add experimental webgu demo

CHANGELOG.md

@@ -11,9 +11,7 @@ Repository: **<git+https://github.com/vladmandic/human.git>**
 
 ### **HEAD -> main** 2021/08/14 mandic00@live.com
 
-
-### **origin/main** 2021/08/13 mandic00@live.com
-
+- complete async work
 - list detect cameras
 - switch to async data reads
 

src/interpolate.ts

@@ -7,6 +7,7 @@ import type { Result, Face, Body, Hand, Item, Gesture, Person } from './result';
 const bufferedResult: Result = { face: [], body: [], hand: [], gesture: [], object: [], persons: [], performance: {}, timestamp: 0 };
 
 export function calc(newResult: Result): Result {
+  if (!newResult) return { face: [], body: [], hand: [], gesture: [], object: [], persons: [], performance: {}, timestamp: 0 };
   // each record is only updated using deep clone when number of detected record changes, otherwise it will converge by itself
   // otherwise bufferedResult is a shallow clone of result plus updated local calculated values
   // thus mixing by-reference and by-value assignments to minimize memory operations