add encoder for centroid position sub module

src/encoders/index.ts

@@ -1,3 +1,4 @@
+import CentroidPosition from './motion/centroid-position';
 import RTTrPM from './motion/rttrpm';
 import Trackable from './motion/trackable';
 import RTTrPHeader from './rttrp-header';
@@ -6,4 +7,5 @@ export const Encoders = {
   RTTrPHeader,
   RTTrPM,
   Trackable,
+  CentroidPosition,
 };

src/encoders/motion/centroid-position.ts

@@ -0,0 +1,18 @@
+export default (latency: number, x: number, y: number, z: number, isLittleEndian: boolean = false): Uint8Array => {
+  const bytes = new Uint8Array(29);
+  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
+
+  let dataOffset = 0;
+  view.setUint8(dataOffset, 0x02);
+  dataOffset += 1;
+  view.setUint16(dataOffset, bytes.byteLength, isLittleEndian);
+  dataOffset += 2;
+  view.setUint16(dataOffset, latency, isLittleEndian);
+  dataOffset += 2;
+  view.setFloat64(dataOffset, x, isLittleEndian);
+  dataOffset += 8;
+  view.setFloat64(dataOffset, y, isLittleEndian);
+  dataOffset += 8;
+  view.setFloat64(dataOffset, z, isLittleEndian);
+  return bytes;
+};