Introduce distance expression

src/style-spec/expression/definitions/index.js

@@ -45,6 +45,7 @@ import FormatExpression from './format.js';
 import ImageExpression from './image.js';
 import Length from './length.js';
 import Within from './within.js';
+import Distance from './distance.js';
 
 import type {Varargs} from '../compound_expression.js';
 import type {ExpressionRegistry} from '../expression.js';
@@ -85,7 +86,8 @@ const expressions: ExpressionRegistry = {
     'to-number': Coercion,
     'to-string': Coercion,
     'var': Var,
-    'within': Within
+    'within': Within,
+    'distance': Distance
 };
 
 function rgba(ctx, [r, g, b, a]) {

src/style-spec/expression/definitions/within.js

@@ -7,22 +7,13 @@ import type {Expression} from '../expression.js';
 import type ParsingContext from '../parsing_context.js';
 import type EvaluationContext from '../evaluation_context.js';
 import type {GeoJSON, GeoJSONPolygon, GeoJSONMultiPolygon} from '@mapbox/geojson-types';
-import Point from '@mapbox/point-geometry';
 import type {CanonicalTileID} from '../../../source/tile_id.js';
+import {updateBBox, boxWithinBox, pointWithinPolygon, segmentIntersectSegment} from '../../util/geometry_util.js';
 
 type GeoJSONPolygons =| GeoJSONPolygon | GeoJSONMultiPolygon;
 
-// minX, minY, maxX, maxY
-type BBox = [number, number, number, number];
 const EXTENT = 8192;
 
-function updateBBox(bbox: BBox, coord: Point) {
-    bbox[0] = Math.min(bbox[0], coord[0]);
-    bbox[1] = Math.min(bbox[1], coord[1]);
-    bbox[2] = Math.max(bbox[2], coord[0]);
-    bbox[3] = Math.max(bbox[3], coord[1]);
-}
-
 function mercatorXfromLng(lng: number) {
     return (180 + lng) / 360;
 }
@@ -31,92 +22,27 @@ function mercatorYfromLat(lat: number) {
     return (180 - (180 / Math.PI * Math.log(Math.tan(Math.PI / 4 + lat * Math.PI / 360)))) / 360;
 }
 
-function boxWithinBox(bbox1: BBox, bbox2: BBox) {
-    if (bbox1[0] <= bbox2[0]) return false;
-    if (bbox1[2] >= bbox2[2]) return false;
-    if (bbox1[1] <= bbox2[1]) return false;
-    if (bbox1[3] >= bbox2[3]) return false;
-    return true;
-}
-
 function getTileCoordinates(p, canonical: CanonicalTileID) {
     const x = mercatorXfromLng(p[0]);
     const y = mercatorYfromLat(p[1]);
     const tilesAtZoom = Math.pow(2, canonical.z);
     return [Math.round(x * tilesAtZoom * EXTENT), Math.round(y * tilesAtZoom * EXTENT)];
 }
 
-function onBoundary(p, p1, p2) {
-    const x1 = p[0] - p1[0];
-    const y1 = p[1] - p1[1];
-    const x2 = p[0] - p2[0];
-    const y2 = p[1] - p2[1];
-    return (x1 * y2 - x2 * y1 === 0) && (x1 * x2 <= 0) && (y1 * y2 <= 0);
-}
-
-function rayIntersect(p, p1, p2) {
-    return ((p1[1] > p[1]) !== (p2[1] > p[1])) && (p[0] < (p2[0] - p1[0]) * (p[1] - p1[1]) / (p2[1] - p1[1]) + p1[0]);
-}
-
-// ray casting algorithm for detecting if point is in polygon
-function pointWithinPolygon(point, rings) {
-    let inside = false;
-    for (let i = 0, len = rings.length; i < len; i++) {
-        const ring = rings[i];
-        for (let j = 0, len2 = ring.length; j < len2 - 1; j++) {
-            if (onBoundary(point, ring[j], ring[j + 1])) return false;
-            if (rayIntersect(point, ring[j], ring[j + 1])) inside = !inside;
-        }
-    }
-    return inside;
-}
-
 function pointWithinPolygons(point, polygons) {
     for (let i = 0; i < polygons.length; i++) {
         if (pointWithinPolygon(point, polygons[i])) return true;
     }
     return false;
 }
 
-function perp(v1, v2) {
-    return (v1[0] * v2[1] - v1[1] * v2[0]);
-}
-
-// check if p1 and p2 are in different sides of line segment q1->q2
-function  twoSided(p1, p2, q1, q2) {
-    // q1->p1 (x1, y1), q1->p2 (x2, y2), q1->q2 (x3, y3)
-    const x1 = p1[0] - q1[0];
-    const y1 = p1[1] - q1[1];
-    const x2 = p2[0] - q1[0];
-    const y2 = p2[1] - q1[1];
-    const x3 = q2[0] - q1[0];
-    const y3 = q2[1] - q1[1];
-    const det1 = (x1 * y3 - x3 * y1);
-    const det2 =  (x2 * y3 - x3 * y2);
-    if ((det1 > 0 && det2 < 0) || (det1 < 0 && det2 > 0)) return true;
-    return false;
-}
-// a, b are end points for line segment1, c and d are end points for line segment2
-function lineIntersectLine(a, b, c, d) {
-    // check if two segments are parallel or not
-    // precondition is end point a, b is inside polygon, if line a->b is
-    // parallel to polygon edge c->d, then a->b won't intersect with c->d
-    const vectorP = [b[0] - a[0], b[1] - a[1]];
-    const vectorQ = [d[0] - c[0], d[1] - c[1]];
-    if (perp(vectorQ, vectorP) === 0) return false;
-
-    // If lines are intersecting with each other, the relative location should be:
-    // a and b lie in different sides of segment c->d
-    // c and d lie in different sides of segment a->b
-    if (twoSided(a, b, c, d) && twoSided(c, d, a, b)) return true;
-    return false;
-}
-
 function lineIntersectPolygon(p1, p2, polygon) {
     for (const ring of polygon) {
         // loop through every edge of the ring
-        for (let j = 0; j < ring.length - 1; ++j) {
-            if (lineIntersectLine(p1, p2, ring[j], ring[j + 1])) {
+        for (let j = 0, len = ring.length, k = len - 1; j < len; k = j++) {
+            const q1 = ring[k];
+            const q2 = ring[j];
+            if (segmentIntersectSegment(p1, p2, q1, q2)) {
                 return true;
             }
         }

src/style-spec/expression/is_constant.js

@@ -2,6 +2,7 @@
 
 import CompoundExpression from './compound_expression.js';
 import Within from './definitions/within.js';
+import Distance from './definitions/distance.js';
 import type {Expression} from './expression.js';
 
 function isFeatureConstant(e: Expression) {
@@ -27,6 +28,10 @@ function isFeatureConstant(e: Expression) {
         return false;
     }
 
+    if (e instanceof Distance) {
+        return false;
+    }
+
     let result = true;
     e.eachChild(arg => {
         if (result && !isFeatureConstant(arg)) { result = false; }

src/style-spec/expression/parsing_context.js

@@ -10,6 +10,7 @@ import EvaluationContext from './evaluation_context.js';
 import CompoundExpression from './compound_expression.js';
 import CollatorExpression from './definitions/collator.js';
 import Within from './definitions/within.js';
+import Distance from './definitions/distance.js';
 import {isGlobalPropertyConstant, isFeatureConstant} from './is_constant.js';
 import Var from './definitions/var.js';
 
@@ -204,6 +205,8 @@ function isConstant(expression: Expression) {
         return false;
     } else if (expression instanceof Within) {
         return false;
+    } else if (expression instanceof Distance) {
+        return false;
     }
 
     const isTypeAnnotation = expression instanceof Coercion ||

src/style-spec/feature_filter/index.js

@@ -98,7 +98,7 @@ function compare(a, b) {
 
 function geometryNeeded(filter) {
     if (!Array.isArray(filter)) return false;
-    if (filter[0] === 'within') return true;
+    if (filter[0] === 'within' || filter[0] === 'distance') return true;
     for (let index = 1; index < filter.length; index++) {
         if (geometryNeeded(filter[index])) return true;
     }
@@ -123,7 +123,6 @@ function convertFilter(filter: ?Array<any>): mixed {
         op === '!in' ? convertNegation(convertInOp(filter[1], filter.slice(2))) :
         op === 'has' ? convertHasOp(filter[1]) :
         op === '!has' ? convertNegation(convertHasOp(filter[1])) :
-        op === 'within' ? filter :
         true;
     return converted;
 }

src/style-spec/package.json

@@ -45,7 +45,9 @@
     "json-stringify-pretty-compact": "^2.0.0",
     "minimist": "^1.2.5",
     "rw": "^1.3.3",
-    "sort-object": "^0.3.2"
+    "sort-object": "^0.3.2",
+    "quickselect": "^2.0.0",
+    "tinyqueue": "^2.0.3"
   },
   "sideEffects": false
 }

src/style-spec/reference/v8.json

@@ -2541,9 +2541,6 @@
       },
       "!has": {
         "doc": "`[\"!has\", key]` `feature[key]` does not exist"
-      },
-      "within": {
-        "doc": "`[\"within\", object]` feature geometry is within object geometry"
       }
     },
     "doc": "The filter operator."
@@ -3475,6 +3472,7 @@
         "group": "Math",
         "sdk-support": {
           "basic functionality": {
+            "js": "2.3.0",
             "android": "9.2.0",
             "ios": "5.9.0",
             "macos": "0.16.0"