nih-plug/BREAKING_CHANGES.md

Breaking changes

Since there is no stable release yet, there is also no proper changelog yet. But since not everyone might want to dive through commit messages to find out what's new and what's changed, this document lists all breaking changes in reverse chronological order. If a new feature did not require any changes to existing code then it will not be listed here.

[2022-10-22]

• The Editor trait and the ParentWindowHandle struct have been moved from nih_plug::plugin to a new nih_plug::editor module. If you only use the prelude module then you won't need to change anything.

• The nih_plug::context module has been split up into nih_plug::context::init, nih_plug::context::process, and nih_plug::context::gui to make it clearer which structs go with which context. You again don't have to change anything if you use the prelude.

• NIH-plug has gained support for asynchronously running background tasks in a simple, type-safe, and realtime-safe way. This sadly does mean that every Plugin instance now needs to define a BackgroundTask type definition and constructor function as Rust does not yet support defaults for associated types (Rust issue #29661):

  type BackgroundTask = ();
  

• The &mut impl InitContext argument to Plugin::initialize() needs to be changed to &mut impl InitContext<Self>.

• The &mut impl ProcessContext argument to Plugin::process() needs to be changed to &mut impl ProcessContext<Self>.

[2022-10-20]

• Some items have been moved out of nih_plug::param::internals. The main Params trait is now located under nih_plug::param, and the PersistentTrait trait, implementations, and helper functions are now part of a new nih_plug::param::persist module. Code importing the Params trait through the prelude module doesn't need to be changed.
• The nih_plug::param module has been renamed to nih_plug::params. Code that only uses the prelude module doesn't need to be changed.
• The create_egui_editor() function from nih_plug_egui now also takes a build closure to apply initialization logic to the egui context.
• Editor and the editor handle returned by Editor::spawn now only require Send and no longer need Sync. This is not a breaking change, but it might be worth being aware of.
• Similar to the above change, Plugin also no longer requires Sync.

[2022-10-13]

• The #[nested] parameter attribute has gained super powers and has its syntax changed. It can now automatically handle many situations that previously required custom Params implementations to have multiple almost identical copies of a parameter struct. The current version supports both fields with unique parameter ID prefixes, and arrays of parameter objects. See the Params trait for more information on the new syntax.

[2022-09-22]

• nih_plug_vizia has been updated. Custom widgets will need to be updated because of changes Vizia itself.
• nih_plug_egui has been updated from egui 0.17 to egui 0.19.

[2022-09-06]

• Parameter values are now accessed using param.value() instead of param.value, with param.value() being an alias for the existing param.plain_value() function. The old approach, while perfectly safe in practice, was technically unsound because it used mutable pointers to parameters that may also be simultaneously read from in an editor GUI. With this change the parameters now use actual relaxed atomic stores and loads to avoid mutable aliasing, which means the value fields are now no longer directly accessible.

[2022-09-04]

• Smoother::next_block_mapped() and Smoother::next_block_exact_mapped() have been redesigned. They now take an index of the element being generated and the float representation of the smoothed value. This makes it easier to use them for modulation, and it makes it possible to smoothly modulate integers and other stepped parameters. Additionally, the mapping functions are now also called for every produced value, even if the smoother has already finished smoothing and is always producing the same value.

[2022-08-19]

• Standalones now use the plugin's default input and output channel counts instead of always defaulting to two inputs and two outputs.
• Plugin::DEFAULT_NUM_INPUTS and Plugin::DEFAULT_NUM_OUTPUTS have been renamed to Plugin::DEFAULT_INPUT_CHANNELS and Plugin::DEFAULT_OUTPUT_CHANNELS respectively to avoid confusion as these constants only affect the main input and output.

[2022-07-18]

• IntRange and FloatRange no longer have min/max methods and instead have next/previous step methods. This is for better compatibility with the new reversed ranges.

[2022-07-06]

• There are new NoteEvent::PolyModulation and NoteEvent::MonoAutomation events as part of polyphonic modulation support for CLAP plugins.
• The block smoothing API has been reworked. Instead of Smoothers having their own built-in block buffer, you now need to provide your own mutable slice for the smoother to fill. This makes the API easier to understand, more flexible, and it allows cloning smoothers without worrying about allocations.In addition, the new implementation is much more efficient when the smoothing period has ended before or during the block.

[2022-07-05]

• The ClapPlugin::CLAP_HARD_REALTIME constant was moved to the general Plugin trait as Plugin::HARD_REALTIME_ONLY, and best-effort support for VST3 has been added.

[2022-07-04]

• The CLAP_DESCRIPTION, CLAP_MANUAL_URL, and CLAP_SUPPORT_URL associated constants from the ClapPlugin are now optional and have the type Option<&'static str> instead of &'static str.
• Most NoteEvent variants now have an additional voice_id field.
• There is a new NoteEvent::VoiceTerminated event a plugin can send to let the host know a voice has been terminated. This needs to be output by CLAP plugins that support polyphonic modulation.
• There is a new NoteEvent::Choke event the host can send to a plugin to let it know that it should immediately terminate all sound associated with a voice or a key.

[2022-07-02]

• The Params::serialize_fields() and Params::deserialize_fields() methods and the State struct now use BTreeMaps instead of HashMaps so the order is consistent the plugin's state to JSON multiple times. These things are part of NIH-plug's internals, so unless you're implementing the Params trait by hand you will not notice any changes.

[2022-06-01]

• The ClapPlugin::CLAP_FEATURES field now uses an array of ClapFeature values instead of &'static strs. CLAP 0.26 contains many new predefined features, and the existing ones now use dashes instead of underscores. Custom features are still possible using ClapFeature::Custom.

[2022-05-27]

• Plugin::process() now takes a new aux: &mut AuxiliaryBuffers parameter. This was needed to allow auxiliary (sidechain) inputs and outputs.
• The Plugin::initialize() method now takes a &mut impl InitContext instead of a &mut impl ProcessContext.

[2022-05-22]

• The current processing mode is now stored in BufferConfig. Previously this could be fetched through a function on the ProcessContext, but this makes more sense as it remains constant until a plugin is deactivated. The BufferConfig now contains a field for the minimum buffer size that may or may not be set depending on the plugin API.
• Previously calling param.non_automatable() when constructing a parameter also made the parameter hidden. Hiding a parameter is now done through param.hide(), while param.non_automatable() simply makes it so that the parameter can only be changed manually and not through automation or modulation.

...

Who knows what happened at this point!