From 008a1d0b0b9491a17af02fbcc1e8cf9a051149b7 Mon Sep 17 00:00:00 2001
From: Florian Klink <flokli@flokli.de>
Date: Mon, 1 Jun 2015 22:36:10 +0200
Subject: [PATCH] use node_id hash to calculate startAngle for client layer

---
 app.js                 |  3 ++-
 bower.json             |  3 ++-
 lib/map/clientlayer.js | 14 +++++++++++---
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/app.js b/app.js
index 50e61c6..71c87e6 100644
--- a/app.js
+++ b/app.js
@@ -13,7 +13,8 @@ require.config({
     "numeral-intl": "../bower_components/numeraljs/min/languages.min",
     "virtual-dom": "../bower_components/virtual-dom/dist/virtual-dom",
     "rbush": "../bower_components/rbush/rbush",
-    "helper": "../helper"
+    "helper": "../helper",
+    "jshashes": "../bower_components/jshashes/hashes"
   },
   shim: {
     "leaflet.label": ["leaflet"],
diff --git a/bower.json b/bower.json
index 20bf6fe..540768f 100644
--- a/bower.json
+++ b/bower.json
@@ -24,7 +24,8 @@
     "roboto-fontface": "~0.3.0",
     "virtual-dom": "~2.0.1",
     "leaflet-providers": "~1.0.27",
-    "rbush": "https://github.com/mourner/rbush.git#~1.3.5"
+    "rbush": "https://github.com/mourner/rbush.git#~1.3.5",
+    "jshashes": "~1.0.5"
   },
   "authors": [
     "Nils Schneider <nils@nilsschneider.net>"
diff --git a/lib/map/clientlayer.js b/lib/map/clientlayer.js
index 7dd5b57..036bf47 100644
--- a/lib/map/clientlayer.js
+++ b/lib/map/clientlayer.js
@@ -1,8 +1,16 @@
-define(["leaflet"],
-  function (L) {
+define(["leaflet", "jshashes"],
+  function (L, jsHashes) {
+    var MD5 = new jsHashes.MD5()
+
     return L.TileLayer.Canvas.extend({
       setData: function (d) {
         this.data = d
+
+        //pre-calculate start angles
+        this.data.all().forEach(function (d) {
+          var hash = MD5.hex(d.node.nodeinfo.node_id)
+          d.startAngle = (parseInt(hash.substr(0, 2), 16) / 255) * 2 * Math.PI
+        })
         this.redraw()
       },
       drawTile: function (canvas, tilePoint) {
@@ -33,7 +41,6 @@ define(["leaflet"],
         var radius = 3
         var a = 1.2
         var startDistance = 12
-        var startAngle = Math.PI
 
         ctx.beginPath()
         nodes.forEach(function (d) {
@@ -47,6 +54,7 @@ define(["leaflet"],
           p.y -= s.y
 
           var distance = startDistance
+          var startAngle = d.startAngle
           var angle = startAngle
 
           for (var i = 0; i < clients; i++) {