Cleanup: move public doc-strings into headers for 'depsgraph'

- Added space below non doc-string comments to make it clear
  these aren't comments for the symbols directly below them.
- Use doxy sections for some headers.

Ref T92709

33 files changed, 282 insertions, 187 deletions

diff --git a/source/blender/depsgraph/DEG_depsgraph.h b/source/blender/depsgraph/DEG_depsgraph.h
index aa184cce433..0b3e028cd06 100644
--- a/source/blender/depsgraph/DEG_depsgraph.h
+++ b/source/blender/depsgraph/DEG_depsgraph.h
@@ -80,45 +80,67 @@ extern "C" {
 /* ************************************************ */
 /* Depsgraph API */
 
-/* CRUD ------------------------------------------- */
+/* -------------------------------------------------------------------- */
+/** \name CRUD
+ * \{ */
 
 /* Get main depsgraph instance from context! */
 
-/* Create new Depsgraph instance */
-/* TODO: what args are needed here? What's the building-graph entry point? */
+/**
+ * Create new Depsgraph instance.
+ *
+ * TODO: what arguments are needed here? What's the building-graph entry point?
+ */
 Depsgraph *DEG_graph_new(struct Main *bmain,
                          struct Scene *scene,
                          struct ViewLayer *view_layer,
                          eEvaluationMode mode);
 
+/**
+ * Replace the "owner" pointers (currently Main/Scene/ViewLayer) of this depsgraph.
+ * Used for:
+ * - Undo steps when we do want to re-use the old depsgraph data as much as possible.
+ * - Rendering where we want to re-use objects between different view layers.
+ */
 void DEG_graph_replace_owners(struct Depsgraph *depsgraph,
                               struct Main *bmain,
                               struct Scene *scene,
                               struct ViewLayer *view_layer);
 
-/* Free Depsgraph itself and all its data */
+/** Free graph's contents and graph itself. */
 void DEG_graph_free(Depsgraph *graph);
 
-/* Node Types Registry ---------------------------- */
+/** \} */
 
-/* Register all node types */
+/* -------------------------------------------------------------------- */
+/** \name Node Types Registry
+ * \{ */
+
+/** Register all node types. */
 void DEG_register_node_types(void);
 
-/* Free node type registry on exit */
+/** Free node type registry on exit. */
 void DEG_free_node_types(void);
 
-/* Update Tagging -------------------------------- */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Update Tagging
+ * \{ */
 
-/* Tag dependency graph for updates when visible scenes/layers changes. */
+/** Tag dependency graph for updates when visible scenes/layers changes. */
 void DEG_graph_tag_on_visible_update(Depsgraph *depsgraph, const bool do_time);
 
-/* Tag all dependency graphs for update when visible scenes/layers changes. */
+/** Tag all dependency graphs for update when visible scenes/layers changes. */
 void DEG_tag_on_visible_update(struct Main *bmain, const bool do_time);
 
-/* NOTE: Will return NULL if the flag is not known, allowing to gracefully handle situations
- * when recalc flag has been removed. */
+/**
+ * \note Will return NULL if the flag is not known, allowing to gracefully handle situations
+ * when recalc flag has been removed.
+ */
 const char *DEG_update_tag_as_string(IDRecalcFlag flag);
 
+/** Tag given ID for an update in all the dependency graphs. */
 void DEG_id_tag_update(struct ID *id, int flag);
 void DEG_id_tag_update_ex(struct Main *bmain, struct ID *id, int flag);
 
@@ -127,48 +149,68 @@ void DEG_graph_id_tag_update(struct Main *bmain,
                              struct ID *id,
                              int flag);
 
-/* Tag all dependency graphs when time has changed. */
+/** Tag all dependency graphs when time has changed. */
 void DEG_time_tag_update(struct Main *bmain);
 
-/* Tag a dependency graph when time has changed. */
+/** Tag a dependency graph when time has changed. */
 void DEG_graph_time_tag_update(struct Depsgraph *depsgraph);
 
-/* Mark a particular datablock type as having changing. This does
- * not cause any updates but is used by external render engines to detect if for
- * example a datablock was removed. */
+/**
+ * Mark a particular data-block type as having changing.
+ * This does not cause any updates but is used by external
+ * render engines to detect if for example a data-block was removed.
+ */
 void DEG_graph_id_type_tag(struct Depsgraph *depsgraph, short id_type);
 void DEG_id_type_tag(struct Main *bmain, short id_type);
 
-/* Set a depsgraph to flush updates to editors. This would be done
- * for viewport depsgraphs, but not render or export depsgraph for example. */
+/**
+ * Set a depsgraph to flush updates to editors. This would be done
+ * for viewport depsgraphs, but not render or export depsgraph for example.
+ */
 void DEG_enable_editors_update(struct Depsgraph *depsgraph);
 
-/* Check if something was changed in the database and inform editors about this. */
+/** Check if something was changed in the database and inform editors about this. */
 void DEG_editors_update(struct Depsgraph *depsgraph, bool time);
 
-/* Clear recalc flags after editors or renderers have handled updates. */
+/** Clear recalc flags after editors or renderers have handled updates. */
 void DEG_ids_clear_recalc(Depsgraph *depsgraph, const bool backup);
 
-/* Restore recalc flags, backed up by a previous call to DEG_ids_clear_recalc.
- * This also clears the backup. */
+/**
+ * Restore recalc flags, backed up by a previous call to #DEG_ids_clear_recalc.
+ * This also clears the backup.
+ */
 void DEG_ids_restore_recalc(Depsgraph *depsgraph);
 
+/** \} */
+
 /* ************************************************ */
 /* Evaluation Engine API */
 
-/* Graph Evaluation  ----------------------------- */
+/* -------------------------------------------------------------------- */
+/** \name Graph Evaluation
+ * \{ */
 
-/* Frame changed recalculation entry point. */
+/**
+ * Frame changed recalculation entry point.
+ *
+ * \note The frame-change happened for root scene that graph belongs to.
+ */
 void DEG_evaluate_on_framechange(Depsgraph *graph, float frame);
 
-/* Data changed recalculation entry point. */
+/**
+ * Data changed recalculation entry point.
+ * Evaluate all nodes tagged for updating.
+ */
 void DEG_evaluate_on_refresh(Depsgraph *graph);
 
-/* Editors Integration  -------------------------- */
+/** \} */
 
-/* Mechanism to allow editors to be informed of depsgraph updates,
+/* -------------------------------------------------------------------- */
+/** \name Editors Integration
+ *
+ * Mechanism to allow editors to be informed of depsgraph updates,
  * to do their own updates based on changes.
- */
+ * \{ */
 
 typedef struct DEGEditorUpdateContext {
   struct Main *bmain;
@@ -181,10 +223,14 @@ typedef void (*DEG_EditorUpdateIDCb)(const DEGEditorUpdateContext *update_ctx, s
 typedef void (*DEG_EditorUpdateSceneCb)(const DEGEditorUpdateContext *update_ctx,
                                         const bool updated);
 
-/* Set callbacks which are being called when depsgraph changes. */
+/** Set callbacks which are being called when depsgraph changes. */
 void DEG_editors_set_update_cb(DEG_EditorUpdateIDCb id_func, DEG_EditorUpdateSceneCb scene_func);
 
-/* Evaluation  ----------------------------------- */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Evaluation
+ * \{ */
 
 bool DEG_is_evaluating(const struct Depsgraph *depsgraph);
 
@@ -192,7 +238,11 @@ bool DEG_is_active(const struct Depsgraph *depsgraph);
 void DEG_make_active(struct Depsgraph *depsgraph);
 void DEG_make_inactive(struct Depsgraph *depsgraph);
 
-/* Evaluation Debug ------------------------------ */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Evaluation Debug
+ * \{ */
 
 void DEG_debug_print_begin(struct Depsgraph *depsgraph);
 
@@ -232,6 +282,8 @@ void DEG_debug_print_eval_time(struct Depsgraph *depsgraph,
                                const void *object_address,
                                float time);
 
+/** \} */
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
diff --git a/source/blender/depsgraph/DEG_depsgraph_build.h b/source/blender/depsgraph/DEG_depsgraph_build.h
index c029d203574..94cba833096 100644
--- a/source/blender/depsgraph/DEG_depsgraph_build.h
+++ b/source/blender/depsgraph/DEG_depsgraph_build.h
@@ -50,17 +50,22 @@ extern "C" {
 
 /* Graph Building -------------------------------- */
 
-/* Build depsgraph for the given scene, and dump results in given graph container. */
+/** Build depsgraph for the given scene layer, and dump results in given graph container. */
 void DEG_graph_build_from_view_layer(struct Depsgraph *graph);
 
-/* Build depsgraph for all objects (so also invisible ones) in the given view layer. */
+/**
+ * Build depsgraph for all objects (so also invisible ones) in the given view layer.
+ */
 void DEG_graph_build_for_all_objects(struct Depsgraph *graph);
 
-/* Special version of builder which produces dependency graph suitable for the render pipeline.
- * It will contain sequencer and compositor (if needed) and all their dependencies. */
+/**
+ * Special version of builder which produces dependency graph suitable for the render pipeline.
+ * It will contain sequencer and compositor (if needed) and all their dependencies.
+ */
 void DEG_graph_build_for_render_pipeline(struct Depsgraph *graph);
 
-/* Builds minimal dependency graph for compositor preview.
+/**
+ * Builds minimal dependency graph for compositor preview.
  *
  * Note that compositor editor might have pinned node tree, which is different from scene's node
  * tree.
@@ -69,18 +74,19 @@ void DEG_graph_build_for_compositor_preview(struct Depsgraph *graph, struct bNod
 
 void DEG_graph_build_from_ids(struct Depsgraph *graph, struct ID **ids, const int num_ids);
 
-/* Tag relations from the given graph for update. */
+/** Tag relations from the given graph for update. */
 void DEG_graph_tag_relations_update(struct Depsgraph *graph);
 
-/* Create or update relations in the specified graph. */
+/** Create or update relations in the specified graph. */
 void DEG_graph_relations_update(struct Depsgraph *graph);
 
-/* Tag all relations in the database for update. */
+/** Tag all relations in the database for update. */
 void DEG_relations_tag_update(struct Main *bmain);
 
 /* Add Dependencies  ----------------------------- */
 
-/* Handle for components to define their dependencies from callbacks.
+/**
+ * Handle for components to define their dependencies from callbacks.
  * This is generated by the depsgraph and passed to dependency callbacks
  * as a symbolic reference to the current DepsNode.
  * All relations will be defined in reference to that node.
@@ -159,23 +165,28 @@ void DEG_add_object_cache_relation(struct DepsNodeHandle *handle,
                                    struct CacheFile *cache_file,
                                    eDepsObjectComponentType component,
                                    const char *description);
-/* Adds relation from DEG_OPCODE_GENERIC_DATABLOCK_UPDATE of a given ID.
- * Is used for such entities as textures and images. */
+/**
+ * Adds relation from #DEG_OPCODE_GENERIC_DATABLOCK_UPDATE of a given ID.
+ * Is used for such entities as textures and images.
+ */
 void DEG_add_generic_id_relation(struct DepsNodeHandle *node_handle,
                                  struct ID *id,
                                  const char *description);
 
-/* Special function which is used from modifiers' updateDepsgraph() callback
+/**
+ * Special function which is used from modifiers' #updateDepsgraph() callback
  * to indicate that the modifier needs to know transformation of the object
  * which that modifier belongs to.
  * This function will take care of checking which operation is required to
- * have transformation for the modifier, taking into account possible simulation
- * solvers. */
+ * have transformation for the modifier, taking into account possible simulation solvers.
+ */
 void DEG_add_modifier_to_transform_relation(struct DepsNodeHandle *node_handle,
                                             const char *description);
 
-/* Adds relations from the given component of a given object to the given node
- * handle AND the component to the point cache component of the node's ID. */
+/**
+ * Adds relations from the given component of a given object to the given node
+ * handle AND the component to the point cache component of the node's ID.
+ */
 void DEG_add_object_pointcache_relation(struct DepsNodeHandle *node_handle,
                                         struct Object *object,
                                         eDepsObjectComponentType component,
diff --git a/source/blender/depsgraph/DEG_depsgraph_debug.h b/source/blender/depsgraph/DEG_depsgraph_debug.h
index 2aea10fd5b4..5c400a1392f 100644
--- a/source/blender/depsgraph/DEG_depsgraph_debug.h
+++ b/source/blender/depsgraph/DEG_depsgraph_debug.h
@@ -37,7 +37,7 @@ struct ViewLayer;
 
 /* ------------------------------------------------ */
 
-/* NOTE: Those flags are same bitmask as G.debug_flags */
+/* NOTE: Those flags are same bit-mask as #G.debug_flags */
 
 void DEG_debug_flags_set(struct Depsgraph *depsgraph, int flags);
 int DEG_debug_flags_get(const struct Depsgraph *depsgraph);
@@ -47,6 +47,12 @@ const char *DEG_debug_name_get(struct Depsgraph *depsgraph);
 
 /* ------------------------------------------------ */
 
+/**
+ * Obtain simple statistics about the complexity of the depsgraph.
+ * \param[out] r_outer:      The number of outer nodes in the graph.
+ * \param[out] r_operations: The number of operation nodes in the graph.
+ * \param[out] r_relations:  The number of relations between (executable) nodes in the graph.
+ */
 void DEG_stats_simple(const struct Depsgraph *graph,
                       size_t *r_outer,
                       size_t *r_operations,
@@ -64,16 +70,16 @@ void DEG_debug_stats_gnuplot(const struct Depsgraph *graph,
 
 /* ************************************************ */
 
-/* Compare two dependency graphs. */
+/** Compare two dependency graphs. */
 bool DEG_debug_compare(const struct Depsgraph *graph1, const struct Depsgraph *graph2);
 
-/* Check that dependencies in the graph are really up to date. */
+/** Check that dependencies in the graph are really up to date. */
 bool DEG_debug_graph_relations_validate(struct Depsgraph *graph,
                                         struct Main *bmain,
                                         struct Scene *scene,
                                         struct ViewLayer *view_layer);
 
-/* Perform consistency check on the graph. */
+/** Perform consistency check on the graph. */
 bool DEG_debug_consistency_check(struct Depsgraph *graph);
 
 #ifdef __cplusplus
diff --git a/source/blender/depsgraph/DEG_depsgraph_query.h b/source/blender/depsgraph/DEG_depsgraph_query.h
index e9195a1eb26..ebb5f4d669c 100644
--- a/source/blender/depsgraph/DEG_depsgraph_query.h
+++ b/source/blender/depsgraph/DEG_depsgraph_query.h
@@ -47,87 +47,106 @@ struct ViewLayer;
 extern "C" {
 #endif
 
-/* *********************** DEG input data ********************* */
+/* -------------------------------------------------------------------- */
+/** \name DEG input data
+ * \{ */
 
-/* Get scene that depsgraph was built for. */
+/** Get scene that depsgraph was built for. */
 struct Scene *DEG_get_input_scene(const Depsgraph *graph);
 
-/* Get view layer that depsgraph was built for. */
+/** Get view layer that depsgraph was built for. */
 struct ViewLayer *DEG_get_input_view_layer(const Depsgraph *graph);
 
-/* Get bmain that depsgraph was built for. */
+/** Get bmain that depsgraph was built for. */
 struct Main *DEG_get_bmain(const Depsgraph *graph);
 
-/* Get evaluation mode that depsgraph was built for. */
+/** Get evaluation mode that depsgraph was built for. */
 eEvaluationMode DEG_get_mode(const Depsgraph *graph);
 
-/* Get time that depsgraph is being evaluated or was last evaluated at. */
+/** Get time that depsgraph is being evaluated or was last evaluated at. */
 float DEG_get_ctime(const Depsgraph *graph);
 
-/* ********************* DEG evaluated data ******************* */
+/** \} */
 
-/* Check if given ID type was tagged for update. */
+/* -------------------------------------------------------------------- */
+/** \name DEG evaluated data
+ * \{ */
+
+/** Check if given ID type was tagged for update. */
 bool DEG_id_type_updated(const struct Depsgraph *depsgraph, short id_type);
 bool DEG_id_type_any_updated(const struct Depsgraph *depsgraph);
 
-/* Check if given ID type is present in the depsgraph */
+/** Check if given ID type is present in the depsgraph */
 bool DEG_id_type_any_exists(const struct Depsgraph *depsgraph, short id_type);
 
-/* Get additional evaluation flags for the given ID. */
+/** Get additional evaluation flags for the given ID. */
 uint32_t DEG_get_eval_flags_for_id(const struct Depsgraph *graph, struct ID *id);
 
-/* Get additional mesh CustomData_MeshMasks flags for the given object. */
+/** Get additional mesh CustomData_MeshMasks flags for the given object. */
 void DEG_get_customdata_mask_for_object(const struct Depsgraph *graph,
                                         struct Object *object,
                                         struct CustomData_MeshMasks *r_mask);
 
-/* Get scene at its evaluated state.
+/**
+ * Get scene at its evaluated state.
  *
  * Technically, this is a copied-on-written and fully evaluated version of the input scene.
  * This function will check that the data-block has been expanded (and copied) from the original
- * one. Assert will happen if it's not. */
+ * one. Assert will happen if it's not.
+ */
 struct Scene *DEG_get_evaluated_scene(const struct Depsgraph *graph);
 
-/* Get view layer at its evaluated state.
- * This is a shortcut for accessing active view layer from evaluated scene. */
+/**
+ * Get view layer at its evaluated state.
+ * This is a shortcut for accessing active view layer from evaluated scene.
+ */
 struct ViewLayer *DEG_get_evaluated_view_layer(const struct Depsgraph *graph);
 
-/* Get evaluated version of object for given original one. */
+/** Get evaluated version of object for given original one. */
 struct Object *DEG_get_evaluated_object(const struct Depsgraph *depsgraph, struct Object *object);
 
-/* Get evaluated version of given ID data-block. */
+/** Get evaluated version of given ID data-block. */
 struct ID *DEG_get_evaluated_id(const struct Depsgraph *depsgraph, struct ID *id);
 
-/* Get evaluated version of data pointed to by RNA pointer */
+/** Get evaluated version of data pointed to by RNA pointer */
 void DEG_get_evaluated_rna_pointer(const struct Depsgraph *depsgraph,
                                    struct PointerRNA *ptr,
                                    struct PointerRNA *r_ptr_eval);
 
-/* Get original version of object for given evaluated one. */
+/** Get original version of object for given evaluated one. */
 struct Object *DEG_get_original_object(struct Object *object);
 
-/* Get original version of given evaluated ID data-block. */
+/** Get original version of given evaluated ID data-block. */
 struct ID *DEG_get_original_id(struct ID *id);
 
-/* Check whether given ID is an original,
+/**
+ * Check whether given ID is an original,
  *
  * Original IDs are considered all the IDs which are not covered by copy-on-write system and are
- * not out-of-main localized data-blocks. */
+ * not out-of-main localized data-blocks.
+ */
 bool DEG_is_original_id(const struct ID *id);
 bool DEG_is_original_object(const struct Object *object);
 
 /* Opposite of the above.
  *
  * If the data-block is not original it must be evaluated, and vice versa. */
+
 bool DEG_is_evaluated_id(const struct ID *id);
 bool DEG_is_evaluated_object(const struct Object *object);
 
-/* Check whether depsgraph is fully evaluated. This includes the following checks:
+/**
+ * Check whether depsgraph is fully evaluated. This includes the following checks:
  * - Relations are up-to-date.
- * - Nothing is tagged for update. */
+ * - Nothing is tagged for update.
+ */
 bool DEG_is_fully_evaluated(const struct Depsgraph *depsgraph);
 
-/* ************************ DEG object iterators ********************* */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name DEG object iterators
+ * \{ */
 
 enum {
   DEG_ITER_OBJECT_FLAG_LINKED_DIRECTLY = (1 << 0),
@@ -207,7 +226,11 @@ void DEG_iterator_objects_end(struct BLI_Iterator *iter);
 
 #define DEG_OBJECT_ITER_FOR_RENDER_ENGINE_END DEG_OBJECT_ITER_END
 
-/* ************************ DEG ID iterators ********************* */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name DEG ID iterators
+ * \{ */
 
 typedef struct DEGIDIterData {
   struct Depsgraph *graph;
@@ -221,15 +244,20 @@ void DEG_iterator_ids_begin(struct BLI_Iterator *iter, DEGIDIterData *data);
 void DEG_iterator_ids_next(struct BLI_Iterator *iter);
 void DEG_iterator_ids_end(struct BLI_Iterator *iter);
 
-/* ************************ DEG traversal ********************* */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name DEG traversal
+ * \{ */
 
 typedef void (*DEGForeachIDCallback)(ID *id, void *user_data);
 typedef void (*DEGForeachIDComponentCallback)(ID *id,
                                               eDepsObjectComponentType component,
                                               void *user_data);
 
-/* NOTE: Modifies runtime flags in depsgraph nodes, so can not be used in
- * parallel. Keep an eye on that!
+/**
+ * \note Modifies runtime flags in depsgraph nodes,
+ * so can not be used in parallel. Keep an eye on that!
  */
 void DEG_foreach_ancestor_ID(const Depsgraph *depsgraph,
                              const ID *id,
@@ -240,8 +268,10 @@ void DEG_foreach_dependent_ID(const Depsgraph *depsgraph,
                               DEGForeachIDCallback callback,
                               void *user_data);
 
-/* Starts traversal from given component of the given ID, invokes callback for every other
- * component  which is directly on indirectly dependent on the source one. */
+/**
+ * Starts traversal from given component of the given ID, invokes callback for every other
+ * component  which is directly on indirectly dependent on the source one.
+ */
 enum {
   /* Ignore transform solvers which depends on multiple inputs and affects final transform.
    * Is used for cases like snapping objects which are part of a rigid body simulation:
@@ -262,6 +292,8 @@ void DEG_foreach_dependent_ID_component(const Depsgraph *depsgraph,
 
 void DEG_foreach_ID(const Depsgraph *depsgraph, DEGForeachIDCallback callback, void *user_data);
 
+/** \} */
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
index 7da3ab78575..51582508b6f 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
@@ -390,8 +390,6 @@ void DepsgraphNodeBuilder::begin_build()
  * NOTE: This is split in two, a static function and a public method of the node builder, to allow
  * the code to access the builder's data more easily. */
 
-/* `id_cow_self` is the user of `id_pointer`, see also `LibraryIDLinkCallbackData` struct
- * definition. */
 int DepsgraphNodeBuilder::foreach_id_cow_detect_need_for_update_callback(ID *id_cow_self,
                                                                          ID *id_pointer)
 {
@@ -440,21 +438,18 @@ static int foreach_id_cow_detect_need_for_update_callback(LibraryIDLinkCallbackD
   return builder->foreach_id_cow_detect_need_for_update_callback(id_cow_self, id);
 }
 
-/* Check for IDs that need to be flushed (COW-updated) because the depsgraph itself created or
- * removed some of their evaluated dependencies.
- *
- * NOTE: Currently the only ID types that depsgraph may decide to not evaluate/generate COW
- * copies for, even though they are referenced by other data-blocks, are Collections and Objects
- * (through their various visibility flags, and the ones from LayerCollections too). However, this
- * code is kept generic as it makes it more future-proof, and optimization here would give
- * negligible performance improvements in typical cases.
- *
- * NOTE: This mechanism may also 'fix' some missing update tagging from non-depsgraph code in
- * some cases. This is slightly unfortunate (as it may hide issues in other parts of Blender
- * code), but cannot really be avoided currently.
- */
 void DepsgraphNodeBuilder::update_invalid_cow_pointers()
 {
+  /* NOTE: Currently the only ID types that depsgraph may decide to not evaluate/generate COW
+   * copies for, even though they are referenced by other data-blocks, are Collections and Objects
+   * (through their various visibility flags, and the ones from #LayerCollections too). However,
+   * this code is kept generic as it makes it more future-proof, and optimization here would give
+   * negligible performance improvements in typical cases.
+   *
+   * NOTE: This mechanism may also 'fix' some missing update tagging from non-depsgraph code in
+   * some cases. This is slightly unfortunate (as it may hide issues in other parts of Blender
+   * code), but cannot really be avoided currently. */
+
   for (const IDNode *id_node : graph_->id_nodes) {
     if (id_node->previously_visible_components_mask == 0) {
       /* Newly added node/ID, no need to check it. */
@@ -1071,10 +1066,6 @@ void DepsgraphNodeBuilder::build_object_pointcache(Object *object)
                      });
 }
 
-/**
- * Build graph nodes for AnimData block and any animated images used.
- * \param id: ID-Block which hosts the AnimData
- */
 void DepsgraphNodeBuilder::build_animdata(ID *id)
 {
   /* Special handling for animated images/sequences. */
@@ -1128,9 +1119,6 @@ void DepsgraphNodeBuilder::build_animdata_nlastrip_targets(ListBase *strips)
   }
 }
 
-/**
- * Build graph nodes to update the current frame in image users.
- */
 void DepsgraphNodeBuilder::build_animation_images(ID *id)
 {
   if (BKE_image_user_id_has_animation(id)) {
@@ -1152,12 +1140,6 @@ void DepsgraphNodeBuilder::build_action(bAction *action)
   add_operation_node(&action->id, NodeType::ANIMATION, OperationCode::ANIMATION_EVAL);
 }
 
-/**
- * Build graph node(s) for Driver
- * \param id: ID-Block that driver is attached to
- * \param fcu: Driver-FCurve
- * \param driver_index: Index in animation data drivers list
- */
 void DepsgraphNodeBuilder::build_driver(ID *id, FCurve *fcurve, int driver_index)
 {
   /* Create data node for this driver */
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.h b/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
index d31290ecbff..c1c80042833 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
@@ -102,6 +102,10 @@ class DepsgraphNodeBuilder : public DepsgraphBuilder {
   virtual void begin_build();
   virtual void end_build();
 
+  /**
+   * `id_cow_self` is the user of `id_pointer`,
+   * see also `LibraryIDLinkCallbackData` struct definition.
+   */
   int foreach_id_cow_detect_need_for_update_callback(ID *id_cow_self, ID *id_pointer);
 
   IDNode *add_id_node(ID *id);
@@ -199,10 +203,23 @@ class DepsgraphNodeBuilder : public DepsgraphBuilder {
   virtual void build_rigidbody(Scene *scene);
   virtual void build_particle_systems(Object *object, bool is_object_visible);
   virtual void build_particle_settings(ParticleSettings *part);
+  /**
+   * Build graph nodes for #AnimData block and any animated images used.
+   * \param id: ID-Block which hosts the #AnimData
+   */
   virtual void build_animdata(ID *id);
   virtual void build_animdata_nlastrip_targets(ListBase *strips);
+  /**
+   * Build graph nodes to update the current frame in image users.
+   */
   virtual void build_animation_images(ID *id);
   virtual void build_action(bAction *action);
+  /**
+   * Build graph node(s) for Driver
+   * \param id: ID-Block that driver is attached to
+   * \param fcu: Driver-FCurve
+   * \param driver_index: Index in animation data drivers list
+   */
   virtual void build_driver(ID *id, FCurve *fcurve, int driver_index);
   virtual void build_driver_variables(ID *id, FCurve *fcurve);
   virtual void build_driver_id_property(ID *id, const char *rna_path);
@@ -280,6 +297,10 @@ class DepsgraphNodeBuilder : public DepsgraphBuilder {
                               void *user_data);
 
   void tag_previously_tagged_nodes();
+  /**
+   * Check for IDs that need to be flushed (COW-updated)
+   * because the depsgraph itself created or removed some of their evaluated dependencies.
+   */
   void update_invalid_cow_pointers();
 
   /* State which demotes currently built entities. */
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_pchanmap.cc b/source/blender/depsgraph/intern/builder/deg_builder_pchanmap.cc
index 17c2925b7f4..79f358213d3 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_pchanmap.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_pchanmap.cc
@@ -30,7 +30,6 @@
 
 namespace blender::deg {
 
-/* Debug contents of map */
 void RootPChanMap::print_debug()
 {
   map_.foreach_item([](StringRefNull key, const Set<StringRefNull> &values) {
@@ -42,13 +41,11 @@ void RootPChanMap::print_debug()
   });
 }
 
-/* Add a mapping. */
 void RootPChanMap::add_bone(const char *bone, const char *root)
 {
   map_.lookup_or_add_default(bone).add(root);
 }
 
-/* Check if there's a common root bone between two bones. */
 bool RootPChanMap::has_common_root(const char *bone1, const char *bone2) const
 {
   const Set<StringRefNull> *bone1_roots = map_.lookup_ptr(bone1);
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_pchanmap.h b/source/blender/depsgraph/intern/builder/deg_builder_pchanmap.h
index 0dd4062c353..42f9ec9cc6a 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_pchanmap.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_pchanmap.h
@@ -29,13 +29,13 @@ namespace blender {
 namespace deg {
 
 struct RootPChanMap {
-  /* Debug contents of map. */
+  /** Debug contents of map. */
   void print_debug();
 
-  /* Add a mapping. */
+  /** Add a mapping. */
   void add_bone(const char *bone, const char *root);
 
-  /* Check if there's a common root bone between two bones. */
+  /** Check if there's a common root bone between two bones. */
   bool has_common_root(const char *bone1, const char *bone2) const;
 
  protected:
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index a333f67839a..b195b2d9e11 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -2073,7 +2073,8 @@ void DepsgraphRelationBuilder::build_shapekeys(Key *key)
  *        and also for the links coming from the shapekey data-blocks
  * - Animation/Drivers affecting the parameters of the geometry are made to
  *   trigger updates on the obdata geometry component, which then trigger
- *   downstream re-evaluation of the individual instances of this geometry. */
+ *   downstream re-evaluation of the individual instances of this geometry.
+ */
 void DepsgraphRelationBuilder::build_object_data_geometry(Object *object)
 {
   ID *obdata = (ID *)object->data;
@@ -2868,7 +2869,8 @@ void DepsgraphRelationBuilder::build_copy_on_write_relations()
   }
 }
 
-/* Nested datablocks (node trees, shape keys) requires special relation to
+/**
+ * Nested datablocks (node trees, shape keys) requires special relation to
  * ensure owner's datablock remapping happens after node tree itself is ready.
  *
  * This is similar to what happens in ntree_hack_remap_pointers().
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations_drivers.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations_drivers.cc
index bf3af571f0b..6e5c1f05cf3 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations_drivers.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations_drivers.cc
@@ -83,7 +83,6 @@ bool DriverDescriptor::is_array() const
   return is_array_;
 }
 
-/* Assumes that 'other' comes from the same RNA group, that is, has the same RNA path prefix. */
 bool DriverDescriptor::is_same_array_as(const DriverDescriptor &other) const
 {
   if (!is_array_ || !other.is_array_) {
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations_drivers.h b/source/blender/depsgraph/intern/builder/deg_builder_relations_drivers.h
index c80c69be9e2..4ad5bdda1ef 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations_drivers.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations_drivers.h
@@ -37,14 +37,17 @@ namespace deg {
 /* Helper class for determining which relations are needed between driver evaluation nodes. */
 class DriverDescriptor {
  public:
-  /* Drivers are grouped by their RNA prefix. The prefix is the part of the RNA
+  /**
+   * Drivers are grouped by their RNA prefix. The prefix is the part of the RNA
    * path up to the last dot, the suffix is the remainder of the RNA path:
    *
+   * \code{.unparsed}
    * fcu->rna_path                     rna_prefix              rna_suffix
    * -------------------------------   ----------------------  ----------
    * 'color'                           ''                      'color'
    * 'rigidbody_world.time_scale'      'rigidbody_world'       'time_scale'
    * 'pose.bones["master"].location'   'pose.bones["master"]'  'location'
+   * \endcode
    */
   StringRef rna_prefix;
   StringRef rna_suffix;
@@ -54,7 +57,7 @@ class DriverDescriptor {
 
   bool driver_relations_needed() const;
   bool is_array() const;
-  /* Assumes that 'other' comes from the same RNA group, that is, has the same RNA path prefix. */
+  /** Assumes that 'other' comes from the same RNA group, that is, has the same RNA path prefix. */
   bool is_same_array_as(const DriverDescriptor &other) const;
   OperationKey depsgraph_key() const;
 
diff --git a/source/blender/depsgraph/intern/depsgraph.cc b/source/blender/depsgraph/intern/depsgraph.cc
index 4c036417ba0..b348ab0f432 100644
--- a/source/blender/depsgraph/intern/depsgraph.cc
+++ b/source/blender/depsgraph/intern/depsgraph.cc
@@ -182,7 +182,6 @@ void Depsgraph::clear_id_nodes()
   clear_physics_relations(this);
 }
 
-/* Add new relation between two nodes */
 Relation *Depsgraph::add_new_relation(Node *from, Node *to, const char *description, int flags)
 {
   Relation *rel = nullptr;
@@ -228,7 +227,6 @@ Relation *Depsgraph::check_nodes_connected(const Node *from,
 
 /* Low level tagging -------------------------------------- */
 
-/* Tag a specific node as needing updates. */
 void Depsgraph::add_entry_tag(OperationNode *node)
 {
   /* Sanity check. */
@@ -280,7 +278,6 @@ ID *Depsgraph::get_cow_id(const ID *id_orig) const
 /* **************** */
 /* Public Graph API */
 
-/* Initialize a new Depsgraph */
 Depsgraph *DEG_graph_new(Main *bmain, Scene *scene, ViewLayer *view_layer, eEvaluationMode mode)
 {
   deg::Depsgraph *deg_depsgraph = new deg::Depsgraph(bmain, scene, view_layer, mode);
@@ -288,10 +285,6 @@ Depsgraph *DEG_graph_new(Main *bmain, Scene *scene, ViewLayer *view_layer, eEval
   return reinterpret_cast<Depsgraph *>(deg_depsgraph);
 }
 
-/* Replace the "owner" pointers (currently Main/Scene/ViewLayer) of this depsgraph.
- * Used for:
- * - Undo steps when we do want to re-use the old depsgraph data as much as possible.
- * - Rendering where we want to re-use objects between different view layers. */
 void DEG_graph_replace_owners(struct Depsgraph *depsgraph,
                               Main *bmain,
                               Scene *scene,
@@ -313,7 +306,6 @@ void DEG_graph_replace_owners(struct Depsgraph *depsgraph,
   }
 }
 
-/* Free graph's contents and graph itself */
 void DEG_graph_free(Depsgraph *graph)
 {
   if (graph == nullptr) {
diff --git a/source/blender/depsgraph/intern/depsgraph.h b/source/blender/depsgraph/intern/depsgraph.h
index 913b61ca563..bfe6ed649f6 100644
--- a/source/blender/depsgraph/intern/depsgraph.h
+++ b/source/blender/depsgraph/intern/depsgraph.h
@@ -72,7 +72,7 @@ struct Depsgraph {
   IDNode *add_id_node(ID *id, ID *id_cow_hint = nullptr);
   void clear_id_nodes();
 
-  /* Add new relationship between two nodes. */
+  /** Add new relationship between two nodes. */
   Relation *add_new_relation(Node *from, Node *to, const char *description, int flags = 0);
 
   /* Check whether two nodes are connected by relation with given
diff --git a/source/blender/depsgraph/intern/depsgraph_build.cc b/source/blender/depsgraph/intern/depsgraph_build.cc
index 9e9191c5ab9..db00c595383 100644
--- a/source/blender/depsgraph/intern/depsgraph_build.cc
+++ b/source/blender/depsgraph/intern/depsgraph_build.cc
@@ -252,7 +252,6 @@ struct Depsgraph *DEG_get_graph_from_handle(struct DepsNodeHandle *node_handle)
 /* ******************** */
 /* Graph Building API's */
 
-/* Build depsgraph for the given scene layer, and dump results in given graph container. */
 void DEG_graph_build_from_view_layer(Depsgraph *graph)
 {
   deg::ViewLayerBuilderPipeline builder(graph);
@@ -283,7 +282,6 @@ void DEG_graph_build_from_ids(Depsgraph *graph, ID **ids, const int num_ids)
   builder.build();
 }
 
-/* Tag graph relations for update. */
 void DEG_graph_tag_relations_update(Depsgraph *graph)
 {
   DEG_DEBUG_PRINTF(graph, TAG, "%s: Tagging relations for update.\n", __func__);
@@ -301,7 +299,6 @@ void DEG_graph_tag_relations_update(Depsgraph *graph)
   }
 }
 
-/* Create or update relations in the specified graph. */
 void DEG_graph_relations_update(Depsgraph *graph)
 {
   deg::Depsgraph *deg_graph = (deg::Depsgraph *)graph;
@@ -312,7 +309,6 @@ void DEG_graph_relations_update(Depsgraph *graph)
   DEG_graph_build_from_view_layer(graph);
 }
 
-/* Tag all relations for update. */
 void DEG_relations_tag_update(Main *bmain)
 {
   DEG_GLOBAL_DEBUG_PRINTF(TAG, "%s: Tagging relations for update.\n", __func__);
diff --git a/source/blender/depsgraph/intern/depsgraph_debug.cc b/source/blender/depsgraph/intern/depsgraph_debug.cc
index 3677f80469c..9e3cbdbec09 100644
--- a/source/blender/depsgraph/intern/depsgraph_debug.cc
+++ b/source/blender/depsgraph/intern/depsgraph_debug.cc
@@ -196,12 +196,6 @@ bool DEG_debug_consistency_check(Depsgraph *graph)
 
 /* ------------------------------------------------ */
 
-/**
- * Obtain simple statistics about the complexity of the depsgraph.
- * \param[out] r_outer:      The number of outer nodes in the graph
- * \param[out] r_operations: The number of operation nodes in the graph
- * \param[out] r_relations:  The number of relations between (executable) nodes in the graph
- */
 void DEG_stats_simple(const Depsgraph *graph,
                       size_t *r_outer,
                       size_t *r_operations,
diff --git a/source/blender/depsgraph/intern/depsgraph_eval.cc b/source/blender/depsgraph/intern/depsgraph_eval.cc
index 0314219b725..7952f27507f 100644
--- a/source/blender/depsgraph/intern/depsgraph_eval.cc
+++ b/source/blender/depsgraph/intern/depsgraph_eval.cc
@@ -60,7 +60,6 @@ static void deg_flush_updates_and_refresh(deg::Depsgraph *deg_graph)
   deg::deg_evaluate_on_refresh(deg_graph);
 }
 
-/* Evaluate all nodes tagged for updating. */
 void DEG_evaluate_on_refresh(Depsgraph *graph)
 {
   deg::Depsgraph *deg_graph = reinterpret_cast<deg::Depsgraph *>(graph);
@@ -77,7 +76,6 @@ void DEG_evaluate_on_refresh(Depsgraph *graph)
   deg_flush_updates_and_refresh(deg_graph);
 }
 
-/* Frame-change happened for root scene that graph belongs to. */
 void DEG_evaluate_on_framechange(Depsgraph *graph, float frame)
 {
   deg::Depsgraph *deg_graph = reinterpret_cast<deg::Depsgraph *>(graph);
diff --git a/source/blender/depsgraph/intern/depsgraph_query.cc b/source/blender/depsgraph/intern/depsgraph_query.cc
index aab4c3ca0f6..6c1947728b5 100644
--- a/source/blender/depsgraph/intern/depsgraph_query.cc
+++ b/source/blender/depsgraph/intern/depsgraph_query.cc
@@ -200,7 +200,6 @@ ID *DEG_get_evaluated_id(const Depsgraph *depsgraph, ID *id)
   return id_node->id_cow;
 }
 
-/* Get evaluated version of data pointed to by RNA pointer */
 void DEG_get_evaluated_rna_pointer(const Depsgraph *depsgraph,
                                    PointerRNA *ptr,
                                    PointerRNA *r_ptr_eval)
diff --git a/source/blender/depsgraph/intern/depsgraph_tag.cc b/source/blender/depsgraph/intern/depsgraph_tag.cc
index 60c64e19bde..2b0d0e6e780 100644
--- a/source/blender/depsgraph/intern/depsgraph_tag.cc
+++ b/source/blender/depsgraph/intern/depsgraph_tag.cc
@@ -755,7 +755,6 @@ const char *DEG_update_tag_as_string(IDRecalcFlag flag)
 
 /* Data-Based Tagging. */
 
-/* Tag given ID for an update in all the dependency graphs. */
 void DEG_id_tag_update(ID *id, int flag)
 {
   DEG_id_tag_update_ex(G.main, id, flag);
@@ -792,7 +791,6 @@ void DEG_graph_time_tag_update(struct Depsgraph *depsgraph)
   deg_graph->tag_time_source();
 }
 
-/* Mark a particular data-block type as having changing. */
 void DEG_graph_id_type_tag(Depsgraph *depsgraph, short id_type)
 {
   if (id_type == ID_NT) {
@@ -817,7 +815,6 @@ void DEG_id_type_tag(Main *bmain, short id_type)
   }
 }
 
-/* Update dependency graph when visible scenes/layers changes. */
 void DEG_graph_tag_on_visible_update(Depsgraph *depsgraph, const bool do_time)
 {
   deg::Depsgraph *graph = (deg::Depsgraph *)depsgraph;
@@ -837,8 +834,6 @@ void DEG_enable_editors_update(Depsgraph *depsgraph)
   graph->use_editors_update = true;
 }
 
-/* Check if something was changed in the database and inform
- * editors about this. */
 void DEG_editors_update(Depsgraph *depsgraph, bool time)
 {
   deg::Depsgraph *graph = (deg::Depsgraph *)depsgraph;
diff --git a/source/blender/depsgraph/intern/depsgraph_type.cc b/source/blender/depsgraph/intern/depsgraph_type.cc
index 43a21692f2a..0405a7d90b4 100644
--- a/source/blender/depsgraph/intern/depsgraph_type.cc
+++ b/source/blender/depsgraph/intern/depsgraph_type.cc
@@ -39,7 +39,6 @@
 
 namespace deg = blender::deg;
 
-/* Register all node types */
 void DEG_register_node_types()
 {
   /* register node types */
@@ -48,7 +47,6 @@ void DEG_register_node_types()
   deg::deg_register_operation_depsnodes();
 }
 
-/* Free registry on exit */
 void DEG_free_node_types()
 {
 }
diff --git a/source/blender/depsgraph/intern/depsgraph_update.cc b/source/blender/depsgraph/intern/depsgraph_update.cc
index bb72320ca67..ec287edbd12 100644
--- a/source/blender/depsgraph/intern/depsgraph_update.cc
+++ b/source/blender/depsgraph/intern/depsgraph_update.cc
@@ -50,7 +50,6 @@ void deg_editors_scene_update(const DEGEditorUpdateContext *update_ctx, bool upd
 
 }  // namespace blender::deg
 
-/* Set callbacks which are being called when depsgraph changes. */
 void DEG_editors_set_update_cb(DEG_EditorUpdateIDCb id_func, DEG_EditorUpdateSceneCb scene_func)
 {
   deg::deg_editor_update_id_cb = id_func;
diff --git a/source/blender/depsgraph/intern/eval/deg_eval.cc b/source/blender/depsgraph/intern/eval/deg_eval.cc
index d6877adb66b..30aeeee5b2c 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval.cc
+++ b/source/blender/depsgraph/intern/eval/deg_eval.cc
@@ -361,13 +361,6 @@ static TaskPool *deg_evaluate_task_pool_create(DepsgraphEvalState *state)
   return BLI_task_pool_create_suspended(state, TASK_PRIORITY_HIGH);
 }
 
-/**
- * Evaluate all nodes tagged for updating,
- * \warning This is usually done as part of main loop, but may also be
- * called from frame-change update.
- *
- * \note Time sources should be all valid!
- */
 void deg_evaluate_on_refresh(Depsgraph *graph)
 {
   /* Nothing to update, early out. */
diff --git a/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc b/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
index 68a72638c7d..116dba054fa 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
+++ b/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
@@ -906,7 +906,9 @@ ID *deg_update_copy_on_write_datablock(const Depsgraph *depsgraph, const IDNode
   return id_cow;
 }
 
-/* NOTE: Depsgraph is supposed to have ID node already. */
+/**
+ * \note Depsgraph is supposed to have ID node already.
+ */
 ID *deg_update_copy_on_write_datablock(const Depsgraph *depsgraph, ID *id_orig)
 {
   IDNode *id_node = depsgraph->find_id_node(id_orig);
@@ -987,10 +989,12 @@ void discard_edit_mode_pointers(ID *id_cow)
 
 }  // namespace
 
-/* Free content of the CoW data-block
+/**
+   Free content of the CoW data-block.
  * Notes:
  * - Does not recurse into nested ID data-blocks.
- * - Does not free data-block itself. */
+ * - Does not free data-block itself.
+ */
 void deg_free_copy_on_write_datablock(ID *id_cow)
 {
   if (!check_datablock_expanded(id_cow)) {
diff --git a/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.h b/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.h
index 70e510b5ef9..bc023766a46 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.h
+++ b/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.h
@@ -50,34 +50,40 @@ struct Depsgraph;
 class DepsgraphNodeBuilder;
 struct IDNode;
 
-/* Makes sure given CoW data-block is brought back to state of the original
+/**
+ * Makes sure given CoW data-block is brought back to state of the original
  * data-block.
  */
 ID *deg_update_copy_on_write_datablock(const struct Depsgraph *depsgraph, const IDNode *id_node);
 ID *deg_update_copy_on_write_datablock(const struct Depsgraph *depsgraph, struct ID *id_orig);
 
-/* Helper function which frees memory used by copy-on-written data-block. */
+/** Helper function which frees memory used by copy-on-written data-block. */
 void deg_free_copy_on_write_datablock(struct ID *id_cow);
 
-/* Callback function for depsgraph operation node which ensures copy-on-write
+/**
+ * Callback function for depsgraph operation node which ensures copy-on-write
  * data-block is ready for use by further evaluation routines.
  */
 void deg_evaluate_copy_on_write(struct ::Depsgraph *depsgraph, const struct IDNode *id_node);
 
-/* Check that given ID is properly expanded and does not have any shallow
- * copies inside. */
+/**
+ * Check that given ID is properly expanded and does not have any shallow
+ * copies inside.
+ */
 bool deg_validate_copy_on_write_datablock(ID *id_cow);
 
-/* Tag given ID block as being copy-on-written. */
+/** Tag given ID block as being copy-on-written. */
 void deg_tag_copy_on_write_id(struct ID *id_cow, const struct ID *id_orig);
 
-/* Check whether ID data-block is expanded.
+/**
+ * Check whether ID data-block is expanded.
  *
  * TODO(sergey): Make it an inline function or a macro.
  */
 bool deg_copy_on_write_is_expanded(const struct ID *id_cow);
 
-/* Check whether copy-on-write data-block is needed for given ID.
+/**
+ * Check whether copy-on-write data-block is needed for given ID.
  *
  * There are some exceptions on data-blocks which are covered by dependency graph
  * but which we don't want to start duplicating.
diff --git a/source/blender/depsgraph/intern/eval/deg_eval_flush.cc b/source/blender/depsgraph/intern/eval/deg_eval_flush.cc
index a015491e2d7..7ec77689ba5 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_flush.cc
+++ b/source/blender/depsgraph/intern/eval/deg_eval_flush.cc
@@ -346,9 +346,6 @@ void invalidate_tagged_evaluated_data(Depsgraph *graph)
 
 }  // namespace
 
-/* Flush updates from tagged nodes outwards until all affected nodes
- * are tagged.
- */
 void deg_graph_flush_updates(Depsgraph *graph)
 {
   /* Sanity checks. */
@@ -395,7 +392,6 @@ void deg_graph_flush_updates(Depsgraph *graph)
   invalidate_tagged_evaluated_data(graph);
 }
 
-/* Clear tags from all operation nodes. */
 void deg_graph_clear_tags(Depsgraph *graph)
 {
   /* Go over all operation nodes, clearing tags. */
diff --git a/source/blender/depsgraph/intern/eval/deg_eval_flush.h b/source/blender/depsgraph/intern/eval/deg_eval_flush.h
index ec661360fdf..d70df62cb38 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_flush.h
+++ b/source/blender/depsgraph/intern/eval/deg_eval_flush.h
@@ -30,12 +30,14 @@ namespace deg {
 
 struct Depsgraph;
 
-/* Flush updates from tagged nodes outwards until all affected nodes
- * are tagged.
+/**
+ * Flush updates from tagged nodes outwards until all affected nodes are tagged.
  */
 void deg_graph_flush_updates(struct Depsgraph *graph);
 
-/* Clear tags from all operation nodes. */
+/**
+ * Clear tags from all operation nodes.
+ */
 void deg_graph_clear_tags(struct Depsgraph *graph);
 
 }  // namespace deg
diff --git a/source/blender/depsgraph/intern/node/deg_node.cc b/source/blender/depsgraph/intern/node/deg_node.cc
index 22345a85576..8bc03d8b736 100644
--- a/source/blender/depsgraph/intern/node/deg_node.cc
+++ b/source/blender/depsgraph/intern/node/deg_node.cc
@@ -311,7 +311,6 @@ Node::~Node()
   }
 }
 
-/* Generic identifier for Depsgraph Nodes. */
 string Node::identifier() const
 {
   return string(nodeTypeAsString(type)) + " : " + name;
diff --git a/source/blender/depsgraph/intern/node/deg_node.h b/source/blender/depsgraph/intern/node/deg_node.h
index a5c58d163a7..7e093ab8765 100644
--- a/source/blender/depsgraph/intern/node/deg_node.h
+++ b/source/blender/depsgraph/intern/node/deg_node.h
@@ -201,6 +201,7 @@ struct Node {
   Node();
   virtual ~Node();
 
+  /** Generic identifier for Depsgraph Nodes. */
   virtual string identifier() const;
 
   virtual void init(const ID * /*id*/, const char * /*subdata*/)
diff --git a/source/blender/depsgraph/intern/node/deg_node_component.cc b/source/blender/depsgraph/intern/node/deg_node_component.cc
index 7d56ef44979..b716877902c 100644
--- a/source/blender/depsgraph/intern/node/deg_node_component.cc
+++ b/source/blender/depsgraph/intern/node/deg_node_component.cc
@@ -43,7 +43,9 @@ namespace blender::deg {
 /* *********** */
 /* Outer Nodes */
 
-/* Standard Component Methods ============================= */
+/* -------------------------------------------------------------------- */
+/** \name Standard Component Methods
+ * \{ */
 
 ComponentNode::OperationIDKey::OperationIDKey()
     : opcode(OperationCode::OPERATION), name(""), name_tag(-1)
@@ -86,7 +88,6 @@ ComponentNode::ComponentNode()
   operations_map = new Map<ComponentNode::OperationIDKey, OperationNode *>();
 }
 
-/* Initialize 'component' node - from pointer data given */
 void ComponentNode::init(const ID * /*id*/, const char * /*subdata*/)
 {
   /* hook up eval context? */
@@ -297,9 +298,12 @@ void ComponentNode::finalize_build(Depsgraph * /*graph*/)
   operations_map = nullptr;
 }
 
-/* Bone Component ========================================= */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Bone Component
+ * \{ */
 
-/* Initialize 'bone component' node - from pointer data given */
 void BoneComponentNode::init(const ID *id, const char *subdata)
 {
   /* generic component-node... */
@@ -315,7 +319,11 @@ void BoneComponentNode::init(const ID *id, const char *subdata)
   this->pchan = BKE_pose_channel_find_name(object->pose, subdata);
 }
 
-/* Register all components. =============================== */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Register All Components
+ * \{ */
 
 DEG_COMPONENT_NODE_DEFINE(Animation, ANIMATION, ID_RECALC_ANIMATION);
 /* TODO(sergey): Is this a correct tag? */
@@ -344,7 +352,11 @@ DEG_COMPONENT_NODE_DEFINE(GenericDatablock, GENERIC_DATABLOCK, 0);
 DEG_COMPONENT_NODE_DEFINE(Visibility, VISIBILITY, 0);
 DEG_COMPONENT_NODE_DEFINE(Simulation, SIMULATION, 0);
 
-/* Node Types Register =================================== */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Node Types Register
+ * \{ */
 
 void deg_register_component_depsnodes()
 {
@@ -375,4 +387,6 @@ void deg_register_component_depsnodes()
   register_node_typeinfo(&DNTI_SIMULATION);
 }
 
+/** \} */
+
 }  // namespace blender::deg
diff --git a/source/blender/depsgraph/intern/node/deg_node_component.h b/source/blender/depsgraph/intern/node/deg_node_component.h
index 4a1841d5d63..9f108af8012 100644
--- a/source/blender/depsgraph/intern/node/deg_node_component.h
+++ b/source/blender/depsgraph/intern/node/deg_node_component.h
@@ -67,6 +67,7 @@ struct ComponentNode : public Node {
   ComponentNode();
   ~ComponentNode();
 
+  /** Initialize 'component' node - from pointer data given. */
   void init(const ID *id, const char *subdata) override;
 
   virtual string identifier() const override;
@@ -224,6 +225,7 @@ DEG_COMPONENT_NODE_DECLARE_GENERIC(Simulation);
 
 /* Bone Component */
 struct BoneComponentNode : public ComponentNode {
+  /** Initialize 'bone component' node - from pointer data given. */
   void init(const ID *id, const char *subdata);
 
   struct bPoseChannel *pchan; /* the bone that this component represents */
diff --git a/source/blender/depsgraph/intern/node/deg_node_id.cc b/source/blender/depsgraph/intern/node/deg_node_id.cc
index 2b1ebc663fe..baad8318de2 100644
--- a/source/blender/depsgraph/intern/node/deg_node_id.cc
+++ b/source/blender/depsgraph/intern/node/deg_node_id.cc
@@ -73,7 +73,6 @@ uint64_t IDNode::ComponentIDKey::hash() const
                                     BLI_ghashutil_strhash_p(name));
 }
 
-/* Initialize 'id' node - from pointer data given. */
 void IDNode::init(const ID *id, const char *UNUSED(subdata))
 {
   BLI_assert(id != nullptr);
diff --git a/source/blender/depsgraph/intern/node/deg_node_id.h b/source/blender/depsgraph/intern/node/deg_node_id.h
index 073469598dc..257e42b8e67 100644
--- a/source/blender/depsgraph/intern/node/deg_node_id.h
+++ b/source/blender/depsgraph/intern/node/deg_node_id.h
@@ -58,6 +58,7 @@ struct IDNode : public Node {
     const char *name;
   };
 
+  /** Initialize 'id' node - from pointer data given. */
   virtual void init(const ID *id, const char *subdata) override;
   void init_copy_on_write(ID *id_cow_hint = nullptr);
   ~IDNode();
diff --git a/source/blender/depsgraph/intern/node/deg_node_operation.cc b/source/blender/depsgraph/intern/node/deg_node_operation.cc
index c25dc6fc8d5..eaae5d2d5dc 100644
--- a/source/blender/depsgraph/intern/node/deg_node_operation.cc
+++ b/source/blender/depsgraph/intern/node/deg_node_operation.cc
@@ -218,8 +218,6 @@ string OperationNode::identifier() const
   return string(operationCodeAsString(opcode)) + "(" + name + ")";
 }
 
-/* Full node identifier, including owner name.
- * used for logging and debug prints. */
 string OperationNode::full_identifier() const
 {
   string owner_str = owner->owner->name;
diff --git a/source/blender/depsgraph/intern/node/deg_node_operation.h b/source/blender/depsgraph/intern/node/deg_node_operation.h
index a17186da941..31cbb9702ba 100644
--- a/source/blender/depsgraph/intern/node/deg_node_operation.h
+++ b/source/blender/depsgraph/intern/node/deg_node_operation.h
@@ -233,6 +233,10 @@ struct OperationNode : public Node {
   OperationNode();
 
   virtual string identifier() const override;
+  /**
+   * Full node identifier, including owner name.
+   * used for logging and debug prints.
+   */
   string full_identifier() const;
 
   virtual void tag_update(Depsgraph *graph, eUpdateSource source) override;