Cleaning up the docs to a marginally acceptable level.

lib/OpenLayers/Layer/UTFGrid.js

@@ -9,7 +9,28 @@
 
 /** 
  * Class: OpenLayers.Layer.UTFGrid
- * MP TODO
+ * This Layer reads from UTFGrid tiled data sources. 
+ * Since UTFGrids are essentially JSON-based ASCII art 
+ * with attached attributes, they are not visibly rendered. 
+ * In order to use them in the map, 
+ * you must add a UTFGrid Control as well.
+ *
+ * Example:
+ *
+ * (start code)
+ * var world_utfgrid = new OpenLayers.Layer.UTFGrid( 
+ *     'UTFGrid Layer', 
+ *     "http://tiles/world_utfgrid/${z}/${x}/${y}.json"
+ * );
+ * map.addLayer(world_utfgrid);
+ * 
+ * var control = new OpenLayers.Control.UTFGrid({
+ *     'div': 'attrsdiv',
+ *     'layers': [world_utfgrid],
+ *     'handlerMode': 'move'
+ * })
+ * (end code)
+ *
  * 
  * Inherits from:
  *  - <OpenLayers.Layer.Grid>
@@ -145,19 +166,30 @@ OpenLayers.Layer.UTFGrid = OpenLayers.Class(OpenLayers.Layer.Grid, {
     utfgridResolution: 4,
 
     /** 
-     * Method: getTileInfo
+     * APIMethod: getTileInfo
      * Get tile information for a given location at the current map resolution.
      *
      * Parameters:
      * loc - {<OpenLayers.LonLat} A location in map coordinates.
      *
      * Returns:
-     * {Object} An object with 
-     *     MP TODO 
-     *     "col", "row", "i", and "j" properties.  The col
-     *     and row values are zero based tile indexes from the top left.  The
-     *     i and j values are the number of pixels to the left and top 
-     *     (respectively) of the given location within the target tile.
+     * {Object} An object with the following properties
+     *
+     *       globalCol: the tile's X  
+     *
+     *       globalRow: the tile's Y 
+     *
+     *       gridCol: the viewport grid X
+     *
+     *       gridRow: the viewpoirt grid Y
+     *
+     *       tile: the associated OpenLayers.Tile.UTFGrid object
+     *
+     *       zoom: the tile zoom level
+     *
+     *       i: the pixel X position relative to the current tile origin
+     *
+     *       j: the pixel Y position relative to the current tile origin
      */
     getTileInfo: function(loc) {
         var res = this.getServerResolution();
@@ -170,8 +202,9 @@ OpenLayers.Layer.UTFGrid = OpenLayers.Class(OpenLayers.Layer.Grid, {
 
         // Get the current grid offset
         var gridOrigin = this.grid[0][0].bounds;
-        // MP TODO rounding errors can cause intermittent problems (4.9999 should be 5)
-        // flooring will cause big problems (4.999 becomes 4)... do round or toFixed later?
+        // Floating point math can cause problems (4.9999 should be 5)
+        // flooring will cause big problems (4.999 becomes 4)... 
+        // Do round or toFixed later?
         var gridColOffset = 
                 (gridOrigin.left - this.tileOrigin.lon) / (res * this.tileSize.w);
         var gridRowOffset = 
@@ -193,8 +226,6 @@ OpenLayers.Layer.UTFGrid = OpenLayers.Class(OpenLayers.Layer.Grid, {
             globalRow: globalRow, 
             gridCol: gridCol, 
             gridRow: gridRow, 
-            gridColOffset: gridColOffset,
-            gridRowOffset: gridRowOffset,
             tile: tile,
             zoom: zoom,
             i: Math.floor((fx - globalCol) * this.tileSize.w),