From 8520e06c5a1354d75b8eb20384903a225a643833 Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@mapbox.com>
Date: Wed, 26 Apr 2017 10:27:38 -0400
Subject: [PATCH] Performance: only draw midpoints in select mode

---
 modules/svg/midpoints.js | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/modules/svg/midpoints.js b/modules/svg/midpoints.js
index a64b92225..112348492 100644
--- a/modules/svg/midpoints.js
+++ b/modules/svg/midpoints.js
@@ -15,6 +15,13 @@ import {
 export function svgMidpoints(projection, context) {
 
     return function drawMidpoints(selection, graph, entities, filter, extent) {
+        var layer = selection.selectAll('.layer-hit');
+
+        if (context.mode().id !== 'select') {
+            layer.selectAll('g.midpoint').remove();
+            return;
+        }
+
         var poly = extent.polygon(),
             midpoints = {};
 
@@ -86,8 +93,6 @@ export function svgMidpoints(projection, context) {
         }
 
 
-        var layer = selection.selectAll('.layer-hit');
-
         var groups = layer
             .selectAll('g.midpoint')
             .filter(midpointFilter)