func__);
+
+  FOREACH_SCENE_OBJECT_BEGIN (scene, ob) {
+    if (ob->lightgroup && ob->lightgroup->name[0]) {
+      BLI_gset_add(used_lightgroups, ob->lightgroup->name);
+    }
+  }
+  FOREACH_SCENE_OBJECT_END;
+
+  if (scene->world && scene->world->lightgroup && scene->world->lightgroup->name[0]) {
+    BLI_gset_add(used_lightgroups, scene->world->lightgroup->name);
+  }
+
+  return used_lightgroups;
+}
+
+static int view_layer_add_used_lightgroups_exec(bContext *C, wmOperator *UNUSED(op))
+{
+  Scene *scene = CTX_data_scene(C);
+  ViewLayer *view_layer = CTX_data_view_layer(C);
+
+  GSet *used_lightgroups = get_used_lightgroups(scene);
+  GSET_FOREACH_BEGIN (const char *, used_lightgroup, used_lightgroups) {
+    if (!BLI_findstring(
+            &view_layer->lightgroups, used_lightgroup, offsetof(ViewLayerLightgroup, name))) {
+      BKE_view_layer_add_lightgroup(view_layer, used_lightgroup);
+    }
+  }
+  GSET_FOREACH_END();
+  BLI_gset_free(used_lightgroups, nullptr);
+
+  if (scene->nodetree) {
+    ntreeCompositUpdateRLayers(scene->nodetree);
+  }
+
+  DEG_id_tag_update(&scene->id, 0);
+  DEG_relations_tag_update(CTX_data_main(C));
+  WM_event_add_notifier(C, NC_SCENE | ND_LAYER, scene);
+
+  return OPERATOR_FINISHED;
+}
+
+void SCENE_OT_view_layer_add_used_lightgroups(wmOperatorType *ot)
+{
+  /* identifiers */
+  ot->name = "Add Used Lightgroups";
+  ot->idname = "SCENE_OT_view_layer_add_used_lightgroups";
+  ot->description = "Add all used Light Groups";
+
+  /* api callbacks */
+  ot->exec = view_layer_add_used_lightgroups_exec;
+
+  /* flags */
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name View Layer Remove Unussed Lightgroups Operator
+ * \{ */
+
+static int view_layer_remove_unused_lightgroups_exec(bContext *C, wmOperator *UNUSED(op))
+{
+  Scene *scene = CTX_data_scene(C);
+  ViewLayer *view_layer = CTX_data_view_layer(C);
+
+  GSet *used_lightgroups = get_used_lightgroups(scene);
+  LISTBASE_FOREACH_MUTABLE (ViewLayerLightgroup *, lightgroup, &view_layer->lightgroups) {
+    if (!BLI_gset_haskey(used_lightgroups, lightgroup->name)) {
+      BKE_view_layer_remove_lightgroup(view_layer, lightgroup);
+    }
+  }
+  BLI_gset_free(used_lightgroups, nullptr);
+
+  if (scene->nodetree) {
+    ntreeCompositUpdateRLayers(scene->nodetree);
+  }
+
+  DEG_id_tag_update(&scene->id, 0);
+  DEG_relations_tag_update(CTX_data_main(C));
+  WM_event_add_notifier(C, NC_SCENE | ND_LAYER, scene);
+
+  return OPERATOR_FINISHED;
+}
+
+void SCENE_OT_view_layer_remove_unused_lightgroups(wmOperatorType *ot)
+{
+  /* identifiers */
+  ot->name = "Remove Unused Lightgroups";
+  ot->idname = "SCENE_OT_view_layer_remove_unused_lightgroups";
+  ot->description = "Remove all unused Light Groups";
+
+  /* api callbacks */
+  ot->exec = view_layer_remove_unused_lightgroups_exec;
+
+  /* flags */
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
 /** \name Light Cache Bake Operator
  * \{ */