From 83030bed54307a1b114d3d8ef360ab0f7140e33b Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@7thposition.com>
Date: Fri, 25 Jul 2014 23:54:01 -0400
Subject: [PATCH] test visibility of gpx coords instead of just comparing
 extents.

---
 js/id/renderer/background.js | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/js/id/renderer/background.js b/js/id/renderer/background.js
index 291248a82..f548d3606 100644
--- a/js/id/renderer/background.js
+++ b/js/id/renderer/background.js
@@ -149,10 +149,14 @@ iD.Background = function(context) {
 
     background.zoomToGpxLayer = function() {
         if (background.hasGpxLayer()) {
-            var gpx = d3.geo.bounds(gpxLayer.geojson());
+            var viewport = context.map().extent().polygon(),
+                coords = _.reduce(gpxLayer.geojson().features, function(coords, feature) {
+                    var c = feature.geometry.coordinates;
+                    return _.union(coords, feature.geometry.type === 'Point' ? [c] : c);
+                }, []);
 
-            if (!context.map().extent().intersects(gpx)) {
-                context.map().extent(gpx);
+            if (!iD.geo.polygonIntersectsPolygon(viewport, coords)) {
+                context.map().extent(d3.geo.bounds(gpxLayer.geojson()));
             }
         }
     };