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.

cmd/sointu-track/main.go

@@ -1,21 +1,33 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"os"
 
 	"github.com/vsariola/sointu/oto"
+	"github.com/vsariola/sointu/rpc"
 	"github.com/vsariola/sointu/tracker/gioui"
 	"github.com/vsariola/sointu/vm"
 )
 
 func main() {
+	syncAddress := flag.String("address", "", "remote RPC server where to send sync data")
+	flag.Parse()
 	audioContext, err := oto.NewContext()
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)
 	}
 	defer audioContext.Close()
+	var syncChannel chan<- []float32
+	if *syncAddress != "" {
+		syncChannel, err = rpc.Sender(*syncAddress)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+	}
 	synthService := vm.SynthService{}
-	gioui.Main(audioContext, synthService)
+	gioui.Main(audioContext, synthService, syncChannel)
 }