Cleanup: IO, reduce code duplication in USD and Alembic exporters

Move the object visibility check from Alembic/USD-specific code into the
`io/common` module.

No functional changes.

4 files changed, 30 insertions, 42 deletions

diff --git a/source/blender/io/alembic/exporter/abc_writer_mesh.cc b/source/blender/io/alembic/exporter/abc_writer_mesh.cc
index 89cb76db9a6..5c005164bcc 100644
--- a/source/blender/io/alembic/exporter/abc_writer_mesh.cc
+++ b/source/blender/io/alembic/exporter/abc_writer_mesh.cc
@@ -159,27 +159,7 @@ ModifierData *ABCGenericMeshWriter::get_liquid_sim_modifier(Scene *scene, Object
 
 bool ABCGenericMeshWriter::is_supported(const HierarchyContext *context) const
 {
-  Object *object = context->object;
-  bool is_dupli = context->duplicator != nullptr;
-  int base_flag;
-
-  if (is_dupli) {
-    /* Construct the object's base flags from its dupli-parent, just like is done in
-     * deg_objects_dupli_iterator_next(). Without this, the visibility check below will fail. Doing
-     * this here, instead of a more suitable location in AbstractHierarchyIterator, prevents
-     * copying the Object for every dupli. */
-    base_flag = object->base_flag;
-    object->base_flag = context->duplicator->base_flag | BASE_FROM_DUPLI;
-  }
-
-  int visibility = BKE_object_visibility(
-      object, DAG_EVAL_RENDER /* TODO(Sybren): add evaluation mode to export options? */);
-
-  if (is_dupli) {
-    object->base_flag = base_flag;
-  }
-
-  return (visibility & OB_VISIBLE_SELF) != 0;
+  return context->is_object_visible(DAG_EVAL_RENDER);
 }
 
 void ABCGenericMeshWriter::do_write(HierarchyContext &context)
diff --git a/source/blender/io/common/IO_abstract_hierarchy_iterator.h b/source/blender/io/common/IO_abstract_hierarchy_iterator.h
index d0d9d72b880..1d78cc38746 100644
--- a/source/blender/io/common/IO_abstract_hierarchy_iterator.h
+++ b/source/blender/io/common/IO_abstract_hierarchy_iterator.h
@@ -37,6 +37,8 @@
 
 #include "IO_dupli_persistent_id.hh"
 
+#include "DEG_depsgraph.h"
+
 #include <map>
 #include <set>
 #include <string>
@@ -111,6 +113,8 @@ struct HierarchyContext {
   bool is_instance() const;
   void mark_as_instance_of(const std::string &reference_export_path);
   void mark_as_not_instanced();
+
+  bool is_object_visible(const enum eEvaluationMode evaluation_mode) const;
 };
 
 /* Abstract writer for objects. Create concrete subclasses to write to USD, Alembic, etc.
diff --git a/source/blender/io/common/intern/abstract_hierarchy_iterator.cc b/source/blender/io/common/intern/abstract_hierarchy_iterator.cc
index fbefc8c8e7e..93e7e677118 100644
--- a/source/blender/io/common/intern/abstract_hierarchy_iterator.cc
+++ b/source/blender/io/common/intern/abstract_hierarchy_iterator.cc
@@ -28,6 +28,7 @@
 #include "BKE_anim_data.h"
 #include "BKE_duplilist.h"
 #include "BKE_key.h"
+#include "BKE_object.h"
 #include "BKE_particle.h"
 
 #include "BLI_assert.h"
@@ -77,6 +78,29 @@ void HierarchyContext::mark_as_not_instanced()
   original_export_path.clear();
 }
 
+bool HierarchyContext::is_object_visible(const enum eEvaluationMode evaluation_mode) const
+{
+  bool is_dupli = duplicator != nullptr;
+  int base_flag;
+
+  if (is_dupli) {
+    /* Construct the object's base flags from its dupli-parent, just like is done in
+     * deg_objects_dupli_iterator_next(). Without this, the visibility check below will fail. Doing
+     * this here, instead of a more suitable location in AbstractHierarchyIterator, prevents
+     * copying the Object for every dupli. */
+    base_flag = object->base_flag;
+    object->base_flag = duplicator->base_flag | BASE_FROM_DUPLI;
+  }
+
+  int visibility = BKE_object_visibility(object, evaluation_mode);
+
+  if (is_dupli) {
+    object->base_flag = base_flag;
+  }
+
+  return (visibility & OB_VISIBLE_SELF) != 0;
+}
+
 EnsuredWriter::EnsuredWriter() : writer_(nullptr), newly_created_(false)
 {
 }
diff --git a/source/blender/io/usd/intern/usd_writer_mesh.cc b/source/blender/io/usd/intern/usd_writer_mesh.cc
index bd2c549e729..b27c68a41f6 100644
--- a/source/blender/io/usd/intern/usd_writer_mesh.cc
+++ b/source/blender/io/usd/intern/usd_writer_mesh.cc
@@ -52,27 +52,7 @@ USDGenericMeshWriter::USDGenericMeshWriter(const USDExporterContext &ctx) : USDA
 
 bool USDGenericMeshWriter::is_supported(const HierarchyContext *context) const
 {
-  Object *object = context->object;
-  bool is_dupli = context->duplicator != nullptr;
-  int base_flag;
-
-  if (is_dupli) {
-    /* Construct the object's base flags from its dupli-parent, just like is done in
-     * deg_objects_dupli_iterator_next(). Without this, the visibility check below will fail. Doing
-     * this here, instead of a more suitable location in AbstractHierarchyIterator, prevents
-     * copying the Object for every dupli. */
-    base_flag = object->base_flag;
-    object->base_flag = context->duplicator->base_flag | BASE_FROM_DUPLI;
-  }
-
-  int visibility = BKE_object_visibility(object,
-                                         usd_export_context_.export_params.evaluation_mode);
-
-  if (is_dupli) {
-    object->base_flag = base_flag;
-  }
-
-  return (visibility & OB_VISIBLE_SELF) != 0;
+  return context->is_object_visible(usd_export_context_.export_params.evaluation_mode);
 }
 
 void USDGenericMeshWriter::do_write(HierarchyContext &context)