Store the minimum buffer size in BufferConfig

src/plugin.rs

@@ -294,8 +294,11 @@ pub struct BusConfig {
 pub struct BufferConfig {
     /// The current sample rate.
     pub sample_rate: f32,
+    /// The minimum buffer size the host will use. This may not be set.
+    pub min_buffer_size: Option<u32>,
     /// The maximum buffer size the host will use. The plugin should be able to accept variable
-    /// sized buffers up to this size.
+    /// sized buffers up to this size, or between the minimum and the maximum buffer size if both
+    /// are set.
     pub max_buffer_size: u32,
 }
 

src/wrapper/clap/wrapper.rs

@@ -1506,7 +1506,7 @@ impl<P: ClapPlugin> Wrapper<P> {
     unsafe extern "C" fn activate(
         plugin: *const clap_plugin,
         sample_rate: f64,
-        _min_frames_count: u32,
+        min_frames_count: u32,
         max_frames_count: u32,
     ) -> bool {
         check_null_ptr!(false, plugin);
@@ -1515,6 +1515,7 @@ impl<P: ClapPlugin> Wrapper<P> {
         let bus_config = wrapper.current_bus_config.load();
         let buffer_config = BufferConfig {
             sample_rate: sample_rate as f32,
+            min_buffer_size: Some(min_frames_count),
             max_buffer_size: max_frames_count,
         };
 

src/wrapper/standalone/wrapper.rs

@@ -200,6 +200,7 @@ impl<P: Plugin, B: Backend> Wrapper<P, B> {
             },
             buffer_config: BufferConfig {
                 sample_rate: config.sample_rate,
+                min_buffer_size: None,
                 max_buffer_size: config.period_size,
             },
             config,

src/wrapper/vst3/wrapper.rs

@@ -690,6 +690,7 @@ impl<P: Vst3Plugin> IAudioProcessor for Wrapper<P> {
         // This is needed when activating the plugin and when restoring state
         self.inner.current_buffer_config.store(Some(BufferConfig {
             sample_rate: setup.sample_rate as f32,
+            min_buffer_size: None,
             max_buffer_size: setup.max_samples_per_block as u32,
         }));