Faust IDE

The online Faust IDE can be used to edit, compile and run Faust code from any recent Web Browser with webassembly support. It works completely on the client side and it is therefore very convenient for situations with many simultaneous users (workshops, classrooms, etc.). It embeds the latest version of the Faust compiler with an efficient webassembly backend and offers polyphonic MIDI support.

Features

Code Editing

The editor engine is based on Monaco Editor. It provides syntax highlighting, auto completion, code hinting and direct access to the online documentation. The documentation command (Ctrl-D) uses the function name at the cursor position to locate the relevant information.

Resetting parameters to their default value

You can double-click knobs or sliders to reset them, or on the group label to reset all its children.

Saving parameter state

Enable Save Params State to preserve DSP control values when running or recompiling the program. The restored values are applied to the new DSP and reflected in both the embedded Faust UI and an already-open Faust UI popup, instead of those controls returning to their declared defaults.

Vim Mode Support

The Monaco Editor supports an optional mode for Vim users. To enable it, open the command pane (F1) and search for 'Toggle Vim Mode'. The same command is used to desactivate this functionality. Alternatively, you can right click on the editor and press 'Open Command Palette' to open the contextual menu.

Project Files

Several DSP files can be added in the top-left Project Files section and edited independently. Any non standard library, like a foo.lib file, can simply be added by drag/drop, then used in the DSP code with import("foo.lib");. DSP files or libraries can also be loaded or saved with the Upload and Save As buttons in the left column.

The project file list is stored in the browser, so files remain available after a reload. Drag/drop supports several files at once, both on the editor overlay and on the Project Files panel. Structural imports are saved immediately before the import finishes, so a reload right after a multi-file drop keeps the imported files.

On Chrome and other Chromium-based browsers, Faust IDE can also use the browser File System Access API to work with local folders:

• Use Mount a disk folder... to authorize a local folder. Mounted folders are remembered by the browser, although Chrome may ask for permission again after a reload or a browser restart.
• Use the eject button next to a mounted disk volume in the file browser to unmount it. Files already copied into the project stay available as local browser copies, but they stop writing back to the disk folder.
• Native Faust files (.dsp and .lib) opened or dropped from a mounted folder are edited in place: after the project copy is saved, changes are also written back to the original disk file.
• Faust IDE checks mounted files before writing them back to disk, before compiling the main file, when the tab regains focus, and periodically while the tab is visible. If another editor changed a mounted file and the Faust IDE copy is still clean, the disk version is reloaded automatically. If both Faust IDE and the disk file changed, Faust IDE blocks automatic write-back and shows conflict actions: reload from disk, overwrite disk, or keep a local copy.
• If a mounted file was deleted, moved, or no longer has browser permission, Faust IDE blocks compile/save for that file and asks the user to restore the file or re-authorize the mounted folder. Browser permission prompts still require an explicit user action; background polling only detects the problem.
• Disk-backed project files are shown in green in Project Files. A green row means Faust IDE knows the original mounted disk file and will write text edits back to it.
• White rows are local browser copies only. They are saved in the browser project storage but are not linked to a real disk file.
• Audio files and other non-Faust formats are imported as local copies, not opened in place.
• Opening or dropping the same mounted file more than once selects the existing green row instead of creating a duplicate untitledN file.
• If a local white file named foo.dsp already exists and you later open/drop a mounted disk file with the same name, Faust IDE keeps the local copy untouched and reports a conflict. Rename or delete the local copy before opening the mounted disk file if you want the disk-backed version.
• The remaining platform limitation is that browsers do not provide a true atomic compare-and-swap write for local files, so a file could still change in the very small interval between Faust IDE's final check and the browser write operation.

Auto-Compiling

While the option is turned on, the diagram or the DSP UI will automatically be updated from the code. The editor will also try to tell if there is an error in your code.

MIDI input

MIDI Input is available for Chrome and Firefox browsers. You can also use the computer keyboard to input MIDI notes. We are using key map as Ablelon Live: A-line and Q-line for keys, ZX to move octave, CV to change velocity.

Polyphonic mode

The polyphonic mode can be activated by selecting a number of voices in the Poly Voices menu on the left. Standard Polyphony Parameters have to be used in the DSP voice.

A global effect can be added using the effect = foo; convention, possibly adapting the voice and effect inputs/outputs to make them compatible.

This is the beginning of the README. Read the rest at the original. Read the full README ↗