/pixels

a shared pixel display controllable via UDP

Primary LanguageOCaml

a shared pixel display controllable via UDP

Dependencies: ocaml 5.0, tsdl

$ dune exec -- server/server.exe
# in another terminal, try one of the basic clients:
$ dune exec -- client/client.exe
# or go write your own!

Pass --help to the server binary for additional settings.

protocol

The server expects UDP packets. An UDP packet should contain one or several concatenated pixel commands. A pixel command consists of 7 bytes, and tells the server to draw one colored pixel:

 XX YY R G B
  • XX: a 16 bits big-endian integer for the x coordinate of the pixel
  • YY: a 16 bits big-endian integer for the y coordinate of the pixel
  • R, G, B: the color of the pixel (the red, green, blue component respectively)

anti-spam measures

The server implements some basic rate-limiting / anti-spam measures based on the client IP address, tweakable using the --nb-clients and --max-age options of the server.

  • there is a limit on the number of visible pixels sent by the same client; after this limit, oldest pixels get removed first. If --nb-clients (an estimation of the number of simultaneous clients) is N and the total number of pixels of the screen is S, then the per-client limit is S / N.

  • pixels decay and disappear after some time (set by --max-age).