From 5ee391dd52183d99e901539c8b92eacb953cacb0 Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@7thposition.com>
Date: Fri, 30 May 2014 15:20:36 -0400
Subject: [PATCH] Better layer sorting to fix z-depth issues..

---
 js/id/core/way.js  | 20 +++++++++++++++
 js/id/svg/lines.js | 63 +++++++++++++++++++++++-----------------------
 2 files changed, 52 insertions(+), 31 deletions(-)

diff --git a/js/id/core/way.js b/js/id/core/way.js
index 3a6e6d6ec..9e2d6f0eb 100644
--- a/js/id/core/way.js
+++ b/js/id/core/way.js
@@ -42,6 +42,26 @@ _.extend(iD.Way.prototype, {
         if (this.nodes[this.nodes.length - 1] === node) return 'suffix';
     },
 
+    layer: function() {
+        // explicit layer tag..
+        if (this.tags.layer !== undefined) return +(this.tags.layer);
+
+        // implied layer tag..
+        if (this.tags.location === 'overground') return 1;
+        if (this.tags.location === 'underground') return -1;
+        if (this.tags.location === 'underwater') return -10;
+
+        if (this.tags.power === 'line') return 20;
+        if (this.tags.power === 'minor_line') return 15;
+        if (this.tags.aerialway) return 10;
+        if (this.tags.bridge) return 1;
+        if (this.tags.cutting) return -1;
+        if (this.tags.tunnel) return -1;
+        if (this.tags.waterway) return -1;
+        if (this.tags.manmade === 'pipeline') return -10;
+        return 0;
+    },
+
     isOneWay: function() {
         // explicit oneway tag..
         if (['yes', '1', '-1'].indexOf(this.tags.oneway) !== -1) { return true; }
diff --git a/js/id/svg/lines.js b/js/id/svg/lines.js
index 61b0efbd5..8ea4418a7 100644
--- a/js/id/svg/lines.js
+++ b/js/id/svg/lines.js
@@ -1,36 +1,36 @@
 iD.svg.Lines = function(projection) {
 
-    var highway_stack = {
-        motorway: 0,
-        motorway_link: 1,
-        trunk: 2,
-        trunk_link: 3,
-        primary: 4,
-        primary_link: 5,
-        secondary: 6,
-        tertiary: 7,
-        unclassified: 8,
-        residential: 9,
-        service: 10,
-        footway: 11
-    };
+    // var highway_stack = {
+    //     motorway: 0,
+    //     motorway_link: 1,
+    //     trunk: 2,
+    //     trunk_link: 3,
+    //     primary: 4,
+    //     primary_link: 5,
+    //     secondary: 6,
+    //     tertiary: 7,
+    //     unclassified: 8,
+    //     residential: 9,
+    //     service: 10,
+    //     footway: 11
+    // };
 
-    function waystack(a, b) {
-        if (!a || !b || !a.tags || !b.tags) return 0;
-        if (a.tags.layer !== undefined && b.tags.layer !== undefined) {
-            return a.tags.layer - b.tags.layer;
-        }
-        if (a.tags.bridge) return 1;
-        if (b.tags.bridge) return -1;
-        if (a.tags.tunnel) return -1;
-        if (b.tags.tunnel) return 1;
-        var as = 0, bs = 0;
-        if (a.tags.highway && b.tags.highway) {
-            as -= highway_stack[a.tags.highway];
-            bs -= highway_stack[b.tags.highway];
-        }
-        return as - bs;
-    }
+    // function waystack(a, b) {
+    //     if (!a || !b || !a.tags || !b.tags) return 0;
+    //     if (a.tags.layer !== undefined && b.tags.layer !== undefined) {
+    //         return a.tags.layer - b.tags.layer;
+    //     }
+    //     if (a.tags.bridge) return 1;
+    //     if (b.tags.bridge) return -1;
+    //     if (a.tags.tunnel) return -1;
+    //     if (b.tags.tunnel) return 1;
+    //     var as = 0, bs = 0;
+    //     if (a.tags.highway && b.tags.highway) {
+    //         as -= highway_stack[a.tags.highway];
+    //         bs -= highway_stack[b.tags.highway];
+    //     }
+    //     return as - bs;
+    // }
 
     return function drawLines(surface, graph, entities, filter) {
         var lines = [],
@@ -47,7 +47,8 @@ iD.svg.Lines = function(projection) {
         }
 
         lines = lines.filter(path);
-        lines.sort(waystack);
+        // lines.sort(waystack);
+        lines.sort(function(a, b) { return a.layer() - b.layer(); });
 
         function drawPaths(klass) {
             var paths = surface.select('.layer-' + klass)