Support (Multi)Point,FeatureCollection and GeometryCollection in bboxClip

.gitignore

@@ -33,4 +33,4 @@ node_modules
 
 .vscode
 
-.nx/
+.nx/

packages/turf-bbox-clip/README.md

@@ -4,13 +4,14 @@
 
 ## bboxClip
 
-Takes a [Feature][1] and a bbox and clips the feature to the bbox using
-[lineclip][2].
-May result in degenerate edges when clipping Polygons.
+Takes a [Feature][1], [Geometry][2] or [FeatureCollection][3] and a bbox and returns the part of the object within the bbox.
+Lines and polygons are clipped using [lineclip][4].
+If a Point or LineString geometry is entirely outside the bbox, a [MultiPoint][5] or [MultiLineString][6] with empty `coordinates` array is returned.
+LineString geometries may also become MultiLineString if the clipping process cuts them into several pieces.
 
 ### Parameters
 
-*   `feature` **[Feature][1]<([LineString][3] | [MultiLineString][4] | [Polygon][5] | [MultiPolygon][6])>** feature to clip to the bbox
+*   `feature` **([Geometry][2] | [Feature][1] | [FeatureCollection][3])** GeoJSON object to clip to the bbox
 *   `bbox` **[BBox][7]** extent in \[minX, minY, maxX, maxY] order
 
 ### Examples
@@ -25,19 +26,19 @@ var clipped = turf.bboxClip(poly, bbox);
 var addToMap = [bbox, poly, clipped]
 ```
 
-Returns **[Feature][1]<([LineString][3] | [MultiLineString][4] | [Polygon][5] | [MultiPolygon][6])>** clipped Feature
+Returns **([Feature][1] | [FeatureCollection][3])** clipped GeoJSON object.
 
 [1]: https://tools.ietf.org/html/rfc7946#section-3.2
 
-[2]: https://github.com/mapbox/lineclip
+[2]: https://tools.ietf.org/html/rfc7946#section-3.1
 
-[3]: https://tools.ietf.org/html/rfc7946#section-3.1.4
+[3]: https://tools.ietf.org/html/rfc7946#section-3.3
 
-[4]: https://tools.ietf.org/html/rfc7946#section-3.1.5
+[4]: https://github.com/mapbox/lineclip
 
-[5]: https://tools.ietf.org/html/rfc7946#section-3.1.6
+[5]: https://tools.ietf.org/html/rfc7946#section-3.1.3
 
-[6]: https://tools.ietf.org/html/rfc7946#section-3.1.7
+[6]: https://tools.ietf.org/html/rfc7946#section-3.1.5
 
 [7]: https://tools.ietf.org/html/rfc7946#section-5
 

packages/turf-bbox-clip/index.ts

@@ -6,26 +6,37 @@ import {
   MultiPolygon,
   GeoJsonProperties,
   Polygon,
+  Point,
+  MultiPoint,
+  Position,
+  FeatureCollection,
+  Geometry,
+  GeometryCollection,
 } from "geojson";
 
 import {
+  featureCollection,
+  geometryCollection,
   lineString,
   multiLineString,
+  multiPoint,
   multiPolygon,
+  point,
   polygon,
 } from "@turf/helpers";
 import { getGeom } from "@turf/invariant";
 import { lineclip, polygonclip } from "./lib/lineclip.js";
 
 /**
- * Takes a {@link Feature} and a bbox and clips the feature to the bbox using
- * [lineclip](https://github.com/mapbox/lineclip).
- * May result in degenerate edges when clipping Polygons.
+ * Takes a {@link Feature}, {@link Geometry} or {@link FeatureCollection} and a bbox and returns the part of the object within the bbox.
+ * Lines and polygons are clipped using [lineclip](https://github.com/mapbox/lineclip).
+ * If a Point or LineString geometry is entirely outside the bbox, a {@link MultiPoint} or {@link MultiLineString} with empty `coordinates` array is returned.
+ * LineString geometries may also become MultiLineString if the clipping process cuts them into several pieces.
  *
  * @function
- * @param {Feature<LineString|MultiLineString|Polygon|MultiPolygon>} feature feature to clip to the bbox
+ * @param {Geometry|Feature|FeatureCollection} feature GeoJSON object to clip to the bbox
  * @param {BBox} bbox extent in [minX, minY, maxX, maxY] order
- * @returns {Feature<LineString|MultiLineString|Polygon|MultiPolygon>} clipped Feature
+ * @returns {Feature|FeatureCollection} clipped GeoJSON object.
  * @example
  * var bbox = [0, 0, 10, 10];
  * var poly = turf.polygon([[[2, 2], [8, 4], [12, 8], [3, 7], [2, 2]]]);
@@ -35,15 +46,72 @@ import { lineclip, polygonclip } from "./lib/lineclip.js";
  * //addToMap
  * var addToMap = [bbox, poly, clipped]
  */
+// pass a specific geometry type or FeatureCollection, get the same type back
 function bboxClip<
-  G extends Polygon | MultiPolygon | LineString | MultiLineString,
+  G extends Point | MultiPoint,
   P extends GeoJsonProperties = GeoJsonProperties,
->(feature: Feature<G, P> | G, bbox: BBox) {
+>(feature: Feature<G, P> | G, bbox: BBox): Feature<Point | MultiPoint, P>;
+function bboxClip<
+  G extends LineString | MultiLineString,
+  P extends GeoJsonProperties = GeoJsonProperties,
+>(
+  feature: Feature<G, P> | G,
+  bbox: BBox
+): Feature<LineString | MultiLineString, P>;
+function bboxClip<
+  G extends Polygon | MultiPolygon,
+  P extends GeoJsonProperties = GeoJsonProperties,
+>(feature: Feature<G, P> | G, bbox: BBox): Feature<Polygon | MultiPolygon, P>;
+function bboxClip<
+  G extends GeometryCollection,
+  P extends GeoJsonProperties = GeoJsonProperties,
+>(feature: Feature<G, P> | G, bbox: BBox): Feature<G, P>;
+function bboxClip<
+  G extends FeatureCollection,
+  P extends GeoJsonProperties = GeoJsonProperties,
+>(feature: G, bbox: BBox): FeatureCollection<Geometry, P>;
+
+// pass a non-specific geometry type, get a generic feature back
+function bboxClip<P extends GeoJsonProperties = GeoJsonProperties>(
+  feature: Feature<Geometry, P>,
+  bbox: BBox
+): Feature<Geometry, P>;
+function bboxClip(feature: Geometry, bbox: BBox): Feature<Geometry>;
+
+// "implementation signature", can't be called directly
+function bboxClip<
+  G extends Geometry,
+  P extends GeoJsonProperties = GeoJsonProperties,
+>(
+  feature: Feature<G, P> | G | FeatureCollection,
+  bbox: BBox
+): Feature<Geometry> | FeatureCollection {
+  if (feature.type === "FeatureCollection") {
+    return featureCollection(
+      feature.features.map((f: Feature) => bboxClip(f, bbox) as Feature)
+    );
+  }
+
+  // const test = { type: "Point", coordinates: [0, 0] } as Geometry;
+  // const out = bboxClip(test, bbox);
+
   const geom = getGeom(feature);
   const type = geom.type;
-  const properties = feature.type === "Feature" ? feature.properties : {};
-  let coords: any[] = geom.coordinates;
+  const properties: GeoJsonProperties =
+    feature.type === "Feature" ? feature.properties : {};
 
+  if (type === "GeometryCollection") {
+    const gs = geom.geometries;
+    const outGs = gs.map(
+      (g: Geometry) => (bboxClip(g, bbox) as Feature<Geometry>).geometry
+    ) as Exclude<Geometry, GeometryCollection>[];
+    return geometryCollection(outGs, properties) as Feature<
+      GeometryCollection,
+      P
+    >;
+  }
+
+  let coords: any[] = geom.coordinates;
   switch (type) {
     case "LineString":
     case "MultiLineString": {
@@ -54,27 +122,47 @@ function bboxClip<
       coords.forEach((line) => {
         lineclip(line, bbox, lines);
       });
-      if (lines.length === 1) {
+      if (lines.length === 1 && type === "LineString") {
         return lineString(lines[0], properties);
       }
       return multiLineString(lines, properties);
     }
-    case "Polygon":
-      return polygon(clipPolygon(coords, bbox), properties);
+    case "Polygon": {
+      const poly = clipPolygon(coords, bbox);
+      return polygon(poly, properties);
+    }
     case "MultiPolygon":
       return multiPolygon(
         coords.map((poly) => {
           return clipPolygon(poly, bbox);
         }),
         properties
       );
+    case "Point": {
+      const coord = geom.coordinates;
+      if (checkCoord(coord, bbox)) return point(coord, properties);
+      return multiPoint([], properties);
+    }
+    case "MultiPoint": {
+      return multiPoint(coords.filter((coord) => checkCoord(coord, bbox)));
+    }
+
     default:
       throw new Error("geometry " + type + " not supported");
   }
 }
 
-function clipPolygon(rings: number[][][], bbox: BBox) {
-  const outRings = [];
+function checkCoord(coord: Position, bbox: BBox) {
+  return (
+    coord[0] >= bbox[0] &&
+    coord[1] >= bbox[1] &&
+    coord[0] <= bbox[2] &&
+    coord[1] <= bbox[3]
+  );
+}
+
+function clipPolygon(rings: Position[][], bbox: BBox) {
+  const outRings: Position[][] = [];
   for (const ring of rings) {
     const clipped = polygonclip(ring, bbox);
     if (clipped.length > 0) {

packages/turf-bbox-clip/package.json

@@ -6,7 +6,8 @@
   "contributors": [
     "Tim Channell <@tcql>",
     "Vladimir Agafonkin <@mourner>",
-    "Denis Carriere <@DenisCarriere>"
+    "Denis Carriere <@DenisCarriere>",
+    "Steve Bennett <@stevage>"
   ],
   "license": "MIT",
   "bugs": {

packages/turf-bbox-clip/test.ts

@@ -28,14 +28,28 @@ test("turf-bbox-clip", (t) => {
     const filename = fixture.filename;
     const name = fixture.name;
     const geojson = fixture.geojson;
-    const feature = geojson.features[0];
-    const bbox = turfBBox(geojson.features[1]);
+    const isFeatureCollection = geojson.features.length > 2;
+    const feature = isFeatureCollection
+      ? featureCollection(geojson.features.slice(0, -1))
+      : geojson.features[0];
+    const clipRegion = geojson.features.slice(-1)[0];
+    const bbox = turfBBox(clipRegion);
     const clipped = bboxClip(feature, bbox);
-    const results = featureCollection([
-      colorize(feature, "#080"),
-      colorize(clipped, "#F00"),
-      colorize(geojson.features[1], "#00F", 3),
-    ]);
+
+    let results;
+    if (isFeatureCollection) {
+      results = featureCollection([
+        ...feature.features.map((f) => colorize(f, "#080", "input")),
+        ...clipped.features.map((c) => colorize(c, "#F00", "output")),
+        colorize(clipRegion, "#00F", "clipping bbox", 3),
+      ]);
+    } else {
+      results = featureCollection([
+        colorize(feature, "#080", "input"),
+        colorize(clipped, "#F00", "output"),
+        colorize(clipRegion, "#00F", "clipping bbox", 3),
+      ]);
+    }
 
     if (process.env.REGEN)
       writeJsonFileSync(directories.out + filename, results);
@@ -44,22 +58,15 @@ test("turf-bbox-clip", (t) => {
   t.end();
 });
 
-test("turf-bbox-clip -- throws", (t) => {
-  t.throws(
-    () => bboxClip(point([5, 10]), [-180, -90, 180, 90]),
-    /geometry Point not supported/
-  );
-  t.end();
-});
-
-function colorize(feature, color, width) {
+function colorize(feature, color, name, width) {
   color = color || "#F00";
   width = width || 6;
   feature.properties = {
     stroke: color,
     fill: color,
     "stroke-width": width,
     "fill-opacity": 0.1,
+    name,
   };
   return feature;
 }

packages/turf-bbox-clip/test/in/feature-collection.geojson

@@ -0,0 +1,94 @@
+{
+  "type": "FeatureCollection",
+  "features": [
+    {
+      "type": "Feature",
+      "properties": {},
+      "geometry": {
+        "coordinates": [92.78854443123498, -4.0631420171898185],
+        "type": "Point"
+      }
+    },
+    {
+      "type": "Feature",
+      "properties": {},
+      "geometry": {
+        "coordinates": [88.80200582619335, -8.780228029258652],
+        "type": "Point"
+      }
+    },
+    {
+      "type": "Feature",
+      "properties": {},
+      "geometry": {
+        "coordinates": [
+          [84.45578448719408, -0.42584674848238535],
+          [104.00625645806042, -17.30113187521333],
+          [108.37396514395846, -11.998337187512362]
+        ],
+        "type": "LineString"
+      }
+    },
+    {
+      "type": "Feature",
+      "properties": {},
+      "geometry": {
+        "coordinates": [
+          [
+            [95.6755173613135, -5.412355325867296],
+            [95.6755173613135, -9.59572648513172],
+            [101.64270834459677, -9.59572648513172],
+            [101.64270834459677, -5.412355325867296],
+            [95.6755173613135, -5.412355325867296]
+          ]
+        ],
+        "type": "Polygon"
+      }
+    },
+
+    {
+      "type": "Feature",
+      "properties": {},
+      "geometry": {
+        "coordinates": [
+          [77.58616268346043, -7.556977393000622],
+          [92.76209967554053, -19.675822211591438],
+          [84.86920130192482, -25.38820065310992]
+        ],
+        "type": "LineString"
+      }
+    },
+    {
+      "type": "Feature",
+      "properties": {},
+      "geometry": {
+        "coordinates": [
+          [
+            [84.5161586806538, 10.150704513809302],
+            [84.5161586806538, 3.6873648155754495],
+            [93.5370745092431, 3.6873648155754495],
+            [93.5370745092431, 10.150704513809302],
+            [84.5161586806538, 10.150704513809302]
+          ]
+        ],
+        "type": "Polygon"
+      }
+    },
+    {
+      "type": "Feature",
+      "properties": {},
+      "geometry": {
+        "coordinates": [
+          [
+            [91.0644737234989, -0.5254035861065773],
+            [91.0644737234989, -15.195974906738272],
+            [98.81078524424902, -15.195974906738272],
+            [98.81078524424902, -0.5254035861065773],
+            [91.0644737234989, -0.5254035861065773]
+          ]
+        ],
+        "type": "Polygon"
+      }
+    }
+  ]
+}