Simplify maxExtent restriction logic and prevent unneeded calls to `getLayerPxFromLonLat`

lib/OpenLayers/Layer/Grid.js

@@ -778,47 +778,33 @@ OpenLayers.Layer.Grid = OpenLayers.Class(OpenLayers.Layer.HTTPRequest, {
         this.clearTileQueue();
 
         //determine new tile bounds
-        var tileWidth, tileHeight, tileBounds;
         var center = bounds.getCenterLonLat();
 
-        //adjust tile bounds to fit in maxExtent restriction
+        var tileWidth = bounds.getWidth() * this.ratio;
-        //if there is a maxExtent restriction
+        var tileHeight = bounds.getHeight() * this.ratio;
-        if(this.maxExtent && bounds.containsBounds(this.maxExtent, true)) {
+        var tileBounds = 
-            bounds.bottom = Math.max(this.maxExtent.bottom, bounds.bottom);
-            bounds.top = Math.min(this.maxExtent.top, bounds.top);
-            bounds.left = Math.max(this.maxExtent.left, bounds.left);
-            bounds.right = Math.min(this.maxExtent.right, bounds.right);
-            tileWidth = bounds.getWidth();
-            tileHeight = bounds.getHeight();
-            tileBounds = bounds;
-            var blPx = this.map.getLayerPxFromLonLat({
-                lon : tileBounds.left,
-                lat : tileBounds.bottom
-            });
-            var trPx = this.map.getLayerPxFromLonLat({
-                lon : tileBounds.right,
-                lat : tileBounds.top
-            });
-            this.tileSize = new OpenLayers.Size(
-                Math.abs(trPx.x - blPx.x),
-                Math.abs(trPx.y - blPx.y)
-            );
-            this._resetTileSize = true;
-        } else {
-            tileWidth = bounds.getWidth() * this.ratio;
-            tileHeight = bounds.getHeight() * this.ratio;
-            tileBounds = 
                 new OpenLayers.Bounds(
                     center.lon - (tileWidth / 2), 
                     center.lat - (tileHeight / 2), 
                     center.lon + (tileWidth / 2), 
                     center.lat + (tileHeight / 2)
                 );
-            if(this._resetTileSize === true) {
+        //adjust tile bounds to fit in maxExtent restriction
-                this.setTileSize();
+        //if there is a maxExtent restriction
-                delete this._resetTileSize;
+        if(this.maxExtent) {
-            }
+            tileBounds.bottom = Math.max(this.maxExtent.bottom, tileBounds.bottom);
+            tileBounds.top = Math.min(this.maxExtent.top, tileBounds.top);
+            tileBounds.left = Math.max(this.maxExtent.left, tileBounds.left);
+            tileBounds.right = Math.min(this.maxExtent.right, tileBounds.right);
+            tileWidth = tileBounds.getWidth();
+            tileHeight = tileBounds.getHeight();
+            var resolution = this.map.getResolution();
+            this.tileSize = new OpenLayers.Size(
+                tileWidth / resolution,
+                tileHeight / resolution
+            );
         }
+        
         var px = this.map.getLayerPxFromLonLat({
             lon: tileBounds.left,
             lat: tileBounds.top

tests/Layer/Grid.html

@@ -467,9 +467,8 @@
                 t.ok(ul.lon === desiredUL.lon && ul.lat === desiredUL.lat, "correct ul passed to translation");
                 return translatedPX;        
             },
-            getResolution: function() {
+            getResolution:function(){return 1;}
-            }
+        };
-        }
 
         var newTile = {
             draw: function() {
@@ -528,7 +527,7 @@
             }
         };
     	//test bound fully contains the maxExtent
-    	//tile bounds -10,10,50,100
+    	//tile bounds -10,10,50,100 -> apply ratio -40,-35,80,145
     	layer.maxExtent = new OpenLayers.Bounds(0,20,40,90);
     	desiredTileBounds = new OpenLayers.Bounds(0,20,40,90);
         translatedPX = {x:0,y:90};
@@ -536,9 +535,10 @@
         
         //test bound overlaps the maxExtent
         bounds = new OpenLayers.Bounds(-10,10,50,100);
-        layer.maxExtent = new OpenLayers.Bounds(-30,20,40,110);
+        //with ratio applied tile bounds are -40,-35,80,145
-    	desiredTileBounds = new OpenLayers.Bounds(-10,20,40,100);
+        layer.maxExtent = new OpenLayers.Bounds(-50,20,40,150);
-        translatedPX = {x:-10,y:100};
+    	desiredTileBounds = new OpenLayers.Bounds(-40,20,40,145);
+        translatedPX = {x:-40,y:145};
         layer.grid = [[ tile ]];
     	layer.initSingleTile(bounds);
     }