NOTE: This project is now obsolete. Its goals are now pursued via the SpaceChem Community Edition project. Please visit that project for the latest gameplay enhancements.

This project will stay online for posterity, but no changes will be made to it and newly reported issues won't be considered. Please share any improvement ideas in the Community Edition issue tracker instead.

This program will modify your SpaceChem game executable to add new features to the game.

Development is done against the Steam version of the game that includes the 63 Corvi DLC, so this is the officially supported version. The GOG version of the game is also supported in an experimental basis. We would like to get feedback from players who have the GOG version before considering the support mature. If you have the GOG version, please try the patcher and send your feedback to the development team; both positive and negative feedback is valuable at this point.

There is a simple GUI. The program tries to automatically detect the steam installation folder, if it can't it must be selected manually. Remember that the executable must be in the original SpaceChem folder: if Steam detects that you've launched the game from the "wrong" folder, it will simply re-launch it from its expected location. It'll then be possible to choose the patches to apply, from the list below

• AllowBondsForUnknownInNotes: The output note editor offers the unknown element (represented by a question mark) to allow denoting variable or unknown atoms in the reactor output. The utility of this element is limited, however, because the game treats it as a noble gas and won't allow any bonds on it. This enhancement alters the behavior so that the unknown element accepts any bonds (as long as the other member of the bond doesn't exceed its own bond limit, of course). Note that the element will still have zero bonds when you drop it into the molecule - you'll need to add the bonds you want manually.
• AllowGreekInResNet & AllowGreekInResNetProdAndSandbox: Gives complete support for Greek annotations/sensors in ResearchNet levels. In the vanilla game it's possible to get Greek annotations/sensors in ResNet productions/sandbox, by copying a reactor from EotL, so the latter patch is merely a QoL one. It's not possible to have Greek sensors in ResNet research assignment, though, so the former patch makes the game easier and it's labeled as "Cheat".
• AllowIllegalBondsInCustomPuzzles: Allow bonds that exceed the bond limit of the participating atoms when editing input and output molecules in ResearchNet puzzles. Puzzle creators have been building unique puzzles like this for a while now, by editing the puzzle data manually, but with this patch, they can do it a bit more easily. As a side effect, arbitrary bonds are also allowed in reactor output notes, so this patch is a superset of AllowBondsForUnknownInNotes and you can't turn on both at the same time.
• DeclassifyDefenses: Shows the normal leaderboard/histograms on defenses, both after completion and on hover on the campaign screens, so that it's easy to see the stats. Sadly the game has no histogram data for these levels, but the friends scores are visible.
• DefaultDebondInDisassemblyReactors: In disassembly reactors, the Bond+ instruction is always ignored because the bonders can only remove bonds in them. This patch replaces Bond+ with Bond- in the instruction toolbar for these reactors, so you don't need to manually switch them to the Bond- state.
• FixWrongOutput: The "wrong output" bug is fixed. The game is known to sometimes accept a molecule for output even when it doesn't completely match the expected molecule. The easiest way to reproduce this is to open the "Swapite" puzzle in ResearchNet 2-11-1: the game will accept the input molecule without any changes. This change will apply a different molecule matching algorithm that hopefully fixes these issues without introducing new ones. Please report any performance issues or unexpected results you encounter.
• ForceLinuxMoleculeOrder and ForceWindowsMoleculeOrder: The game tries to make sure that every time a puzzle has random molecule inputs, the sequence of those molecules is the same every time you start the puzzle. The Linux port, however, relies on an old version of Mono that has a different random number generation algorithm, yielding a different random sequence compared to Windows. This can make the same solution have a different cycle score, or sometimes even fail, when played on a different OS than where it was created. This pair of patches allows you to pick either algorithm explicitly, instead of relying on what your .NET implementation provides.
• FixTelekinesis: Fixes the Telekinesis bug, which, in very specific circumstances, allows a waldo to "hold" and manipulate a molecule without touching it.
• MoreFeaturesInResNetResearch: Increase the upper limit of allowed reactor features in custom ResearchNet research puzzles. You can have up to 4 sensors, fusion lasers, fission lasers and quantum tunnels in a puzzle now. A Split instruction triggers all fission lasers in a reactor and a Fuse instruction triggers all fusion lasers. Sensing instructions will activate if any of the sensors detects the specified element. Quantum tunnels work in a "round-robin" fashion: tunnel #1 will teleport atoms to tunnel #2, tunnel #2 will teleport to tunnel #3 and so on, except for the highest-numbered tunnel, which will teleport to tunnel #1. Please read the "Compatibility Notes" section below if you also want to run the original game alongside the modified version.
• RemoveYouTubeUpload: Remove the "Upload to YouTube" option from the solution recording UI. This option hasn't been working for years because it's trying to use services that have been removed by Google. By enabling this patch, the game will simply save the recorded video file on your desktop and won't offer you the broken YouTube upload option.
• ResNetProdCustomAmount: Allows changing the amount of outputs needed for ResNet production puzzles. The amount can be specified in the JSON, like for researchs. The output count used by the game is 4x the amount in the file, to keep the 10 -> 40 behaviour of the vanilla game.
• ReverseOrderCustomResNetAssignments: The ResearchNet custom assignments are normally sorted by ascending creation date, meaning that you need to scroll the most to get to the latest puzzles. By enabling this patch, the order is reversed, so you can quickly open your most recent assignments and only need to scroll for the older ones.
• ShowBonderPriority: The priority of a bonder is shown in the top right corner of the cell. Bonder priority is something used by experienced players to predict which bonds will form when not all of the possible bonds can be formed during a Bond+ instruction (usually because of the maximum bonds limit of one of the atoms involved).
• ShowOver100kCycles: The cycles counter in the game switches to +INF after 100k cycles. This patch makes it continue with 100K, up until 9999K, then 10M. The value displayed updates at the start of the new thousand (e.g. 100999 is shown as 100K).
• ShowReactorPriority: The priority of reactors, tanks and printers is shown in production and defense puzzles. Priority is useful for cycles optimization: in some cases, you can save one cycle by making sure that the reactor that's outputting a molecule has lower priority than the reactor accepting it, allowing the molecule to be accepted in the same cycle. Inputs' and outputs' priority isn't shown, as they both trigger before anything else.
• StricterCollisionChecks: Adds new collision checks and changes the timing of some existing ones to fix collision-related issues, including particle smashing. It does not fix missed collisions mid-rotation: fixing those would require more frequent collision checks, which is a lot harder to do. It's also stricter than the Reddit leaderboard rules, which allow Input+Fuse and Split+Out in certain cases: this patch will always report a collision caused by the red waldo even if the blue waldo would have resolved it afterwards.
• SuperFastForward: Allows you to run the simulation at maximum speed by holding down Ctrl and clicking on any of the speed buttons in the bottom left corner. (The game can handle 32,767 cycles per second without pervasive changes to the engine. If your computer can't handle a level at this speed, it will just go as fast as it can.) Expect heavy lagging when triggering this speed.

There is currently one patch that may cause compatibility issues with the vanilla game:

• When MoreFeaturesInResNetResearch is active, the puzzle descriptions used by the game are extended with new fields to store the selected feature counts. When the vanilla game loads these descriptions, it will ignore the new fields and enforce the old limits. When it's loading a puzzle solution, it will also remove the "extra" features it finds that are above the expected limits. The result is, whenever you open the Custom Assignments screen in ResearchNet with the vanilla game, you will lose features in your existing solutions, and restoring those features is tricky at the moment. If you wish to switch between the vanilla and patched versions of the game, it's better to avoid opening this screen, or even to use different game profiles for the two versions.
  Exporting puzzles should work normally, but if you publish your puzzle somewhere, please let the players know that they will need to patch their game to be able to play the puzzle properly. The MoreFeaturesInResNetResearch is the only patch necessary, all others can stay disabled if the player prefers the original game behavior.

The project consists of a Visual Studio 2015 solution file. You should be able to build it with either Visual Studio, or the Mono development tools on Linux.

To add new patches, please read the "How it works" section below, then refer to PATCHING.md for the low-level details.

You will need to get the Mono.Cecil library from NuGet. This library does the heavy lifting in assembly modification.

The SpaceChem executable is obfuscated, and one part of the obfuscation is renaming identifiers. The new names are not legal symbols in C#, so you can't just pull the binary as a dependency and access the types. It's still possible to create IL code manually and overwrite the existing code with it, but doing that from a C# program is very cumbersome.

To work around this, the code contains "decoy" types, methods and fields. These are readable counterparts of the obfuscated elements, which can be used normally from C# code. When you need to change a method, you need to find all the obfuscated functionality your method is going to use, create "decoy" counterparts of that functionality (just enough to make things compile, i.e. no need to copy method bodies), then write the new method body. Annotate the new method with [Replaced], then annotate everything else you've added with [Decoy]. Both of these attributes will need the obfuscated name of the corresponding real element. It is also possible to inject new fields into SpaceChem types by declaring your field on the decoy and annotating it with [Injected]. Please note that field initializers won't work; you'll need to replace the constructor if you can't work with the field being initialized to its default.

During patching, the assembly will load itself with Cecil, find all annotated elements, then replace method bodies of the SpaceChem assembly where requested. While replacing, it will inspect the code and replace any mentions of "decoy" elements with their real counterparts. This way, you can let the C# compiler do the IL generation for you. Refer to the Patcher class for details.

• Kudos to gtw123, whose ShenzhenMod project inspired me to give this a try. He pointed out the right tools to get this started.
• darkid and 12345ieee for their immense help in understanding game internals.
• 12345ieee again, for building the user interface of the tool