Editing Paired ARC+DIR file

'''ARC''' files (likely short for '''Archive''') and '''DIR''' files (technically short for '''Bundle''', though '''Directory''' makes more sense and avoids conflict with [[BUN file|'''BUN''' files]]) are two peas in a pod, together representing one of the many Binary Large Object (BLOB) archive formats used in ''[[Pikmin]]''.  Together, they will henceforth be referred to as the ''paired ARC+DIR file'' archive.

With minimal metadata, {{unsure|the paired ARC+DIR file archive was likely used to reduce load time by packing several files into one}}.  The purpose it serves is different from the [[BUN file|bundle]] archive, however, {{unsure|as standalone files within the archive can be unpacked independently of the files before it}}.  This makes the paired ARC+DIR file useful for archiving large directories with varied purposes.

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== File structure ==
As mentioned before, the paired ARC+DIR file archive consists of two files: the mock-directory (DIR) and the BLOB archive (ARC).  Think of the mock-directory as a map to navigate through the BLOB archive.

=== DIR ===
DIR files consist of a header followed by a repeating struct for each mock-filepath.

Here is <code>/dataDir/archives/pelletsbin.dir</code> annotated for reference.

[[File:DIR_file_documentation.png]][[File:Minty_Meeo_Documentation_Legend.png]]

{| class="wikitable" 
|+ Header
! Offset	|| Size		|| Purpose
|-
| 0x00		|| 4 		|| Size of DIR file	
|-
| 0x04		|| 4 		|| Number of structs	
|-
|}

{| class="wikitable" 
|+ Mock-directory struct
! Offset	|| Size		|| Purpose
|-
| 0x00		|| 4 		|| Offset of file in ARC	
|-
| 0x04		|| 4 		|| Size of file in ARC		
|-
| 0x08		|| 4	 	|| Mock-directory string length	
|-
| 0x0C		|| 0x08 value 	|| Mock-directory path		
|-
|}

==== Mock-directory ====
The DIR file emulates filepaths.  When a file is unpacked in-game, it is assumed that whatever code is responsible treats the entry in the DIR file as a legitimate filepath on the disc, starting from the root.

=== ARC ===
Here is <code>/dataDir/archives/pelletsbin.arc</code> annotated to demonstrate searching the BLOB archive.  Without the DIR file as a guide, the only way you could possibly differentiate between files would be with the <code>0xCC</code> padding between files.

[[File:ARC_file_documentation.png]][[File:Minty_Meeo_Documentation_Legend.png]]

==== <code>0xCC</code> padding ====
For whatever reason, files in the ARC are always padded out to have an amount of bytes that is a multiple of 32.  These bytes are not included in the file size recorded in the DIR for each file, so the exact purpose of this is unknown.  {{unsure|It could be an absolute necessity, or it could be completely unnecessary.}}

== Extra information ==
Every paired ARC+DIR file archive has an uncompressed copy elsewhere on the disc.
* In <code>/dataDir/tekis</code> and <code>/dataDir/bosses</code>, a file named <code>arc_all.ini</code> can be found.  These INI files holds nothing, but give us a hint at how the developer's archiving tool functioned.
* It is unknown if every file in the archives is identical to its uncompressed sister file.
In the [[OpenGL / Dolphin System]], many files are not read from the paired ARC+DIR file archives like they are in the final game, and are instead read from the un-archived versions.  

Paired ARC+DIR file archives that have "bin" in their filename curiously only contain the '''BIN''' files from their respective directory.

The <code>log.txt</code> files left in the root of [[Pikmin|''Pikmin'' versions USA Demo, USA v1.00, and JPN v1.02]] detail the plugin "[[OpenGL / Dolphin System|plugTexConv]]" creating a paired ARC+DIR file archive.

{{Credits|[[User:Minty_Meeo|Minty_Meeo]]}}

[[Category:Pikmin]]
[[Category:File formats]]