From 84c5345cee93cb58780ca4a03476734b4809b7c1 Mon Sep 17 00:00:00 2001
From: Tom MacWright <tom@macwright.org>
Date: Mon, 12 Nov 2012 13:40:17 -0500
Subject: [PATCH] Map performance improvements

---
 css/map.css           | 24 +++++++++++++++++-------
 js/iD/renderer/Map.js | 33 +++++++++++++++++++++++++++++++--
 2 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/css/map.css b/css/map.css
index db8862224..af8c90116 100644
--- a/css/map.css
+++ b/css/map.css
@@ -80,10 +80,12 @@ circle.teaser-point {
 /* highways */
 .stroke.highway-residential {
     stroke:#E8E8E8;
-    stroke-width:8;
+    stroke-width:4;
 }
 .casing.highway-residential {
+    stroke:#E8E8E8;
     stroke-width:10;
+    opacity:0.4;
 }
 
 .stroke.highway-unclassified,
@@ -123,33 +125,41 @@ circle.teaser-point {
 
 .stroke.highway-motorway, .stroke.highway-motorway_link {
     stroke:#809BC0;
-    stroke-width:7;
+    stroke-width:3;
 }
 .casing.highway-motorway, .casing.highway-motorway_link {
+    stroke:#809BC0;
     stroke-width:9;
+    opacity:0.4;
 }
 
-.casing.highway-trunk, .casing.highway-trunk_link {
-    stroke-width:9;
-}
 .stroke.highway-trunk, .stroke.highway-trunk_link {
     stroke-width:7;
+    opacity:0.4;
+    stroke:#7FC97F;
+}
+.casing.highway-trunk, .casing.highway-trunk_link {
+    stroke-width:4;
     stroke:#7FC97F;
 }
 
 .stroke.highway-primary, .stroke.highway-primary_link {
     stroke:#FD969A;
-    stroke-width:10;
+    stroke-width:5;
 }
 .casing.highway-primary, .casing.highway-primary_link {
+    stroke:#FF6363;
+    opacity:0.4;
     stroke-width:12;
 }
 
 .stroke.highway-secondary, .stroke.highway-secondary_link {
     stroke:#FDBF6F;
-    stroke-width:9;
+    stroke-width:4;
 }
 .casing.highway-secondary, .casing.highway-secondary_link {
+    opacity:0.4;
+    stroke:#FDBF6F;
     stroke-width:11;
 }
 
diff --git a/js/iD/renderer/Map.js b/js/iD/renderer/Map.js
index 500c70583..a3f46d5a9 100755
--- a/js/iD/renderer/Map.js
+++ b/js/iD/renderer/Map.js
@@ -123,6 +123,9 @@ iD.Map = function(elem) {
 
         var ways = all.filter(function(a) {
             return a.type === 'way' && !iD.Way.isClosed(a);
+        }).map(function(x) {
+            x._line = nodeline(x);
+            return x;
         }).sort(iD.Style.waystack),
         areas = all.filter(function(a) {
             return a.type === 'way' && iD.Way.isClosed(a);
@@ -147,7 +150,7 @@ iD.Map = function(elem) {
         casings.exit().remove();
         casings.enter().append('path');
         casings.order()
-            .attr('d', nodeline)
+            .attr('d', function(d) { return d._line; })
             .attr('class', class_casing)
             .classed('active', function(d) {
                 return d.id === selected_id;
@@ -158,7 +161,7 @@ iD.Map = function(elem) {
         strokes.enter().append('path')
             .on('click', selectClick);
         strokes.order()
-            .attr('d', nodeline)
+            .attr('d', function(d) { return d._line; })
             .attr('class', class_stroke)
             .classed('active', function(d) {
                 return d.id === selected_id;
@@ -232,11 +235,37 @@ iD.Map = function(elem) {
         iD.operations.remove(map, d);
     });
 
+    var fastTranslate = [0,0];
+
     function zoomPan() {
+        var translate;
+        var fast = projection.scale() === d3.event.scale;
+        if (fast) {
+            fastTranslate[0] -= projection.translate()[0] - d3.event.translate[0];
+            fastTranslate[1] -= projection.translate()[1] - d3.event.translate[1];
+        }
         projection
             .translate(d3.event.translate)
             .scale(d3.event.scale);
+        if (fast) {
+            fastRedraw();
+        } else {
+            redraw();
+        }
+    }
+
+    // Slow redraw - going out of turbo mode.
+    var slowDraw = _.debounce(function() {
+        fastTranslate = [0,0];
         redraw();
+        r.attr('transform', '');
+    }, 500);
+
+    function fastRedraw(translate) {
+        dispatch.move(map);
+        tileclient.redraw();
+        r.attr('transform', 'translate(' + fastTranslate + ')');
+        slowDraw();
     }
 
     function redraw() {