Update live waveform using rtaudio

DynamicIsland/audio/AudioBridge.mm

@@ -0,0 +1,47 @@
+/*
+ * Atoll (DynamicIsland)
+ * Copyright (C) 2024-2026 Atoll Contributors
+ *
+ * Objective-C++ implementation bridging AudioProcessor to Swift.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+
+#import "AudioBridge.h"
+#import "AudioProcessor.hpp"
+
+@implementation AudioBridge {
+    AudioProcessor *processor;
+}
+
+- (instancetype)init {
+    self = [super init];
+    if (self) {
+        processor = new AudioProcessor();
+    }
+    return self;
+}
+
+- (void)processBuffer:(const float *)buffer count:(int)count {
+    processor->process(buffer, count);
+}
+
+- (simd_float4)getSmoothedMagnitudes {
+    // Calls getBand() which does memory_order_relaxed atomic loads —
+    // no heap allocation, safe to call from the render thread
+    return simd_make_float4(
+        processor->getBand(0),
+        processor->getBand(1),
+        processor->getBand(2),
+        processor->getBand(3)
+    );
+}
+
+- (void)dealloc {
+    delete processor;
+}
+
+@end