extract plugin crate

plugin/src/lv2.rs

@@ -0,0 +1,40 @@
+use crate::*;
+
+/// A LV2 plugin.
+#[derive(Debug)]
+pub struct LV2Plugin {
+    pub world:        livi::World,
+    pub instance:     livi::Instance,
+    pub plugin:       livi::Plugin,
+    pub features:     Arc<livi::Features>,
+    pub port_list:    Vec<livi::Port>,
+    pub input_buffer: Vec<livi::event::LV2AtomSequence>,
+    pub ui_thread:    Option<JoinHandle<()>>,
+}
+
+impl LV2Plugin {
+    const INPUT_BUFFER: usize = 1024;
+    pub fn new (uri: &str) -> Usually<Self> {
+        let world = livi::World::with_load_bundle(&uri);
+        let features = world
+            .build_features(livi::FeaturesBuilder {
+                min_block_length: 1,
+                max_block_length: 65536,
+            });
+        let plugin = world.iter_plugins().nth(0)
+            .unwrap_or_else(||panic!("plugin not found: {uri}"));
+        Ok(Self {
+            instance: unsafe {
+                plugin
+                    .instantiate(features.clone(), 48000.0)
+                    .expect(&format!("instantiate failed: {uri}"))
+            },
+            port_list: plugin.ports().collect::<Vec<_>>(),
+            input_buffer: Vec::with_capacity(Self::INPUT_BUFFER),
+            ui_thread: None,
+            world,
+            features,
+            plugin,
+        })
+    }
+}