rewrite unsafe code in midi handling

daw-backend/src/audio/engine.rs

@@ -317,15 +317,9 @@ impl Engine {
             self.project.reset_read_ahead_targets();
 
             // Render the entire project hierarchy into the mix buffer
-            // Note: We need to use a raw pointer to avoid borrow checker issues
-            // The midi_clip_pool is part of project, so we extract a reference before mutable borrow
-            let midi_pool_ptr = &self.project.midi_clip_pool as *const _;
-            // SAFETY: The midi_clip_pool is not mutated during render, only read
-            let midi_pool_ref = unsafe { &*midi_pool_ptr };
             self.project.render(
                 &mut self.mix_buffer,
                 &self.audio_pool,
-                midi_pool_ref,
                 &mut self.buffer_pool,
                 playhead_seconds,
                 self.sample_rate,
@@ -2149,15 +2143,11 @@ impl Engine {
             Query::ExportAudio(settings, output_path) => {
                 // Perform export directly - this will block the audio thread but that's okay
                 // since we're exporting and not playing back anyway
-                // Use raw pointer to get midi_pool reference before mutable borrow of project
-                let midi_pool_ptr: *const _ = &self.project.midi_clip_pool;
-                let midi_pool_ref = unsafe { &*midi_pool_ptr };
 
                 // Pass event_tx directly - Rust allows borrowing different fields simultaneously
                 match crate::audio::export_audio(
                     &mut self.project,
                     &self.audio_pool,
-                    midi_pool_ref,
                     &settings,
                     &output_path,
                     Some(&mut self.event_tx),

daw-backend/src/audio/export.rs

@@ -1,5 +1,4 @@
 use super::buffer_pool::BufferPool;
-use super::midi_pool::MidiClipPool;
 use super::pool::AudioPool;
 use super::project::Project;
 use crate::command::AudioEvent;
@@ -69,7 +68,6 @@ impl Default for ExportSettings {
 pub fn export_audio<P: AsRef<Path>>(
     project: &mut Project,
     pool: &AudioPool,
-    midi_pool: &MidiClipPool,
     settings: &ExportSettings,
     output_path: P,
     mut event_tx: Option<&mut rtrb::Producer<AudioEvent>>,
@@ -87,7 +85,7 @@ pub fn export_audio<P: AsRef<Path>>(
     // Ensure export mode is disabled even if an error occurs.
     let result = match settings.format {
         ExportFormat::Wav | ExportFormat::Flac => {
-            let samples = render_to_memory(project, pool, midi_pool, settings, event_tx.as_mut().map(|tx| &mut **tx))?;
+            let samples = render_to_memory(project, pool, settings, event_tx.as_mut().map(|tx| &mut **tx))?;
             // Signal that rendering is done and we're now writing the file
             if let Some(ref mut tx) = event_tx {
                 let _ = tx.push(AudioEvent::ExportFinalizing);
@@ -99,10 +97,10 @@ pub fn export_audio<P: AsRef<Path>>(
             }
         }
         ExportFormat::Mp3 => {
-            export_mp3(project, pool, midi_pool, settings, output_path, event_tx)
+            export_mp3(project, pool, settings, output_path, event_tx)
         }
         ExportFormat::Aac => {
-            export_aac(project, pool, midi_pool, settings, output_path, event_tx)
+            export_aac(project, pool, settings, output_path, event_tx)
         }
     };
 
@@ -125,7 +123,6 @@ pub fn export_audio<P: AsRef<Path>>(
 pub fn render_to_memory(
     project: &mut Project,
     pool: &AudioPool,
-    midi_pool: &MidiClipPool,
     settings: &ExportSettings,
     mut event_tx: Option<&mut rtrb::Producer<AudioEvent>>,
 ) -> Result<Vec<f32>, String>
@@ -162,7 +159,6 @@ pub fn render_to_memory(
         project.render(
             &mut render_buffer,
             pool,
-            midi_pool,
             &mut buffer_pool,
             playhead,
             settings.sample_rate,
@@ -302,7 +298,6 @@ fn write_flac<P: AsRef<Path>>(
 fn export_mp3<P: AsRef<Path>>(
     project: &mut Project,
     pool: &AudioPool,
-    midi_pool: &MidiClipPool,
     settings: &ExportSettings,
     output_path: P,
     mut event_tx: Option<&mut rtrb::Producer<AudioEvent>>,
@@ -382,7 +377,6 @@ fn export_mp3<P: AsRef<Path>>(
         project.render(
             &mut render_buffer,
             pool,
-            midi_pool,
             &mut buffer_pool,
             playhead,
             settings.sample_rate,
@@ -472,7 +466,6 @@ fn export_mp3<P: AsRef<Path>>(
 fn export_aac<P: AsRef<Path>>(
     project: &mut Project,
     pool: &AudioPool,
-    midi_pool: &MidiClipPool,
     settings: &ExportSettings,
     output_path: P,
     mut event_tx: Option<&mut rtrb::Producer<AudioEvent>>,
@@ -552,7 +545,6 @@ fn export_aac<P: AsRef<Path>>(
         project.render(
             &mut render_buffer,
             pool,
-            midi_pool,
             &mut buffer_pool,
             playhead,
             settings.sample_rate,

daw-backend/src/audio/project.rs

@@ -349,7 +349,6 @@ impl Project {
         &mut self,
         output: &mut [f32],
         audio_pool: &AudioClipPool,
-        midi_pool: &MidiClipPool,
         buffer_pool: &mut BufferPool,
         playhead_seconds: f64,
         sample_rate: u32,
@@ -374,7 +373,6 @@ impl Project {
                 track_id,
                 output,
                 audio_pool,
-                midi_pool,
                 buffer_pool,
                 ctx,
                 any_solo,
@@ -389,7 +387,6 @@ impl Project {
         track_id: TrackId,
         output: &mut [f32],
         audio_pool: &AudioClipPool,
-        midi_pool: &MidiClipPool,
         buffer_pool: &mut BufferPool,
         ctx: RenderContext,
         any_solo: bool,
@@ -437,7 +434,8 @@ impl Project {
             }
             Some(TrackNode::Midi(track)) => {
                 // Render MIDI track directly into output
-                track.render(output, midi_pool, ctx.playhead_seconds, ctx.sample_rate, ctx.channels);
+                // Access midi_clip_pool from self - safe because we only need immutable access
+                track.render(output, &self.midi_clip_pool, ctx.playhead_seconds, ctx.sample_rate, ctx.channels);
             }
             Some(TrackNode::Group(group)) => {
                 // Read group properties and transform context (index-based child iteration to avoid clone)
@@ -462,7 +460,6 @@ impl Project {
                         child_id,
                         &mut group_buffer,
                         audio_pool,
-                        midi_pool,
                         buffer_pool,
                         child_ctx,
                         any_solo,

lightningbeam-ui/lightningbeam-editor/src/export/audio_exporter.rs

@@ -54,7 +54,7 @@ pub fn export_audio<P: AsRef<Path>>(
 fn export_audio_daw_backend<P: AsRef<Path>>(
     project: &mut Project,
     pool: &AudioPool,
-    midi_pool: &MidiClipPool,
+    _midi_pool: &MidiClipPool,
     settings: &AudioExportSettings,
     output_path: P,
 ) -> Result<(), String> {
@@ -78,7 +78,6 @@ fn export_audio_daw_backend<P: AsRef<Path>>(
     daw_backend::audio::export::export_audio(
         project,
         pool,
-        midi_pool,
         &daw_settings,
         output_path,
         None,
@@ -89,7 +88,7 @@ fn export_audio_daw_backend<P: AsRef<Path>>(
 fn export_audio_ffmpeg_mp3<P: AsRef<Path>>(
     project: &mut Project,
     pool: &AudioPool,
-    midi_pool: &MidiClipPool,
+    _midi_pool: &MidiClipPool,
     settings: &AudioExportSettings,
     output_path: P,
     cancel_flag: &Arc<AtomicBool>,
@@ -114,7 +113,6 @@ fn export_audio_ffmpeg_mp3<P: AsRef<Path>>(
     let pcm_samples = render_to_memory(
         project,
         pool,
-        midi_pool,
         &daw_settings,
         None, // No progress events for now
     )?;
@@ -292,7 +290,7 @@ fn receive_and_write_packets(
 fn export_audio_ffmpeg_aac<P: AsRef<Path>>(
     project: &mut Project,
     pool: &AudioPool,
-    midi_pool: &MidiClipPool,
+    _midi_pool: &MidiClipPool,
     settings: &AudioExportSettings,
     output_path: P,
     cancel_flag: &Arc<AtomicBool>,
@@ -317,7 +315,6 @@ fn export_audio_ffmpeg_aac<P: AsRef<Path>>(
     let pcm_samples = render_to_memory(
         project,
         pool,
-        midi_pool,
         &daw_settings,
         None, // No progress events for now
     )?;