Point on line fix (#689)

* Replace custom lineIntersects function with @turf/line-intersects, resolves #344 * Fixing missing semi-colon * Add dynamic outputs for expectedLocation * Update benchmark * Add dynamic geojson tests in/out * Truncate dynamic geojson test/out * Round precision & dist * Add test case for #344 * Add between line (helps visualize line between both points)
Turfjs · Apr 25, 2017 · 2263a80 · 2263a80
1 parent d103758
commit 2263a80
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diff --git a/packages/turf-point-on-line/bench.js b/packages/turf-point-on-line/bench.js
@@ -1,31 +1,38 @@
-var pointOnLine = require('./');
-var Benchmark = require('benchmark');
-var fs = require('fs');
-var point = require('@turf/helpers').point;
+const Benchmark = require('benchmark');
+const path = require('path');
+const fs = require('fs');
+const load = require('load-json-file');
+const pointOnLine = require('./');
 
-var route1 = JSON.parse(fs.readFileSync(__dirname + '/test/in/route1.geojson'));
-var route2 = JSON.parse(fs.readFileSync(__dirname + '/test/in/route2.geojson'));
-var line1 = JSON.parse(fs.readFileSync(__dirname + '/test/in/line1.geojson'));
+const directory = path.join(__dirname, 'test', 'in') + path.sep;
+const fixtures = fs.readdirSync(directory).map(filename => {
+    return {
+        filename,
+        name: path.parse(filename).name,
+        geojson: load.sync(directory + filename)
+    };
+});
 
-var pt1 = point([-97.79617309570312,22.254624939561698]);
-var pt2 = point([-79.0850830078125,37.60117623656667]);
-var pt3 = point([-112.60660171508789,45.96021963947196]);
+/**
+ * Benchmark Results
+ *
+ * ==after (@turf/line-intersect)==
+ * line1 x 234,231 ops/sec ±1.78% (88 runs sampled)
+ * route1 x 161 ops/sec ±1.53% (80 runs sampled)
+ * route2 x 184 ops/sec ±1.96% (80 runs sampled)
+ *
+ * ==before (original)==
+ * line1 x 272,785 ops/sec ±1.29% (87 runs sampled)
+ * route1 x 195 ops/sec ±2.23% (80 runs sampled)
+ * route2 x 218 ops/sec ±2.42% (78 runs sampled)
+ */
+const suite = new Benchmark.Suite('turf-linestring-to-polygon');
+for (const {name, geojson} of fixtures) {
+    const [line, point] = geojson.features;
+    suite.add(name, () => pointOnLine(line, point));
+}
 
-var suite = new Benchmark.Suite('turf-point-on-line');
 suite
-  .add('turf-point-on-line#simple',function () {
-      pointOnLine(line1, pt1);
-  })
-  .add('turf-point-on-line#route1',function () {
-      pointOnLine(route1, pt2);
-  })
-  .add('turf-point-on-line#route2',function () {
-      pointOnLine(route2, pt3);
-  })
-  .on('cycle', function (event) {
-      console.log(String(event.target));
-  })
-  .on('complete', function () {
-
-  })
-  .run();
+    .on('cycle', e => console.log(String(e.target)))
+    .on('complete', () => {})
+    .run();
diff --git a/packages/turf-point-on-line/index.js b/packages/turf-point-on-line/index.js
@@ -1,8 +1,10 @@
 var distance = require('@turf/distance');
-var point = require('@turf/helpers').point;
+var helpers = require('@turf/helpers');
 var bearing = require('@turf/bearing');
 var destination = require('@turf/destination');
-
+var lineIntersects = require('@turf/line-intersect');
+var point = helpers.point;
+var lineString = helpers.lineString;
 /**
  * Takes a {@link Point} and a {@link LineString} and calculates the closest Point on the LineString.
  *
@@ -71,19 +73,10 @@ module.exports = function (line, pt, units) {
         var direction = bearing(start, stop);
         var perpendicularPt1 = destination(pt, heightDistance, direction + 90, units);
         var perpendicularPt2 = destination(pt, heightDistance, direction - 90, units);
-        var intersect = lineIntersects(
-            perpendicularPt1.geometry.coordinates[0],
-            perpendicularPt1.geometry.coordinates[1],
-            perpendicularPt2.geometry.coordinates[0],
-            perpendicularPt2.geometry.coordinates[1],
-            start.geometry.coordinates[0],
-            start.geometry.coordinates[1],
-            stop.geometry.coordinates[0],
-            stop.geometry.coordinates[1]
-        );
-        var intersectPt;
-        if (intersect) {
-            intersectPt = point(intersect);
+        var intersect = lineIntersects(lineString([perpendicularPt1.geometry.coordinates, perpendicularPt2.geometry.coordinates]), lineString([start.geometry.coordinates, stop.geometry.coordinates]));
+        var intersectPt = null;
+        if (intersect.features.length > 0) {
+            intersectPt = intersect.features[0];
             intersectPt.properties.dist = distance(pt, intersectPt, units);
             intersectPt.properties.location = length + distance(start, closestPt, units);
         }
@@ -108,48 +101,3 @@ module.exports = function (line, pt, units) {
 
     return closestPt;
 };
-
-// modified from http://jsfiddle.net/justin_c_rounds/Gd2S2/light/
-function lineIntersects(line1StartX, line1StartY, line1EndX, line1EndY, line2StartX, line2StartY, line2EndX, line2EndY) {
-    // if the lines intersect, the result contains the x and y of the intersection (treating the lines as infinite) and booleans for whether line segment 1 or line segment 2 contain the point
-    var denominator, a, b, numerator1, numerator2;
-    var result = {
-        x: null,
-        y: null,
-        onLine1: false,
-        onLine2: false
-    };
-    denominator = ((line2EndY - line2StartY) * (line1EndX - line1StartX)) - ((line2EndX - line2StartX) * (line1EndY - line1StartY));
-    if (denominator === 0) {
-        if (result.x !== null && result.y !== null) {
-            return result;
-        } else {
-            return false;
-        }
-    }
-    a = line1StartY - line2StartY;
-    b = line1StartX - line2StartX;
-    numerator1 = ((line2EndX - line2StartX) * a) - ((line2EndY - line2StartY) * b);
-    numerator2 = ((line1EndX - line1StartX) * a) - ((line1EndY - line1StartY) * b);
-    a = numerator1 / denominator;
-    b = numerator2 / denominator;
-
-    // if we cast these lines infinitely in both directions, they intersect here:
-    result.x = line1StartX + (a * (line1EndX - line1StartX));
-    result.y = line1StartY + (a * (line1EndY - line1StartY));
-
-    // if line1 is a segment and line2 is infinite, they intersect if:
-    if (a > 0 && a < 1) {
-        result.onLine1 = true;
-    }
-    // if line2 is a segment and line1 is infinite, they intersect if:
-    if (b > 0 && b < 1) {
-        result.onLine2 = true;
-    }
-    // if line1 and line2 are segments, they intersect if both of the above are true
-    if (result.onLine1 && result.onLine2) {
-        return [result.x, result.y];
-    } else {
-        return false;
-    }
-}
diff --git a/packages/turf-point-on-line/package.json b/packages/turf-point-on-line/package.json
@@ -23,17 +23,20 @@
   },
   "homepage": "https://github.com/Turfjs/turf",
   "devDependencies": {
-    "benchmark": "^1.0.0",
-    "tape": "^3.5.0",
     "@turf/along": "^4.1.0",
-    "@turf/distance": "^4.1.0",
     "@turf/helpers": "^4.1.0",
-    "@turf/line-distance": "^4.1.0"
+    "@turf/line-distance": "^4.1.0",
+    "@turf/truncate": "^4.1.0",
+    "benchmark": "^2.1.4",
+    "load-json-file": "^2.0.0",
+    "tape": "^4.6.3",
+    "write-json-file": "^2.0.0"
   },
   "dependencies": {
     "@turf/bearing": "^4.1.0",
     "@turf/destination": "^4.1.0",
     "@turf/distance": "^4.1.0",
-    "@turf/helpers": "^4.1.0"
+    "@turf/helpers": "^4.1.0",
+    "@turf/line-intersect": "^4.1.0"
   }
 }