Ported the obj parser.

include/assets/file_parsers/obj_parser.hpp

@@ -0,0 +1,100 @@
+#pragma once
+
+#include <filesystem>
+#include <system_error>
+#include <string_view>
+#include "assets/data/mesh_data.hpp"
+#include "assets/data_stores.hpp"
+#include "assets/path_id_lookups.hpp"
+#include <unordered_map>
+#include "util/array_hash.hpp"
+
+namespace assets::obj_parser_error
+{
+enum class codes {
+	ok = 0,
+	cannot_open_file,
+	malformed_vertex,
+	malformed_texture_coordinate,
+	malformed_normal,
+	malformed_face,
+	face_index_out_of_range,
+	unknown_line_begin,
+	use_material_without_material_library,
+	unknown_material_name
+};
+} // namespace obj_loader_error
+
+namespace assets
+{
+
+struct obj_parser
+{
+	static constexpr auto name = std::string_view("obj");
+	using data_type = mesh_data;
+	using store_type = mesh_store;
+	using lookup_type = mesh_id_lookup;
+
+	// TODO port this mess to the new interface
+	[[nodiscard]] std::error_code prefetch(
+		path_id_lookups& lookups
+	);
+
+	[[nodiscard]] std::error_code load(
+		path_id_lookups& lookups,
+		data_stores& stores,
+		bool pedantic = false
+	);
+
+protected:
+	using component_indices = std::array<z3d::vertex_index, 3>;
+
+	class prefetcher_context
+	{
+	public:
+		prefetcher_context(
+			path_id_lookups& id_lookups
+		);
+
+		void operator()(lookup_type::const_pointer entry) noexcept;
+
+	private:
+		path_id_lookups* m_id_lookups;
+		std::vector<char> m_buffer{};
+	};
+
+	class parser_context
+	{
+	public:
+		parser_context(
+			path_id_lookups& m_id_lookups,
+			data_stores& m_stores
+		);
+
+		void operator()(lookup_type::const_pointer entry) noexcept;
+
+	protected:
+		void reset();
+
+		z3d::vertex_index find_or_push_vertex(const component_indices& vertex_comp_indices);
+
+		[[nodiscard]] std::optional<texture_id> fetch_texture_id(
+			const std::filesystem::path& mtl_dir,
+			std::string_view filename,
+			std::string_view texture_type_name
+		);
+
+	private:
+		path_id_lookups* m_id_lookups;
+		data_stores* m_stores;
+		data_type m_mesh{};
+		std::vector<mesh_vertex_components::position> m_position_buffer{};
+		std::vector<mesh_vertex_components::normal> m_normal_buffer{};
+		std::vector<mesh_vertex_components::tex_coord> m_tex_coord_buffer{};
+		std::unordered_map<component_indices, z3d::vertex_index> m_vertex_comp_indices_to_vertex_index{};
+	};
+
+private:
+	std::vector<lookup_type::const_pointer> m_path_buffer;
+};
+}