feat(avlivebody): viz mode picker and scene toggle

avlivebody-mac/Sources/AVLiveBody/AVLiveBodyApp.swift

@@ -46,7 +46,8 @@ struct ContentView: View {
 
     var body: some View {
         ZStack(alignment: .topTrailing) {
-            LayeredSceneView(controller: controller, renderer: renderer)
+            LayeredSceneView(controller: controller, renderer: renderer,
+                             showScene: settings.showScene)
             StatusBar(consumer: consumer)
                 .frame(maxWidth: .infinity, alignment: .top)
             HStack(alignment: .top) {

avlivebody-mac/Sources/AVLiveBody/LayeredSceneView.swift

@@ -10,6 +10,7 @@ import SwiftUI
 struct LayeredSceneView: NSViewRepresentable {
     let controller: SceneController
     let renderer: SceneRenderer?
+    let showScene: Bool
 
     func makeNSView(context: Context) -> NSView {
         controller.setUp()
@@ -42,7 +43,7 @@ struct LayeredSceneView: NSViewRepresentable {
     }
 
     func updateNSView(_ nsView: NSView, context: Context) {
-        context.coordinator.mtk?.isHidden = false   // visibility via showScene handled by caller setting renderer.uniforms / hidden
+        context.coordinator.mtk?.isHidden = !showScene
     }
 
     func makeCoordinator() -> Coordinator { Coordinator() }

avlivebody-mac/Sources/AVLiveBody/SettingsPanel.swift

@@ -37,6 +37,16 @@ struct SettingsPanel: View {
                     slider("Opacite video", $settings.videoOpacity,
                            0...1)
                 }
+
+                group("Scene") {
+                    Toggle("Fond shader", isOn: $settings.showScene)
+                    Picker("Mode", selection: $settings.vizMode) {
+                        ForEach(0..<10, id: \.self) { i in
+                            Text(Self.modeName(i)).tag(i)
+                        }
+                    }
+                    .pickerStyle(.menu)
+                }
             }
             .padding(16)
         }
@@ -44,6 +54,12 @@ struct SettingsPanel: View {
         .background(.ultraThinMaterial)
     }
 
+    static func modeName(_ i: Int) -> String {
+        let n = ["storm","tunnel","plasma","kaleido","voronoi",
+                 "metaballs","starfield","bars","hands3d","openpos"]
+        return n.indices.contains(i) ? "\(i) \(n[i])" : "\(i)"
+    }
+
     @ViewBuilder
     private func group(_ title: String,
                        @ViewBuilder _ content: () -> some View)