Rem
This type allows us to implement the 'eachin' support for pak files.
files.
End Rem
Type TPakFileEnum
Field _index:Int
Field _pak:TPakFile
Method HasNext:Int()
Return _index < _pak.FileCount()
End Method
Method NextObject:Object()
Local value:Object = TPakFileChunk(_pak._fileList.ValueAtIndex(_index)).URL
_index :+ 1
Return value
End Method
End Type
Rem
This type allows the user to request files from the pak framework by using the pak:: protocol
when requesting streams.
End Rem
Type TPAKStreamFactory Extends TStreamFactory
Method CreateStream:TStream(url:Object,proto:String,path:String,readable:Int,writeable:Int)
If (proto.ToLower() = "pak")
' If a physical file exists, override the pak file.
If (FileType(path) = 1)
Return OpenStream(path, readable, writeable)
EndIf
' Look for file in pak files.
path = Replace(path, "/", "\")
For Local pak:TPakFile = EachIn TPakFile.PakFilePool
If (pak.ContainsFile(path))
Return CreateBankStream(pak.GetFileBank(path))
EndIf
Next
EndIf
End Method
End Type
New TPAKStreamFactory
Rem
This type stores details on an individual file chunk contained within a
pak file.
End Rem
Type TPakFileChunk
Field URL:String
Field DataOffset:Int
Field DataSize:Int
Rem
Saves this chunks data from a physical file to a bank, encrypts and compresses it, then
returns it in the form of a bank.
End Rem
Method CompileDataBank:TBank(encrypted:Int, compressed:Int, encryptionKey:String)
Local bank:TBank = LoadBank(URL)
If (bank = Null) Return Null
If (compressed = True)
bank = CompressBank(bank)
EndIf
If (encrypted = True)
bank = EncryptBank(bank, encryptionKey)
EndIf
Return bank
End Method
Rem
Loads this chunks data out of a given stream, encrypts and compresses it, then
returns it in the form of a bank.
End Rem
Method GetDataBank:TBank(mainStream:TStream, encrypted:Int, compressed:Int, encryptionKey:String)
' If this chunk is still waiting to be saved to a file, then
' you can get its data just by loading it out of the physical file.
If (DataSize = 0 And FileType(URL) = 1)
Return LoadBank(URL)
EndIf
Local bank:TBank = CreateBank(DataSize)
ReadBank(bank, mainStream, 0, DataSize)
If (encrypted = True)
bank = DecryptBank(bank, encryptionKey)
EndIf
If (compressed = True)
bank = DecompressBank(bank)
EndIf
Return bank
End Method
End Type
Rem
This type stores all the code used to access, save and load multiple files into
a single 'pak' file.
Files can also be encrypted, and compressed for security purposes.
End Rem
Type TPakFile
Global PakFilePool:TList = New TList
Field Encrypted:Int
Field EncryptionKey:String
Field Compressed:Int
Field _fileList:TList = New TList
Field _mainDataStream:TStream = Null
Field _mainDataOffset:Int = 0
Rem
Gets a bank that contains the data for the given file.
End Rem
Method GetFileBank:TBank(url:String)
For Local file:TPakFileChunk = EachIn _fileList
If (file.URL.ToLower() = url.ToLower())
SeekStream(_mainDataStream, _mainDataOffset + file.DataOffset)
Return file.GetDataBank(_mainDataStream, Encrypted, Compressed, EncryptionKey)
EndIf
Next
End Method
Rem
Returns the number of file chunks in this pak file.
End Rem
Method FileCount:Int()
Return _fileList.Count()
End Method
Rem
Clears all files out of this pak file.
End Rem
Method Clear()
_fileList.Clear()
End Method
Rem
Adds support to this type for enumeration. So that the user can use the eachin keyword
to iterate through all files in this pak file.
End Rem
Method ObjectEnumerator:TPakFileEnum()
Local enum:TPakFileEnum = New TPakFileEnum
enum._index = 0
enum._pak = Self
Return enum
End Method
Rem
Adds a reference to a physical file into this pak file. The file must
exist when and if Save is called so its data can be read.
End Rem
Method AddFile(url:String)
Local file:TPakFileChunk = New TPakFileChunk
file.URL = Replace(url, "/", "\")
ListAddLast(_fileList, file)
End Method
Rem
Removes a reference to a physical file from this pak file.
End Rem
Method RemoveFile(url:String)
For Local file:TPakFileChunk = EachIn _fileList
If (file.URL.ToLower() = url.ToLower())
ListRemove(_fileList, file)
EndIf
Next
End Method
Rem
Adds all the files within a directory into this pak file.
End Rem
Method AddDirectory(url:String)
url = StripSlash(url) + "/"
Local files:String[] = LoadDir(url, True)
For Local file:String = EachIn files
If (FileType(url + file) = 1)
AddFile(url + file)
Else If (FileType(url + file) = 2)
AddDirectory(url + file + "/")
EndIf
Next
End Method
Rem
Remove all the files within this pak file that are in the given directory.
End Rem
Method RemoveDirectory(url:String)
For Local file:TPakFileChunk = EachIn _fileList
If (StripSlash(ExtractDir(file.URL)).ToLower() = StripSlash(ExtractDir(url)).ToLower())
ListRemove(_fileList, file)
EndIf
Next
End Method
Rem
Returns true if the given file exists in this pak file.
End Rem
Method ContainsFile:Int(url:String)
url = Replace(url, "/", "\")
For Local file:TPakFileChunk = EachIn _fileList
If (file.URL.ToLower() = url.ToLower())
Return True
EndIf
Next
End Method
Rem
Saves this pak file to a physical file. All file that are referenced in
this pak file must exist for this function to operate correctly.
End Rem
Method Save(url:Object)
Local stream:TStream = WriteStream(url)
' Write in the header contains details on how
' this pak file is tored.
WriteString(stream, "PAK")
WriteByte(stream, Encrypted)
WriteByte(stream, Compressed)
WriteInt(stream, _fileList.Count())
Local offset:Int = 0
Local dataChunks:TList = New TList
' Write out the file table as well as working out
' file offsets and compiling the files data.
For Local file:TPakFileChunk = EachIn _fileList
' Compile this files data and add it to the chunk list.
Local dataBank:TBank = file.CompileDataBank(Encrypted, Compressed, EncryptionKey)
If (dataBank = Null)
Continue
EndIf
ListAddLast(dataChunks, dataBank)
' Write out the file table information for this file.
WriteInt(stream, file.URL.Length)
WriteString(stream, file.URL)
WriteInt(stream, offset)
WriteInt(stream, BankSize(dataBank))
offset :+ BankSize(dataBank)
Next
' Write out the data block which contains all the files data chunks
' appended together.
For Local data:TBank = EachIn dataChunks
WriteBank(data, stream, 0, BankSize(data))
Next
CloseStream(stream)
End Method
Rem
Loads this pak file from a physical file. No file data will actually be loaded
until the user requests it.
End Rem
Method Load(url:Object)
Local stream:TStream = ReadStream(url)
If (stream = Null) Return
' Make sure the header is there, if its not the file
' has been corrupted and we can ignore loading it.
If (ReadString(stream, 3) <> "PAK") Then Return
Encrypted = ReadByte(stream)
Compressed = ReadByte(stream)
Local fileCount:Int = ReadInt(Stream)
' Read in the file table.
For Local fileIndex:Int = 0 To fileCount - 1
Local url:String = ReadString(stream, ReadInt(stream))
Local offset:Int = ReadInt(stream)
Local size:Int = ReadInt(stream)
Local chunk:TPakFileChunk = New TPakFileChunk
chunk.URL = url
chunk.DataOffset = offset
chunk.DataSize = size
ListAddLast(_fileList, chunk)
Next
_mainDataOffset = StreamPos(stream)
_mainDataStream = stream
End Method
Rem
Initializes a new instance of this pak file and adds it to the
main pak file pool.
End Rem
Method New()
ListAddLast(PakFilePool, Self)
End Method
Rem
Disposes of all resources held by this pak file.
End Rem
Method Dispose()
If (_mainDataStream)
CloseStream(_mainDataStream)
_mainDataStream = Null
EndIf
ClearList(_fileList)
ListRemove(PakFilePool, Self)
End Method
End Type
Rem
Creates a new pak file instance.
End Rem
Function CreatePakFile:TPakFile()
Return New TPakFile
End Function
Rem
Loads a given pak file from the given url.
url : URL to load pak file from.
encryptionKey : If the pak file is encrypted this is the
key that will be used to decrypt it.
End Rem
Function LoadPakFile:TPakFile(url:Object, encryptionKey:String = "")
Local pak:TPakFile = New TPakFile
pak.EncryptionKey = encryptionKey
pak.Load(url)
Return pak
End Function
Rem
Saves a given pak file to the given url.
pak : Pak file to save.
url : URL to save pak file to.
compress : If set to true the pak file will be compressed.
encrypt : If set to true the pak file will be encrypted.
encryptionKey : If the pak file is being encrypted this is the key it will be encrypted with.
End Rem
Function SavePakFile(pak:TPakFile, url:Object, compress:Int = False, encrypt:Int = False, encryptionKey:String = "")
pak.Compressed = compress
pak.Encrypted = encrypt
pak.EncryptionKey = encryptionKey
pak.Save(url)
End Function
Rem
Clears all files out of the given pak file.
pak : Pak file to clear.
End Rem
Function ClearPakFile(pak:TPakFile)
pak.Clear()
End Function
Rem
Disposes of all resources in a given pak file.
pak : Pak file to dispose.
End Rem
Function DisposePakFile(pak:TPakFile)
pak.Dispose()
End Function
Rem
Returns true if the pak file contains the given file.
pak : Pak file to search.
url : URL of file to search for.
End Rem
Function PakFileContainsFile:Int(pak:TPakFile, url:String)
Return pak.ContainsFile(url)
End Function
Rem
Adds the given physical file to the pak file. The file must exist
when and if Save is called for it to be saved correctly.
pak : Pak file to clear.
url : URL of physical file to add to pak file.
End Rem
Function AddFileToPakFile(pak:TPakFile, url:String)
pak.AddFile(url)
End Function
Rem
Removes the given physical file from the pak file.
pak : Pak file to remove physical file from.
url : URL of physical file to remove.
End Rem
Function RemoveFileFromPakFile(pak:TPakFile, url:String)
pak.RemoveFile(url)
End Function
Rem
Adds the given directory and all the files contained in it to the pak file. The directory
and its files must exist when and if Save is called for it to be saved correctly.
pak : Pak file to clear.
url : URL of physical directory to add to pak file.
End Rem
Function AddDirToPakFile(pak:TPakFile, url:String)
pak.AddDirectory(url)
End Function
Rem
Removes the given physical directory from the pak file.
pak : Pak file to remove physical file from.
url : URL of physical directory to remove.
End Rem
Function RemoveDirFromPakFile(pak:TPakFile, url:String)
pak.RemoveDirectory(url)
End Function
Rem
Returns the amount of physical files contained in the given pak file.
pak : Pak file to count files.
End Rem
Function PakFileFileCount:Int(pak:TPakFile)
Return pak.FileCount()
End Function
Rem
Return a bank containing the data of the given physical file stored
in the given pak file.
pak : Pak file to extract data from.
url : URL of physical file to retrieve data for.
End Rem
Function PakFileGetFileBank:TBank(pak:TPakFile, url:String)
Return pak.GetFileBank(url)
End Function
Rem
Looks through all pak files, and all physical files for the given resource. If it exists
this function will return true, else false.
url : URL of resource file to look for.
End Rem
Function FileExists:Int(url:String)
url = Replace(url, "\", "/")
If (FileType(url) = 1) Return True
For Local pak:TPakFile = EachIn TPakFile.PakFilePool
If (pak.ContainsFile(url))
Return True
EndIf
Next
Return False
End Function
Rem
This function will compress a bank's data and return it in another bank.
Credit to Mark Sibly for this code.
End Rem
Function CompressBank:TBank(bank:TBank)
Local size:Int = bank.Size()
Local out_size:Int = size + size / 10 + 32
Local out:TBank = TBank.Create(out_size)
compress(out.Buf() + 4, out_size, bank.Buf(), size)
out.PokeByte(0, size)
out.PokeByte(1, size Shr 8)
out.PokeByte(2, size Shr 16)
out.PokeByte(3, size Shr 24)
out.Resize(out_size + 4)
Return out
End Function
Rem
This function will decompress a bank's data and returns it in another bank.
Credit to Mark Sibly for this code.
End Rem
Function DecompressBank:TBank(bank:TBank)
Local out_size:Int
out_size :| (bank.PeekByte(0))
out_size :| (bank.PeekByte(1) Shl 8)
out_size :| (bank.PeekByte(2) Shl 16)
out_size :| (bank.PeekByte(3) Shl 24)
Local out:TBank = TBank.Create(out_size)
uncompress(out.Buf(), out_size, bank.Buf() + 4, bank.Size() - 4)
Return out
End Function
Rem
This function will encrypt a bank using a simple XOr encryption algorithem and return
the encrypted data in another bank.
TODO: Use a less repetative, more powerfull encryption algorithem, XOr is near useless.
End Rem
Function EncryptBank:TBank(bank:TBank, key:String)
Local cryptBank:TBank = CreateBank(BankSize(bank))
For Local index:Int = 0 To BankSize(bank) - 1
Local plain:Int = PeekByte(bank, index)
Local keyIndex:Int = key[index Mod key.Length]
PokeByte(cryptBank, index, plain ~ keyIndex)
Next
Return cryptBank
End Function
Rem
This function will decrypt a bank using a simple XOr encryption algorithem and return
the decrypted data in another bank.
TODO: Use a less repetative, more powerfull encryption algorithem, XOr is near useless.
End Rem
Function DecryptBank:TBank(bank:TBank, key:String)
Return EncryptBank(bank, key) ' Encryption and decryption uses same algorithem.
End Function
Rem
Compiling pak file example
End Rem
' Create a new pak file and set it up as compressed.
Local pak:TPakFile = New TPakFile
pak.Compressed = True
' Add every file in our bin directory to the pak file.
pak.AddDirectory("Bin\")
' Save this pak file to a physical file.
pak.Save("game.dat")
' Dispose of resources held by pak file.
pak.Dispose()
Rem
Using pak file example
End Rem
' Create a new pak file and set it up as compressed.
Local pak:TPakFile = New TPakFile
pak.Compressed = True
' Load it from our file.
pak.Load("game.dat")
' Lets extract some resources from it.
local image:TImage = LoadImage("pak::Bin\Graphics\MyImage.png")
local sound:TSound = LoadSound("pak::Bin\Audio\MySound.wav")
' Dispose of resources held by pak file.
pak.Dispose() |
