Function P_OpenMapData

src/p_openmap.cpp:114–376

//===========================================================================

MapData *P_OpenMapData(const char * mapname, bool justcheck)
{
	MapData * map = new MapData;
	FileReader * wadReader = nullptr;
	bool externalfile = !strnicmp(mapname, "file:", 5);
	
	if (externalfile)
	{
		mapname += 5;
		if (!FileExists(mapname))
		{
			delete map;
			return NULL;
		}
		map->resource = FResourceFile::OpenResourceFile(mapname);
		wadReader = map->resource->GetContainerReader();
	}
	else
	{
		FString fmt;
		int lump_wad;
		int lump_map;
		int lump_name = -1;
		
		// Check for both *.wad and *.map in order to load Build maps
		// as well. The higher one will take precedence.
		// Names with more than 8 characters will only be checked as .wad and .map.
		if (strlen(mapname) <= 8) lump_name = fileSystem.CheckNumForName(mapname);
		fmt.Format("maps/%s.wad", mapname);
		lump_wad = fileSystem.CheckNumForFullName(fmt.GetChars());
		fmt.Format("maps/%s.map", mapname);
		lump_map = fileSystem.CheckNumForFullName(fmt.GetChars());
		
		if (lump_name > lump_wad && lump_name > lump_map && lump_name != -1)
		{
			int lumpfile = fileSystem.GetFileContainer(lump_name);
			int nextfile = fileSystem.GetFileContainer(lump_name+1);

			map->lumpnum = lump_name;

			if (lumpfile != nextfile)
			{
				// The following lump is from a different file so whatever this is,
				// it is not a multi-lump Doom level so let's assume it is a Build map.
				map->MapLumps[0].Reader = fileSystem.ReopenFileReader(lump_name);
				if (!P_IsBuildMap(map))
				{
					delete map;
					return NULL;
				}
				return map;
			}

			// This case can only happen if the lump is inside a real WAD file.
			// As such any special handling for other types of lumps is skipped.
			map->MapLumps[0].Reader = fileSystem.ReopenFileReader(lump_name);
			strncpy(map->MapLumps[0].Name, fileSystem.GetFileFullName(lump_name), 8);
			map->InWad = true;