Add support for packed clients (#802)

* First iteration of pack reader and interface

* Fix memory leak and remove logs

* Complete packed asset interface and begin on file loading replacement

* Implement proper BinaryIO error

* Improve AssetMemoryBuffer for reading and implement more reading

* Repair more file loading code and improve how navmeshes are loaded

* Missing checks implementation

* Revert addition of Manifest class and migration changes

* Resolved all feedback.

dCommon/dClient/Pack.cpp

@@ -0,0 +1,118 @@
+#include "Pack.h"
+
+#include "ZCompression.h"
+
+Pack::Pack(const std::filesystem::path& filePath) {
+	m_FilePath = filePath;
+
+	if (!std::filesystem::exists(filePath)) {
+		return;
+	}
+
+	m_FileStream = std::ifstream(filePath, std::ios::in | std::ios::binary);
+
+	m_FileStream.read(m_Version, 7); 
+
+	m_FileStream.seekg(-8, std::ios::end); // move file pointer to 8 bytes before the end (location of the address of the record count)
+
+	uint32_t recordCountPos = 0;
+	BinaryIO::BinaryRead<uint32_t>(m_FileStream, recordCountPos);
+
+	m_FileStream.seekg(recordCountPos, std::ios::beg);
+
+	BinaryIO::BinaryRead<uint32_t>(m_FileStream, m_RecordCount);
+
+	for (int i = 0; i < m_RecordCount; i++) {
+		PackRecord record;
+		BinaryIO::BinaryRead<PackRecord>(m_FileStream, record);
+
+		m_Records.push_back(record);
+	}
+
+	m_FileStream.close();
+}
+
+bool Pack::HasFile(uint32_t crc) {
+	for (const auto& record : m_Records) {
+		if (record.m_Crc == crc) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+bool Pack::ReadFileFromPack(uint32_t crc, char** data, uint32_t* len) {
+	// Time for some wacky C file reading for speed reasons
+
+	PackRecord pkRecord{};
+
+	for (const auto& record : m_Records) {
+		if (record.m_Crc == crc) {
+			pkRecord = record;
+			break;
+		}
+	}
+
+	if (pkRecord.m_Crc == 0) return false;
+
+	size_t pos = 0;
+	pos += pkRecord.m_FilePointer;
+
+	bool isCompressed = (pkRecord.m_IsCompressed & 0xff) > 0;
+	auto inPackSize = isCompressed ? pkRecord.m_CompressedSize : pkRecord.m_UncompressedSize;
+
+	FILE* file;
+#ifdef _WIN32
+	fopen_s(&file, m_FilePath.string().c_str(), "rb");
+#elif __APPLE__
+	// macOS has 64bit file IO by default
+	file = fopen(m_FilePath.string().c_str(), "rb");
+#else
+	file = fopen64(m_FilePath.string().c_str(), "rb");
+#endif
+
+	fseek(file, pos, SEEK_SET);
+
+	if (!isCompressed) {
+		char* tempData = (char*)malloc(pkRecord.m_UncompressedSize);
+		fread(tempData, sizeof(uint8_t), pkRecord.m_UncompressedSize, file);
+
+		*data = tempData;
+		*len = pkRecord.m_UncompressedSize;
+		fclose(file);
+
+		return true;
+	}
+
+	pos += 5; // skip header
+
+	fseek(file, pos, SEEK_SET);
+
+	char* decompressedData = (char*)malloc(pkRecord.m_UncompressedSize);
+	uint32_t currentReadPos = 0;
+
+	while (true) {
+		if (currentReadPos >= pkRecord.m_UncompressedSize) break;
+
+		uint32_t size;
+		fread(&size, sizeof(uint32_t), 1, file);
+		pos += 4; // Move pointer position 4 to the right
+
+		char* chunk = (char*)malloc(size);
+		fread(chunk, sizeof(int8_t), size, file);
+		pos += size; // Move pointer position the amount of bytes read to the right
+
+		int32_t err;
+		currentReadPos += ZCompression::Decompress((uint8_t*)chunk, size, reinterpret_cast<uint8_t*>(decompressedData + currentReadPos), ZCompression::MAX_SD0_CHUNK_SIZE, err);
+
+		free(chunk);
+	}
+
+	*data = decompressedData;
+	*len = pkRecord.m_UncompressedSize;
+
+	fclose(file);
+
+	return true;
+}