From 4204ac4462dd16217557ef48ef928e30798d0d4c Mon Sep 17 00:00:00 2001
From: unspeaker <hora.nqma@protonmail.com>
Date: Fri, 5 Jul 2024 21:33:50 +0300
Subject: [PATCH] perf: remove allocation from sampler callback

---
 src/model/sampler.rs | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/src/model/sampler.rs b/src/model/sampler.rs
index d6af341a..47ee028c 100644
--- a/src/model/sampler.rs
+++ b/src/model/sampler.rs
@@ -68,14 +68,8 @@ impl Sampler {
         }
         // Emit next chunk of each currently playing voice,
         // dropping voices that have reached their ends.
-        let mut voices = vec![];
-        std::mem::swap(&mut voices, &mut self.voices);
         let gain = 0.5;
-        loop {
-            if voices.len() < 1 {
-                break
-            }
-            let mut voice = voices.swap_remove(0);
+        self.voices.retain_mut(|voice|{
             if let Some(chunk) = voice.chunk(scope.n_frames() as usize) {
                 for (i, channel) in chunk.iter().enumerate() {
                     let buffer = &mut mixed[i % channel_count];
@@ -83,9 +77,11 @@ impl Sampler {
                         buffer[i] += sample * gain;
                     }
                 }
-                self.voices.push(voice);
+                true
+            } else {
+                false
             }
-        }
+        });
         // Write output buffer to output ports.
         for (i, port) in self.ports.audio_outs.values_mut().enumerate() {
             let buffer = &mixed[i];