Add more basic fields for PolyModSynth

Cargo.lock

@@ -2939,6 +2939,8 @@ name = "poly_mod_synth"
 version = "0.1.0"
 dependencies = [
  "nih_plug",
+ "rand 0.8.5",
+ "rand_pcg 0.3.1",
 ]
 
 [[package]]
@@ -3057,7 +3059,7 @@ dependencies = [
  "rand_chacha 0.2.2",
  "rand_core 0.5.1",
  "rand_hc",
- "rand_pcg",
+ "rand_pcg 0.2.1",
 ]
 
 [[package]]
@@ -3127,6 +3129,15 @@ dependencies = [
  "rand_core 0.5.1",
 ]
 
+[[package]]
+name = "rand_pcg"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59cad018caf63deb318e5a4586d99a24424a364f40f1e5778c29aca23f4fc73e"
+dependencies = [
+ "rand_core 0.6.3",
+]
+
 [[package]]
 name = "range-alloc"
 version = "0.1.2"

plugins/examples/poly_mod_synth/Cargo.toml

@@ -10,3 +10,6 @@ crate-type = ["cdylib"]
 
 [dependencies]
 nih_plug = { path = "../../../", features = ["assert_process_allocs"] }
+
+rand = "0.8.5"
+rand_pcg = "0.3.1"

plugins/examples/poly_mod_synth/src/lib.rs

@@ -1,4 +1,6 @@
 use nih_plug::prelude::*;
+use rand::Rng;
+use rand_pcg::Pcg32;
 use std::sync::Arc;
 
 /// The number of simultaneous voices for this synth.
@@ -13,6 +15,9 @@ const MAX_BLOCK_SIZE: usize = 64;
 struct PolyModSynth {
     params: Arc<PolyModSynthParams>,
 
+    /// A pseudo-random number generator. This will always be reseeded with the same seed when the
+    /// synth is reset. That way the output is deterministic when rendering multiple times.
+    prng: Pcg32,
     /// The synth's voices. Inactive voices will be set to `None` values.
     voices: [Option<Voice>; NUM_VOICES as usize],
     /// The next internal voice ID, used only to figure out the oldest voice for voice stealing.
@@ -39,6 +44,15 @@ struct Voice {
     /// The voices internal ID. Each voice has an internal voice ID one higher than the previous
     /// voice. This is used to steal the last voice in case all 16 voices are in use.
     internal_voice_id: u64,
+
+    /// The voice's current phase. This is randomized at the start of the voice
+    phase: f32,
+    /// The phase increment. This is based on the voice's frequency, derived from the note index.
+    /// Since we don't support pitch expressions or pitch bend, this value stays constant for the
+    /// duration of the voice.
+    phase_delta: f32,
+    /// The square root of the note's velocity. This is used as a gain multiplier.
+    velocity_sqrt: f32,
 }
 
 impl Default for PolyModSynth {
@@ -46,6 +60,7 @@ impl Default for PolyModSynth {
         Self {
             params: Arc::new(PolyModSynthParams::default()),
 
+            prng: Pcg32::new(420, 1337),
             // `[None; N]` requires the `Some(T)` to be `Copy`able
             voices: [0; NUM_VOICES as usize].map(|_| None),
             next_internal_voice_id: 0,
@@ -77,6 +92,9 @@ impl Plugin for PolyModSynth {
     // `context.set_current_voice_capacity()` in `initialize()` and in `process()` (when the
     // capacity changes) to inform the host about this.
     fn reset(&mut self) {
+        // This ensures the output is at least somewhat deterministic when rendering to audio
+        self.prng = Pcg32::new(420, 1337);
+
         self.voices.fill(None);
         self.next_internal_voice_id = 0;
     }
@@ -125,6 +143,10 @@ impl Plugin for PolyModSynth {
                                 );
 
                                 // TODO: Add and set the other fields
+                                voice.phase = self.prng.gen();
+                                voice.phase_delta =
+                                    util::midi_note_to_freq(note) / context.transport().sample_rate;
+                                voice.velocity_sqrt = velocity.sqrt();
                             }
                             NoteEvent::NoteOff {
                                 timing,
@@ -211,6 +233,10 @@ impl PolyModSynth {
             internal_voice_id: self.next_internal_voice_id,
             channel,
             note,
+
+            velocity_sqrt: 1.0,
+            phase: 0.0,
+            phase_delta: 0.0,
         };
         self.next_internal_voice_id = self.next_internal_voice_id.wrapping_add(1);
 

src/wrapper/clap/context.rs

@@ -131,6 +131,7 @@ impl<P: ClapPlugin> ProcessContext for WrapperProcessContext<'_, P> {
         PluginApi::Clap
     }
 
+    #[inline]
     fn transport(&self) -> &Transport {
         &self.transport
     }

src/wrapper/standalone/context.rs

@@ -101,6 +101,7 @@ impl<P: Plugin, B: Backend> ProcessContext for WrapperProcessContext<'_, P, B> {
         PluginApi::Standalone
     }
 
+    #[inline]
     fn transport(&self) -> &Transport {
         &self.transport
     }

src/wrapper/vst3/context.rs

@@ -135,6 +135,7 @@ impl<P: Vst3Plugin> ProcessContext for WrapperProcessContext<'_, P> {
         PluginApi::Vst3
     }
 
+    #[inline]
     fn transport(&self) -> &Transport {
         &self.transport
     }