keep vertex to edges index outside of Vertex class

web/app/brep/edgeIndex.js

@@ -0,0 +1,54 @@
+import {Edge} from './topo/edge';
+import BrepCurve from './geom/curves/brepCurve';
+
+export default class EdgeIndex {
+  
+  constructor() {
+    this.index = new Map();
+  }
+
+  addEdge(edge, tag) {
+    if (edge.halfEdge1) {
+      this.addHalfEdge(edge.halfEdge1, tag);
+    }
+    if (edge.halfEdge2) {
+      this.addHalfEdge(edge.halfEdge2, tag);
+    }
+  }
+
+  addHalfEdge(he, tag) {
+    this._edgesForVertex(he.vertexA).add([he, tag]);
+  }
+
+  _edgesForVertex(v) {
+    let edges = this.index.get(v);
+    if (!edges) {
+      edges = new Set();
+      this.index.set(v, edges);
+    }
+    return edges;
+  }
+
+  getHalfEdge(a, b, tag) {
+    let edges = this.index.get(a);
+    if (edges) {
+      for (let [he, _tag] of edges) {
+        if (he.vertexB === b && (tag === undefined || tag === _tag)) {
+          return he;
+        }
+      }
+    }
+    return null;
+  }
+
+  getHalfEdgeOrCreate(a, b, curveCreate, invertedToCurve, tag) {
+    let he = this.getHalfEdge(a, b, tag);
+    if (he === null) {
+      let curve = curveCreate ? curveCreate() : BrepCurve.createLinearCurve(a.point, b.point); 
+      const e = new Edge(curve, invertedToCurve?b:a, invertedToCurve?a:b);
+      he = invertedToCurve ? e.halfEdge2 : e.halfEdge1;
+      this.addEdge(e, tag);
+    }
+    return he;
+  }
+}

web/app/brep/topo/edge.js

@@ -1,6 +1,5 @@
 import {TopoObject} from './topo-object'
 import {Vertex} from "./vertex";
-import {Point} from "../geom/point";
 
 export class Edge extends TopoObject {
 
@@ -9,8 +8,6 @@ export class Edge extends TopoObject {
     this.curve = curve;
     this.halfEdge1 = new HalfEdge(this, false, a, b);
     this.halfEdge2 = new HalfEdge(this, true, b, a);
-    a.edges.add(this.halfEdge1);
-    b.edges.add(this.halfEdge2);
   }
 
   static fromCurve(curve) {

web/app/brep/topo/vertex.js

@@ -5,15 +5,5 @@ export class Vertex extends TopoObject {
   constructor(point) {
     super();
     this.point = point;
-    this.edges = new Set();
-  }
- 
-  edgeFor(other) {
-    for (let e of this.edges) {
-      if (e.vertexB == other) {
-        return e;
-      }
-    }
-    return null;
   }
 }