chore: 🤖 add nodejs example

node-example.mjs

@@ -0,0 +1,79 @@
+import createDotLottiePlayerModule from "./release/wasm/DotLottiePlayer.mjs";
+import fs from "fs";
+import path from "path";
+
+const wasmBinary = fs.readFileSync(
+  path.join("./release/wasm/DotLottiePlayer.wasm")
+);
+
+const Module = await createDotLottiePlayerModule({
+  wasmBinary,
+});
+
+const WIDTH = 200;
+const HEIGHT = 200;
+
+const dotLottie = new Module.DotLottiePlayer({
+  autoplay: false,
+  loop_animation: false,
+  mode: Module.Mode.values[1],
+  speed: 1,
+  use_frame_interpolation: false,
+});
+
+const data = await fetch(
+  "https://lottie.host/647eb023-6040-4b60-a275-e2546994dd7f/zDCfp5lhLe.json"
+).then((res) => res.text());
+
+const loaded = dotLottie.load_animation_data(data, WIDTH, HEIGHT);
+
+if (!loaded) {
+  console.log("failed to load animation data");
+}
+
+dotLottie.set_frame(10.0);
+const rendered = dotLottie.render();
+
+if (!rendered) {
+  console.log("failed to render");
+}
+
+const frameBuffer = dotLottie.buffer();
+
+const bmpBuffer = createBMP(WIDTH, WIDTH, frameBuffer);
+
+fs.writeFileSync("./output.bmp", bmpBuffer);
+
+// This is for demonstration purposes only. to avoid adding a dependency
+function createBMP(width, height, frameBuffer) {
+  // Each pixel in BMP is 4 bytes (BGRA)
+  const bmpDataSize = width * height * 4;
+  const headerSize = 54;
+  const fileSize = bmpDataSize + headerSize;
+  const bmpBuffer = Buffer.alloc(fileSize);
+
+  // Bitmap file header
+  bmpBuffer.write("BM", 0); // Signature
+  bmpBuffer.writeInt32LE(fileSize, 2); // File size
+  bmpBuffer.writeInt32LE(headerSize, 10); // Pixel data offset
+
+  // DIB header
+  bmpBuffer.writeInt32LE(40, 14); // DIB header size
+  bmpBuffer.writeInt32LE(width, 18); // Width
+  bmpBuffer.writeInt32LE(-height, 22); // Height (negative for top-down bitmap)
+  bmpBuffer.writeInt16LE(1, 26); // Color planes
+  bmpBuffer.writeInt16LE(32, 28); // Bits per pixel
+  bmpBuffer.writeInt32LE(0, 30); // Compression (0 for none)
+
+  // Convert RGBA to BGRA and write pixel data
+  for (let i = 0; i < width * height; i++) {
+    const rgbaIndex = i * 4;
+    const bgraIndex = headerSize + i * 4;
+    bmpBuffer[bgraIndex + 0] = frameBuffer[rgbaIndex + 2]; // Blue
+    bmpBuffer[bgraIndex + 1] = frameBuffer[rgbaIndex + 1]; // Green
+    bmpBuffer[bgraIndex + 2] = frameBuffer[rgbaIndex + 0]; // Red
+    bmpBuffer[bgraIndex + 3] = frameBuffer[rgbaIndex + 3]; // Alpha
+  }
+
+  return bmpBuffer;
+}