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_test.go

@@ -0,0 +1,24 @@
+package rpc_test
+
+import (
+	"testing"
+
+	"github.com/vsariola/sointu/rpc"
+)
+
+func TestSendReceive(t *testing.T) {
+	receiver, err := rpc.Receiver()
+	if err != nil {
+		t.Fatalf("rpc.Receiver error: %v", err)
+	}
+	sender, err := rpc.Sender("127.0.0.1")
+	if err != nil {
+		t.Fatalf("rpc.Sender error: %v", err)
+	}
+	value := []float32{42}
+	sender <- value
+	valueGot := <-receiver
+	if valueGot[0] != value[0] {
+		t.Fatalf("rpc.Sender error: %v", err)
+	}
+}