Move path related function into the math package

packages/math/index.ts

@@ -2,9 +2,11 @@ export * from "./arc";
 export * from "./angle";
 export * from "./curve";
 export * from "./line";
+export * from "./path";
 export * from "./point";
 export * from "./polygon";
 export * from "./range";
+export * from "./rectangle";
 export * from "./segment";
 export * from "./triangle";
 export * from "./types";

packages/math/path.ts

@@ -0,0 +1,27 @@
+import { pointDistance } from "./point";
+import type { LocalPoint } from "./types";
+
+/**
+ * Checks if the first and last point are close enough to be considered a loop
+ *
+ * @param points
+ * @param threshold
+ * @returns
+ */
+export const pathIsALoop = (
+  points: readonly LocalPoint[],
+  /** supply if you want the loop detection to account for current zoom */
+  threshold: number,
+  //zoomValue: Zoom["value"] = 1 as NormalizedZoomValue,
+): boolean => {
+  if (points.length >= 3) {
+    const [first, last] = [points[0], points[points.length - 1]];
+    const distance = pointDistance(first, last);
+
+    // Adjusting LINE_CONFIRM_THRESHOLD to current zoom so that when zoomed in
+    // really close we make the threshold smaller, and vice versa.
+
+    return distance <= threshold; // LINE_CONFIRM_THRESHOLD / zoomValue;
+  }
+  return false;
+};