initial commit

packages/free-d/src/encode.ts

@@ -0,0 +1,41 @@
+import { FreeDPosition, FreeDMessageType } from './types';
+import { checksum, positionToFreeDUnits, rotationToFreeDUnits } from './utils';
+
+function positionMessageToBytes(message: FreeDPosition): Uint8Array {
+  const bytes = new Uint8Array(29);
+
+  bytes[0] = FreeDMessageType.Position;
+  bytes[1] = message.id;
+
+  bytes.set(rotationToFreeDUnits(message.pan), 2);
+  bytes.set(rotationToFreeDUnits(message.tilt), 5);
+  bytes.set(rotationToFreeDUnits(message.roll), 8);
+
+  bytes.set(positionToFreeDUnits(message.posX), 11);
+  bytes.set(positionToFreeDUnits(message.posY), 14);
+  bytes.set(positionToFreeDUnits(message.posZ), 17);
+
+  bytes[20] = Math.trunc(message.zoom / 65536);
+  bytes[21] = Math.trunc((message.zoom / 256) % 256);
+  bytes[22] = message.zoom % 256;
+
+  bytes[23] = Math.trunc(message.focus / 65536);
+  bytes[24] = Math.trunc((message.focus / 256) % 256);
+  bytes[25] = message.focus % 256;
+
+  if (message.spare !== undefined) {
+    bytes[26] = message.spare >> 8;
+    bytes[27] = message.spare % 256;
+  }
+
+  bytes[28] = checksum(bytes.subarray(0, 28));
+  return bytes;
+}
+export function encode(message: FreeDPosition): Uint8Array {
+  switch (message.type) {
+    case FreeDMessageType.Position:
+      return positionMessageToBytes(message);
+    default:
+      throw new Error('unsupported freeD message type');
+  }
+}