TGDB.net - Game news, cheats, solutions, walkthroughs, trainers, saved games and much more!

COMMAND & CONQUER FILE FORMATS

Revision 4

by Vladan Bato (bat22@geocities.com)

This document explains the file formats used by Command & Conquer.

Command & Conquer is a tradmark of Westwood Studios, Inc.
Command & Conquer is Copyright (C)1995 Westwood Studios, Inc.

The information provided here is meant for programmers that want to make
editor and utilites for Command & Conquer. My explanation might not be
the best one, but it should be enough.

I can't guarantee that the information in here is correct. If you find any
errors, please report them to me.

In this document I'll use Pascal notation, and any code samples will be in
Pascal....
I wanted to rewrite them in C, but I don't have the time to test the code.
So, to avoid any risks, I'll use the code from Mix Manager.

In case you don't know, the information contained here has been used to
make the program Mix Manager, which contains a lot of conversion utilities
for the various formats. For more info, check my homepage (see the end of
the document).

===================
1. THE .MIX FILES
===================

You probably already know the format of these files, but I will add a
description here for completeness.

The MIX file consists of two parts :
-A header including the index of all the files contained within
-A body containing all the files

It's format is :

Header : record
NumFiles : word; {Number of files in MIX}
DataSize : longint; {Size of body}
Index : array [1..NumFiles] of
record
ID : longint; {File ID}
Start : longint; {Offset of file from the start of the
body}
Size : longint; {file size}
end;
end;

The ID field is computed from the original filename, which is not stored in
the MIX.
The records are always sorted by the ID field (the numbers are signed
longints).
Note that the offsets are relative to the start of the body so to find the
actual offset in the MIX you have to add the size of the header which is
NumFiles*12+6

===================
2. THE .PAL FILES
===================

The most easiest files....
These files contain the palette in the same format used by VGA cards.

Palette : array [0..255] of record
red,green,blue:byte;
end;

Note that only the first 6 bits of each number are used, giving a total of
262144 possible colors (as opposed to the 8 bits used by .PCX files for
example).

=================================
3. THE TEMPLATE AND .BIN FILES
=================================

The Template files contain the map graphics, and can be found in the
theater specific MIX files (TEMPERAT.MIX, WINTER.MIX, DESERT.MIX).
The .BIN files contain the maps for the missions and are used in conjunction
with the .INI files.

I won't explain them here. They are explained with great detail in the
document titled "Command & Conquer maps" I wrote some time ago.
The said document can be found on my homepage.

===================
5. THE .SHP FILES
===================

The .SHP files contain almost all the graphics : units, structures,
trees,...
The header has the following structure :

Header : record
NumImages : word; {Number of images}
A,B : word; {Unknown}
Width,
Height : word; {Width and Height of the images}
C : longint; {Unknown}
end;

If you know something about those unknown fields, please e-mail me.
Following that there's an array of records, one for each image :

Offsets : array [0..NumImages+1] of
record
Offset : longint; {Offset and format of image in file}
RefOffs : longint; {Offset and format of image on
which it is based}
end;

The most significant byte (last) of the Offset and RefOffs fields
contains the format, while the lower three are used for the offset.
The format byte can have one of the three values : 80h, 40h, 20h.
I will call the three image formats Format80, Format40 and Format20.

The Format80 images are compressed with a compression method I'll explain
later.

The Format40 images must be xor-ed with a Format80 image. That's what the
RefOffs field is used for. It tells which Format80 image they are
based upon. The Format40 will be explained in detail later.

The Format20 images use the same format as the Format40, the difference is
that they are xor-ed with the image that precedes them in the file. That can
be either in Format20 or in Format40.
The offset part of the RefOffs field contains the number of the first
Format40 image in the chain, and the format field is always 48h.

Here's an example :

0) Off0(three bytes) 80h 000000h 00h
1) Off1(three bytes) 80h 000000h 00h
2) Off2(three bytes) 40h Off1 80h
3) Off3(three bytes) 80h 000000h 00h
4) Off4(three bytes) 40h Off1 80h
5) Off5(three bytes) 20h 000400h 48h
6) Off6(three bytes) 20h 000400h 48h
7) Off7(three bytes) 40h Off3 80h

For example to draw image 7, you have to draw the image 3 first (whose
offset
and format are given) and then xor image 7 over it.

To draw image 6, you have to xor it over the previous image, i.e. 5, which
is format20 again, that means that it has to be xor-ed over image 4, which
is in format40, i.e. it must be xor-ed over the image in format80 it has a
reference to. In this case it's image 1. Thus the chain is 1,4,5,6.
This is one way to see it, the other could be :
Image 6 is in Format20, the RefOffs field contains the number of the first
Format40 image in the chain, in this case image 4. To draw Image 4, the
Image 1 has to be drawn first, next is image 4, and then all the images
from the 4th to the 6th have to be xor-ed over the previous.

I made some experiments and found out that you don't have to use the
Format40 and Format20 images. I tried converting all of them into Format80
and it worked.

Also, when changing graphics, note that all the unit and structure graphics
should be drawn using the GDI colors, which will be automatically converted
for the other sides.
The palette you should use is one of those found in DESERT.MIX, WINTER.MIX
and TEMPERAT.MIX. The GDI colors are colors 0B0h-0BFh. The other colors
won't be converted and will remain the same for all the sides (be sure to
use only the colors that are the same all three palettes).

The above applies only to the graphics that appear in all three theaters
(the .SHP file found in CONQUER.MIX). The graphics for the structures and
overlays that appear in a single theater (found inside the theater specific
MIX) can use the palette entries that are unique for that theater (and will
be shown with garbled colors in the others).

Also a special color is used for shadows. It's color 04h. In the palettes
it's bright green, but C&C puts a shadow instead of it. I don't know how
the shadows are calculated however.

You should've noticed that the array has NumImages+2 elements when only
NumImages elements are needed. The last one contains zeros, and the one
before
that points to the end of the file. These two can be used to identify the
file as a .SHP.

Here's the description of the compression formats : Format80 and Format40.

----------
Format80
----------

There are several different commands, with different sizes : form 1 to 5
bytes.
The positions mentioned below always refer to the destination buffer (i.e.
the uncompressed image). The relative positions are relative to the current
position in the destination buffer, which is one byte beyond the last
written
byte.

I will give some sample code at the end.

(1) 1 byte
+---+---+---+---+---+---+---+---+
| 1 | 0 | | | | | | |
+---+---+---+---+---+---+---+---+
\_______________________/
|
Count

This one means : copy next Count bytes as is from Source to Dest.

(2) 2 bytes
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| 0 | | | | | | | | | | | | | | | | |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
\___________/\__________________________________________________/
| |
Count-3 Relative Pos.

This means copy Count bytes from Dest at Current Pos.-Rel. Pos. to
Current position.
Note that you have to add 3 to the number you find in the bits 4-6 of the
first byte to obtain the Count.
Note that if the Rel. Pos. is 1, that means repeat Count times the
previous
byte.

(3) 3 bytes
+---+---+---+---+---+---+---+---+ +---------------+---------------+
| 1 | 1 | | | | | | | | | |
+---+---+---+---+---+---+---+---+ +---------------+---------------+
\_______________________/ Pos
|
Count-3

Copy Count bytes from Pos, where Pos is absolute from the start of the
destination buffer. (Pos is a word, that means that the images can't be
larger than 64K)

(4) 4 bytes
+---+---+---+---+---+---+---+---+ +-------+-------+ +-------+
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | | | | | |
+---+---+---+---+---+---+---+---+ +-------+-------+ +-------+
Count Color

Write Color Count times.
(Count is a word, color is a byte)

(5) 5 bytes