Universe Resources

Reference material and tutorials on the Universe.

This page contains only the bare-bones information.

  • Generic server (see attachment).

  • (make-package model message) to update model and send a message.

  • A main function start-big-bang to launch the windows.

      (define (start-big-bang my-name initial-model)
    (big-bang initial-model
      (on-draw draw-h)
      (on-key key-h)
      (on-receive receive-h)

      (register LOCALHOST) ;; or ip address: "10.213.69.91"
      (name my-name)       ;; sets window name
      (close-on-stop true)))

  • The launch-many-worlds command to quickly and easily start several windows.

      (launch-many-worlds
      (start-big-bang "whale" (make-model "blue" "gray"))
      (start-big-bang "squirrel" (make-model "red" "yellow")))

Sending Structures

The simplest way to send a structure is to take it apart into the individual pieces (numbers, strings, and lists), and send those individually. For example, send both the x and y coordinates separately, instead of sending a posn.

You cannot send whole structures without a hack. The hack is to make a separate file that contains a little bit of lower level Racket code and require it.

Here are the three lines you need to put in a file (by itself) to create a msg structure that can be sent between worlds. See the message creation step of the walkthrough.

    #lang racket
    (provide (all-defined-out))
    (define-struct msg (from to info) #:prefab)

Internet Connectivity

Windows at School

At school you can connect to other computers on the same network. Find the server’s IP address by opening Windows PowerShell and running ip /addr (note the space before the slash).

At Home

At home you will probably need to set up some port forwarding like a Minecraft server needs; use the port clause in both the server and the client if you need to specify the port. The current default port is 4567.

Additional Resources

Last modified August 18, 2023: 2022-2023 End State (7352e87)