Universe Resources

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-receive receive-h)
        (on-key key-h)
  
        (register LOCALHOST)
        (name my-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 Posns

One possibility is to send the coordinates in a posn as numbers in a list.

You cannot send whole posns without a hack. The hack is to make a separate file that contains a little bit of lower level Racket code and require it. The best place for this code would be in your posn-util.rkt file! You need to use Racket mode for that file, not Beginning Student.

    #lang racket
    (provide (all-defined-out))
    (define-struct posn (x y) #:prefab)

Additional Resources

• Universe in Racket Documentation. See especially Section 2.4.7, the examples, where a ball-bouncing example is developed.

• Universe tutorial by Sub