feat: udp stream

test/pixelstream/fade-green-blue.js

@@ -0,0 +1,55 @@
+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 speed = parseFloat(process.argv[5] || '0.5'); // cycles per second
+
+if (!host) {
+  console.error('Usage: node fade-green-blue.js <device-ip> [port] [pixels] [speed-hz]');
+  process.exit(1);
+}
+
+const socket = dgram.createSocket('udp4');
+const intervalMs = 50;
+let tick = 0;
+const isBroadcast = host === '255.255.255.255' || host.endsWith('.255');
+
+function generateFrame() {
+  const timeSeconds = (tick * intervalMs) / 1000;
+  const phase = timeSeconds * speed * Math.PI * 2;
+  const blend = (Math.sin(phase) + 1) * 0.5; // 0..1
+
+  const green = Math.round(255 * (1 - blend));
+  const blue = Math.round(255 * blend);
+
+  let payload = 'RAW:';
+  const gHex = green.toString(16).padStart(2, '0');
+  const bHex = blue.toString(16).padStart(2, '0');
+
+  for (let i = 0; i < pixels; i++) {
+    payload += '00';
+    payload += gHex;
+    payload += bHex;
+  }
+
+  return payload;
+}
+
+function sendFrame() {
+  const payload = generateFrame();
+  const message = Buffer.from(payload, 'utf8');
+  socket.send(message, port, host);
+  tick += 1;
+}
+
+setInterval(sendFrame, intervalMs);
+
+if (isBroadcast) {
+  socket.bind(() => {
+    socket.setBroadcast(true);
+  });
+}
+
+console.log(`Streaming green/blue fade to ${host}:${port} with ${pixels} pixels (speed=${speed}Hz)`);
+