From f8585962b4eec5ce5bbd3814c66d881c0106c77d Mon Sep 17 00:00:00 2001
From: "Seul-gi Choi(Chase)" <cs09gi@gmail.com>
Date: Mon, 15 Oct 2018 20:57:23 +0900
Subject: [PATCH] fix the way zoom comes from

fix zoom from view to tilegrid
---
 src/ol/source/BingMaps.js | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/ol/source/BingMaps.js b/src/ol/source/BingMaps.js
index a3ad5320cf..01a8533118 100644
--- a/src/ol/source/BingMaps.js
+++ b/src/ol/source/BingMaps.js
@@ -241,7 +241,10 @@ class BingMaps extends TileImage {
 
       this.setAttributions(function(frameState) {
         const attributions = [];
-        const zoom = frameState.viewState.zoom;
+        const viewState = frameState.viewState;
+        const tileGrid = this.getTileGrid();
+        const tileCoord = tileGrid.getTileCoordForCoordAndResolution(viewState.center, viewState.resolution);
+        const zoom = tileCoord[0];
         resource.imageryProviders.map(function(imageryProvider) {
           let intersecting = false;
           const coverageAreas = imageryProvider.coverageAreas;
@@ -264,7 +267,7 @@ class BingMaps extends TileImage {
 
         attributions.push(TOS_ATTRIBUTION);
         return attributions;
-      });
+      }.bind(this));
     }
 
     this.setState(SourceState.READY);