Add user preference to show waveforms as stacked stereo

lightningbeam-ui/lightningbeam-editor/src/config.rs

@@ -45,6 +45,10 @@ pub struct AppConfig {
     #[serde(default = "defaults::debug")]
     pub debug: bool,
 
+    /// Show waveforms as stacked stereo instead of combined mono
+    #[serde(default = "defaults::waveform_stereo")]
+    pub waveform_stereo: bool,
+
     /// Theme mode ("light", "dark", or "system")
     #[serde(default = "defaults::theme_mode")]
     pub theme_mode: String,
@@ -63,6 +67,7 @@ impl Default for AppConfig {
             reopen_last_session: defaults::reopen_last_session(),
             restore_layout_from_file: defaults::restore_layout_from_file(),
             debug: defaults::debug(),
+            waveform_stereo: defaults::waveform_stereo(),
             theme_mode: defaults::theme_mode(),
         }
     }
@@ -263,5 +268,6 @@ mod defaults {
     pub fn reopen_last_session() -> bool { false }
     pub fn restore_layout_from_file() -> bool { true }
     pub fn debug() -> bool { false }
+    pub fn waveform_stereo() -> bool { false }
     pub fn theme_mode() -> String { "system".to_string() }
 }

lightningbeam-ui/lightningbeam-editor/src/main.rs

@@ -4389,6 +4389,7 @@ impl eframe::App for EditorApp {
                 target_format: self.target_format,
                 pending_menu_actions: &mut pending_menu_actions,
                 clipboard_manager: &mut self.clipboard_manager,
+                waveform_stereo: self.config.waveform_stereo,
             };
 
             render_layout_node(
@@ -4661,6 +4662,8 @@ struct RenderContext<'a> {
     pending_menu_actions: &'a mut Vec<MenuAction>,
     /// Clipboard manager for paste availability checks
     clipboard_manager: &'a mut lightningbeam_core::clipboard::ClipboardManager,
+    /// Whether to show waveforms as stacked stereo
+    waveform_stereo: bool,
 }
 
 /// Recursively render a layout node with drag support
@@ -5141,6 +5144,7 @@ fn render_pane(
                 target_format: ctx.target_format,
                 pending_menu_actions: ctx.pending_menu_actions,
                 clipboard_manager: ctx.clipboard_manager,
+                waveform_stereo: ctx.waveform_stereo,
             };
             pane_instance.render_header(&mut header_ui, &mut shared);
         }
@@ -5210,6 +5214,7 @@ fn render_pane(
                 target_format: ctx.target_format,
                 pending_menu_actions: ctx.pending_menu_actions,
                 clipboard_manager: ctx.clipboard_manager,
+                waveform_stereo: ctx.waveform_stereo,
             };
 
             // Render pane content (header was already rendered above)

lightningbeam-ui/lightningbeam-editor/src/panes/mod.rs

@@ -215,6 +215,8 @@ pub struct SharedPaneState<'a> {
     pub pending_menu_actions: &'a mut Vec<crate::menu::MenuAction>,
     /// Clipboard manager for cut/copy/paste operations
     pub clipboard_manager: &'a mut lightningbeam_core::clipboard::ClipboardManager,
+    /// Whether to show waveforms as stacked stereo (true) or combined mono (false)
+    pub waveform_stereo: bool,
 }
 
 /// Trait for pane rendering

lightningbeam-ui/lightningbeam-editor/src/panes/timeline.rs

@@ -928,6 +928,7 @@ impl TimelinePane {
         raw_audio_cache: &std::collections::HashMap<usize, (Vec<f32>, u32, u32)>,
         waveform_gpu_dirty: &mut std::collections::HashSet<usize>,
         target_format: wgpu::TextureFormat,
+        waveform_stereo: bool,
     ) -> Vec<(egui::Rect, uuid::Uuid, f64, f64)> {
         let painter = ui.painter();
 
@@ -1273,7 +1274,7 @@ impl TimelinePane {
                                                         tex_width: crate::waveform_gpu::tex_width() as f32,
                                                         total_frames: total_frames as f32,
                                                         segment_start_frame: 0.0,
-                                                        display_mode: 0.0,
+                                                        display_mode: if waveform_stereo { 1.0 } else { 0.0 },
                                                         _pad1: [0.0, 0.0],
                                                         tint_color: tint,
                                                         screen_size: [screen_size.x, screen_size.y],
@@ -2154,7 +2155,7 @@ impl PaneRenderer for TimelinePane {
 
         // Render layer rows with clipping
         ui.set_clip_rect(content_rect.intersect(original_clip_rect));
-        let video_clip_hovers = self.render_layers(ui, content_rect, shared.theme, document, shared.active_layer_id, shared.selection, shared.midi_event_cache, shared.raw_audio_cache, shared.waveform_gpu_dirty, shared.target_format);
+        let video_clip_hovers = self.render_layers(ui, content_rect, shared.theme, document, shared.active_layer_id, shared.selection, shared.midi_event_cache, shared.raw_audio_cache, shared.waveform_gpu_dirty, shared.target_format, shared.waveform_stereo);
 
         // Render playhead on top (clip to timeline area)
         ui.set_clip_rect(timeline_rect.intersect(original_clip_rect));

lightningbeam-ui/lightningbeam-editor/src/preferences/dialog.rs

@@ -33,6 +33,7 @@ struct PreferencesState {
     reopen_last_session: bool,
     restore_layout_from_file: bool,
     debug: bool,
+    waveform_stereo: bool,
     theme_mode: ThemeMode,
 }
 
@@ -48,6 +49,7 @@ impl From<(&AppConfig, &Theme)> for PreferencesState {
             reopen_last_session: config.reopen_last_session,
             restore_layout_from_file: config.restore_layout_from_file,
             debug: config.debug,
+            waveform_stereo: config.waveform_stereo,
             theme_mode: theme.mode(),
         }
     }
@@ -65,6 +67,7 @@ impl Default for PreferencesState {
             reopen_last_session: false,
             restore_layout_from_file: true,
             debug: false,
+            waveform_stereo: false,
             theme_mode: ThemeMode::System,
         }
     }
@@ -335,6 +338,10 @@ impl PreferencesDialog {
             .default_open(false)
             .show(ui, |ui| {
                 ui.checkbox(&mut self.working_prefs.debug, "Enable debug mode");
+                ui.checkbox(
+                    &mut self.working_prefs.waveform_stereo,
+                    "Show waveforms as stacked stereo",
+                );
             });
     }
 
@@ -359,6 +366,7 @@ impl PreferencesDialog {
         temp_config.reopen_last_session = self.working_prefs.reopen_last_session;
         temp_config.restore_layout_from_file = self.working_prefs.restore_layout_from_file;
         temp_config.debug = self.working_prefs.debug;
+        temp_config.waveform_stereo = self.working_prefs.waveform_stereo;
         temp_config.theme_mode = self.working_prefs.theme_mode.to_string_lower();
 
         // Validate
@@ -380,6 +388,7 @@ impl PreferencesDialog {
         config.reopen_last_session = self.working_prefs.reopen_last_session;
         config.restore_layout_from_file = self.working_prefs.restore_layout_from_file;
         config.debug = self.working_prefs.debug;
+        config.waveform_stereo = self.working_prefs.waveform_stereo;
         config.theme_mode = self.working_prefs.theme_mode.to_string_lower();
 
         // Apply theme immediately