some fun stuff

Cargo.toml

@@ -4,7 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-clap = "4.5.20"
+clap = { version = "4.5.20", features = ["derive"] }
 eframe = "0.29.1"
 egui = "0.29.1"
 jack = "0.13.0"

src/main.rs

@@ -1,8 +1,10 @@
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
 
+use clap::Parser;
 use eframe::egui::*;
 
 fn main() -> eframe::Result {
+	let args = Args::parse();
 	let options = eframe::NativeOptions {
 		viewport: egui::ViewportBuilder::default(),
 		..Default::default()
@@ -15,33 +17,104 @@ fn main() -> eframe::Result {
 			cc.egui_ctx.set_theme(egui::Theme::Dark);
 			// egui_extras::install_image_loaders(&cc.egui_ctx);
 
-			Ok(Box::<FslcMix>::new(FslcMix::new(5)))
+			Ok(Box::<FslcMix>::new(FslcMix::new(args.channels)))
 		}),
 	)
 }
 
+/// A mixer that supports an arbitrary number of channels.
+#[derive(Parser, Debug)]
+#[command(version, about, long_about = None)]
+struct Args {
+	/// Number of channels
+	#[arg(short, long, default_value_t = 5)]
+	channels: u8,
+}
+
 struct FslcMix {
 	channels: Vec<MixChannel>,
 	master: MixChannel,
+	normalize: bool,
+	ui_size: egui::Vec2,
 }
 
 impl FslcMix {
 	fn new(num_channels: u8) -> Self {
 		Self { 
-			channels: (0..num_channels).map(|_| MixChannel::default()).collect(),
-			master: MixChannel { channel_name: "Master".to_owned(), ..Default::default() }
+			channels: (1..=num_channels).map(|i| 
+				MixChannel { 
+					channel_name: format!("Channel {}", i), 
+					..Default::default() 
+				} 
+			).collect(),
+			master: MixChannel { 
+				channel_name: "Master".to_owned(), 
+				..Default::default() 
+			},
+			normalize: false,
+			ui_size: egui::Vec2::new(400.0, 200.0), // This size doesn't matter since it's
+													// overritten
 		}
 	}
+
+	fn mix(&mut self, inputs : Vec<&[f32]>, output : &mut [f32]) {
+		// Sanity check
+		assert!(inputs.len() == self.channels.len());
+		// Initialize to zeros
+		for i in 0..output.len() {
+			output[i] = 0.0;
+		}
+		if self.master.mute {
+			return;
+		}
+		// TODO: short circuit
+		let any_solo = self.channels.iter()
+			.fold(false, |any_so_far, channel| {
+				channel.solo || any_so_far
+			});
+		// Mix each channel together
+		for channel_index in 0..inputs.len() {
+			let channel = &mut self.channels[channel_index];
+			let input = inputs[channel_index];
+			channel.mix(input, output, any_solo);
+		}
+		// Apply the master channel's mix and normalize if necessary
+		let norm_factor = inputs.len() as f32;
+		// Bypass its mix() function since we do it slightly different here
+		for i in 0..output.len() {
+			if self.normalize {
+				output[i] /= norm_factor;
+			}
+			let sample = output[i] * self.master.gain;
+			let out_sample = if self.master.limit && sample >= 1.0 {
+				1.0
+			} else if self.master.limit && sample <= -1.0 {
+				-1.0
+			} else {
+				sample
+			};
+			if out_sample > self.master.max {
+				self.master.max = out_sample;
+			}
+			output[i] = out_sample;
+
+		}
+		self.master.last = output[output.len() - 1];
+	}
 }
 
 impl eframe::App for FslcMix {
 	fn update(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame) {
-	    egui::Window::new("Mixer (FSLCMix)")
-			.default_pos([100.0, 100.0])
-			.title_bar(true)
+	    //egui::Window::new("Mixer (FSLCMix)")
+		//	.default_pos([100.0, 100.0])
+		//	.title_bar(true)
+		egui::CentralPanel::default()
 			.show(ctx, |ui|{
 				ui.vertical(|ui| {
-					ui.label("Licensed under the GPLv3.");
+					ui.horizontal(|ui| {
+						// ui.label("Licensed under the GPLv3.");
+						ui.toggle_value(&mut self.normalize, "Normalize")
+					});
 				});
 				ui.horizontal(|ui| {
 					self.master.ui(ui);
@@ -50,7 +123,10 @@ impl eframe::App for FslcMix {
 						channel.ui(ui);
 					}
 				});
+				self.ui_size = ui.min_size();
 			});
+		let window_size = self.ui_size + egui::vec2(20.0, 40.0);
+		// frame.set_window_size(window_size);
 	}
 }
 
@@ -65,19 +141,27 @@ struct MixChannel {
 }
 
 impl MixChannel {
-	fn mix(&mut self, input : &[f32], output : &mut [f32]) {
+
+	fn mix(&mut self, input : &[f32], output : &mut [f32], any_solo : bool) {
+		if self.mute || (any_solo && !self.solo) {
+			self.last = 0.0;
+			return;
+		}
 		// Sanity check
 		assert!(input.len() == output.len());
 		for i in 0..input.len() {
 			let sample = input[i] * self.gain;
-			if self.limit && sample >= 1.0 {
-				output[i] = 1.0;
+			let out_sample = if self.limit && sample >= 1.0 {
+				1.0
+			} else if self.limit && sample <= -1.0 {
+				-1.0
 			} else {
-				output[i] = sample;
-			}
-			if output[i] > self.max {
-				self.max = output[i];
+				sample
+			};
+			if out_sample > self.max {
+				self.max = out_sample;
 			}
+			output[i] += out_sample;
 		}
 		self.last = output[output.len() - 1];
 	}
@@ -91,6 +175,11 @@ impl MixChannel {
 				ui.add(egui::Slider::new(&mut self.gain, 0.0..=1.2).text("Gain").vertical());
 				self.levels_bar(ui, self.last);
 			});
+
+			let btn = ui.button("Reset Gain");
+			if btn.clicked() {
+				self.gain = 1.0;
+			}
 			ui.horizontal(|ui| {
 				ui.toggle_value(&mut self.mute, "M");
 				ui.toggle_value(&mut self.solo, "S");
@@ -107,7 +196,7 @@ impl MixChannel {
 		let filled_rect = Rect::from_min_max(rect.min, rect.min + vec2(rect.width(), filled_height)); 
 		let remaining_rect = Rect::from_min_max(filled_rect.max, rect.max); 
 		painter.rect_filled(filled_rect, 0.0, Color32::from_rgb(0, 200, 0)); 
-		painter.rect_filled(remaining_rect, 0.0, Color32::from_rgb(200, 0, 0)); 
+painter.rect_filled(remaining_rect, 0.0, Color32::from_rgb(200, 0, 0)); 
 		painter.rect_stroke(rect, 0.0, (1.0, Color32::WHITE)); 
 		response.on_hover_cursor(egui::CursorIcon::PointingHand) 
 			.on_hover_text(format!("{:.1} db", value.log10()));