add decoder for trackable

src/decoders/index.ts

@@ -2,6 +2,7 @@ import CentroidAccelVelocity from './motion/centroid-accel-velocity';
 import CentroidPosition from './motion/centroid-position';
 import OrientationEuler from './motion/orientation-euler';
 import OrientationQuaternion from './motion/orientation-quaternion';
+import Trackable from './motion/trackable';
 import TrackedPointAccelVelocity from './motion/tracked-point-accel-velocity';
 import TrackedPointPosition from './motion/tracked-point-position';
 import ZoneCollisionDetection from './motion/zone-collision-detection';
@@ -10,6 +11,7 @@ import RTTrPHeader from './rttrp';
 
 export const Decoders = {
   RTTrPHeader,
+  Trackable,
   CentroidPosition,
   CentroidAccelVelocity,
   TrackedPointPosition,

src/decoders/motion/trackable.ts

@@ -0,0 +1,98 @@
+import { Decoders } from '..';
+import { Trackable, TrackableModule } from '../../models';
+
+const textDecoder = new TextDecoder('utf-8');
+
+export default (bytes: Uint8Array, isLittleEndian: boolean = false): Trackable => {
+  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
+
+  let dataOffset = 0;
+  const type = view.getUint8(0);
+  dataOffset += 1;
+  if (type !== 0x01 && type !== 0x51) {
+    throw new Error('Trackable module must have a type of 0x01 or 0x51');
+  }
+
+  const size = view.getUint16(dataOffset, isLittleEndian);
+  dataOffset += 2;
+  if (size !== bytes.byteLength) {
+    throw new Error('Trackable module size mismatch');
+  }
+  const nameLength = view.getUint8(dataOffset);
+  dataOffset += 1;
+  const name = textDecoder.decode(bytes.subarray(4, 4 + nameLength));
+  dataOffset += nameLength;
+  let timestamp;
+
+  if (type === 0x51) {
+    timestamp = view.getUint32(dataOffset, isLittleEndian);
+    dataOffset += 4;
+  }
+  const numberOfModules = view.getUint8(dataOffset);
+  dataOffset += 1;
+
+  const modules: TrackableModule[] = [];
+  let trackableModuleOffset = dataOffset;
+
+  for (let index = 0; index < numberOfModules; index++) {
+    const moduleData = bytes.subarray(trackableModuleOffset);
+    const moduleType = moduleData[0];
+    switch (moduleType) {
+      case 0x02: {
+        const module = Decoders.CentroidPosition(moduleData, isLittleEndian);
+        modules.push(module);
+        trackableModuleOffset += module.size;
+        break;
+      }
+      case 0x03: {
+        const module = Decoders.OrientationQuaternion(moduleData, isLittleEndian);
+        modules.push(module);
+        trackableModuleOffset += module.size;
+        break;
+      }
+      case 0x04: {
+        const module = Decoders.OrientationEuler(moduleData, isLittleEndian);
+        modules.push(module);
+        trackableModuleOffset += module.size;
+        break;
+      }
+      case 0x06: {
+        const module = Decoders.TrackedPointPosition(moduleData, isLittleEndian);
+        modules.push(module);
+        trackableModuleOffset += module.size;
+        break;
+      }
+      case 0x20: {
+        const module = Decoders.CentroidAccelVelocity(moduleData, isLittleEndian);
+        modules.push(module);
+        trackableModuleOffset += module.size;
+        break;
+      }
+      case 0x21: {
+        const module = Decoders.TrackedPointAccelVelocity(moduleData, isLittleEndian);
+        modules.push(module);
+        trackableModuleOffset += module.size;
+        break;
+      }
+      case 0x22: {
+        const module = Decoders.ZoneCollisionDetection(moduleData, isLittleEndian);
+        modules.push(module);
+        trackableModuleOffset += module.size;
+        break;
+      }
+      default:
+        console.error(`unknown trackable submodule type: ${moduleType}`);
+        break;
+    }
+  }
+
+  return {
+    type,
+    size,
+    nameLength,
+    name,
+    timestamp,
+    numberOfModules,
+    modules,
+  };
+};

src/models.ts

@@ -9,6 +9,25 @@ export type RTTrPHeader = {
   subModuleCount: number;
 };
 
+export type TrackableModule =
+  | CentroidPosition
+  | CentroidAccelVelocity
+  | TrackedPointPosition
+  | TrackedPointAccelVelocity
+  | OrientationEuler
+  | OrientationQuaternion
+  | ZoneCollisionDetection;
+
+export type Trackable = {
+  type: number;
+  size: number;
+  nameLength: number;
+  name: string;
+  timestamp?: number;
+  numberOfModules: number;
+  modules: TrackableModule[];
+};
+
 export type CentroidPosition = {
   type: number;
   size: number;