Allow other people to see my sketch in real time via a web site

I want to create a website that allows me to sketch something in real time and for people to be able to view that sketch in real time.

My thoughts - all clients ne开发者_运维百科ed to connect to a game server - including me the sketcher. I sketch something and the "sketch data" gets sent to all clients, and their displays get updated.

My questions - I know this has been done before, but how to represent a sketch? With RGB values for each pixel?

If I'm sketching in realtime then clients need to be updated a couple of times each second ( to make it look fluid ) - do real games update clients that frequently?

Real multiplayer games update clients about 50~ times a second - if all have a fast connection (so 20 ping is achieved).
Well yes, I guess sending it as an array of points (1 dimensional - containing all the points) - and the simply 'draw lines' between all points - like you do in C#.
If you don't draw lines and simply draw the pixel it wont look like a sketch but like a lot of dots.