re Turfjs#415 use module'd turf-point-on-line

miccferr · Jun 16, 2016 · 636b34b · 636b34b
1 parent 81e2f55
commit 636b34b
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Showing 2 changed files with 5 additions and 114 deletions.
diff --git a/packages/turf-line-slice/index.js b/packages/turf-line-slice/index.js
@@ -1,8 +1,5 @@
-var distance = require('turf-distance');
-var point = require('turf-helpers').point;
 var linestring = require('turf-helpers').lineString;
-var bearing = require('turf-bearing');
-var destination = require('turf-destination');
+var pointOnLine = require('turf-point-on-line');
 
 /**
  * Takes a {@link LineString|line}, a start {@link Point}, and a stop point
@@ -66,8 +63,8 @@ module.exports = function lineSlice(startPt, stopPt, line) {
         throw new Error('input must be a LineString Feature or Geometry');
     }
 
-    var startVertex = pointOnLine(startPt, coords);
-    var stopVertex = pointOnLine(stopPt, coords);
+    var startVertex = pointOnLine(line, startPt);
+    var stopVertex = pointOnLine(line, stopPt);
     var ends;
     if (startVertex.properties.index <= stopVertex.properties.index) {
         ends = [startVertex, stopVertex];
@@ -81,110 +78,3 @@ module.exports = function lineSlice(startPt, stopPt, line) {
     clipLine.geometry.coordinates.push(ends[1].geometry.coordinates);
     return clipLine;
 };
-
-function pointOnLine(pt, coords) {
-    var units = 'miles';
-    var closestPt = point([Infinity, Infinity], {
-        dist: Infinity
-    });
-    for (var i = 0; i < coords.length - 1; i++) {
-        var start = point(coords[i]);
-        var stop = point(coords[i + 1]);
-        //start
-        start.properties.dist = distance(pt, start, units);
-        //stop
-        stop.properties.dist = distance(pt, stop, units);
-        //perpendicular
-        var direction = bearing(start, stop);
-        var perpendicularPt = destination(pt, 1000, direction + 90, units); // 1000 = gross
-        var intersect = lineIntersects(
-      pt.geometry.coordinates[0],
-      pt.geometry.coordinates[1],
-      perpendicularPt.geometry.coordinates[0],
-      perpendicularPt.geometry.coordinates[1],
-      start.geometry.coordinates[0],
-      start.geometry.coordinates[1],
-      stop.geometry.coordinates[0],
-      stop.geometry.coordinates[1]
-    );
-        if (!intersect) {
-            perpendicularPt = destination(pt, 1000, direction - 90, units); // 1000 = gross
-            intersect = lineIntersects(
-        pt.geometry.coordinates[0],
-        pt.geometry.coordinates[1],
-        perpendicularPt.geometry.coordinates[0],
-        perpendicularPt.geometry.coordinates[1],
-        start.geometry.coordinates[0],
-        start.geometry.coordinates[1],
-        stop.geometry.coordinates[0],
-        stop.geometry.coordinates[1]
-      );
-        }
-        perpendicularPt.properties.dist = Infinity;
-        var intersectPt;
-        if (intersect) {
-            intersectPt = point(intersect);
-            intersectPt.properties.dist = distance(pt, intersectPt, units);
-        }
-
-        if (start.properties.dist < closestPt.properties.dist) {
-            closestPt = start;
-            closestPt.properties.index = i;
-        }
-        if (stop.properties.dist < closestPt.properties.dist) {
-            closestPt = stop;
-            closestPt.properties.index = i;
-        }
-        if (intersectPt && intersectPt.properties.dist < closestPt.properties.dist) {
-            closestPt = intersectPt;
-            closestPt.properties.index = i;
-        }
-    }
-
-    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,
-        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-line-slice/package.json b/packages/turf-line-slice/package.json
@@ -34,6 +34,7 @@
     "turf-bearing": "^3.0.10",
     "turf-destination": "^3.0.10",
     "turf-distance": "^3.0.10",
-    "turf-helpers": "^3.0.10"
+    "turf-helpers": "^3.0.10",
+    "turf-point-on-line": "^3.0.10"
   }
 }