timowest · January 28, 2013 07:25 · Jan 28, 2013
diff --git a/gistfile1.clj b/gistfile1.clj
@@ -0,0 +1,81 @@
+(ns synth
+  (include "cmath" 
+           "lv2/lv2plug.in/ns/lv2core/lv2.h"))
+
+(defstruct Synth
+  (sample-rate double)
+  (phase float)
+  (freq float*)
+  (output float*))
+
+(defn ^void* instantiate 
+  [^LV2_Descriptor.const* descriptor 
+   ^double rate 
+   ^char.const* bundle-path 
+   ^LV2_Feature.const*.const* features]
+  (let [self (new Synth)]
+    (set! (.sample-rate self) rate)
+    self))
+
+(defn connect-port 
+  [^LV2_Handle instance ^uint port ^void* data]
+  (let [self (cast Synth* instance)]
+    (match port
+           (uint 0) (set! (.freq self) (cast float* data))
+           (uint 1) (set! (.output self) (cast float* data)))))
+
+(defn activate
+  [^LV2_Handle instance]
+  (let [self (cast Synth* instance)]
+    (set! (.phase self) (float 0.0))))
+
+(defn run
+  [^LV2_Handle instance ^uint32_t n-samples]
+  (let [self (cast Synth* instance)
+        PI (float 3.1415)
+        volume (float 0.3)
+        freq (pref (.freq self))
+        output (.output self)
+        samples-per-cycle (/ (float (.sample-rate self)) freq)
+        phase-increment (/ (float 1.0) samples-per-cycle)]
+    (dotimes [pos (long n-samples)]
+      (pset! output pos (* (sin (* (.phase self) (float 2.0) PI)) volume))
+      (set! (.phase self) (+ (.phase self) phase-increment))
+      (if (> (.phase self) (float 1.0))
+        (set! (.phase self) (float 0.0))))))
+
+(defn deactivate 
+  [^LV2_Handle instance])
+
+(defn cleanup
+  [^LV2_Handle instance]
+  (delete (cast Synth* instance)))
+
+(defn ^void.const* extension-data
+  [^char.const* uri]
+  nil)
+
+(extern "C"
+"
+/** The LV2_Descriptor for this plugin. */
+static const LV2_Descriptor descriptor = {
+    \"http://lv2plug.in/plugins/eg-synth\",
+    instantiate,
+    connect_port,
+    activate,
+    run,
+    deactivate,
+    cleanup,
+    extension_data
+};
+
+LV2_SYMBOL_EXPORT
+const LV2_Descriptor*
+lv2_descriptor(uint32_t index) {
+    switch (index) {
+        case 0:  return &descriptor;
+        default: return 0;
+    }
+}")
+
+