feat(packages): ludic.net - a party over UDP: peers, reliable ordered delivery, the hello's frame and the host's pids, join codes, room codes through a matchmaker with STUN, punching and a relay, the MTU cap and the wire codec; messages in on an inbox, the session's end and a silent guest as facts

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/ludic.net/room.ludic

@@ -0,0 +1,83 @@
+# room.ludic - a party across two home routers. The host registers its outside and inside
+# addresses with the matchmaker and is given a six-letter room code; a guest hands over the code
+# and its own addresses and gets the host's back. Behind one router, the inside addresses.
+const NET_R_IDLE: int = 0
+const NET_R_STUN: int = 1        # asking what this machine looks like from outside
+const NET_R_REGISTER: int = 2    # the host: asking for a room
+const NET_R_ROOM: int = 3        # the host: registered, watching for guests
+const NET_R_ASK: int = 4         # a guest: asking the room for the host
+const NET_R_DONE: int = 5        # a guest: the hello is on its way
+
+var net__r_state: int = 0
+var net__r_role: int = 0          # 1 host, 2 guest
+var net__r_t: float = 0.0
+var net__r_tries: int = 0
+var net__pub_ip: int = 0
+var net__pub_port: int = 0
+var net__room: string = ""        # the host's room code, or the one a guest asked for
+var net__http: int = 0
+var net__poll_t: float = 0.0
+var net__relay_t: float = 0.0
+var net__dial_heard: float = 0.0
+
+# room codes are on when the game named a matchmaker
+export function net_room_on() -> bool { return len(net__conf().signal_url) > 0 }
+export function net_room() -> string { return net__room }
+export function net_room_asking() -> bool { return net__r_state == NET_R_STUN or net__r_state == NET_R_ASK }
+
+# the host (after net_host or net_become_host): a room at the matchmaker, if there is one
+export function net_room_host() -> void {
+  if not net_room_on() { return }
+  net__r_role = 1
+  net__room = ""
+  net__seen = new []string
+  net__stun_begin()
+}
+
+# a guest by room code: the matchmaker's answer brings the host's address (the hello is set first)
+export function net_room_join(code: string) -> bool {
+  if not net_room_on() {
+    net__why = NET_WHY_NO_MATCHMAKER
+    return false
+  }
+  net__init()
+  if not net__socket() { return false }
+  net__r_role = 2
+  net__room = Text.upper(code)
+  net__wait_more = 20                           # the matchmaker answers before the host does
+  net__wait_for_host()
+  net__stun_begin()
+  return true
+}
+
+function net__stun_begin() -> void {
+  net__r_state = NET_R_STUN
+  net__r_t = 0.0
+  net__r_tries = 0
+  net__pub_ip = 0
+  net__pub_port = 0
+  if net__conf().no_stun {
+    net__r_tries = 3
+    return
+  }
+  net__stun_send()
+}
+
+function net__room_body(role_key: string) -> string {
+  var pub = ""
+  if net__pub_ip != 0 { pub = net__addr_text(net__pub_ip, net__pub_port) }
+  return "{\"" + role_key + "\": \"" + pub + "\", \"local\": \"" + net__local_text() + "\"}"
+}
+
+function net__json_str(v: Val, key: string) -> string {
+  if v == null or value_has(v, key) == 0 { return "" }
+  return value_as_str(value_get(v, key))
+}
+
+function net__addr_text(ip: int, port: int) -> string { return `{Udp.ip_text(ip)}:{port}` }
+
+function net__local_text() -> string {
+  var ip = NetSocket.local_ip()
+  if ip == 0 { ip = Udp.ip("127.0.0.1") }
+  return net__addr_text(ip, net_port())
+}