FeatherMC/src/world/RegionFile.h

#pragma once
#include "Common.h"
#include "Types.h"

#include <string>
#include <iostream>
#include <fstream>

namespace Feather
{
	class RegionFile
	{
		char m_header[8KB];
		int32_t m_offsets[1KB];

		// TEMP
		std::ifstream* m_stream;

		std::string m_path;

		inline int GetOffsetIndex(RegionLocalPos pos) { return pos.x + pos.z * 32; }
	public:
		RegionFile(std::string path);

		// Packed data about the offset into the region file to parse chunk data from
		inline int GetOffset(RegionLocalPos pos) { return m_offsets[GetOffsetIndex(pos)]; }

		// Contains data for this chunk?
		inline bool HasChunk(ChunkPos pos) { return GetOffset(RegionLocalPos(pos)) != 0; }

		// TEMP
		std::ifstream* GetChunkStream(RegionLocalPos pos) {
			m_stream->seekg(GetSectorNumber(GetOffset(pos)));
			return m_stream;
		}

		// Unpack sector num from result of GetOffset()
		static int GetSectorNumber(int packedOffset) { return (packedOffset >> 8) * 4096; }

		// Unpack sector count from result of GetOffset()
		static int GetSectorCount(int packedOffset) { return packedOffset & 0xFF; }
	};
}