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                                Dirt Track Racing

                         Copyright + 1999 Ratbag, Pty Ltd.

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1. Introduction
2. Disclaimer
3. Running the extractpf Utility
4. An Example
5. Anticipated Frequently Asked Questions

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   1. Introduction
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Most of the game data for Dirt Track Racing (DTR) is stored in three files,
data.pf, min.pf and store.pf (.pf stands for Packed File). The data.pf file 
will be on the CD if you chose to do a minimal installation. 

Some data, such as saved games, are stored un-packed in the data subdirectory 
of the DTR directory. However, other files can also be placed in the data
directory, and the game will use them. This means you can create your own 
data files (for example a new skin for a car), and then select it in DTR.

This readme explains how this can be done.

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   2. Disclaimer
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Ratbag can not offer any support if you use this method to modify your copy
of DTR. If you have any problems or questions relating to adding your own
data, please do not post them directly to Ratbag or DTR's publisher. 

Instead, please post them to a forum or a newsgroup. Other people who have
encountered the same problems may be able to help you.

It is recommended that only experienced computer users should attempt to 
modify DTR's data. If you have problems with DTR after adding your own data, 
you should delete and reinstall the game. You will however lose all of your 
saved games and records.

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   3. Running the extractpf Utility
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Being able to add your own data doesn't help much if you don't know what to
add... Therefore, the extractpf.exe utility also included in this directory
is provided. It can be used to unpack the data.pf, min.pf and store.pf files.
This will provide a template for you to create your own data files.

The basic syntax for running extract.pf is (from an MSDOS prompt):

extractpf <filename>.pf

This will then create all of the files in the packed file, in a subdirectory
of the current directory.

It is recommended that you don't unpack the data files from the directory
to which they are installed. This will unpack the files to a location spread
through your actual game data, making it confusing to work out what was the
original data, and what is your new data.

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   4. An Example
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The most common use of this feature of DTR will be to create your own skin
(paintjob) for a car. This section of this readme will go through all of the
steps to do this.

First, we need to unpack the original data files. We will begin by copying
them all to a directory. From an MSDOS prompt:

C:
cd\
md dtr_test
cd dtr_test
copy D:\Data\data.pf
copy D:\Data\min.pf
copy D:\Data\store.pf

Where D: is your CDROM drive. Make sure you have enough space on your C:
drive (or whichever drive you use) first. The above commands copy the data
files from the DTR CD - you could instead copy them from the installation
directory on your hard drive. Note that store.pf on the CD will be in the
original condition, whereas store.pf on your hard drive will be modified
with your preferences and other data.

Now to unpack the data files. Since the data is spread across all 3 of the 
.pf files, you need to unpack all 3 to get a complete set of data. Unpacking
the files will take up roughly the same amount of disk space as the original
packed files, so make sure you have enough disk space for this before
continuing. First copy the extractpf.exe utility into your working directory:

copy "C:\Program Files\Ratbag\Dirt Track Racing\mods\extractpf.exe"

Where "C:\Program Files\Ratbag\Dirt Track Racing\" is the directory in which
you installed DTR (this is the default). Now run it:

extractpf data.pf
extractpf min.pf
extractpf store.pf

(This will take some time).

The easiest way to create any new entity in DTR is to copy one from the
existing data, then modify it. All of the original DTR skins will now be
in the C:\dtr_test\data\skins\ directory, each in their own subdirectory.
Select one you'd like to modify (eg 'mars GT red'). 

Create a 'skins' subdirectory in your DTR install data directory 
(eg C:\Program Files\Ratbag\Dirt Track Racing\data\skins\), then copy the
whole 'mars GT red' directory in there. All skins must be in a different
directory, therefore your own 'mars GT red' directory will be ignored unless
you change its name. Change it to something unique like 'my own car'.

Now go into the 'my own car' directory, and open the skin.str file (it is
just a text file, so use notepad, or DOS edit). Look for the section of this
file which looks something like:

[display names]
english = Flaming Mars GT

Change the name under which you would like your new skin to appear in the
game interface, eg:

[display names]
english = My Modified Mars GT

Now go into the 'textures' subdirectory. This directory contains a file
called 'texture.tga' (it may be different if you selected a different car 
to modify initially). This is an image file which is used as the paintwork 
for the car, which you can modify using a paint programme.

Once you have done all of this, you should be able to run DTR and have the
new car skin appear for you to select, and race with.

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   5. Anticipated Frequently Asked Questions
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1. Can I make DTR crash by adding my own data?
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Yes - we can not validate absolutely everything to make sure that what has
been added will not cause problems.

2. Can I break DTR (ie not crash but not work properly either)?
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Yes, for the same reasons.

3. Can I cheat by adding my own data?
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Yes.

4. In single player or multiplayer?
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Both.

5. So extractpf means that if I play multiplayer, everyone else is probably
   cheating?
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No. Here is a full description of how things work:

DTR will accept data outside of the packed files, and use it in addition to
the data in the packed files. Specifically, when searching for a file DTR 
will first look in the packed files - if it is not there, it will look
external to the packed files. DTR requires this to work properly. 

This means that you can *add* your own data to DTR, but you can't *modify*
the existing data. You don't need extractpf to be able to add your own data -
extractpf just makes it easier for you to know what to add.

To cheat in multiplayer, you might want to increase the power of a car, and
then race with that (or modify any of the other parameters). However, because
of the way DTR works, you can't modify the existing data. To be able to change
a car's power or other parameters, you'd need to first add a new car of your
own.

In multiplayer, however, it is only possible to select a particular car, if
*everyone* connected to the game has that particular car. So if you are
playing against someone, they can only be using their own modified car, if
you've also copied the car from them. If you do ever copy a car from someone,
and then they use it in a multiplayer game, keep in mind that they may be
cheating. But then so could you.

You can create your own skin, and then you are able to use it in a multiplayer
game, if everybody in the game has the car that skin uses. If other players
do not have the skin, they will see a default skin on your car. The skins
define various parameters, including initial tuning values, and upgrade 
levels. This means it would be possible to create a skin with different
upgrade levels to the defaults, and race with it in multiplayer, without
anyone else knowing. However, the multiplayer cars should already be at the
maximum upgrade level. The actual effects of the upgrades are defined in the
cars. In theory, you should not be able to get an advantage here.

6. What are all these different files?
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Here is a brief description of some of the file formats used by DTR:

.de2 - Ratbag's proprietary 3D object format.
.tex - Ratbag's proprietary texture format.
.tra - Ratbag's proprietary terrain definition format.
.str - 'Store' file, contains various forms of configuration data, in plain
       text format. One of the most editable file formats in DTR.
.tga - Targa image format - editable with many common paint programmes.
.txt - Ordinary text file.
.lt, .alp, .sus - Plain text format files holding various data.

7. Will Ratbag be releasing utilities to create these files, eg .de2, .tex?
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No, sorry.

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Dirt Track Racing + 1999 Ratbag Pty Ltd. All Rights Reserved. 
Dirt Track Racing, Ratbag, the Ratbag logo, and the Difference Engine are 
trademarks.
