Buffering the layer data to improve the map navigation
Map navigation is an important factor to take into account to make the user experience better.
When we pan the map, many times we get to see blank areas (meaning that the content is loading) and after a few seconds the image appears.
On gridded layers and WMS layers working in single tile mode, we can improve this at the cost of increasing the requests number or increasing the computation time at the server side.
Note
Most of the raster layers inherit from the base class OpenLayers.Layer.Grid, which is responsible for dividing each zoom level into tiles.
For WMS layers working in single tile mode, the grid is formed only by one tile, which fills the whole map view.
The idea behind improving map navigation is simple; load the tiles outside the map view so that they are loaded before the user pans the map view in that direction.
This recipe shows you how to preload content outside the map view, both for gridded layers and also for WMS layers...
