OBJ: New C++ based wavefront OBJ importer

This takes state of soc-2020-io-performance branch as it was at
e9bbfd0c8c7 (2021 Oct 31), merges latest master (2022 Apr 4),
adds a bunch of tests, and fixes a bunch of stuff found by said
tests. The fixes are detailed in the differential.

Timings on my machine (Windows, VS2022 release build, AMD Ryzen
5950X 32 threads):

- Rungholt minecraft level (269MB file, 1 mesh): 54.2s -> 14.2s
  (memory usage: 7.0GB -> 1.9GB).
- Blender 3.0 splash scene: "I waited for 90 minutes and gave up"
  -> 109s. Now, this time is not great, but at least 20% of the
  time is spent assigning unique names for the imported objects
  (the scene has 24 thousand objects). This is not specific to obj
  importer, but rather a general issue across blender overall.

Test suite file updates done in Subversion tests repository.

Reviewed By: @howardt, @sybren
Differential Revision: https://developer.blender.org/D13958

1 files changed, 38 insertions, 0 deletions

diff --git a/source/blender/io/wavefront_obj/importer/obj_import_nurbs.hh b/source/blender/io/wavefront_obj/importer/obj_import_nurbs.hh
new file mode 100644
index 00000000000..56ac299283d
--- /dev/null
+++ b/source/blender/io/wavefront_obj/importer/obj_import_nurbs.hh
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup obj
+ */
+
+#pragma once
+
+#include "BKE_curve.h"
+
+#include "BLI_utility_mixins.hh"
+
+#include "DNA_curve_types.h"
+
+#include "obj_import_objects.hh"
+
+namespace blender::io::obj {
+
+/**
+ * Make a Blender NURBS Curve block from a Geometry of GEOM_CURVE type.
+ */
+class CurveFromGeometry : NonMovable, NonCopyable {
+ private:
+  const Geometry &curve_geometry_;
+  const GlobalVertices &global_vertices_;
+
+ public:
+  CurveFromGeometry(const Geometry &geometry, const GlobalVertices &global_vertices)
+      : curve_geometry_(geometry), global_vertices_(global_vertices)
+  {
+  }
+
+  Object *create_curve(Main *bmain, const OBJImportParams &import_params);
+
+ private:
+  void create_nurbs(Curve *curve);
+};
+}  // namespace blender::io::obj