Ported union, difference, and intersect to clipper2-ts to improve performance

.monorepolint.config.mjs

@@ -148,6 +148,7 @@ export default {
         },
       },
       includePackages: [...TS_PACKAGES, ...JS_PACKAGES],
+      excludePackages: ["@turf/internal"],
     }),
 
     packageEntry({
@@ -157,6 +158,7 @@ export default {
         },
       },
       includePackages: [...TS_PACKAGES, ...JS_PACKAGES],
+      excludePackages: ["@turf/internal"],
     }),
 
     packageEntry({
@@ -165,6 +167,7 @@ export default {
           funding: "https://opencollective.com/turf",
         },
       },
+      excludePackages: ["@turf/internal"],
     }),
 
     packageScript({
@@ -174,7 +177,7 @@ export default {
           test: "pnpm run /test:.*/",
         },
       },
-      excludePackages: [MAIN_PACKAGE],
+      excludePackages: [MAIN_PACKAGE, "@turf/internal"],
     }),
 
     packageScript({
@@ -184,6 +187,7 @@ export default {
         },
       },
       includePackages: [...TS_PACKAGES, ...JS_PACKAGES],
+      excludePackages: ["@turf/internal"],
     }),
 
     packageScript({
@@ -226,6 +230,7 @@ export default {
         },
       },
       includePackages: [...TS_PACKAGES, ...JS_PACKAGES],
+      excludePackages: ["@turf/internal"],
     }),
 
     requireDependency({
@@ -240,6 +245,7 @@ export default {
         },
       },
       includePackages: TS_PACKAGES,
+      excludePackages: ["@turf/internal"],
     }),
 
     requireDependency({

nx.json

@@ -6,7 +6,11 @@
       "{projectRoot}/package.json",
       "{projectRoot}/tsconfig.json"
     ],
-    "sources": ["{projectRoot}/index.{js,ts}", "{projectRoot}/lib/**"]
+    "sources": [
+      "{projectRoot}/index.{js,ts}",
+      "{projectRoot}/lib/**",
+      "{projectRoot}/src/**"
+    ]
   },
   "targetDefaults": {
     "build": {

packages/internal/LICENSE

@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2017 TurfJS
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

packages/internal/README.md

@@ -0,0 +1,23 @@
+# @turf/internal
+
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+<!-- This file is automatically generated. Please don't edit it directly. If you find an error, edit the source file of the module in question (likely index.js or index.ts), and re-run "yarn docs" from the root of the turf project. -->
+
+---
+
+This module is part of the [Turfjs project](https://turfjs.org/), an open source module collection dedicated to geographic algorithms. It is maintained in the [Turfjs/turf](https://github.com/Turfjs/turf) repository, where you can create PRs and issues.
+
+### Installation
+
+Install this single module individually:
+
+```sh
+$ npm install @turf/internal
+```
+
+Or install the all-encompassing @turf/turf module that includes all modules as functions:
+
+```sh
+$ npm install @turf/turf
+```

packages/internal/package.json

@@ -0,0 +1,59 @@
+{
+  "name": "@turf/internal",
+  "version": "7.3.1",
+  "description": "Common functionality used across multiple Turf packages.",
+  "author": "Turf Authors",
+  "contributors": [
+    "James Beard <@smallsaucepan>"
+  ],
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/Turfjs/turf/issues"
+  },
+  "homepage": "https://github.com/Turfjs/turf",
+  "repository": {
+    "type": "git",
+    "url": "git://github.com/Turfjs/turf.git"
+  },
+  "funding": "https://opencollective.com/turf",
+  "publishConfig": {
+    "access": "public"
+  },
+  "type": "module",
+  "exports": {
+    "./package.json": "./package.json",
+    "./clipper2": {
+      "import": {
+        "types": "./dist/esm/clipper2.d.ts",
+        "default": "./dist/esm/clipper2.js"
+      },
+      "require": {
+        "types": "./dist/cjs/clipper2.d.cts",
+        "default": "./dist/cjs/clipper2.cjs"
+      }
+    }
+  },
+  "sideEffects": false,
+  "files": [
+    "dist"
+  ],
+  "scripts": {
+    "build": "tsup",
+    "test": "pnpm run /test:.*/",
+    "test:tape": "tsx test.ts"
+  },
+  "devDependencies": {
+    "@babel/core": "^7.26.10",
+    "@babel/types": "^7.26.10",
+    "@types/babel__core": "^7.20.5",
+    "@types/tape": "^5.8.1",
+    "tape": "^5.9.0",
+    "tsup": "^8.4.0"
+  },
+  "dependencies": {
+    "@types/geojson": "^7946.0.10",
+    "clipper2-ts": "^2.0.1",
+    "jsbi": "^4.3.2",
+    "tslib": "^2.8.1"
+  }
+}

packages/internal/src/clipper2/index.ts

@@ -0,0 +1,188 @@
+import { PolyPathD, PathD, PathsD, PolyTreeD, areaD } from "clipper2-ts";
+import { Polygon, MultiPolygon, Position } from "geojson";
+
+/*
+ * Clipper2 scaling factor used when converting between decimal and integer
+ * values for internal clipper2 calculations.
+ * For Turf's purposes defaults to 8 decimal places retained, which is approx
+ * 1mm if using decimal degrees at the equator.
+ */
+const TURF_CLIPPER2_SCALE_FACTOR = 8;
+
+/**
+ * Converts a multipolygon to a flattened array of clipper2 paths.
+ */
+function multiPolygonToPaths(coords: Position[][][]): PathsD {
+  const paths: PathsD = [];
+
+  for (const polygon of coords) {
+    for (const ring of polygonToPaths(polygon)) {
+      paths.push(ring);
+    }
+  }
+
+  return paths;
+}
+
+/**
+ * Converts a polygon to a flattened array of clipper2 paths.
+ */
+function polygonToPaths(coords: Position[][]): PathsD {
+  const paths: PathsD = [];
+
+  for (const [idx, ring] of coords.entries()) {
+    // Defensive checking against incorrectly wound Geojson polygons.
+    const checkedRing =
+      idx === 0
+        ? enforceOuterRing(ringToPath(ring))
+        : enforceInnerRing(ringToPath(ring));
+
+    paths.push(checkedRing);
+  }
+
+  return paths;
+}
+
+/**
+ * Make sure this ring is wound as an outer ring, according to clipper2
+ * expectations. That is, clockwise.
+ */
+function enforceOuterRing(path: PathD): PathD {
+  if (areaD(path) < 0) {
+    return path.reverse();
+  }
+
+  return path;
+}
+
+/**
+ * Make sure this ring is wound as an inner ring, according to clipper2
+ * expectations. That is, counter clockwise.
+ */
+function enforceInnerRing(path: PathD): PathD {
+  if (areaD(path) > 0) {
+    // Leave original array untouched.
+    return [...path].reverse();
+  }
+
+  return path;
+}
+
+/**
+ * Converts a ring to a clipper2 path.
+ */
+function ringToPath(ring: Position[]): PathD {
+  return ring.map(([x, y]) => ({ x, y }));
+}
+
+/**
+ * Construct the output Geojson based on a clipper2 tree. The tree is useful
+ * for propertly handing holes.
+ *
+ * @param polyTree hierarchy of outer and inner contours found by clipper2
+ */
+function polyTreeToGeoJSON(polyTree: PolyTreeD): Polygon | MultiPolygon | null {
+  const polygons: Position[][][] = [];
+
+  // Process each top-level polygon (initally all outer contours)
+  for (let i = 0; i < polyTree.count; i++) {
+    const child = polyTree.child(i);
+    processPolyPath(child, polygons);
+  }
+
+  if (polygons.length === 0) {
+    return null;
+  }
+
+  // If exactly 1 polygon return as Geojson Polygon
+  if (polygons.length === 1) {
+    return {
+      type: "Polygon",
+      coordinates: polygons[0],
+    };
+  }
+
+  // If anything else return as MultiPolygon
+  return {
+    type: "MultiPolygon",
+    coordinates: polygons,
+  };
+}
+
+/**
+ * Processes a polyPath. Depending on whether the path denotes an outer ring or a hole, will add a polygon to the list of polygons.
+ * Recurses to children of this polyPath in turn.
+ *
+ * @param polyPath outer or inner contour of a polygon to process
+ * @param polygons array of completed polygons that this function may add to
+ */
+function processPolyPath(polyPath: PolyPathD, polygons: Position[][][]) {
+  // Don't look closely at holes during recursion ...
+  if (!polyPath.isHole) {
+    const rings: Position[][] = [];
+    // Add the outer ring.
+    const outerRing = pathToCoordinates(polyPath.poly);
+    if (outerRing.length > 0) {
+      rings.push(outerRing);
+    }
+
+    // ... instead add holes here.
+    // Add any holes (direct children are the holes). Do this now rather than
+    // during recursion given we already have the outer ring handy.
+    for (let i = 0; i < polyPath.count; i++) {
+      const child = polyPath.child(i);
+
+      const holeRing = pathToCoordinates(child.poly);
+      if (holeRing.length > 0) {
+        rings.push(holeRing);
+      }
+    }
+    polygons.push(rings);
+  }
+
+  // Now recurse into each child to handle nested levels.
+  for (let i = 0; i < polyPath.count; i++) {
+    processPolyPath(polyPath.child(i), polygons);
+  }
+}
+
+/**
+ * Converts a clipper2 path to an array of Geojson Positions.
+ * Automatically closes the path unless overridden e.g. for a lineString.
+ *
+ * @param path clipper2 path to convert to Positions
+ * @param [closeIt=true] close the path by making sure first and last positions are equal
+ */
+function pathToCoordinates(
+  path: PathD | null,
+  closeIt: boolean = true
+): Position[] {
+  const coords: Position[] = [];
+
+  if (!path || typeof path.length !== "number") {
+    return coords;
+  }
+
+  for (let i = 0; i < path.length; i++) {
+    const pt = path[i];
+    coords.push([pt.x, pt.y]);
+  }
+
+  // GeoJSON requires the first and last coordinates to be identical (closed ring)
+  if (coords.length > 0 && closeIt) {
+    const first = coords[0];
+    const last = coords[coords.length - 1];
+    if (first[0] !== last[0] || first[1] !== last[1]) {
+      coords.push([first[0], first[1]]);
+    }
+  }
+
+  return coords;
+}
+
+export {
+  multiPolygonToPaths,
+  polygonToPaths,
+  polyTreeToGeoJSON,
+  TURF_CLIPPER2_SCALE_FACTOR,
+};

packages/internal/test.ts

@@ -0,0 +1,16 @@
+import test from "tape";
+import { FillRule, ClipType, PolyTreeD, ClipperD } from "clipper2-ts";
+import {
+  TURF_CLIPPER2_SCALE_FACTOR,
+  multiPolygonToPaths,
+  polygonToPaths,
+  polyTreeToGeoJSON,
+} from "./src/clipper2/index.js";
+
+test("clipper2", (t) => {
+  const clipper = new ClipperD(TURF_CLIPPER2_SCALE_FACTOR);
+
+  clipper.clear();
+
+  t.end();
+});

packages/internal/tsconfig.json

@@ -0,0 +1,3 @@
+{
+  "extends": "../../tsconfig.shared.json"
+}