feat: more matrix stream examples

test/pixelstream/meteor-rain.js

@@ -0,0 +1,132 @@
+const dgram = require('dgram');
+
+const {
+  clamp,
+  createFrame,
+  fadeFrame,
+  frameToPayload,
+  hexToRgb,
+  samplePalette,
+  toIndex,
+} = require('./shared-frame-utils');
+
+const DEFAULT_PORT = 4210;
+const DEFAULT_WIDTH = 16;
+const DEFAULT_HEIGHT = 16;
+const DEFAULT_INTERVAL_MS = 45;
+const DEFAULT_METEOR_COUNT = 12;
+const BASE_SPEED_MIN = 4;
+const BASE_SPEED_MAX = 10;
+const TRAIL_DECAY = 0.76;
+
+const paletteStops = [
+  { stop: 0.0, color: hexToRgb('0a0126') },
+  { stop: 0.3, color: hexToRgb('123d8b') },
+  { stop: 0.7, color: hexToRgb('21c7d9') },
+  { stop: 1.0, color: hexToRgb('f7ffff') },
+];
+
+const host = process.argv[2];
+const port = parseInt(process.argv[3] || String(DEFAULT_PORT), 10);
+const width = parseInt(process.argv[4] || String(DEFAULT_WIDTH), 10);
+const height = parseInt(process.argv[5] || String(DEFAULT_HEIGHT), 10);
+const intervalMs = parseInt(process.argv[6] || String(DEFAULT_INTERVAL_MS), 10);
+const meteorCount = parseInt(process.argv[7] || String(DEFAULT_METEOR_COUNT), 10);
+
+if (!host) {
+  console.error('Usage: node meteor-rain.js <device-ip> [port] [width] [height] [interval-ms] [meteor-count]');
+  process.exit(1);
+}
+
+if (Number.isNaN(port) || Number.isNaN(width) || Number.isNaN(height) || Number.isNaN(intervalMs) || Number.isNaN(meteorCount)) {
+  console.error('Invalid numeric argument. Expected integers for port, width, height, interval-ms, and meteor-count.');
+  process.exit(1);
+}
+
+if (width <= 0 || height <= 0) {
+  console.error('Matrix dimensions must be positive integers.');
+  process.exit(1);
+}
+
+if (meteorCount <= 0) {
+  console.error('Meteor count must be a positive integer.');
+  process.exit(1);
+}
+
+const socket = dgram.createSocket('udp4');
+const isBroadcast = host === '255.255.255.255' || host.endsWith('.255');
+const frame = createFrame(width, height);
+const meteors = createMeteors(meteorCount, width, height);
+const frameTimeSeconds = intervalMs / 1000;
+
+if (isBroadcast) {
+  socket.bind(() => {
+    socket.setBroadcast(true);
+  });
+}
+
+socket.on('error', (error) => {
+  console.error('Socket error:', error.message);
+});
+
+function createMeteors(count, matrixWidth, matrixHeight) {
+  const meteorList = [];
+  for (let index = 0; index < count; ++index) {
+    meteorList.push(spawnMeteor(matrixWidth, matrixHeight));
+  }
+  return meteorList;
+}
+
+function spawnMeteor(matrixWidth, matrixHeight) {
+  const angle = (Math.PI / 4) * (0.6 + Math.random() * 0.8);
+  const speed = BASE_SPEED_MIN + Math.random() * (BASE_SPEED_MAX - BASE_SPEED_MIN);
+  return {
+    x: Math.random() * matrixWidth,
+    y: -Math.random() * matrixHeight,
+    vx: Math.cos(angle) * speed,
+    vy: Math.sin(angle) * speed,
+  };
+}
+
+function drawMeteor(meteor) {
+  const col = Math.round(meteor.x);
+  const row = Math.round(meteor.y);
+  if (col < 0 || col >= width || row < 0 || row >= height) {
+    return;
+  }
+
+  const energy = clamp(1.2 - Math.random() * 0.2, 0, 1);
+  frame[toIndex(col, row, width)] = samplePalette(paletteStops, energy);
+}
+
+function updateMeteors(deltaSeconds) {
+  meteors.forEach((meteor, index) => {
+    meteor.x += meteor.vx * deltaSeconds;
+    meteor.y += meteor.vy * deltaSeconds;
+
+    drawMeteor(meteor);
+
+    if (meteor.x > width + 1 || meteor.y > height + 1) {
+      meteors[index] = spawnMeteor(width, height);
+    }
+  });
+}
+
+function generateFrame() {
+  fadeFrame(frame, TRAIL_DECAY);
+  updateMeteors(frameTimeSeconds);
+  return frameToPayload(frame);
+}
+
+function sendFrame() {
+  const payload = generateFrame();
+  const message = Buffer.from(payload, 'utf8');
+  socket.send(message, port, host);
+}
+
+setInterval(sendFrame, intervalMs);
+
+console.log(
+  `Streaming meteor rain to ${host}:${port} (${width}x${height}, interval=${intervalMs}ms, meteors=${meteorCount})`,
+);
+