Replace ACCEPTS_MIDI bool with new enum

So we can gate future MIDI CC support behind an additional option since
this involves more work on the VST3 side.

plugins/examples/gain-gui-egui/src/lib.rs

@@ -70,7 +70,7 @@ impl Plugin for Gain {
     const DEFAULT_NUM_INPUTS: u32 = 2;
     const DEFAULT_NUM_OUTPUTS: u32 = 2;
 
-    const ACCEPTS_MIDI: bool = false;
+    const MIDI_INPUT: MidiConfig = MidiConfig::None;
     const SAMPLE_ACCURATE_AUTOMATION: bool = true;
 
     fn params(&self) -> Arc<dyn Params> {

plugins/examples/gain-gui-iced/src/lib.rs

@@ -67,7 +67,7 @@ impl Plugin for Gain {
     const DEFAULT_NUM_INPUTS: u32 = 2;
     const DEFAULT_NUM_OUTPUTS: u32 = 2;
 
-    const ACCEPTS_MIDI: bool = false;
+    const MIDI_INPUT: MidiConfig = MidiConfig::None;
     const SAMPLE_ACCURATE_AUTOMATION: bool = true;
 
     fn params(&self) -> Arc<dyn Params> {

plugins/examples/gain-gui-vizia/src/lib.rs

@@ -67,7 +67,7 @@ impl Plugin for Gain {
     const DEFAULT_NUM_INPUTS: u32 = 2;
     const DEFAULT_NUM_OUTPUTS: u32 = 2;
 
-    const ACCEPTS_MIDI: bool = false;
+    const MIDI_INPUT: MidiConfig = MidiConfig::None;
     const SAMPLE_ACCURATE_AUTOMATION: bool = true;
 
     fn params(&self) -> Arc<dyn Params> {

plugins/examples/gain/src/lib.rs

@@ -103,7 +103,7 @@ impl Plugin for Gain {
     const DEFAULT_NUM_INPUTS: u32 = 2;
     const DEFAULT_NUM_OUTPUTS: u32 = 2;
 
-    const ACCEPTS_MIDI: bool = false;
+    const MIDI_INPUT: MidiConfig = MidiConfig::None;
     // Setting this to `true` will tell the wrapper to split the buffer up into smaller blocks
     // whenever there are inter-buffer parameter changes. This way no changes to the plugin are
     // required to support sample accurate automation and the wrapper handles all of the boring

plugins/examples/sine/src/lib.rs

@@ -103,7 +103,7 @@ impl Plugin for Sine {
     const DEFAULT_NUM_INPUTS: u32 = 0;
     const DEFAULT_NUM_OUTPUTS: u32 = 2;
 
-    const ACCEPTS_MIDI: bool = true;
+    const MIDI_INPUT: MidiConfig = MidiConfig::Basic;
     const SAMPLE_ACCURATE_AUTOMATION: bool = true;
 
     fn params(&self) -> Arc<dyn Params> {

plugins/examples/stft/src/lib.rs

@@ -87,7 +87,7 @@ impl Plugin for Stft {
     const DEFAULT_NUM_INPUTS: u32 = 2;
     const DEFAULT_NUM_OUTPUTS: u32 = 2;
 
-    const ACCEPTS_MIDI: bool = false;
+    const MIDI_INPUT: MidiConfig = MidiConfig::None;
     const SAMPLE_ACCURATE_AUTOMATION: bool = true;
 
     fn params(&self) -> Arc<dyn Params> {

src/plugin.rs

@@ -41,9 +41,9 @@ pub trait Plugin: Default + Send + Sync + 'static {
     /// 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
+    /// Whether the plugin accepts note events, and which level of . If this is set to
-    /// receive any note events.
+    /// [`MidiConfig::None`], then the plugin won't receive any note events.
-    const ACCEPTS_MIDI: bool = false;
+    const MIDI_INPUT: MidiConfig = MidiConfig::None;
     /// If enabled, the audio processing cycle may be split up into multiple smaller chunks if
     /// parameter values change occur in the middle of the buffer. Depending on the host these
     /// blocks may be as small as a single sample. Bitwig Studio sends at most one parameter change
@@ -303,15 +303,30 @@ pub enum ProcessStatus {
     KeepAlive,
 }
 
-/// Event for (incoming) notes. Right now this only supports a very small subset of the MIDI
+/// Determines which note events a plugin receives.
-/// specification. See the util module for convenient conversion functions.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub enum MidiConfig {
+    /// The plugin will not have a note input port and will thus not receive any not events.
+    None,
+    /// The plugin receives note on/off events, pressure, and potentially a couple standardized
+    /// expression types depending on the plugin standard and host.
+    Basic,
+    // // TODO:
+    // /// The plugin receives full MIDI CCs as well as pitch bend information. For VST3 plugins this
+    // /// involves adding
+    // MidiCCs,
+}
+
+/// Event for (incoming) notes. The set of supported note events depends on the value of
+/// [`Plugin::MIDI_INPUT`]. Also check out the [`util`][crate::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)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 pub enum NoteEvent {
-    /// A note on event.
+    /// A note on event, available on [`MidiConfig::Basic`] and up.
     NoteOn {
         timing: u32,
         /// The note's channel, from 0 to 16.
@@ -322,7 +337,7 @@ pub enum NoteEvent {
         /// 127 levels available in MIDI.
         velocity: f32,
     },
-    /// A note off event.
+    /// A note off event, available on [`MidiConfig::Basic`] and up.
     NoteOff {
         timing: u32,
         /// The note's channel, from 0 to 16.

src/prelude.rs

@@ -19,7 +19,7 @@ pub use crate::param::range::{FloatRange, IntRange};
 pub use crate::param::smoothing::{Smoother, SmoothingStyle};
 pub use crate::param::{BoolParam, FloatParam, IntParam, Param, ParamFlags};
 pub use crate::plugin::{
-    BufferConfig, BusConfig, ClapPlugin, Editor, NoteEvent, ParentWindowHandle, Plugin,
+    BufferConfig, BusConfig, ClapPlugin, Editor, MidiConfig, NoteEvent, ParentWindowHandle, Plugin,
     ProcessStatus, Vst3Plugin,
 };
 pub use crate::wrapper::state::PluginState;

src/wrapper/clap/wrapper.rs

@@ -72,7 +72,8 @@ use crate::event_loop::{EventLoop, MainThreadExecutor, TASK_QUEUE_CAPACITY};
 use crate::param::internals::{ParamPtr, Params};
 use crate::param::ParamFlags;
 use crate::plugin::{
-    BufferConfig, BusConfig, ClapPlugin, Editor, NoteEvent, ParentWindowHandle, ProcessStatus,
+    BufferConfig, BusConfig, ClapPlugin, Editor, MidiConfig, NoteEvent, ParentWindowHandle,
+    ProcessStatus,
 };
 use crate::util::permit_alloc;
 use crate::wrapper::state::{self, PluginState};
@@ -116,7 +117,8 @@ pub struct Wrapper<P: ClapPlugin> {
     /// The current buffer configuration, containing the sample rate and the maximum block size.
     /// Will be set in `clap_plugin::activate()`.
     current_buffer_config: AtomicCell<Option<BufferConfig>>,
-    /// The incoming events for the plugin, if `P::ACCEPTS_MIDI` is set.
+    /// The incoming events for the plugin, if `P::MIDI_INPUT` is set to `MidiConfig::Basic` or
+    /// higher.
     ///
     /// TODO: Maybe load these lazily at some point instead of needing to spool them all to this
     ///       queue first
@@ -867,7 +869,7 @@ impl<P: ClapPlugin> Wrapper<P> {
             //     true
             // }
             (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_NOTE_ON) => {
-                if P::ACCEPTS_MIDI {
+                if P::MIDI_INPUT >= MidiConfig::Basic {
                     let event = &*(event as *const clap_event_note);
                     input_events.push_back(NoteEvent::NoteOn {
                         // When splitting up the buffer for sample accurate automation all events
@@ -882,7 +884,7 @@ impl<P: ClapPlugin> Wrapper<P> {
                 false
             }
             (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_NOTE_OFF) => {
-                if P::ACCEPTS_MIDI {
+                if P::MIDI_INPUT >= MidiConfig::Basic {
                     let event = &*(event as *const clap_event_note);
                     input_events.push_back(NoteEvent::NoteOff {
                         timing: raw_event.time - current_sample_idx as u32,
@@ -895,7 +897,7 @@ impl<P: ClapPlugin> Wrapper<P> {
                 false
             }
             (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_NOTE_EXPRESSION) => {
-                if P::ACCEPTS_MIDI {
+                if P::MIDI_INPUT >= MidiConfig::Basic {
                     // We currently don't report supporting this at all in the event filter, add that once
                     // we support MIDI CCs
                     // TODO: Implement pressure and other expressions along with MIDI CCs
@@ -904,7 +906,7 @@ impl<P: ClapPlugin> Wrapper<P> {
                 false
             }
             (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_MIDI) => {
-                if P::ACCEPTS_MIDI {
+                if P::MIDI_INPUT >= MidiConfig::Basic {
                     // We currently don't report supporting this at all in the event filter, add that once
                     // we support MIDI CCs
                     // TODO: Implement raw MIDI handling once we add CCs
@@ -1392,7 +1394,7 @@ impl<P: ClapPlugin> Wrapper<P> {
             &wrapper.clap_plugin_gui as *const _ as *const c_void
         } else if id == CStr::from_ptr(CLAP_EXT_LATENCY) {
             &wrapper.clap_plugin_latency as *const _ as *const c_void
-        } else if id == CStr::from_ptr(CLAP_EXT_NOTE_PORTS) && P::ACCEPTS_MIDI {
+        } else if id == CStr::from_ptr(CLAP_EXT_NOTE_PORTS) && P::MIDI_INPUT >= MidiConfig::Basic {
             &wrapper.clap_plugin_note_ports as *const _ as *const c_void
         } else if id == CStr::from_ptr(CLAP_EXT_PARAMS) {
             &wrapper.clap_plugin_params as *const _ as *const c_void
@@ -1618,7 +1620,7 @@ impl<P: ClapPlugin> Wrapper<P> {
             // TODO: Implement midi CC handling
             // | (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_NOTE_EXPRESSION)
             // | (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_MIDI)
-                if P::ACCEPTS_MIDI =>
+                if P::MIDI_INPUT >= MidiConfig::Basic =>
             {
                 true
             }
@@ -1870,7 +1872,7 @@ impl<P: ClapPlugin> Wrapper<P> {
     unsafe extern "C" fn ext_note_ports_count(_plugin: *const clap_plugin, is_input: bool) -> u32 {
         // TODO: Outputting notes
         match is_input {
-            true if P::ACCEPTS_MIDI => 1,
+            true if P::MIDI_INPUT >= MidiConfig::Basic => 1,
             _ => 0,
         }
     }
@@ -1882,7 +1884,7 @@ impl<P: ClapPlugin> Wrapper<P> {
         info: *mut clap_note_port_info,
     ) -> bool {
         match (index, is_input) {
-            (0, true) if P::ACCEPTS_MIDI => {
+            (0, true) if P::MIDI_INPUT >= MidiConfig::Basic => {
                 *info = std::mem::zeroed();
 
                 let info = &mut *info;

src/wrapper/vst3/wrapper.rs

@@ -19,7 +19,7 @@ use super::util::VstPtr;
 use super::view::WrapperView;
 use crate::context::Transport;
 use crate::param::ParamFlags;
-use crate::plugin::{BufferConfig, BusConfig, NoteEvent, ProcessStatus, Vst3Plugin};
+use crate::plugin::{BufferConfig, BusConfig, MidiConfig, NoteEvent, ProcessStatus, Vst3Plugin};
 use crate::util::permit_alloc;
 use crate::wrapper::state;
 use crate::wrapper::util::{process_wrapper, u16strlcpy};
@@ -71,7 +71,7 @@ impl<P: Vst3Plugin> IComponent for Wrapper<P> {
             x if x == vst3_sys::vst::MediaTypes::kAudio as i32 => 1,
             x if x == vst3_sys::vst::MediaTypes::kEvent as i32
                 && dir == vst3_sys::vst::BusDirections::kInput as i32
-                && P::ACCEPTS_MIDI =>
+                && P::MIDI_INPUT >= MidiConfig::Basic =>
             {
                 1
             }
@@ -119,7 +119,7 @@ impl<P: Vst3Plugin> IComponent for Wrapper<P> {
             (t, d, 0)
                 if t == vst3_sys::vst::MediaTypes::kEvent as i32
                     && d == vst3_sys::vst::BusDirections::kInput as i32
-                    && P::ACCEPTS_MIDI =>
+                    && P::MIDI_INPUT >= MidiConfig::Basic =>
             {
                 *info = mem::zeroed();
 
@@ -172,7 +172,7 @@ impl<P: Vst3Plugin> IComponent for Wrapper<P> {
             (t, d, 0)
                 if t == vst3_sys::vst::MediaTypes::kEvent as i32
                     && d == vst3_sys::vst::BusDirections::kInput as i32
-                    && P::ACCEPTS_MIDI =>
+                    && P::MIDI_INPUT >= MidiConfig::Basic =>
             {
                 kResultOk
             }
@@ -743,7 +743,7 @@ impl<P: Vst3Plugin> IAudioProcessor for Wrapper<P> {
                     parameter_values_changed = false;
                 }
 
-                if P::ACCEPTS_MIDI {
+                if P::MIDI_INPUT >= MidiConfig::Basic {
                     let mut input_events = self.inner.input_events.borrow_mut();
                     if let Some(events) = data.input_events.upgrade() {
                         let num_events = events.get_event_count();