feat: add the ability to use Sointu as a sync-tracker

There is a new "sync" opcode that saves the top-most signal every 256 samples to the new "syncBuffer" output. Additionally, you can enable saving the current fractional row as sync[0], avoiding calculating the beat in the shader, but also calculating the beat correctly when the beat is modulated.

rpc/rpc.go

@@ -0,0 +1,57 @@
+package rpc
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"net/rpc"
+)
+
+type SyncServer struct {
+	channel chan []float32
+}
+
+func (s *SyncServer) Sync(syncData []float32, reply *int) error {
+	select {
+	case s.channel <- syncData:
+	default:
+	}
+	return nil
+}
+
+func Receiver() (<-chan []float32, error) {
+	c := make(chan []float32, 1)
+	server := &SyncServer{channel: c}
+	rpc.Register(server)
+	rpc.HandleHTTP()
+	l, e := net.Listen("tcp", ":31337")
+	if e != nil {
+		log.Fatal("listen error:", e)
+		return nil, fmt.Errorf("net.listen failed: %v", e)
+	}
+	go func() {
+		defer close(c)
+		http.Serve(l, nil)
+	}()
+	return c, nil
+}
+
+func Sender(serverAddress string) (chan<- []float32, error) {
+	c := make(chan []float32, 256)
+	client, err := rpc.DialHTTP("tcp", serverAddress+":31337")
+	if err != nil {
+		log.Fatal("dialing:", err)
+		return nil, fmt.Errorf("rpc.DialHTTP failed: %v", err)
+	}
+	go func() {
+		for msg := range c {
+			var reply int
+			err = client.Call("SyncServer.Sync", msg, &reply)
+			if err != nil {
+				log.Fatal("SyncServer.Sync error:", err)
+			}
+		}
+	}()
+	return c, nil
+}