[Bf-blender-cvs] [03c0bb75c58] temp-usd-prev-export2: USD Export: shared code to get active uv name.

[Michael Kowalski]

Commit: 03c0bb75c58b9cfc1c65445c460d66e4986da28a
Author: Michael Kowalski
Date:   Sun Dec 26 19:12:33 2021 -0500
Branches: temp-usd-prev-export2
https://developer.blender.org/rB03c0bb75c58b9cfc1c65445c460d66e4986da28a

USD Export: shared code to get active uv name.

Added CustomData_get_active_layer_name() function to
BKE_customdata.h to return the name of the active
layer of a given type, as this functionality can
be used in both the USD export and Collada IO
utility functions when retrieving the name of a
mesh's active UV layer.  Refactored the USD Preview
Surface code to use this function.

===================================================================

M	source/blender/blenkernel/BKE_customdata.h
M	source/blender/blenkernel/intern/customdata.c
M	source/blender/io/usd/intern/usd_writer_abstract.cc

===================================================================

diff --git a/source/blender/blenkernel/BKE_customdata.h b/source/blender/blenkernel/BKE_customdata.h
index 68d29235469..35c5db57d84 100644
--- a/source/blender/blenkernel/BKE_customdata.h
+++ b/source/blender/blenkernel/BKE_customdata.h
@@ -441,6 +441,12 @@ int CustomData_get_render_layer(const struct CustomData *data, int type);
 int CustomData_get_clone_layer(const struct CustomData *data, int type);
 int CustomData_get_stencil_layer(const struct CustomData *data, int type);
 
+/**
+ * Returns name of the active layer of the given type or NULL
+ * if no such active layer is defined.
+ */
+const char *CustomData_get_active_layer_name(const struct CustomData *data, int type);
+
 /**
  * Copies the data from source to the data element at index in the first layer of type
  * no effect if there is no layer of type.
diff --git a/source/blender/blenkernel/intern/customdata.c b/source/blender/blenkernel/intern/customdata.c
index 090de26c230..bf2760d3db3 100644
--- a/source/blender/blenkernel/intern/customdata.c
+++ b/source/blender/blenkernel/intern/customdata.c
@@ -2405,6 +2405,13 @@ int CustomData_get_stencil_layer(const CustomData *data, int type)
   return (layer_index != -1) ? data->layers[layer_index].active_mask : -1;
 }
 
+const char *CustomData_get_active_layer_name(const struct CustomData *data, int type)
+{
+  /* Get the layer index of the active layer of this type. */
+  int layer_index = CustomData_get_active_layer_index(data, type);
+  return layer_index < 0 ? NULL : data->layers[layer_index].name;
+}
+
 void CustomData_set_layer_active(CustomData *data, int type, int n)
 {
   for (int i = 0; i < data->totlayer; i++) {
diff --git a/source/blender/io/usd/intern/usd_writer_abstract.cc b/source/blender/io/usd/intern/usd_writer_abstract.cc
index 470718b49c8..b254739c5bf 100644
--- a/source/blender/io/usd/intern/usd_writer_abstract.cc
+++ b/source/blender/io/usd/intern/usd_writer_abstract.cc
@@ -38,49 +38,21 @@ static const pxr::TfToken roughness("roughness", pxr::TfToken::Immortal);
 static const pxr::TfToken surface("surface", pxr::TfToken::Immortal);
 }  // namespace usdtokens
 
-namespace blender::io::usd {
-
-/* The following three utility function for getting active layers
- * were coppied from the collada utils. */
-
-/* Returns name of the active layer of the given type or null
- * if no such active layer is defined. */
-static const char *customData_get_active_layer_name(const CustomData *data, int type)
+static std::string get_mesh_active_uvlayer_name(const Object *ob)
 {
-  /* get the layer index of the active layer of type */
-  int layer_index = CustomData_get_active_layer_index(data, type);
-  if (layer_index < 0) {
-    return nullptr;
+  if (!ob || ob->type != OB_MESH || !ob->data) {
+    return "";
   }
 
-  return data->layers[layer_index].name;
-}
+  const Mesh *me =static_cast<Mesh *>(ob->data);
 
-/* Returns name of the active UV layer or the empty string if no active
- * UV Layer defined. */
-static std::string get_active_uvlayer_name(Mesh *me)
-{
-  int num_layers = CustomData_number_of_layers(&me->ldata, CD_MLOOPUV);
-  if (num_layers) {
-    const char *layer_name = customData_get_active_layer_name(&me->ldata, CD_MLOOPUV);
-    if (layer_name) {
-      return std::string(layer_name);
-    }
-  }
-  return "";
-}
+  const char *name = CustomData_get_active_layer_name(&me->ldata, CD_MLOOPUV);
 
-/* Returns name of the acive Layer or empty String if no active UV Layer defined,
- * assuming the Object is of type MESH. */
-static std::string get_active_uvlayer_name(Object *ob)
-{
-  if (!ob || ob->type != OB_MESH) {
-    return "";
-  }
-  Mesh *me = static_cast<Mesh *>(ob->data);
-  return get_active_uvlayer_name(me);
+  return name ? name : "";
 }
 
+namespace blender::io::usd {
+
 USDAbstractWriter::USDAbstractWriter(const USDExporterContext &usd_export_context)
     : usd_export_context_(usd_export_context), frame_has_been_written_(false), is_animated_(false)
 {
@@ -139,9 +111,9 @@ pxr::UsdShadeMaterial USDAbstractWriter::ensure_usd_material(const HierarchyCont
   usd_material = pxr::UsdShadeMaterial::Define(stage, usd_path);
 
   if (material->use_nodes && this->usd_export_context_.export_params.generate_preview_surface) {
-    std::string active_uv_name = get_active_uvlayer_name(context.object);
+    std::string active_uv = get_mesh_active_uvlayer_name(context.object);
     create_usd_preview_surface_material(
-        this->usd_export_context_, material, usd_material, active_uv_name);
+        this->usd_export_context_, material, usd_material, active_uv);
   }
   else {
     create_usd_viewport_material(this->usd_export_context_, material, usd_material);