From 679086b8d0bc393f698b289454d698a0f0c6b33c Mon Sep 17 00:00:00 2001
From: Christopher Baines <cbaines8@gmail.com>
Date: Sat, 2 Mar 2013 22:13:01 +0000
Subject: Update some libs, and improve display on different zoom levels

---
 resources/op2geojson.js | 77 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 60 insertions(+), 17 deletions(-)

(limited to 'resources/op2geojson.js')

diff --git a/resources/op2geojson.js b/resources/op2geojson.js
index a4233fd..d928310 100644
--- a/resources/op2geojson.js
+++ b/resources/op2geojson.js
@@ -5,7 +5,7 @@ op2geojson = function() {
 	var instance = {},
 		geojson;
 
-	instance.fetch = function(url, data, zoom, callback) {
+	instance.fetch = function(url, data, zoom, latitude, callback) {
 		var postCallback = function(data) {
 			// Add nodes and ways to the layer
 			var features = [];
@@ -31,23 +31,43 @@ op2geojson = function() {
 				}
 			});
 
+            var format = new OpenLayers.Format.GeoJSON;
+            // circumference of the Earth * cos(latitude)/2^(zoom level +8)
+            var latitudeInRadians = latitude * Math.PI/180;
+            var metersPerPixel = (40075000 * Math.cos(latitudeInRadians))/(Math.pow(2, (zoom + 8)));
+
 			$.each(ways, function(i, way) {
-				if (zoom < 16) {
-					var node = nodes[way.nodes[0]];
-					var point = {
-						type : "Feature",
-						id : way.id,
-						geometry : {
-							type : "Point",
-							coordinates : [node.lon,node.lat]
-						},
-						properties : {}
-					};
-					_.extend(point.properties, way.tags);
-					features.push(point);
-				} else {
-					features.push(instance.lineString(way, nodes));
-				}
+                if (!_.isUndefined(way.tags) && (
+                    way.tags.amenity == "hospital" ||
+                    !_.isUndefined(way.tags.place) ||
+                    way.tags.landuse == "residential")) {
+
+				    var area = instance.wayToPolygon(way, nodes);
+
+                    var areaGeo = format.parseGeometry(area.geometry);
+
+                    var geodesicArea = areaGeo.getGeodesicArea();
+                    var averageWidth = Math.sqrt(geodesicArea);
+                    var pixelsOfAverageWidth = averageWidth / metersPerPixel;
+
+                    if (pixelsOfAverageWidth < 10) {
+                        var node = nodes[way.nodes[0]];
+                        var centroid = areaGeo.getCentroid();
+                        var point = {
+                            type : "Feature",
+                            id : way.id,
+                            geometry : {
+                                type : "Point",
+                                coordinates : [centroid.x, centroid.y]
+                            },
+                            properties : {}
+                        };
+                        _.extend(point.properties, way.tags);
+                        features.push(point);
+                    } else {
+                        features.push(area);
+                    }
+                }
 			});
 
 			$.each(relations, function(i, relation) {
@@ -167,6 +187,29 @@ op2geojson = function() {
 		return poly;
 	}
 
+	instance.wayToPolygon = function(way, nodeArray) {
+		// Get the node coordinates from nodeArray
+		var coordinates = [];
+		for (id in way.nodes) {
+			var node = nodeArray[way.nodes[id]];
+			coordinates.push([node.lon,node.lat]);
+		}
+
+		// Create the LineString
+		var poly = {
+			type : "Feature",
+			geometry : {
+				type : "Polygon",
+				coordinates : [coordinates]
+			},
+			properties : {}
+		};
+
+		// Add the tags
+		_.extend(poly.properties, way.tags);
+		return poly;
+	}
+
 	return instance;
 
 };
-- 
cgit v1.2.3