use raw_window_handle::{HasRawWindowHandle, RawWindowHandle}; use std::any::Any; use std::pin::Pin; use std::sync::Arc; use crate::buffer::Buffer; use crate::context::{GuiContext, ProcessContext}; use crate::param::internals::Params; /// Basic functionality that needs to be implemented by a plugin. The wrappers will use this to /// expose the plugin in a particular plugin format. /// /// This is super basic, and lots of things I didn't need or want to use yet haven't been /// implemented. Notable missing features include: /// /// - Sidechain inputs /// - Multiple output busses /// - Special handling for offline processing /// - Transport and other context information in the process call /// - Sample accurate automation (this would be great, but sadly few hosts even support it so until /// they do we'll ignore that it's a thing) /// - Parameter hierarchies/groups /// - Bypass parameters, right now the VST3 wrapper generates one for you /// - Outputting parameter changes from the plugin /// - MIDI CC handling /// - Outputting MIDI events #[allow(unused_variables)] pub trait Plugin: Default + Send + Sync + 'static { const NAME: &'static str; const VENDOR: &'static str; const URL: &'static str; const EMAIL: &'static str; /// Semver compatible version string (e.g. `0.0.1`). Hosts likely won't do anything with this, /// but just in case they do this should only contain decimals values and dots. const VERSION: &'static str; /// The default number of inputs. Some hosts like, like Bitwig and Ardour, use the defaults /// instead of setting up the busses properly. const DEFAULT_NUM_INPUTS: u32 = 2; /// The default number of inputs. Some hosts like, like Bitwig and Ardour, use the defaults /// instead of setting up the busses properly. const DEFAULT_NUM_OUTPUTS: u32 = 2; /// Whether the plugin accepts note events. If this is set to `false`, then the plugin won't /// receive any note events. const ACCEPTS_MIDI: bool = false; /// The plugin's parameters. The host will update the parameter values before calling /// `process()`. These parameters are identified by strings that should never change when the /// plugin receives an update. fn params(&self) -> Pin<&dyn Params>; /// The plugin's editor, if it has one. The actual editor instance is created in /// [Editor::spawn]. A plugin editor likely wants to interact with the plugin's parameters and /// other shared data, so you'll need to move [Arc] pointing to any data you want to access into /// the editor. You can later modify the parameters through the [GuiContext] and [ParamSetter] /// after the editor GUI has been created. fn editor(&self) -> Option> { None } // // The following functions follow the lifetime of the plugin. // /// Whether the plugin supports a bus config. This only acts as a check, and the plugin /// shouldn't do anything beyond returning true or false. fn accepts_bus_config(&self, config: &BusConfig) -> bool { config.num_input_channels == 2 && config.num_output_channels == 2 } /// Initialize the plugin for the given bus and buffer configurations. If the plugin is being /// restored from an old state, then that state will have already been restored at this point. /// If based on those parameters (or for any reason whatsoever) the plugin needs to introduce /// latency, then you can do so here using the process context. Depending on how the host /// restores plugin state, this function may also be called twice in rapid succession. If the /// plugin fails to inialize for whatever reason, then this should return `false`. /// /// Before this point, the plugin should not have done any expensive initialization. Please /// don't be that plugin that takes twenty seconds to scan. fn initialize( &mut self, bus_config: &BusConfig, buffer_config: &BufferConfig, context: &mut impl ProcessContext, ) -> bool { true } /// Process audio. The host's input buffers have already been copied to the output buffers if /// they are not processing audio in place (most hosts do however). All channels are also /// guarenteed to contain the same number of samples. Lastly, denormals have already been taken /// case of by NIH-plug, and you can optionally enable the `assert_process_allocs` feature to /// abort the program when any allocation accurs in the process function while running in debug /// mode. /// /// TODO: Provide a way to access auxiliary input channels if the IO configuration is /// assymetric /// TODO: Pass transport and other context information to the plugin fn process(&mut self, buffer: &mut Buffer, context: &mut impl ProcessContext) -> ProcessStatus; } /// Provides auxiliary metadata needed for a VST3 plugin. pub trait Vst3Plugin: Plugin { /// The unique class ID that identifies this particular plugin. You can use the /// `*b"fooofooofooofooo"` syntax for this. /// /// This will be shuffled into a different byte order on Windows for project-compatibility. const VST3_CLASS_ID: [u8; 16]; /// One or more categories, separated by pipe characters (`|`), up to 127 characters. Anything /// logner than that will be truncated. See the VST3 SDK for examples of common categories: /// const VST3_CATEGORIES: &'static str; /// [Self::VST3_CLASS_ID] in the correct order for the current platform so projects and presets /// can be shared between platforms. This should not be overridden. const PLATFORM_VST3_CLASS_ID: [u8; 16] = swap_vst3_uid_byte_order(Self::VST3_CLASS_ID); } #[cfg(not(target_os = "windows"))] const fn swap_vst3_uid_byte_order(uid: [u8; 16]) -> [u8; 16] { uid } #[cfg(target_os = "windows")] const fn swap_vst3_uid_byte_order(mut uid: [u8; 16]) -> [u8; 16] { // No mutable references in const functions, so we can't use `uid.swap()` let original_uid = uid; uid[0] = original_uid[3]; uid[1] = original_uid[2]; uid[2] = original_uid[1]; uid[3] = original_uid[0]; uid[4] = original_uid[5]; uid[5] = original_uid[4]; uid[6] = original_uid[7]; uid[7] = original_uid[6]; uid } /// An editor for a [Plugin]. pub trait Editor: Send + Sync { /// Create an instance of the plugin's editor and embed it in the parent window. As explained in /// [Plugin::editor], you can then read the parameter values directly from your [Params] object, /// and modifying the values can be done using the functions on the [ParamSetter]. When you /// change a parameter value that way it will be broadcasted to the host and also updated in /// your [Params] struct. /// /// This function should return a handle to the editor, which will be dropped when the editor /// gets closed. Implement the [Drop] trait on the returned handle if you need to explicitly /// handle the editor's closing behavior. /// /// The wrapper guarantees that a previous handle has been dropped before this function is /// called again. // // TODO: Think of how this would work with the event loop. On Linux the wrapper must provide a // timer using VST3's `IRunLoop` interface, but on Window and macOS the window would // normally register its own timer. Right now we just ignore this because it would // otherwise be basically impossible to have this still be GUI-framework agnostic. Any // callback that deos involve actual GUI operations will still be spooled to the IRunLoop // instance. fn spawn(&self, parent: ParentWindowHandle, context: Arc) -> Box; /// Return the (currnent) size of the editor in pixels as a `(width, height)` pair. fn size(&self) -> (u32, u32); // TODO: Reconsider adding a tick function here for the Linux `IRunLoop`. To keep this platform // and API agnostic, add a way to ask the GuiContext if the wrapper already provides a // tick function. If it does not, then the Editor implementation must handle this by // itself. This would also need an associated `PREFERRED_FRAME_RATE` constant. // TODO: Add the things needed for DPI scaling // TODO: Resizing } /// A raw window handle for platform and GUI framework agnostic editors. pub struct ParentWindowHandle { pub handle: RawWindowHandle, } unsafe impl HasRawWindowHandle for ParentWindowHandle { fn raw_window_handle(&self) -> RawWindowHandle { self.handle } } /// We only support a single main input and output bus at the moment. #[derive(Debug, Clone, Copy, PartialEq, Eq)] pub struct BusConfig { /// The number of input channels for the plugin. pub num_input_channels: u32, /// The number of output channels for the plugin. pub num_output_channels: u32, } /// Configuration for (the host's) audio buffers. #[derive(Debug, Clone, Copy, PartialEq)] pub struct BufferConfig { /// The current sample rate. pub sample_rate: f32, /// The maximum buffer size the host will use. The plugin should be able to accept variable /// sized buffers up to this size. pub max_buffer_size: u32, } /// Indicates the current situation after the plugin has processed audio. #[derive(Debug, Clone, Copy, PartialEq, Eq)] pub enum ProcessStatus { /// Something went wrong while processing audio. Error(&'static str), /// The plugin has finished processing audio. When the input is silent, the most may suspend the /// plugin to save resources as it sees fit. Normal, /// The plugin has a (reverb) tail with a specific length in samples. Tail(u32), /// This plugin will continue to produce sound regardless of whether or not the input is silent, /// and should thus not be deactivated by the host. This is essentially the same as having an /// infite tail. KeepAlive, } /// Event for (incoming) notes. Right now this only supports a very small subset of the MIDI /// specification. See the util module for convenient conversion functions. /// /// All of the timings are sample offsets withing the current buffer. /// /// TODO: Add more events as needed #[derive(Debug, Copy, Clone, PartialEq, Eq)] pub enum NoteEvent { NoteOn { timing: u32, channel: u8, note: u8, velocity: u8, }, NoteOff { timing: u32, channel: u8, note: u8, velocity: u8, }, } impl NoteEvent { /// Return the sample within the current buffer this event belongs to. pub fn timing(&self) -> u32 { match &self { NoteEvent::NoteOn { timing, .. } => *timing, NoteEvent::NoteOff { timing, .. } => *timing, } } }