From f3cd1d8dfde1ba538c20ce4eee39a675d9a42027 Mon Sep 17 00:00:00 2001
From: ahocevar <andreas.hocevar@gmail.com>
Date: Thu, 9 Aug 2018 17:22:49 +0200
Subject: [PATCH] Round center in viewState

---
 src/ol/PluggableMap.js | 11 ++---------
 src/ol/View.js         |  9 +++++++--
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/src/ol/PluggableMap.js b/src/ol/PluggableMap.js
index ffddf09188..7f70ddf671 100644
--- a/src/ol/PluggableMap.js
+++ b/src/ol/PluggableMap.js
@@ -1179,19 +1179,12 @@ class PluggableMap extends BaseObject {
       for (let i = 0, ii = layerStatesArray.length; i < ii; ++i) {
         layerStates[getUid(layerStatesArray[i].layer)] = layerStatesArray[i];
       }
-      viewState = view.getState();
-      let focus = this.focus_;
-      if (!focus) {
-        focus = viewState.center;
-        const pixelResolution = viewState.resolution / this.pixelRatio_;
-        focus[0] = Math.round(focus[0] / pixelResolution) * pixelResolution;
-        focus[1] = Math.round(focus[1] / pixelResolution) * pixelResolution;
-      }
+      viewState = view.getState(this.pixelRatio_);
       frameState = /** @type {module:ol/PluggableMap~FrameState} */ ({
         animate: false,
         coordinateToPixelTransform: this.coordinateToPixelTransform_,
         extent: extent,
-        focus: focus,
+        focus: this.focus_ ? this.focus_ : viewState.center,
         index: this.frameIndex_++,
         layerStates: layerStates,
         layerStatesArray: layerStatesArray,
diff --git a/src/ol/View.js b/src/ol/View.js
index 6583af494d..bfa03058a8 100644
--- a/src/ol/View.js
+++ b/src/ol/View.js
@@ -894,16 +894,21 @@ class View extends BaseObject {
   }
 
   /**
+   * @param {number} pixelRatio Pixel ratio for center rounding.
    * @return {module:ol/View~State} View state.
    */
-  getState() {
+  getState(pixelRatio) {
     const center = /** @type {module:ol/coordinate~Coordinate} */ (this.getCenter());
     const projection = this.getProjection();
     const resolution = /** @type {number} */ (this.getResolution());
+    const pixelResolution = resolution / pixelRatio;
     const rotation = this.getRotation();
     return (
       /** @type {module:ol/View~State} */ ({
-        center: center.slice(),
+        center: [
+          Math.round(center[0] / pixelResolution) * pixelResolution,
+          Math.round(center[1] / pixelResolution) * pixelResolution
+        ],
         projection: projection !== undefined ? projection : null,
         resolution: resolution,
         rotation: rotation,