Files
Z3D/source/assets/file_parsers/mtl_parser.cpp
2025-03-31 21:41:24 +02:00

568 lines
14 KiB
C++

#include "assets/file_parsers/mtl_parser.hpp"
#include <charconv>
#include <fstream>
#include <array>
#include "util/logger.hpp"
#include "util/for_each.hpp"
#include "util/line_parser.hpp"
#include <execution>
namespace assets::mtl_parser_error
{
struct category : std::error_category
{
[[nodiscard]] const char* name() const noexcept override
{
return "mtl_parser";
}
[[nodiscard]] std::string message(int ev) const override
{
// TODO these are incomplete
switch (static_cast<codes>(ev))
{
using enum codes;
case cannot_open_file:
return "Cannot open mtl file.";
case cannot_open_texture:
return "Cannot open texture file.";
case malformed_ambient_color:
return "File contains malformed 'Ka' statement.";
case malformed_diffuse_color:
return "File contains malformed 'Kd' statement.";
case malformed_specular_color:
return "File contains malformed 'Ks' statement.";
case malformed_specular_exponent:
return "File contains malformed 'Ns' statement.";
case malformed_dissolve:
return "File contains malformed 'd' statement.";
case unknown_line_begin:
return "Unknown mtl line begin";
default:
using namespace std::string_literals;
return "unrecognized error ("s + std::to_string(ev) + ")";
}
}
};
} // namespace mtl_parser_error
inline std::error_category& mtl_parser_error_category()
{
static assets::mtl_parser_error::category category;
return category;
}
namespace assets::mtl_parser_error
{
inline std::error_code make_error_code(codes e)
{
return { static_cast<int>(e), mtl_parser_error_category() };
}
} // namespace mtl_loader_error
std::error_code assets::mtl_parser::prefetch(
path_id_lookups& lookups
) {
namespace fs = std::filesystem;
using mtl_parser_error::codes;
using mtl_parser_error::make_error_code;
auto buffer = std::vector<char>(8 * 1024, '\0');
auto in = std::ifstream{};
auto path_buffer = fs::path{};
auto filename_buffer = fs::path{};
const auto process_file = [&]()
{
in.open(filename_buffer);
if (not in.is_open()) {
ztu::logger::error("Could not open .mtl file '%'", filename_buffer);
return;
}
filename_buffer.remove_filename();
find_textures(buffer, path_buffer, filename_buffer, in, queue.texture.files);
in.close();
};
// TODO properly extract
for (const auto file : paths.files)
{
filename_buffer.assign(file);
process_file();
}
for (const auto directory : paths.directories)
{
for (const auto& file : fs::directory_iterator{ directory }) {
filename_buffer.assign(file.path());
// Avoid heap allocation of .extension()
if (not std::string_view(filename_buffer.c_str()).ends_with(".obj"))
{
continue;
}
process_file();
}
}
return {};
}
std::error_code assets::mtl_parser::load(
path_id_lookups& lookups,
data_stores& stores,
bool pedantic
) {
m_path_buffer.clear();
lookups.material_libraries.by_extension(".mtl", m_path_buffer);
auto store_mutex = std::mutex{};
// TODO who protects the material id lookup
// TODO who protects the material store
std::for_each(
std::execution::parallel_unsequenced_policy{},
m_path_buffer.begin(),
m_path_buffer.end(),
parser_context{
lookups.textures,
lookups.materials,
stores.materials,
stores.material_libraries,
store_mutex
}
);
return {};
}
inline std::error_category& connector_error_category()
{
static assets::mtl_parser_error::category category;
return category;
}
namespace assets::mtl_parser_error
{
inline std::error_code make_error_code(const codes e)
{
return { static_cast<int>(e), connector_error_category() };
}
} // namespace mtl_loader_error
assets::mtl_parser::parser_context::parser_context(
const texture_id_lookup& texture_id_lookup,
material_id_lookup& material_id_lookup,
material_store& material_store,
store_type& store
) :
m_texture_id_lookup{ &texture_id_lookup },
m_material_id_lookup{ &material_id_lookup },
m_material_store{ &material_store },
m_store{ &store }
{
m_buffer.reserve(32);
}
void assets::mtl_parser::parser_context::reset()
{
m_buffer.clear();
}
void assets::mtl_parser::parser_context::operator()(lookup_type::const_pointer entry) noexcept
{
using mtl_parser_error::codes;
using mtl_parser_error::make_error_code;
namespace fs = std::filesystem;
const auto& [ filename, id ] = *entry;
// TODO unroll stuff
auto in = std::ifstream{ filename };
if (not in.is_open())
{
ztu::logger::warn("Cannot open mtl file %.", filename);
return;
}
const auto base_dir = fs::canonical(fs::path(filename).parent_path());
auto name = std::string{};
auto material = material_data{};
const auto push_material = [&]()
{
if (not name.empty())
{
const auto [ id_it, is_new ] = m_material_id_lookup->try_emplace(filename / name);
const auto material_id = id_it->second;
m_material_store->insert(id, material);
m_buffer.emplace(name, material_id);
}
name = {};
material = {};
};
const auto ec = ztu::parse_lines<codes>(
in,
pedantic,
ztu::make_line_parser("newmtl ", ztu::is_not_repeating, [&](const auto& param)
{
push_material();
name = param;
return codes::ok;
}),
ztu::make_line_parser("Ka ", ztu::is_not_repeating, [&](const auto& param)
{
material_components::ambient_filter ambient_filter;
if (parse_numeric_vector(param, ambient_filter) != std::errc{}) [[unlikely]]
{
return codes::malformed_ambient_color; // TODO rename to filter
}
material.ambient_filter() = ambient_filter;
material.component_flags |= material_components::flags::ambient_filter;
return codes::ok;
}),
ztu::make_line_parser("Kd ", ztu::is_not_repeating, [&](const auto& param)
{
material_components::diffuse_filter diffuse_filter;
if (parse_numeric_vector(param, diffuse_filter) != std::errc{}) [[unlikely]]
{
return codes::malformed_diffuse_color;
}
material.diffuse_filter() = diffuse_filter;
material.component_flags |= material_components::flags::diffuse_filter;
return codes::ok;
}),
ztu::make_line_parser("Ks ", ztu::is_not_repeating, [&](const auto& param)
{
material_components::specular_filter specular_filter;
if (parse_numeric_vector(param, specular_filter) != std::errc{}) [[unlikely]]
{
return codes::malformed_specular_color;
}
material.specular_filter() = specular_filter;
material.component_flags |= material_components::flags::specular_filter;
return codes::ok;
}),
ztu::make_line_parser("Ns ", ztu::is_not_repeating, [&](const auto& param)
{
z3d::vec<1, material_components::shininess> shininess;
if (parse_numeric_vector(param, shininess) != std::errc{}) [[unlikely]]
{
return codes::malformed_specular_exponent;
}
material.shininess() = shininess[0];
material.component_flags |= material_components::flags::shininess;
return codes::ok;
}),
ztu::make_line_parser("d ", ztu::is_not_repeating, [&](const auto& param)
{
z3d::vec<1, material_components::alpha> alpha{};
if (parse_numeric_vector(param, alpha) != std::errc{}) [[unlikely]]
{
return codes::malformed_dissolve;
}
material.alpha() = alpha[0];
material.component_flags |= material_components::flags::alpha;
return codes::ok;
}),
ztu::make_line_parser("map_Ka ", ztu::is_not_repeating, [&](const auto& param)
{
if (const auto texture_id = fetch_texture_id(param, "ambient filter"))
{
material.ambient_filter_texture_id() = *texture_id;
material.component_flags |= material_components::flags::ambient_filter_texture;
}
return codes::ok;
}),
ztu::make_line_parser("map_Kd ", ztu::is_not_repeating, [&](const auto& param)
{
if (const auto texture_id = fetch_texture_id(param, "diffuse filter"))
{
material.diffuse_filter_texture_id() = *texture_id;
material.component_flags |= material_components::flags::diffuse_filter_texture;
}
return codes::ok;
}),
ztu::make_line_parser("map_Ks ", ztu::is_not_repeating, [&](const auto& param)
{
if (const auto texture_id = fetch_texture_id(param, "specular filter"))
{
material.specular_filter_texture_id() = *texture_id;
material.component_flags |= material_components::flags::specular_filter_texture;
}
return codes::ok;
}),
ztu::make_line_parser("map_Ns ", ztu::is_not_repeating, [&](const auto& param)
{
if (const auto texture_id = fetch_texture_id(param, "shininess"))
{
material.shininess_texture_id() = *texture_id;
material.component_flags |= material_components::flags::shininess_texture;
}
return codes::ok;
}),
ztu::make_line_parser("map_d ", ztu::is_not_repeating, [&](const auto& param)
{
if (const auto texture_id = fetch_texture_id(param, "alpha"))
{
material.alpha_texture_id() = *texture_id;
material.component_flags |= material_components::flags::alpha_texture;
}
return codes::ok;
}),
ztu::make_line_parser("bump ", ztu::is_not_repeating, [&](const auto& param)
{
if (const auto texture_id = fetch_texture_id(param, "bump"))
{
material.bump_texture_id() = *texture_id;
material.component_flags |= material_components::flags::bump_texture;
}
return codes::ok;
})
);
if (ec != codes::ok)
{
const auto e = make_error_code(ec);
ztu::logger::error("Error while parsing mtl file %: %", filename, e.message());
}
push_material();
m_store->insert(id, m_buffer);
}
std::optional<assets::texture_id> assets::mtl_parser::parser_context::fetch_texture_id(
const std::filesystem::path& mtl_dir,
std::string_view filename,
std::string_view texture_type_name
) {
auto texture_filename = std::filesystem::path(filename);
if (texture_filename.is_relative())
{
texture_filename = mtl_dir / texture_filename;
}
const auto texture_id_it = m_texture_id_lookup->find(texture_filename);
if (texture_id_it == m_texture_id_lookup->end())
{
ztu::logger::warn(
"%-texture at % has not been registered and can therefor not be used.",
texture_type_name,
texture_filename
);
return std::nullopt;
}
return texture_id_it->second;
}
template<typename T, std::size_t Count>
std::errc parse_numeric_vector(std::string_view param, std::array<T, Count>& values)
{
const auto end = param.end();
auto it = param.begin();
for (auto& value : values)
{
if (it >= end)
{
return std::errc::invalid_argument;
}
const auto [ptr, ec] = std::from_chars(it, end, value);
if (ec != std::errc{})
{
return ec;
}
it = ptr + 1; // skip space in between components
}
return {};
};
void assets::mtl_parser::find_textures(
std::span<char> buffer,
std::filesystem::path& path_buffer,
const std::filesystem::path& base_directory,
std::ifstream& in,
ztu::string_list& texture_filenames
) {
using namespace std::string_view_literals;
// TODO 'bump' is missing!!!
static constexpr auto keyword = "\nmap_"sv;
using long_postfix_type = std::array<char, 2>;
static constexpr auto postfix_length = std::tuple_size_v<long_postfix_type>;
static constexpr auto make_postfix = [](const std::string_view str) static constexpr
{
auto postfix = long_postfix_type{};
assert(str.length() >= postfix_length);
std::copy_n(str.begin(), postfix.size(), postfix.begin());
return postfix;
};
static constexpr auto postfixes = std::array{
make_postfix("d "),
make_postfix("Ka"),
make_postfix("Kd"),
make_postfix("Ks"),
make_postfix("Ns")
};
const auto buffer_view = std::string_view(buffer);
// Add linebreak to simplify line begin search.
buffer.front() = '\n';
auto leftover = std::size_t{ 1 };
enum class match {
exact,
overflowed,
none
};
const auto check_match = [](std::string_view& potential_match) static -> match
{
std::cout << '\'' << potential_match.substr(0, std::min(40ul, potential_match.size())) << '\'' << std::endl;
if (potential_match.length() < postfix_length)
{
return match::overflowed;
}
const auto postfix = make_postfix(potential_match);
// Optimized for SIMD.
if (not std::ranges::contains(postfixes, postfix))
{
return match::none;
}
const auto long_match = postfix.back() != ' ';
if (long_match and (
potential_match.length() < postfix_length + sizeof(' ') or
potential_match[postfix_length] != ' '
)) {
return match::overflowed;
}
const auto actual_postfix_length = std::size_t{ 1 } + static_cast<std::size_t>(long_match);
const auto filename_begin = actual_postfix_length + sizeof(' ');
const auto filename_end = potential_match.find('\n', filename_begin);
if (filename_end == std::string_view::npos)
{
return match::overflowed;
}
const auto length = filename_end - filename_begin;
potential_match = potential_match.substr(filename_begin, length);
return match::exact;
};
do
{
// Keep some old characters to continue matching interrupted sequence.
std::copy(buffer.end() - leftover, buffer.end(), buffer.begin());
in.read(buffer.data() + leftover, buffer.size() - leftover);
const auto str = buffer_view.substr(0, leftover + in.gcount());
auto pos = std::string_view::size_type{};
while ((pos = str.find(keyword, pos)) != std::string_view::npos)
{
const auto keyword_end = pos + keyword.size();
auto potential_match = str.substr(keyword_end);
const auto match_type = check_match(potential_match);
if (match_type == match::exact)
{
path_buffer.assign(potential_match);
if (path_buffer.is_relative())
{
path_buffer = base_directory;
path_buffer /= potential_match;
}
texture_filenames.push_back(path_buffer.c_str());
pos += potential_match.size();
leftover = 0;
}
else if (match_type == match::overflowed)
{
if (pos == 0) [[unlikely]]
{
ztu::logger::error("Ignoring string match, as it exceeds buffer size of % characters.", buffer.size());
leftover = 0;
}
else
{
leftover = str.size() - pos;
}
break;
}
else
{
leftover = keyword.size();
}
}
} while (not in.eof());
}