gui experiment

src/editor.rs

@@ -0,0 +1,65 @@
+use atomic_float::AtomicF32;
+use nih_plug::{editor::Editor, util};
+use nih_plug_vizia::{
+    ViziaState, ViziaTheming, assets, create_vizia_editor,
+    vizia::prelude::*,
+    widgets::{ParamSlider, PeakMeter, ResizeHandle},
+};
+use std::sync::{Arc, atomic::Ordering};
+
+use crate::GainParams;
+
+#[derive(Lens)]
+struct Data {
+    params: Arc<GainParams>,
+    peak_meter: Arc<AtomicF32>,
+}
+
+impl Model for Data {}
+
+pub(crate) fn default_state() -> Arc<ViziaState> {
+    ViziaState::new(|| (200, 150))
+}
+
+pub(crate) fn create(
+    params: Arc<GainParams>,
+    peak_meter: Arc<AtomicF32>,
+    editor_state: Arc<ViziaState>,
+) -> Option<Box<dyn Editor>> {
+    create_vizia_editor(editor_state, ViziaTheming::Custom, move |cx, _| {
+        assets::register_noto_sans_light(cx);
+        assets::register_noto_sans_thin(cx);
+
+        Data {
+            params: params.clone(),
+            peak_meter: peak_meter.clone(),
+        }
+        .build(cx);
+
+        VStack::new(cx, |cx| {
+            Label::new(cx, "Gain GUI")
+                .font_family(vec![FamilyOwned::Name(String::from(assets::NOTO_SANS))])
+                .font_weight(FontWeightKeyword::Thin)
+                .font_size(30.0)
+                .height(Pixels(50.0))
+                .child_top(Stretch(1.0))
+                .child_bottom(Pixels(0.0));
+
+            Label::new(cx, "Gain");
+            ParamSlider::new(cx, Data::params, |params| &params.gain);
+
+            PeakMeter::new(
+                cx,
+                Data::peak_meter
+                    .map(|peak_meter| util::gain_to_db(peak_meter.load(Ordering::Relaxed))),
+                Some(Duration::from_millis(600)),
+            )
+            .top(Pixels(10.0));
+        })
+        .row_between(Pixels(0.0))
+        .child_left(Stretch(1.0))
+        .child_right(Stretch(1.0));
+
+        ResizeHandle::new(cx);
+    })
+}

src/lib.rs

@@ -1,42 +1,37 @@
-use nih_plug::{params::persist, prelude::*};
-use parking_lot::Mutex;
-use std::sync::Arc;
+use atomic_float::AtomicF32;
+use nih_plug::prelude::*;
+use nih_plug_vizia::ViziaState;
+use std::sync::{Arc, atomic::Ordering};
 
-struct Gain {
+mod editor;
+
+const PEAK_METER_DECAY_MS: f64 = 150.0;
+
+pub struct Gain {
     params: Arc<GainParams>,
+
+    // gotta normalize peak meters response based on sample rate :)
+    peak_meter_decay_weight: f32,
+    // current peak meter value, stored in Arc to share between GUI and processing
+    peak_meter: Arc<AtomicF32>,
 }
 
 #[derive(Params)]
 struct GainParams {
+    #[persist = "editor-state"]
+    editor_state: Arc<ViziaState>,
+
     #[id = "gain"]
     pub gain: FloatParam,
-
-    #[persist = "industry_secrets"]
-    pub random: Mutex<Vec<f32>>,
-
-    #[nested(group = "Subparameters")]
-    pub sub_params: SubParams,
-
-    #[nested(array, group = "Array Parameters")]
-    pub array_params: [ArrayParams; 3],
-}
-
-#[derive(Params)]
-struct SubParams {
-    #[id = "thing"]
-    pub nested_parameter: FloatParam,
-}
-
-#[derive(Params)]
-struct ArrayParams {
-    #[id = "noope"]
-    pub nope: FloatParam,
 }
 
 impl Default for Gain {
     fn default() -> Self {
         Self {
             params: Arc::new(GainParams::default()),
+
+            peak_meter_decay_weight: 1.0,
+            peak_meter: Arc::new(AtomicF32::new(util::MINUS_INFINITY_DB)),
         }
     }
 }
@@ -44,45 +39,21 @@ impl Default for Gain {
 impl Default for GainParams {
     fn default() -> Self {
         Self {
-            // gain stored as linear gain.
+            editor_state: editor::default_state(),
+
             gain: FloatParam::new(
                 "Gain",
                 util::db_to_gain(0.0),
                 FloatRange::Skewed {
                     min: -30.0,
                     max: 30.0,
-                    // makes range appear as if linear while displaying decibel values
                     factor: FloatRange::gain_skew_factor(-30.0, 30.0),
                 },
             )
-            // logarithmic smoothing because value is stored as linear
             .with_smoother(SmoothingStyle::Logarithmic(50.0))
             .with_unit(" dB")
             .with_value_to_string(formatters::v2s_f32_gain_to_db(2))
             .with_string_to_value(formatters::s2v_f32_gain_to_db()),
-
-            // persisted values can be initialized like any other
-            random: Mutex::new(Vec::new()),
-            sub_params: SubParams {
-                nested_parameter: FloatParam::new(
-                    "Unused Nested Parameter",
-                    0.5,
-                    FloatRange::Skewed {
-                        min: 2.0,
-                        max: 2.4,
-                        factor: FloatRange::skew_factor(2.0),
-                    },
-                )
-                .with_value_to_string(formatters::v2s_f32_rounded(2)),
-            },
-
-            array_params: [1, 2, 3].map(|i| ArrayParams {
-                nope: FloatParam::new(
-                    format!("Nope {i}"),
-                    0.5,
-                    FloatRange::Linear { min: 1.0, max: 2.0 },
-                ),
-            }),
         }
     }
 }
@@ -102,11 +73,7 @@ impl Plugin for Gain {
         AudioIOLayout {
             main_input_channels: NonZeroU32::new(2),
             main_output_channels: NonZeroU32::new(2),
-
-            aux_input_ports: &[],
-            aux_output_ports: &[],
-
-            names: PortNames::const_default(),
+            ..AudioIOLayout::const_default()
         },
         AudioIOLayout {
             main_input_channels: NonZeroU32::new(1),
@@ -125,6 +92,27 @@ impl Plugin for Gain {
         self.params.clone()
     }
 
+    fn editor(&mut self, _async_executor: AsyncExecutor<Self>) -> Option<Box<dyn Editor>> {
+        editor::create(
+            self.params.clone(),
+            self.peak_meter.clone(),
+            self.params.editor_state.clone(),
+        )
+    }
+
+    fn initialize(
+        &mut self,
+        _audio_io_layout: &AudioIOLayout,
+        buffer_config: &BufferConfig,
+        _context: &mut impl InitContext<Self>,
+    ) -> bool {
+        self.peak_meter_decay_weight = 0.25f64
+            .powf((buffer_config.sample_rate as f64 * PEAK_METER_DECAY_MS / 1000.0).recip())
+            as f32;
+
+        true
+    }
+
     fn process(
         &mut self,
         buffer: &mut Buffer,
@@ -132,10 +120,27 @@ impl Plugin for Gain {
         _context: &mut impl ProcessContext<Self>,
     ) -> ProcessStatus {
         for channel_samples in buffer.iter_samples() {
-            let gain = self.params.gain.smoothed.next();
+            let mut amplitude = 0.0;
+            let num_samples = channel_samples.len();
 
+            let gain = self.params.gain.smoothed.next();
             for sample in channel_samples {
                 *sample *= gain;
+                amplitude += *sample;
+            }
+
+            // save resources by only doing GUI calculations when GUI is open
+            if self.params.editor_state.is_open() {
+                amplitude = (amplitude / num_samples as f32).abs();
+                let current_peak_meter = self.peak_meter.load(Ordering::Relaxed);
+                let new_peak_meter = if amplitude > current_peak_meter {
+                    amplitude
+                } else {
+                    current_peak_meter * self.peak_meter_decay_weight
+                        + amplitude * (1.0 - self.peak_meter_decay_weight)
+                };
+
+                self.peak_meter.store(new_peak_meter, Ordering::Relaxed);
             }
         }