Documenting the featureDx, xOffset and rightOfDateLine member variables.

lib/OpenLayers/Renderer.js

@@ -73,6 +73,17 @@ OpenLayers.Renderer = OpenLayers.Class({
      */
     map: null,
     
+    /**
+     * Property: featureDx
+     * {Number} Feature offset in x direction. Will be calculated for and
+     * applied to the current feature while rendering. Looking at the center of
+     * the feature bounds and the renderer extent, we calculate how many world
+     * widths the two are away from each other. This value is used to shift the
+     * feature as close as possible to the center of the current renderer
+     * extent. This ensures that the feature is visible in the current
+     * viewport.
+     */
+    
     /**
      * Constructor: OpenLayers.Renderer 
      *

lib/OpenLayers/Renderer/Elements.js

@@ -373,6 +373,28 @@ OpenLayers.Renderer.Elements = OpenLayers.Class(OpenLayers.Renderer, {
      */    
     xmlns: null,
     
+    /**
+     * Property: xOffset
+     * {Number} Offset to apply to the renderer viewport translation in x
+     * direction. If the renderer extent's center is on the right of the
+     * dateline (i.e. exceeds the world bounds), we shift the viewport to the
+     * left by one world width. This avoids that features disappear from the
+     * map viewport. Because our dateline handling logic in other places
+     * ensures that extents crossing the dateline always have a center
+     * exceeding the world bounds on the left, we need this offset to make sure
+     * that the same is true for the renderer extent in pixel space as well.
+     */
+    
+    /**
+     * Property: rightOfDateLine
+     * {Boolean} Keeps track of the location of the map extent's center
+     * relative to the date line. The <setExtent> method compares this value
+     * (which is the one from the previous <setExtent> call) with the current
+     * position of the map extent relative to the date line and updates the
+     * xOffset when the extent's center has moved from one side of the date
+     * line to the other.
+     */
+    
     /**
      * Property: Indexer
      * {<OpenLayers.ElementIndexer>} An instance of OpenLayers.ElementsIndexer