From cadc54cc4e8682265d395e719fe440c91d771e06 Mon Sep 17 00:00:00 2001
From: Tim Schaub <tim.schaub@gmail.com>
Date: Wed, 9 Apr 2008 15:54:01 +0000
Subject: [PATCH] Fixing panning for odd-sized viewports (broken in r6492). 
 This makes map.getViewPortPxFromLonLat return fractional pixel values.  To
 get integer pixel values, use map.getPixelFromLonLat.  A better solution may
 be possible in the future.  r=crschmidt (closes #1503)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@6831 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
---
 lib/OpenLayers/Layer.js |  6 ++++--
 lib/OpenLayers/Map.js   | 20 +++++++++++++-------
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/lib/OpenLayers/Layer.js b/lib/OpenLayers/Layer.js
index 3cf5d7ef4d..f18374d21c 100644
--- a/lib/OpenLayers/Layer.js
+++ b/lib/OpenLayers/Layer.js
@@ -997,6 +997,8 @@ OpenLayers.Layer = OpenLayers.Class({
 
     /**
      * APIMethod: getViewPortPxFromLonLat
+     * Returns a pixel location given a map location.  This method will return
+     *     fractional pixel values.
      * 
      * Parameters:
      * lonlat - {<OpenLayers.LonLat>}
@@ -1011,8 +1013,8 @@ OpenLayers.Layer = OpenLayers.Class({
             var resolution = this.map.getResolution();
             var extent = this.map.getExtent();
             px = new OpenLayers.Pixel(
-                Math.round(1/resolution * (lonlat.lon - extent.left)),
-                Math.round(1/resolution * (extent.top - lonlat.lat))
+                (1/resolution * (lonlat.lon - extent.left)),
+                (1/resolution * (extent.top - lonlat.lat))
             );    
         }
         return px;
diff --git a/lib/OpenLayers/Map.js b/lib/OpenLayers/Map.js
index 2639317132..5362cd826e 100644
--- a/lib/OpenLayers/Map.js
+++ b/lib/OpenLayers/Map.js
@@ -1593,8 +1593,8 @@ OpenLayers.Map = OpenLayers.Class({
         var newPx = this.getViewPortPxFromLonLat(lonlat);
 
         if ((originPx != null) && (newPx != null)) {
-            this.layerContainerDiv.style.left = (originPx.x - newPx.x) + "px";
-            this.layerContainerDiv.style.top  = (originPx.y - newPx.y) + "px";
+            this.layerContainerDiv.style.left = Math.round(originPx.x - newPx.x) + "px";
+            this.layerContainerDiv.style.top  = Math.round(originPx.y - newPx.y) + "px";
         }
     },
 
@@ -2022,17 +2022,23 @@ OpenLayers.Map = OpenLayers.Class({
 
     /**
      * APIMethod: getPixelFromLonLat
+     * Returns a pixel location given a map location.  The map location is
+     *     translated to an integer pixel location (in viewport pixel
+     *     coordinates) by the current base layer.
      * 
      * Parameters:
-     * lonlat - {<OpenLayers.LonLat>}
+     * lonlat - {<OpenLayers.LonLat>} A map location.
      * 
      * Returns: 
      * {<OpenLayers.Pixel>} An OpenLayers.Pixel corresponding to the 
-     *                      <OpenLayers.LonLat> translated into view port 
-     *                      pixels by the current base layer.
+     *     <OpenLayers.LonLat> translated into view port pixels by the current
+     *     base layer.
      */
     getPixelFromLonLat: function (lonlat) {
-        return this.getViewPortPxFromLonLat(lonlat);
+        var px = this.getViewPortPxFromLonLat(lonlat);
+        px.x = Math.round(px.x);
+        px.y = Math.round(px.y);
+        return px;
     },
 
 
@@ -2116,7 +2122,7 @@ OpenLayers.Map = OpenLayers.Class({
      */
     getLayerPxFromLonLat: function (lonlat) {
        //adjust for displacement of layerContainerDiv
-       var px = this.getViewPortPxFromLonLat(lonlat);
+       var px = this.getPixelFromLonLat(lonlat);
        return this.getLayerPxFromViewPortPx(px);         
     },