Live Variables

Shoebot is not limited to what you write inside your .bot file; you can open your sketch for receiving and reacting to data from outside applications and environments.

These can be created using the var() command.

Using the live variables GUI

When a script uses the var keyword, the corresponding widget will appear in the live variables GUI.

The following code will make a slider with a minimum value of 0, a maximum value of 100, and an initial (default) value of 25.

var('a_number', NUMBER, 25., 0., 100.)
_images/live_vars.png

For readability names are capitalized and underscores replaced by spaces, so ‘a_number’ is displayed as ‘A number’.

Setting variables in the command line

Live variables can be set from the commandline using JSON syntax:

$ sbot --vars='{ "hue": 32 }' examples/vars/circle_circle.bot

This means that a Shoebot script can be called with different parameters without having to change the script itself – just specify the live variable initial values with --vars.

Socket server

If shoebot is run with the –serverport option, a socket server will also be started. Socket servers can accept connections from other applications or even across the network in order to set variables inside running Shoebot scripts.

$ sbot -s examples/animation/hypnoval.bot
Listening on port 7777...

Once it’s running, it’s easy to connect with telnet:

$ telnet 127.0.0.1 7777

This gets you into the shell, where you can use the commands below to list and set variables, rewind and go to frames.

The following commands can also be sent through other applications like Pure Data; there is a simple PD example in examples/socketcontrol/helloworld.pd. Be sure to take a look at the socket server examples in action inside the examples/socketserver directory.

Socketserver commands

Command

Description

goto 100

go to frame 100

pause

pause playback

rewind

set FRAME to 0

restart

set FRAME to 0 and reset all variables

vars

show content of all live variables

set n=1

set variable ‘n’ to value 1

n=1

set variable ‘n’ to value 1

help

show list of all commands

Using the live shell

Shoebot provides a live shell for communication with text editors, as well as livecoding.

All the socket server commands above are available, along with load_base64 which allows livecoding.

To experiment with the shell, run an example with the -l option:

$ sbot -l examples/animation/hypnoval.bot

The shell accepts all the socket server commands, along with a couple more; these can be useful for an editor or IDE.

Live Shell commands

Command

Description

quit

quit shoebot

load_base64

used by IDE/Editor to send new code to Shoebot