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, 151 insertions, 0 deletions

diff --git a/source/blender/io/wavefront_obj/importer/obj_import_file_reader.hh b/source/blender/io/wavefront_obj/importer/obj_import_file_reader.hh
new file mode 100644
index 00000000000..c8d8b78fc0e
--- /dev/null
+++ b/source/blender/io/wavefront_obj/importer/obj_import_file_reader.hh
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup obj
+ */
+
+#pragma once
+
+#include "BLI_fileops.hh"
+#include "IO_wavefront_obj.h"
+#include "obj_import_mtl.hh"
+#include "obj_import_objects.hh"
+
+namespace blender::io::obj {
+
+/* Note: the OBJ parser implementation is planned to get fairly large changes "soon",
+ * so don't read too much into current implementation... */
+class OBJParser {
+ private:
+  const OBJImportParams &import_params_;
+  blender::fstream obj_file_;
+  Vector<std::string> mtl_libraries_;
+
+ public:
+  OBJParser(const OBJImportParams &import_params);
+
+  void parse(Vector<std::unique_ptr<Geometry>> &r_all_geometries,
+             GlobalVertices &r_global_vertices);
+  Span<std::string> mtl_libraries() const;
+};
+
+enum class eOBJLineKey {
+  V,
+  VN,
+  VT,
+  F,
+  L,
+  CSTYPE,
+  DEG,
+  CURV,
+  PARM,
+  O,
+  G,
+  S,
+  USEMTL,
+  MTLLIB,
+  COMMENT
+};
+
+constexpr eOBJLineKey line_key_str_to_enum(const std::string_view key_str)
+{
+  if (key_str == "v" || key_str == "V") {
+    return eOBJLineKey::V;
+  }
+  if (key_str == "vn" || key_str == "VN") {
+    return eOBJLineKey::VN;
+  }
+  if (key_str == "vt" || key_str == "VT") {
+    return eOBJLineKey::VT;
+  }
+  if (key_str == "f" || key_str == "F") {
+    return eOBJLineKey::F;
+  }
+  if (key_str == "l" || key_str == "L") {
+    return eOBJLineKey::L;
+  }
+  if (key_str == "cstype" || key_str == "CSTYPE") {
+    return eOBJLineKey::CSTYPE;
+  }
+  if (key_str == "deg" || key_str == "DEG") {
+    return eOBJLineKey::DEG;
+  }
+  if (key_str == "curv" || key_str == "CURV") {
+    return eOBJLineKey::CURV;
+  }
+  if (key_str == "parm" || key_str == "PARM") {
+    return eOBJLineKey::PARM;
+  }
+  if (key_str == "o" || key_str == "O") {
+    return eOBJLineKey::O;
+  }
+  if (key_str == "g" || key_str == "G") {
+    return eOBJLineKey::G;
+  }
+  if (key_str == "s" || key_str == "S") {
+    return eOBJLineKey::S;
+  }
+  if (key_str == "usemtl" || key_str == "USEMTL") {
+    return eOBJLineKey::USEMTL;
+  }
+  if (key_str == "mtllib" || key_str == "MTLLIB") {
+    return eOBJLineKey::MTLLIB;
+  }
+  if (key_str == "#") {
+    return eOBJLineKey::COMMENT;
+  }
+  return eOBJLineKey::COMMENT;
+}
+
+/**
+ * All texture map options with number of arguments they accept.
+ */
+class TextureMapOptions {
+ private:
+  Map<const std::string, int> tex_map_options;
+
+ public:
+  TextureMapOptions()
+  {
+    tex_map_options.add_new("-blendu", 1);
+    tex_map_options.add_new("-blendv", 1);
+    tex_map_options.add_new("-boost", 1);
+    tex_map_options.add_new("-mm", 2);
+    tex_map_options.add_new("-o", 3);
+    tex_map_options.add_new("-s", 3);
+    tex_map_options.add_new("-t", 3);
+    tex_map_options.add_new("-texres", 1);
+    tex_map_options.add_new("-clamp", 1);
+    tex_map_options.add_new("-bm", 1);
+    tex_map_options.add_new("-imfchan", 1);
+  }
+
+  /**
+   * All valid option strings.
+   */
+  Map<const std::string, int>::KeyIterator all_options() const
+  {
+    return tex_map_options.keys();
+  }
+
+  int number_of_args(StringRef option) const
+  {
+    return tex_map_options.lookup_as(std::string(option));
+  }
+};
+
+class MTLParser {
+ private:
+  char mtl_file_path_[FILE_MAX];
+  /**
+   * Directory in which the MTL file is found.
+   */
+  char mtl_dir_path_[FILE_MAX];
+  blender::fstream mtl_file_;
+
+ public:
+  MTLParser(StringRef mtl_library_, StringRefNull obj_filepath);
+
+  void parse_and_store(Map<std::string, std::unique_ptr<MTLMaterial>> &r_mtl_materials);
+};
+}  // namespace blender::io::obj