maestro refacto to grrom, getpositions actions transfered to Observer, changed to frustum, with subscription

Observer/frustum.js

@@ -0,0 +1,33 @@
+export class Frustum {
+
+    constructor(planes) {
+        if(!Frustum.#validatePlanes(planes)) throw(new Error('Invalid frustum planes'))
+        this.planes = planes.map(p => ({ ...p }))
+    }
+
+    static #validatePlanes(planes) {
+        if(!Array.isArray(planes) || planes.length !== 6) return(false)
+        for(const p of planes) {
+            if(!p || typeof(p) !== 'object') return(false)
+            if(typeof(p.nx) !== 'number' || Number.isNaN(p.nx)) return(false)
+            if(typeof(p.ny) !== 'number' || Number.isNaN(p.ny)) return(false)
+            if(typeof(p.nz) !== 'number' || Number.isNaN(p.nz)) return(false)
+            if(typeof(p.d) !== 'number' || Number.isNaN(p.d)) return(false)
+        }
+        return(true)
+    }
+
+    static fromPlanes(planes) {
+        if(!Frustum.#validatePlanes(planes)) return(null)
+        return(new Frustum(planes))
+    }
+
+    containsPoint(position) {
+        for(const p of this.planes) {
+            const dist = p.nx * position.x + p.ny * position.y + p.nz * position.z + p.d
+            if(dist < 0) return(false)
+        }
+        return(true)
+    }
+
+}