feat(): parsePathCurve

Author: ShaMan123

intersect.d.ts

@@ -35,6 +35,18 @@ declare function findPathIntersections(path1: Path, path2: Path, justCount?: boo
 
 export default findPathIntersections;
 
+/**
+ * Parse a path so it is suitable to pass to {@link findPathIntersections}
+ * Used in order to opt out of internal path caching.
+ * 
+ * @example
+ * const p1 = parsePathCurve('M0,0L100,100');
+ * const p2 = parsePathCurve([ [ 'M', 0, 100 ], [ 'L', 100, 0 ] ]);
+ * const intersections = findPathIntersections(p1, p2);
+ * 
+ */
+export declare function parsePathCurve(path: Path): PathComponent[]
+
 /**
  * A string in the form of 'M150,150m0,-18a18,18,0,1,1,0,36a18,18,0,1,1,0,-36z'
  * or something like:

intersect.js

@@ -395,8 +395,8 @@ function findBezierIntersections(bez1, bez2, justCount) {
  * @return {import("./intersect").Intersection[] | number}
  */
 export default function findPathIntersections(path1, path2, justCount) {
-  path1 = getPathCurve(path1);
-  path2 = getPathCurve(path2);
+  path1 = path1.parsed ? path1 : getPathCurve(path1);
+  path2 = path2.parsed ? path2 : getPathCurve(path2);
 
   var x1, y1, x2, y2, x1m, y1m, x2m, y2m, bez1, bez2,
       res = justCount ? 0 : [];
@@ -766,7 +766,7 @@ function curveBBox(x0, y0, x1, y1, x2, y2, x3, y3) {
 }
 
 /**
- * Handles caches
+ * An impure version of {@link parsePathCurve} handling caching
  */
 function getPathCurve(path) {
 
@@ -795,6 +795,36 @@ function getPathCurve(path) {
   return (pth.curve = pathToCurve(abs));
 }
 
+/**
+ * A pure version of {@link getPathCurve}
+ * @param {import("./intersect").Path} path
+ * @returns {import("./intersect").PathComponent[]}
+ */
+export function parsePathCurve(path) {
+
+  const abs = (pathToAbsolute(
+    !Array.isArray(path) ?
+      parsePathString(path) :
+      path)
+  );
+
+  const curve = pathToCurve(abs);
+
+  /**
+   * Flag to skip {@link getPathCurve}
+   */
+  return Object.defineProperty(
+    curve,
+    'parsed',
+    {
+      value: true,
+      configurable: false,
+      enumerable: false,
+      writable: false
+    }
+  );
+}
+
 function pathToCurve(absPath) {
 
   var curvedPath = pathClone(absPath),

test/intersect.spec.js

@@ -1,4 +1,4 @@
-import intersect from 'path-intersection';
+import intersect, { parsePathCurve } from 'path-intersection';
 import { expect } from 'chai';
 
 import domify from 'domify';
@@ -21,6 +21,21 @@ describe('path-intersection', function() {
       expect(intersections).to.have.length(1);
     });
 
+    it('parsePathCurve', function() {
+
+      // when
+      var parsed1 = parsePathCurve(p1);
+      var parsed2 = parsePathCurve(p2);
+
+      // then
+      expect(parsed1).to.deep.eq([['M', 0, 0], ['C', 0, 0, 100, 100, 100, 100]])
+      expect(parsed1.parsed).to.eq(true)
+
+      expect(parsed2).to.deep.eq([['M', 0, 100], ['C', 0, 100, 100, 0, 100, 0]])
+      expect(parsed2.parsed).to.eq(true)
+
+    });
+
 
     it('should expose intersection', function() {