Happy new year to the wonderful Godot community!
2020 has been a tough year for most of us personally, but a good year for
Godot development nonetheless with a huge amount of work done towards Godot
4.0 and great improvements backported to the long-lived 3.2 branch.
We've had close to 400 contributors to engine code this year, authoring near
7,000 commit! (And that's only for the `master` branch and for the engine code,
there's a lot more when counting docs, demos and other first-party repos.)
Here's to a great year 2021 for all Godot users 🎆
UDPServer now uses a single socket which is shared with the
PacketPeerUDP it creates and has a new `poll` function to read incoming
packets on that socket and delivers them to the appropriate peer.
PacketPeerUDP created this way never reads from the socket, but are
allowed to write on it using sendto.
This is needed because Windows (unlike Linux/BSD) does not support
packet routing when multiple sockets are bound on the same address/port.
UDP sockets can be "connected" to filter packets from a specific source.
In case of a bound socket (e.g. server), a new socket can be created on
the same address/port that will receive all packets that are not
filtered by a more specific socket (e.g. the previously connect socket).
This way, a UDPServer can listen to new packets, and return a new
PacketPeerUDP when receiving one, knowing that is a "new client".
