Early support for measurements

src/main.rs

@@ -2,7 +2,7 @@ use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
 use cpal::SampleFormat;
 
 use egui::epaint::Hsva;
-use egui::Color32;
+use egui::{Color32, Label, Widget};
 use egui_plot::{Legend, Line, Plot};
 
 use std::mem::swap;
@@ -105,8 +105,49 @@ struct MyApp {
     ui_selections: MyAppUiSelections,
 }
 
+struct Db(f64);
+
+trait MeasurementValueType {
+    fn label_format(&self) -> String;
+}
+
+struct Measurement<T: MeasurementValueType> {
+    name: &'static str,
+    values: Vec<T>,
+}
+
+impl MeasurementValueType for Db {
+    fn label_format(&self) -> String {
+        format!("{:2.2} dB", self.0)
+    }
+}
+
+impl<T: MeasurementValueType> Widget for Measurement<T> {
+    fn ui(self, ui: &mut egui::Ui) -> egui::Response {
+        ui.group(|ui| {
+            ui.label(self.name);
+            ui.vertical(|ui| {
+                for (chan, value) in self.values.iter().enumerate() {
+                    ui.colored_label(CHANNEL_COLOURS[chan], value.label_format());
+                }
+            })
+        }).response
+    }
+}
+
 impl eframe::App for MyApp {
     fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
+        let measurements = vec![Measurement::<Db> {
+            name: &"RMS",
+            values: self
+                .last_result
+                .fft_analyses
+                .lock()
+                .unwrap()
+                .iter()
+                .map(|x| Db(lin_to_db(x.total_power as f64)))
+                .collect(),
+        }];
         egui::SidePanel::left("left_panel").show(ctx, |ui| {
             egui::ComboBox::from_label("Source")
                 .selected_text(self.audio_devices[self.ui_selections.audio_device].clone())
@@ -127,6 +168,11 @@ impl eframe::App for MyApp {
             });
         });
         egui::CentralPanel::default().show(ctx, |ui| {
+            ui.horizontal(|ui| {
+                for meas in measurements {
+                    self.meas_box(ui, meas);
+                }
+            });
             ui_plot(ui, self.last_result.clone());
         });
     }
@@ -178,6 +224,9 @@ impl MyApp {
             self.fft_progress.store(0, Ordering::Relaxed);
         }
     }
+    fn meas_box<T: MeasurementValueType>(&mut self, ui: &mut egui::Ui, meas: Measurement<T>) {
+        ui.add(meas);
+    }
     fn new(cc: &eframe::CreationContext) -> Self {
         let host = cpal::default_host();
         println!("Audio host: {}", host.id().name());