Trying to understand ZLib

Ok, I've been trying to get my head around using the zlib compression. These are the routines I've come up with, which are intened to turn arrays of bytes, ints and strings into compressed arrays (of bytes), and then back again. It seems to work here, but if someone who understands this properly could take a look, I'd be grateful.

Strict

'------------------------------------------------------------------------------
'------------------------------------------------------------------------------
'  BYTES
'------------------------------------------------------------------------------
'------------------------------------------------------------------------------

Function CompressBytes:Byte[](Bytes:Byte[],CompressLevel=9)

	Local length = Len(Bytes) * 2

	Local Compressed:Byte[length]
	
	Compressed[0] = Len(Bytes) & $FF
	Compressed[1] = (Len(Bytes) Shr 8) & $FF
	Compressed[2] = (Len(Bytes) Shr 16) & $FF

	Local DataPointer:Byte Ptr
	Local CompPointer:Byte Ptr
	
	DataPointer = Bytes
	CompPointer = Compressed
	CompPointer :+ 3
	
	compress2(CompPointer,length, DataPointer,Len(Bytes), CompressLevel)
		
	Return Compressed[..(length-1+3)]

End Function

Function DecompressBytes:Byte[](Compressed:Byte[])

	Local Size = Compressed[0] + (Compressed[1] Shl 8) + (Compressed[2] Shl 16)

	Local length = Size+1

	Local Uncompressed:Byte[length]

	Local CompPointer:Byte Ptr
	Local DataPointer:Byte Ptr

	CompPointer = Compressed
	CompPointer :+ 3
	DataPointer = Uncompressed
		
	uncompress(DataPointer,length, CompPointer,Len(Compressed))
		
	Return Uncompressed[..(length-1)]

End Function

'------------------------------------------------------------------------------
'------------------------------------------------------------------------------
'  INTS
'------------------------------------------------------------------------------
'------------------------------------------------------------------------------

Function CompressInts:Byte[](Ints:Int[],CompressLevel=9)

	Local length = Len(Ints) * 6

	Local Compressed:Byte[length]

	Compressed[0] = Len(Ints) & $FF
	Compressed[1] = (Len(Ints) Shr 8) & $FF
	Compressed[2] = (Len(Ints) Shr 16) & $FF

	Local DataPointer:Byte Ptr
	Local CompPointer:Byte Ptr
	
	DataPointer = Ints
	CompPointer = Compressed
	CompPointer :+ 3
	
	compress2(CompPointer,length, DataPointer,Len(Ints) * 4, CompressLevel)
		
	Return Compressed[..(length-1+3)]

End Function

Function DecompressInts:Int[](Compressed:Byte[])

	Local Size = Compressed[0] + (Compressed[1] Shl 8) + (Compressed[2] Shl 16)

	Local length = Size * 4

	Local Uncompressed:Int[Size]

	Local CompPointer:Byte Ptr
	Local DataPointer:Byte Ptr

	CompPointer = Compressed
	CompPointer :+ 3
	DataPointer = Uncompressed
		
	uncompress(DataPointer,length, CompPointer,Len(Compressed))
		
	Return Uncompressed

End Function

'------------------------------------------------------------------------------
'------------------------------------------------------------------------------
'  STRINGS
'------------------------------------------------------------------------------
'------------------------------------------------------------------------------

Function CompressStrings:Byte[](Strings:String[],CompressLevel=9)

	Local TotalSize = 2

	TotalSize :+ Len(Strings) * 2

	Local i:Int

	For i = 0 To Len(Strings)-1
		TotalSize :+ Len(Strings[i])
	Next

	Local StringsBank:TBank = CreateBank(TotalSize)

	Local StringBankStream:TBankStream = CreateBankStream(StringsBank)

	WriteShort StringBankStream, Len(Strings)

	For i = 0 To Len(Strings)-1
		WriteShort StringBankStream, Len(Strings[i])
		WriteString StringBankStream, Strings[i]
	Next

	SeekStream StringBankStream,0

	Local Byted:Byte[] = LoadStream(StringBankStream)

	CloseStream(StringBankStream)

	Return CompressBytes(Byted)

End Function

Function DecompressStrings:String[](Compressed:Byte[])

	Local Byted:Byte[] = DecompressBytes(Compressed)

	Local StrCount = Byted[0] + (Byted[1] Shl 8)

	Local Strings:String[StrCount]

	Local p = 2
	Local i:Int, j:Int, Length:Int

	For i = 0 To (StrCount-1)
		Length = Byted[p] + (Byted[p+1] Shl 8)
		p :+ 2
		Strings[i] = ""
		For j = 0 To (Length-1)
			Strings[i] :+ Chr$(Byted[p+j])
		Next
		p :+ Length
	Next

	Return Strings

End Function

I gave it up to understand the docs of Zlib.

http://www.blitzbasic.com/Community/posts.php?topic=41626

An you'll be fine.... :)