# data-streams/osc-stream

A [readable-](https://streams.spec.whatwg.org/#rs-model) and [writable stream](https://streams.spec.whatwg.org/#ws-model) of [OSC Messages](http://opensoundcontrol.org/spec-1_0), wrapping an underlying [OSC Websocket client](https://github.com/adzialocha/osc-js/wiki/Websocket-Client-Plugin) (from the [@adzialocha/osc-js](https://github.com/adzialocha/osc-js/) library).

## Prequisites

Requires an _OSC bridge server_ running on your local network, to enable bi-directional messaging between the `OSCStream` class instance and a remote OSC controller. You can use the [@petitatelier/osc-bridge](https://github.com/petitatelier/data-streams/tree/master/packages/osc-bridge) command-line utility to start one. See _demo_ instructions hereafter.

## Usage

```html
  <script type="module">
    import { OSCStream , OSCMessageHTMLFormatter } from "@petitatelier/osc-stream";
    const oscStream = new OSCStream({ host: "0.0.0.0", port: 8080 });

    oscStream.readable
      .pipeThrough( OSCMessageHTMLFormatter)
      .pipeTo( streamingElement.writable)
      .catch( err => console.error( "Something went wrong!", err));

    const oscWriter = oscStream.writable.getWriter();
    oscWriter.write( new self.OSC.Message( "/ping"))
      .catch( err => console.error( "Something went wrong!", err));
  </script>
```

## Demo

<img height="400" title="`OSCStream` class demo · Screencopy"
  src="https://raw.githubusercontent.com/petitatelier/data-streams/master/demos/images/osc-stream-demo-screencopy.png" >

Run following command and navigate to http://127.0.0.1:8081/demos/osc-stream.html:

    $ npm run dev:osc

## Prerequisite

### OSC bridge server

The `npm run dev:osc` command will start an _OSC bridge server_, along with the local
dev HTTP server, enabling bi-directional messaging between a _remote OSC controller_
and the `OSCStream` class instance of the demo.

Before starting the _OSC bridge server_, you might want to tweak its configuration;
see the `config` section of the [package.json](../../package.json) at the root of
this monorepo.

```
{
  …
  "config": {
    "http-server": {
      "host": "0.0.0.0",
      "port": "8081"
    },
    "osc-bridge": {
      "udp-server": {
        "host": "0.0.0.0",
        "port": "7400"
      },
      "udp-client": {
        "host": "192.168.178.29",
        "port": "7500"
      },
      "ws-server": {
        "host": "0.0.0.0",
        "port": "8080"
      }
    }
  },
  …
}
```

### OSC remote controller

You will also need to configure your remote _OSC controller app_, to send its
outgoing messages to the _OSC bridge server_.

Use the IP address of the network adapter listed by the _OSC bridge server_
upon start. For instance, if you get following output, your computer and
the _OSC bridge server_ will be reachable at IP `192.168.178.47`:

```
$ npm run dev:osc

> @petitatelier/data-streams@ dev:osc …
> osc-bridge & npm run dev && fg

OSC Websocket <-> UDP bridge server
Bridging OSC over Web Socket to/from `ws://0.0.0.0:8080`
Listening for OSC over UDP on `0.0.0.0:7400`
Broadcasting OSC over UDP to `192.168.178.29:7500`
Local host reachable at: [ en0: `192.168.178.47` ]
…
```

And if you were using the popular [TouchOSC](https://hexler.net/software/touchosc)
_remote OSC controller app_, you would consequently configure its _Host_ and
_Port (outgoing)_ fields with IP `192.168.178.47` and port `7400`, as shown
in screencopy hereafter:

<img height="400" alt="TouchOSC configuration · Screencopy"
  src="https://raw.githubusercontent.com/petitatelier/data-streams/master/demos/images/touchosc-config.png">