From f35648659f929845dd844d0f557b4ddfc7bc059f Mon Sep 17 00:00:00 2001
From: Joel Wetzell <jwetzell@yahoo.com>
Date: Sat, 15 Mar 2025 08:51:20 -0500
Subject: [PATCH] add encoder for zone sub modules

---
 src/encoders/index.ts                         |  4 ++++
 .../motion/zone-collision-detection.ts        | 23 +++++++++++++++++++
 src/encoders/motion/zone-object.ts            | 20 ++++++++++++++++
 3 files changed, 47 insertions(+)
 create mode 100644 src/encoders/motion/zone-collision-detection.ts
 create mode 100644 src/encoders/motion/zone-object.ts

diff --git a/src/encoders/index.ts b/src/encoders/index.ts
index bde4ce3..77121f3 100644
--- a/src/encoders/index.ts
+++ b/src/encoders/index.ts
@@ -6,6 +6,8 @@ import RTTrPM from './motion/rttrpm';
 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';
+import ZoneObject from './motion/zone-object';
 import RTTrPHeader from './rttrp-header';
 
 export const Encoders = {
@@ -18,4 +20,6 @@ export const Encoders = {
   TrackedPointPosition,
   CentroidAccelVelocity,
   TrackedPointAccelVelocity,
+  ZoneCollisionDetection,
+  ZoneObject,
 };
diff --git a/src/encoders/motion/zone-collision-detection.ts b/src/encoders/motion/zone-collision-detection.ts
new file mode 100644
index 0000000..8c37ddc
--- /dev/null
+++ b/src/encoders/motion/zone-collision-detection.ts
@@ -0,0 +1,23 @@
+export default (zoneObjectModules: Uint8Array[], isLittleEndian: boolean = false): Uint8Array => {
+  let totalZoneModuleSize = 1 + 2 + 1;
+
+  zoneObjectModules.forEach((zoneObjectModule) => {
+    totalZoneModuleSize += zoneObjectModule.byteLength;
+  });
+
+  const bytes = new Uint8Array(totalZoneModuleSize);
+  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
+
+  let dataOffset = 0;
+  view.setUint8(dataOffset, 0x22);
+  dataOffset += 1;
+  view.setUint16(dataOffset, bytes.byteLength, isLittleEndian);
+  dataOffset += 2;
+  view.setUint8(dataOffset, zoneObjectModules.length);
+  dataOffset += 1;
+  zoneObjectModules.forEach((zoneObjectModule) => {
+    bytes.set(zoneObjectModule, dataOffset);
+    dataOffset += zoneObjectModule.length;
+  });
+  return bytes;
+};
diff --git a/src/encoders/motion/zone-object.ts b/src/encoders/motion/zone-object.ts
new file mode 100644
index 0000000..e9731c1
--- /dev/null
+++ b/src/encoders/motion/zone-object.ts
@@ -0,0 +1,20 @@
+const textEncoder = new TextEncoder();
+
+export default (name: string): Uint8Array => {
+  const totalZoneObjectModuleSize = 1 + 1 + name.length;
+  const bytes = new Uint8Array(totalZoneObjectModuleSize);
+  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
+
+  let dataOffset = 0;
+  view.setUint8(dataOffset, totalZoneObjectModuleSize);
+  dataOffset += 1;
+  view.setUint8(dataOffset, name.length);
+  dataOffset += 1;
+
+  const nameBytes = textEncoder.encode(name);
+  nameBytes.forEach((byte) => {
+    view.setUint8(dataOffset, byte);
+    dataOffset += 1;
+  });
+  return bytes;
+};