Write canvas in Client and send to Server (Array of point)?

Hi everyone. I have a problem. I can’t send matrix of point ( write canvas) and after that i finish to write a canvas (for example with a button???) I want the server to get the dot array.
I have saw Example 2: Shared drawing canvas on Processing site but i don’t know how do.

Thanks so much everyone that can help me.


The Processing examples (in the File menu) for SharedCanvasClient and SharedCanvasServer work:



Start the server first and then the client.

Start with simple modifications to the examples and build on that.

There are resources here:


I have tried but I’m a begginer and i don’t know which functions use.
For example i don’t need a continued communication but first of all i want write a canvas after click on a button and finally send all to server.