[OFS Extension] Custom Lua Injector - Execute Custom Lua Scripts on Selected Actions

Software
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Custom Lua Injector

A powerful OpenFunscripter extension that allows you to execute custom Lua code on selected actions without creating separate extensions. Perfect for quick one-time scripts and rapid prototyping.

:brain: TL;DR
This extension lets you run Lua code on just the actions you select (by dragging on the timeline) in OpenFunscripter.
It’s perfect for quick, one-off editing without building a whole extension.

Features

  • Modify Drag-Selected Actions: Write and run one-off Lua code that applies only to the actions you’ve selected in the timeline
  • Code Library: Save and load frequently used code snippets
  • Built-in Examples: 4 practical examples to get you started
  • Comprehensive Help: Detailed documentation and API references
  • Safe Execution: Sandboxed environment for secure code execution
  • Keyboard Shortcuts: Quick access via key bindings

:hammer_and_wrench: Installation :hammer_and_wrench:

Download from GitHub:

  1. Go to the GitHub repository: GitHub - Hyeoyoms/CustomLuaInjector
  2. Click the green “<> Code” button.
  3. Select “Download ZIP”.
  4. Extract the main.lua file from the ZIP archive.
  5. (Alternatively, if you’re familiar with Git, you can clone the repository.)

Place the .lua file in your OFS extensions folder:

  • The typical path is: C:\Users\[YOUR_USERNAME]\AppData\Roaming\OFS\OFS3_data\extensions\
  • You can optionally create a subfolder within extensions (e.g., CustomLuaInjector) to keep things organized and place the main.lua file there.
  • Quick Tip to find the folder: In OFS, go to Extensions > Extension directory. This will usually open a folder one level above where the extensions folder is located or directly into a script folder. Navigate to the extensions subfolder within OFS3_data.

Load in OFS:

  • The extension should appear in your Extensions menu in OFS after placing it in the folder. You might need to restart OFS if it doesn’t show up immediately.

Usage

  1. Select Actions: Drag to select actions in the OFS timeline
  2. Enter Code: Type your Lua code in the input field
  3. Execute: Click “Execute Code” to run your script

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The Lua code I used in the video works as follows:

  • It searches through the selected actions to find those with a pos value of 90.
  • For each of those, it calculates the time interval between the current action and the next one.
  • If the interval is 130ms (0.13 seconds) or greater, it satisfies the condition.
    • (In the context of the video, this corresponds to a 4-cell interval in OFS when using tempo 450 with a 16th grid. 3-cell intervals are ignored.)
  • It then creates a new action at the time = current action’s at + 62.02ms, with pos set to 80.
    • (Although on review, 67.02ms would have been the precise 2-cell offset — this was a small my mistake.)
  • All newly created actions are added to the script.

Example Code

– Increase all selected positions by 10%

for i, action in ipairs(selectedActions) do action.pos = math.min(100, action.pos * 1.1); end;

– Remove actions with position ≤ 50

for i = #selectedActions, 1, -1 do if selectedActions[i].pos <= 50 then script:markForRemoval(getActionIndex(selectedActions[i])); end; end; script:removeMarked();

– Add intermediate action when gap is large

for i, action in ipairs(selectedActions) do if action.pos == 90 and i < #selectedActions and (selectedActions[i + 1].at - action.at) >= 0.13 then table.insert(script.actions, Action.new(action.at + 0.06702, 80, false)); end; end;

Available Functions & Variables

OFS Official API

  • script: Active funscript object (from ofs.Script(ofs.ActiveIdx()))
  • Action.new(at, pos, selected): Constructor for creating new actions
  • script:selectedIndices(): Get array of selected action indices
  • script:markForRemoval(idx): Mark action for removal
  • script:removeMarked(): Remove all marked actions
  • script:sort(): Sort actions by time
  • script:commit(): Apply changes to OFS
  • Standard Lua libraries: math, table, string, pairs, ipairs, etc.

Extension Helper Functions

  • selectedActions: Pre-built array of currently selected actions
  • getActionIndex(targetAction): Find the index of a specific action
  • addAction(at, pos, selected): Convenient wrapper for creating and adding actions
  • print(...): Output text to extension result area (overrides standard print)

API Reference

For complete API documentation, visit: How to create an extension - Extension API Reference

Tips

  • Use semicolons (;) to separate multiple statements
  • action.at is time in seconds (0.1 = 100ms)
  • action.pos is position value (0-100)
  • Always validate array bounds with i < #selectedActions
  • Use math.min/max for position clamping

Contributing

Feel free to submit issues and pull requests to improve this extension.

License

This project is open source and available under the MIT License.

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