feat: udp stream

test/pixelstream/rainbow.js

@@ -0,0 +1,59 @@
+const dgram = require('dgram');
+
+const host = process.argv[2];
+const port = parseInt(process.argv[3] || '4210', 10);
+const pixels = parseInt(process.argv[4] || '64', 10);
+const intervalMs = parseInt(process.argv[5] || '30', 10);
+
+if (!host) {
+  console.error('Usage: node rainbow.js <device-ip> [port] [pixels] [interval-ms]');
+  process.exit(1);
+}
+
+const socket = dgram.createSocket('udp4');
+let offset = 0;
+const isBroadcast = host === '255.255.255.255' || host.endsWith('.255');
+
+function wheel(pos) {
+  pos = 255 - pos;
+  if (pos < 85) {
+    return [255 - pos * 3, 0, pos * 3];
+  }
+  if (pos < 170) {
+    pos -= 85;
+    return [0, pos * 3, 255 - pos * 3];
+  }
+  pos -= 170;
+  return [pos * 3, 255 - pos * 3, 0];
+}
+
+function generateFrame() {
+  let payload = 'RAW:';
+  for (let i = 0; i < pixels; i++) {
+    const colorIndex = (i * 256 / pixels + offset) & 255;
+    const [r, g, b] = wheel(colorIndex);
+    payload += r.toString(16).padStart(2, '0');
+    payload += g.toString(16).padStart(2, '0');
+    payload += b.toString(16).padStart(2, '0');
+  }
+
+  offset = (offset + 1) & 255;
+  return payload;
+}
+
+function sendFrame() {
+  const payload = generateFrame();
+  const message = Buffer.from(payload, 'utf8');
+  socket.send(message, port, host);
+}
+
+setInterval(sendFrame, intervalMs);
+
+if (isBroadcast) {
+  socket.bind(() => {
+    socket.setBroadcast(true);
+  });
+}
+
+console.log(`Streaming rainbow pattern to ${host}:${port} with ${pixels} pixels (interval=${intervalMs}ms)`);
+