Trelay - a set of utilities to simplify work with Terraria Networking.

Use trelay.Fscan to read data from a reader (network) as sent by Terraria.

var ln uint16
var id byte
_, err := trelay.Fscan(r, &ln, &id)
if err != nil { /* ... */ }
switch id {
case 1:
  var ver string
  _, err := trelay.Fscan(r, &ver)
/* ... */

Or use trelay.Packet to read an entire packet into a buffer.

var p trelay.Packet
_, err := trelay.Fscan(r, &p) // p.ReadFrom(r) also works!
if err != nil { /* ... */ }

switch p.ID {
case 1:
  var ver string
  _, err := trelay.Fscan(p, &ver)
/* ... */

Use trelay.Fprint to write data as expected by Terraria.

// do not forget to cast constants to correct types
_, err := trelay.Fprint(w, uint16(15), byte(1), "Terraria123")

Or write to trelay.Packet to build a packet in memory when length is not known in advance.

p := &trelay.Packet{ID: 1}
trelay.Fprint(p, "Terraria123") // writes to Packet never* fail

_, err := trelay.Fprint(w, p) // no need to p.Bytes(), Fprint will use p.WriteTo
if err != nil { /* ... */ }

*Assumes Fprint-supported types and no memory issues.

Reuse trelay.Packet whenever possible to avoid unnecessary memory allocations.

_, err := trelay.Fscan(conn, &packet) // Fscan into Packet clears it
if err != nil { /* ... */ }