add node-canvas sources and examples

node-sources/.gitignore

@@ -0,0 +1 @@
+node_modules

node-sources/README.md

@@ -0,0 +1,33 @@
+# interact with letterbox using nodejs
+
+A small set of modules to send UDP packets that consist of the contents of a node-canvas to the octopus server.
+
+## setup
+
+run `npm install`
+
+## run examples
+
+### render
+
+stuff on canvas and send contents to octopus
+
+- `node render.js [<host>]`
+
+### scan image
+
+load image stuff on canvas and send contents to octopus
+preserves the image ratio and scans from top to bottom
+
+- `node scan-image.js <path-to-image> [<host>]`
+
+
+## convert protobuf schema 
+
+There is a shell script to convert the latest .proto file to an es6 module used with all example scripts.
+Calling this will output / overwrite [packet.js](./packet.js).
+
+```
+./convert-proto.js ../protobuf/schema.proto
+```
+

node-sources/convert-proto.js

@@ -0,0 +1,28 @@
+#!/usr/bin/env node
+
+import { readFileSync, writeFileSync } from 'node:fs';
+import { resolve } from 'node:path';
+import { argv } from 'node:process';
+import { parseSchema } from 'pbjs';
+
+// convert .proto to es6 module
+
+console.log(argv)
+const p = resolve(argv[2])
+console.log(p)
+
+if (!p.endsWith('.proto')) {
+    process.exit(1)
+}
+
+const raw = readFileSync(p)
+console.log(raw.toString())
+const replaced = raw.toString().replace(/( \[[^\]]+\])/g, '')
+console.log(replaced)
+
+const f = parseSchema(Buffer.from(replaced))
+try {
+    writeFileSync('packet.js', f.toJavaScript({es6:true}))
+} catch (e) {
+    console.error(e)
+}