Augmentrex

Augmentrex is a reverse engineering tool for the Steam version of Hellgate: London. It provides a generic framework for doing in-memory interaction with the Hellgate: London process from managed code. Users can write plugins to add additional functionality.

(The name comes from the in-game device, Augmentrex 3000, which is used to add new affixes to items.)

Features

Core features include:

• EasyHook-based injection into the game process.
• Custom commands and reloadable plugins can be written in any managed language.
• Core APIs and commands for manipulating game memory and global hot keys.
• Built-in OutputDebugString() listener for game output.
• Automatic detection and launching of the game.

Custom commands included with the core:

• patch-long-ray-vm: Disables the game's ray casting engine, fixing the vast majority of frame rate issues (commonly known as the 1 FPS bug).
• patch-cc-agent: Disables the game's capsule-capsule collision agent, fixing frame rate issues for certain skills (e.g. Blademaster's Whirlwind).

Plugins included with the core:

• simple-test: Just a simple a plugin that outputs a message on startup and shutdown.

(Developers can use these as examples for implementing custom commands and plugins.)

Installation

Archives with compiled binaries are available from the releases page.

Augmentrex requires .NET Framework 4.7.2 to run.

If you want to build Augmentrex from source, you will need Visual Studio 2019 (any edition). The code base is written in C# 8.0, so earlier versions will not work.

Simply open Alkahest.sln and build it with the Debug + x86 configuration. All build artifacts will end up in the Build directory.

Configuration

Advanced users can have a look in Augmentrex.exe.config if they wish to change configuration values. Here are some values you might be interested in changing:

• gamePath: If Augmentrex cannot locate the game executable via Steam, you can set this value explicitly. For example, on my system, I would set this to C:\Program Files (x86)\Steam\steamapps\common\HELLGATE_London\bin\Hellgate_sp_x86.exe.
• gameArguments: Any command line arguments to pass to the game. I personally dislike the keyboard hook the game does to disable the Win key, so I would leave -nokeyhooks here.
• gameConsoleEnabled and debugListenerEnabled: You can set these to False if you are not interested in debug output from the game process.
• hotKeyBeepFrequency: Set to 0 if you do not want a beep sound when pressing a hot key.
• disabledPlugins: This can be used to disable individual plugins without removing the files from the Augmentrex directory.
• runCommands: You can use this to run commands at startup. For example, you could set it to patch-cc-agent; patch-long-ray-vm; key --add -s F1 patch-long-ray-vm to enable patch-cc-agent and patch-long-ray-vm at startup and set a Shift+F1 key binding to toggle patch-long-ray-vm.

Usage

Simply launch Augmentrex.exe. Augmentrex will locate the game executable via Steam and launch it for you, then attach to the game process.

Once the game is open, you can type patch-long-ray-vm and/or patch-cc-agent to toggle those patches (even during gameplay).

If you get an EasyHook error along the lines of STATUS_INTERNAL_ERROR with code 5, you will need to do the following:

• Close Augmentrex and the game.
• Navigate to your Hellgate_sp_x86.exe file.
• Right click -> Properties -> Compatibility.
• Tick the "Run in 640 x 480 screen resolution" option.
• Click OK.

It is unclear why this is necessary on some systems, but the good news is that the game will run with the correct video settings even with this option enabled (i.e. not actually 640x480). If you want to run the game without Augmentrex, though, you will have to go back and untick that option.

Known Issues

The patch-long-ray-vm command has a few side effects to be aware of:

• You can see portal names and enemy nameplates through terrain.
• Collision detection for ranged attacks will be non-functional, allowing both you and certain enemy types to attack through some types of terrain.
• Enemy corpses will often just vanish when they die, or less frequently, end up in weird poses.
• Certain bosses (Ash and Oculis, possibly others) rely on ray casting for some of their attacks. You have to toggle the command off before you engage these bosses, or you will not be able to kill them.

As far as I am aware, the patch-cc-agent command has no negative side effects.

Background

I started work on this project because I finally got sick of the dreaded 1 FPS bug the game suffers from. Through various efforts (static reverse engineering, dynamic debugging, CPU profiling), I finally managed to figure out why the game's frame rate would drop so severely. It turns out that the game makes an excessive number of ray cast queries under certain circumstances. I still need to figure out exactly why that happens, but for now, disabling ray casting altogether makes the game actually playable. This is done by patching the hkpMoppLongRayVirtualMachine::queryRayOnTree() function from the Havok Physics library used in the game, so that it simply returns rather than running the bytecode passed to it. This effectively disables ray casting. Again, just to be clear, this is treating the symptom rather than the cause, but it does at least work.

In the future, I will be investigating various other frame rate issues with the game, and so I figured I would need a more generic framework for making changes to the game executable. Thus, this project, and the fix being a plugin.

By the way, while I love this game (which you can probably tell by the fact that I bothered to do all this), I absolutely cannot recommend that anyone go and buy it on Steam. This 1 FPS bug has existed for almost a decade, from all the way back when the game was online-only. The bug was almost certainly introduced by HanbitSoft when they took over the game from Flagship Studios. They have been aware of the bug for all this time. Even when they re-released the game as a single player title on Steam, they spent months pretending that people's PCs just did not meet the game's minimum requirements.

To be perfectly clear: They are selling a broken product that is unplayable to the vast majority of people. They were fully aware of this, and proceeded with putting it on Steam anyway. They then went on to completely ignore the issue and to this day have not fixed it, nor even acknowledged it. I actively encourage everyone to report the game as being broken on the store page, because it is. They should not be allowed to make money by selling such a blatantly broken product.

Still, for those who bought the game and would still like to play it, this project will help you do that.

Contributing

Please see CONTRIBUTING.md.

License

Please see LICENSE.md.

Funding

I work on open source software projects such as this one in my spare time, and make them available free of charge under permissive licenses. If you like my work and would like to support me, you might consider sponsoring me. Please only donate if you want to and have the means to do so; I want to be very clear that all open source software I write will always be available for free and you should not feel obligated to donate or pay for it in any way.