Here's the screenshot:
Here's the entire 300KB image that the above was cropped from:
Here's how I did it.
First I have to say that the solution is a VC.net 2002 solution since the solution file Version is 7.0. I could not get any of the code to compile with VC++6.0...there are just too many language differences. So, I downloaded and installed the free VC++2005. I also downloaded and installed the DirectX 9.0C SDK and the Debugging Tools for Windows...both available for free from http://MSDN.microsoft.com
DirectX 9.0C SDK: http://www.microsoft.com/downloads/details.aspx?FamilyID=b7bc31fa-2df1-44fd-95a4-c2555446aed4&DisplayLang=en
Debugging Tools for Windows: http://www.microsoft.com/whdc/DevTools/Debugging/default.mspx
When I opened the solution it got converted. The only significant message is:
The single-threaded run-time library switches (/MLd, /ML) have been removed from the C++ compiler. The project has been automatically converted to use the corresponding multi-threaded run-time library switches (/MTd, /MT).
Project upgraded successfully.
I tried to build and got an error right away concerning inline debuging. So, I selected Build|Configuration Manager from the VC++2005 IDE and changed "Debug with inlines and memory log" from the top left drop down box entitled: "Active Solution Configuration" then clicked close.
Another error is that "../msdn/dsound.h" was missing (all paths are relative to game or idlib folders). I created a folder "C:\Doom3\msdn" and copied the entire DirectX 9.0C SDK folder into it so that the path is just like it's hard coded in the code.
I tried again and got stopped by the error that it could not find "dbghelp.lib". This is not hard-coded anywhere so I selected Tools|Options from the VC++2005 IDE and clicked on Projects and Solutions, then selected VC++ Directories. Then I selected Library Files from the drop down box located in the top right of the dialog box. I then clicked the new line button (looks like the New Folder button) and copied the path to it: C:\Program Files\Debugging Tools for Windows\sdk\lib\i386 and pressed enter.
I tried another build and this time it was dbghelp.h, so I went back to that dialog box and selected Include Files and copied the path to it: C:\Program Files\Debugging Tools for Windows\sdk\inc and pressed enter.
I tried again, but this time I got stopped due to the missing odbc32.lib. Well, I had kept my VC++6.0 development system up-to-date on everything so I just added that to the library files in that same dialog window: C:\Program Files\Microsoft Visual Studio\VC98\Lib
This time everything compiled with just the one error that you can see in the above image. In the C:\DOOM3\debugdll folder was that beautifully "gamex86.dll". I renamed my original "gamex86.dll" in my out-of-the-box retail installation folder: "C:\Program Files\Doom 3" and copied "gamex86.dll" from the C:\DOOM3\debugdll folder. Ran Doom3 and it worked fine. I didn't have to make any changes to any of the code at all...no fixes required...nice and smooth.
Now it's just a matter of learning all the classes and figuring out where new classes can be inserted.