BKE: Utilities to create curves and point clouds without attributes

Same as #118297.

Pull Request: https://projects.blender.org/blender/blender/pulls/120368

source/blender/blenkernel/BKE_curves.hh

@@ -859,6 +859,8 @@ CurvesGeometry curves_copy_curve_selection(const CurvesGeometry &curves,
                                            const IndexMask &curves_to_copy,
                                            const AttributeFilter &attribute_filter);
 
+CurvesGeometry curves_new_no_attributes(int point_num, int curve_num);
+
 std::array<int, CURVE_TYPES_NUM> calculate_type_counts(const VArray<int8_t> &types);
 
 /* -------------------------------------------------------------------- */

source/blender/blenkernel/BKE_pointcloud.hh

@@ -46,6 +46,8 @@ struct PointCloudRuntime {
   MEM_CXX_CLASS_ALLOC_FUNCS("PointCloudRuntime");
 };
 
+PointCloud *pointcloud_new_no_attributes(int totpoint);
+
 }  // namespace blender::bke
 
 void *BKE_pointcloud_add(Main *bmain, const char *name);

source/blender/blenkernel/intern/curves_geometry.cc

@@ -1430,6 +1430,14 @@ void CurvesGeometry::remove_attributes_based_on_types()
   }
 }
 
+CurvesGeometry curves_new_no_attributes(int point_num, int curve_num)
+{
+  CurvesGeometry curves(0, curve_num);
+  curves.point_num = point_num;
+  CustomData_free_layer_named(&curves.point_data, "position", 0);
+  return curves;
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */

source/blender/blenkernel/intern/pointcloud.cc

@@ -403,3 +403,15 @@ void BKE_pointcloud_batch_cache_free(PointCloud *pointcloud)
     BKE_pointcloud_batch_cache_free_cb(pointcloud);
   }
 }
+
+namespace blender::bke {
+
+PointCloud *pointcloud_new_no_attributes(int totpoint)
+{
+  PointCloud *pointcloud = BKE_pointcloud_new_nomain(0);
+  pointcloud->totpoint = totpoint;
+  CustomData_free_layer_named(&pointcloud->pdata, "position", 0);
+  return pointcloud;
+}
+
+}  // namespace blender::bke