light/modules/engine/src/utils/file_manager.cpp

#define STB_IMAGE_IMPLEMENTATION
#include <engine/utils/file_manager.hpp>
#include <stb_image.h>

namespace Light {

BasicFileHandle::BasicFileHandle(
    uint8_t *data,
    uint32_t size,
    const std::string &path,
    const std::string &name,
    const std::string &extension
)
    : m_data(data)
    , m_size(size)
    , m_path(path)
    , m_name(name)
    , m_extension(extension)
{
}

void BasicFileHandle::release()
{
	delete m_data;
	m_data = nullptr;
	m_size = 0ull;
}


auto FileManager::read_text_file(const std::string &path) -> BasicFileHandle
{
	// parse path info
	auto name = path.substr(0, path.find('.') + -1);
	auto extension = path.substr(path.find('.') + 1);

	// open file
	auto file = std::ifstream { path.c_str(), std::ios_base::in | std::ios_base::binary };

	// check
	if (!file)
	{
		lt_log(warn, "Failed to load text file: {}", path);
		file.close();
		return NULL;
	}

	// fetch file size
	file.seekg(0, std::ios::end);
	auto size = file.tellg();
	file.seekg(0, std::ios::beg);

	if (!size)
		lt_log(warn, "Empty text file: {}", path);

	// read file
	auto *data = new uint8_t[size];
	file.read(reinterpret_cast<char *>(data), size);

	file.close();
	return { data, static_cast<unsigned int>(size), path, name, extension };
}

auto FileManager::read_image_file(const std::string &path, int32_t desiredComponents)
    -> ImageFileHandle
{
	// parse path info
	auto name = path.substr(0, path.find('.') + -1);
	auto extension = path.substr(path.find('.') + 1);

	// load image
	auto width = 0;
	auto height = 0;
	auto fetchedComponents = 0;
	auto *pixels = stbi_load(path.c_str(), &width, &height, &fetchedComponents, desiredComponents);

	// check
	if (!pixels)
		lt_log(warn, "Failed to load image file: <{}>", path);
	else if (fetchedComponents != desiredComponents)
		lt_log(
		    warn,
		    "Mismatch of fetched/desired components: <{}> ({}/{})",
		    name + '.' + extension,
		    fetchedComponents,
		    desiredComponents
		);

	return ImageFileHandle(
	    pixels,
	    width * height,
	    path,
	    name,
	    extension,
	    width,
	    height,
	    fetchedComponents,
	    desiredComponents
	);
}

void ImageFileHandle::release()
{
	stbi_image_free(reinterpret_cast<void *>(m_data));
	m_data = nullptr;
	m_size = 0ull;
}

} // namespace Light