Add a stub for poly_mod_synth

This will serve as an example implementation for polyphonic modulation.

Cargo.lock

@@ -2934,6 +2934,13 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "poly_mod_synth"
+version = "0.1.0"
+dependencies = [
+ "nih_plug",
+]
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.16"

Cargo.toml

@@ -25,6 +25,7 @@ members = [
   "plugins/examples/gain_gui_iced",
   "plugins/examples/gain_gui_vizia",
   "plugins/examples/midi_inverter",
+  "plugins/examples/poly_mod_synth",
   "plugins/examples/sine",
   "plugins/examples/stft",
 

README.md

@@ -170,9 +170,12 @@ examples.
   [egui](plugins/examples/gain_gui_egui),
   [iced](plugins/examples/gain_gui_iced), and
   [VIZIA](plugins/examples/gain_gui_vizia).
-- [**midi-inverter**](plugins/examples/midi-inverter) takes note/MIDI events and
+- [**midi_inverter**](plugins/examples/midi_inverter) takes note/MIDI events and
   flips around the note, channel, expression, pressure, and CC values. This
   example demonstrates how to receive and output those events.
+- [**poly_mod_synth**](plugins/examples/poly_mod_synth) is a simple polyphonic
+  synthesizer with support for polyphonic modulation in supported CLAP hosts.
+  This demonstrates how polyphonic modulation can be used in NIH-plug.
 - [**sine**](plugins/examples/sine) is a simple test tone generator plugin with
   frequency smoothing that can also make use of MIDI input instead of generating
   a static signal based on the plugin's parameters.

plugins/examples/poly_mod_synth/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "poly_mod_synth"
+version = "0.1.0"
+edition = "2021"
+authors = ["Robbert van der Helm <mail@robbertvanderhelm.nl>"]
+license = "ISC"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+nih_plug = { path = "../../../", features = ["assert_process_allocs"] }

plugins/examples/poly_mod_synth/src/lib.rs

@@ -0,0 +1,79 @@
+use nih_plug::prelude::*;
+use std::sync::Arc;
+
+/// A simple polyphonic synthesizer with support for CLAP's polyphonic modulation. See
+/// `NoteEvent::PolyModulation` for another source of information on how to use this.
+struct PolyModSynth {
+    params: Arc<PolyModSynthParams>,
+}
+
+#[derive(Default, Params)]
+struct PolyModSynthParams {}
+
+impl Default for PolyModSynth {
+    fn default() -> Self {
+        Self {
+            params: Arc::new(PolyModSynthParams::default()),
+        }
+    }
+}
+
+impl Plugin for PolyModSynth {
+    const NAME: &'static str = "Poly Mod Synth";
+    const VENDOR: &'static str = "Moist Plugins GmbH";
+    const URL: &'static str = "https://youtu.be/dQw4w9WgXcQ";
+    const EMAIL: &'static str = "info@example.com";
+
+    const VERSION: &'static str = "0.0.1";
+
+    const DEFAULT_NUM_INPUTS: u32 = 2;
+    const DEFAULT_NUM_OUTPUTS: u32 = 2;
+
+    // We won't need any MIDI CCs here, we just want notes and polyphonic modulation
+    const MIDI_INPUT: MidiConfig = MidiConfig::Basic;
+    const MIDI_OUTPUT: MidiConfig = MidiConfig::Basic;
+    const SAMPLE_ACCURATE_AUTOMATION: bool = true;
+
+    fn params(&self) -> Arc<dyn Params> {
+        self.params.clone()
+    }
+
+    fn process(
+        &mut self,
+        _buffer: &mut Buffer,
+        _aux: &mut AuxiliaryBuffers,
+        context: &mut impl ProcessContext,
+    ) -> ProcessStatus {
+        // TODO: Split blocks, so something cool
+        while let Some(event) = context.next_event() {
+            match event {
+                _ => (),
+            }
+        }
+
+        ProcessStatus::Normal
+    }
+}
+
+impl ClapPlugin for PolyModSynth {
+    const CLAP_ID: &'static str = "com.moist-plugins-gmbh.poly-mod-synth";
+    const CLAP_DESCRIPTION: Option<&'static str> =
+        Some("A simple polyphonic synthesizer with support for polyphonic modulation");
+    const CLAP_MANUAL_URL: Option<&'static str> = Some(Self::URL);
+    const CLAP_SUPPORT_URL: Option<&'static str> = None;
+    const CLAP_FEATURES: &'static [ClapFeature] = &[
+        ClapFeature::Instrument,
+        ClapFeature::Synthesizer,
+        ClapFeature::Stereo,
+    ];
+}
+
+// The VST3 verison of this plugin isn't too interesting as it will not support polyphonic
+// modulation
+impl Vst3Plugin for PolyModSynth {
+    const VST3_CLASS_ID: [u8; 16] = *b"PolyM0dSynth1337";
+    const VST3_CATEGORIES: &'static str = "Instrument|Synth";
+}
+
+nih_export_clap!(PolyModSynth);
+nih_export_vst3!(PolyModSynth);