utility.cpp

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#include "utility.hpp"
#include <nlohmann/json.hpp>
 
namespace rendering_engine
{
using namespace boost::filesystem;
 
path const Utility::sDefaultShadersBinaryRelativePath = {"/Content/Shaders/"};
path const Utility::sContentRelativePathFolder = path{} / "Content";
path const Utility::sTextureRelativePathFolder = sContentRelativePathFolder / "Textures";
path const Utility::sModelsRelativePathFolder = sContentRelativePathFolder / "Models";
path const Utility::sShadersRelativePathFolder = sContentRelativePathFolder / "Shaders";
path const Utility:: sAppConfigFilePath = path{} / "Config" / "app_config.json";
 
path Utility::sShadersBinaryPath;
path Utility::sApplicationPath;
path Utility::sBuildPath;
 
static PackEntries sPackEntries;
static bool sPackEntriesLoaded = false;
path const Utility::sContentPackageFilePath = path{} / "Content" / "Pack.bin";
path const Utility::sContentPackEntriesFilePath = path{} / "Content" / "Pack.json";
 
void Utility::InitializePaths(int argc, char* argv[])
{
    sApplicationPath = boost::filesystem::path(argv[0]);
 
    sBuildPath = FindPath( "Build" );
    sShadersBinaryPath = sBuildPath += sDefaultShadersBinaryRelativePath;
}
 
AppConfig Utility::ReadConfigFile()
{
    AppConfig cfg;
 
    std::ifstream f(GetConfigFilePath().string());
    if (!f.is_open())
    {
        return cfg;
    }
 
    try
    {
        nlohmann::json appConfigData = nlohmann::json::parse(f);
 
        if (appConfigData.contains("appName"))
            cfg.appName = appConfigData["appName"].get<std::string>();
 
        if (appConfigData.contains("isFullScreen"))
            cfg.isFullScreen = appConfigData["isFullScreen"].get<bool>();
 
        if (appConfigData.contains("screenWidth"))
            cfg.screenWidth = appConfigData["screenWidth"].get<float>();
 
        if (appConfigData.contains("screenHeight"))
            cfg.screenHeight = appConfigData["screenHeight"].get<float>();
    }
    catch (const std::exception& e)
    {
        return cfg;
    }
 
    return cfg;
}
 
std::vector<char> Utility::ReadShaderBinaryFile( std::string const & filename )
{
    std::ifstream file(filename, std::ios::ate | std::ios::binary);
 
    if (!file.is_open()) 
    {
        throw std::runtime_error("failed to open shader binary file!");
    }
 
    size_t fileSize = (size_t) file.tellg();
    std::vector<char> buffer(fileSize);
 
    file.seekg(0);
    file.read(buffer.data(), fileSize);
 
    file.close();
 
    return buffer;
}
 
std::vector<std::string> Utility::GetListOfFilesInDirectory( std::string directory )
{
    std::vector<std::string> shaderFileNames;
 
    try
    {
        //check if parameter string is directory
        if( boost::filesystem::exists( boost::filesystem::path( directory ) ) && boost::filesystem::is_directory( boost::filesystem::path( directory ) ) )
        {
            boost::filesystem::path pathToDirectory = boost::filesystem::path( directory );
 
            if( boost::filesystem::is_directory( pathToDirectory ) )
            {
                for( boost::filesystem::directory_entry& x : boost::filesystem::directory_iterator( pathToDirectory ) )
                {
                    size_t dot = x.path().string().find_last_of( "." );
 
                    if( std::string{ "spv" } == x.path().string().substr( dot + 1 ) )
                    {
                        std::cout << "Shader binary file: " << x.path().string() << "\n";
                        shaderFileNames.push_back( x.path().string() );
                    }
                }
            }
        }
    }
    catch( const boost::filesystem::filesystem_error& ex )
    {
        std::cout << ex.what() << '\n';
    }
 
    return shaderFileNames;
}
 
boost::filesystem::path Utility::GetApplicationPath()
{
    return sApplicationPath;
}
 
boost::filesystem::path Utility::GetBuildPath()
{
    return sBuildPath;
}
 
boost::filesystem::path Utility::GetShadersBinaryPath()
{
    return sShadersBinaryPath;
}
 
 
boost::filesystem::path Utility::FindPath(std::string fileOrFolderName, std::string searchingFrom)
{
    boost::filesystem::path result;
    for( boost::filesystem::directory_entry& x : boost::filesystem::directory_iterator(searchingFrom) )
    {
        if( x.path().filename().string() == fileOrFolderName )
        {
            result = x.path().generic_path();
        }
    }
    return result;
}
 
std::vector<std::string> Utility::GetListOfFileNamesInDirectory(const char* directory, std::string extToSearch)
{
    std::vector<std::string> imageFileNames;
 
    try
    {
        //check if parameter string is directory
        if( boost::filesystem::exists(boost::filesystem::path(directory)) && boost::filesystem::is_directory(boost::filesystem::path(directory)) )
        {
            boost::filesystem::path pathToDirectory = boost::filesystem::path(directory);
 
            if( boost::filesystem::is_directory(pathToDirectory) )
            {
                for( boost::filesystem::directory_entry& x : boost::filesystem::directory_iterator(pathToDirectory) )
                {
                    size_t dot = x.path().string().find_last_of(".");
 
                    if( extToSearch == x.path().string().substr(dot + 1) )
                    {
                        imageFileNames.push_back(x.path().string());
                    }
                }
            }
        }
    }
    catch( const boost::filesystem::filesystem_error& ex )
    {
        std::cout << ex.what() << '\n';
    }
 
    return imageFileNames;
}
 
boost::filesystem::path Utility::ResolveProjectRoot()
{
    auto exeDir = boost::filesystem::canonical(boost::filesystem::path(boost::filesystem::current_path())); // default
    if (exeDir.filename() == "Debug" || exeDir.filename() == "Release")
        exeDir = exeDir.parent_path(); // step out of Debug/Release
    if (exeDir.filename() == "Binaries")
        exeDir = exeDir.parent_path(); // step out of Binaries
    return exeDir;
}
 
boost::filesystem::path Utility::GetTextureFolderPath()
{
    return ResolveProjectRoot() / sTextureRelativePathFolder;
}
 
boost::filesystem::path Utility::GetModelsFolderPath()
{
    return ResolveProjectRoot() / sModelsRelativePathFolder;
}
 
boost::filesystem::path Utility::GetShadersFolderPath()
{
    return ResolveProjectRoot() / sShadersRelativePathFolder;
}
 
boost::filesystem::path Utility::GetConfigFilePath()
{
    return ResolveProjectRoot() / sAppConfigFilePath;
}
 
bool Utility::IsPackageProvided()
{
    const auto root = ResolveProjectRoot();
    return boost::filesystem::exists(root / sContentPackageFilePath) &&
        boost::filesystem::exists(root / sContentPackEntriesFilePath);
}
 
const PackEntries& Utility::GetPackEntries()
{
    if (sPackEntriesLoaded)
        return sPackEntries;
 
    sPackEntries.clear();
 
    // Path to Pack.json
    const boost::filesystem::path jsonPath = ResolveProjectRoot() / sContentPackEntriesFilePath;
 
    if (!boost::filesystem::exists(jsonPath))
    {
        sPackEntriesLoaded = true;
        return sPackEntries; // empty
    }
 
    // Load JSON
    std::ifstream f(jsonPath.string());
    if (!f.is_open())
    {
        std::cerr << "[ERROR] Failed to open Pack.json\n";
        sPackEntriesLoaded = true;
        return sPackEntries;
    }
 
    nlohmann::json j;
    f >> j;
 
    // Parse entries
    for (auto it = j.begin(); it != j.end(); ++it)
    {
        PackEntry entry;
        entry.offset = it.value().value("offset", 0);
        entry.size = it.value().value("size", 0);
        sPackEntries[it.key()] = entry;
    }
 
    sPackEntriesLoaded = true;
    return sPackEntries;
}
 
std::vector<uint8_t> Utility::ReadPackedFile(const std::string& entryPath)
{
    std::vector<std::uint8_t> data;
 
    if (!IsPackageProvided())
        return data;
 
    const path binPath = ResolveProjectRoot() / sContentPackageFilePath;
    const path jsonPath = ResolveProjectRoot() / sContentPackEntriesFilePath;
 
    if (!boost::filesystem::exists(binPath) ||
        !boost::filesystem::exists(jsonPath))
    {
        std::cerr << "[Utility::ReadPackedFile] Missing Pack.bin or Pack.json\n";
        return data;
    }
 
    GetPackEntries();
    // Check if this entry exists in Pack.json
    auto it = sPackEntries.find(entryPath);
    if (it == sPackEntries.end())
    {
        std::cerr << "[Utility::ReadPackedFile] No such packed entry: "
            << entryPath << std::endl;
        return data; // empty
    }
 
    const PackEntry& entry = it->second;
 
    std::ifstream bin(binPath.string(), std::ios::binary);
    if (!bin)
    {
        std::cerr << "[Utility::ReadPackedFile] Failed to open Pack.bin: "
            << binPath.string() << std::endl;
        return data;
    }
 
    // Read the memory region [offset, offset + size)
 
    data.resize(entry.size);
 
    bin.seekg(entry.offset, std::ios::beg);
    if (!bin.good())
    {
        std::cerr << "[Utility::ReadPackedFile] Seek error for entry: "
            << entryPath << std::endl;
        return {};
    }
 
    bin.read(reinterpret_cast<char*>(data.data()), entry.size);
    if (!bin.good())
    {
        std::cerr << "[Utility::ReadPackedFile] Read error for entry: "
            << entryPath << std::endl;
        return {};
    }
 
    return data;
}
 
}