improved single responsibility of graphs

projects/nls-guilloche/src/lib/models/graph.model.ts

@@ -15,6 +15,7 @@
  */
 
 import { Point } from './point.model';
+import { Config } from './config.model';
 
 export interface Graph {
   id: string;
@@ -29,6 +30,10 @@ export interface Graph {
     direction?: Point;
     vector: number; // degree between 0 and 360
   };
+  spread: {
+    amount: number;
+    spacing: number
+  };
   stroke: number; // stroke width
   nodes?: Point[]; // orientation points
 }