There we go. What David's said here is what I was grasping for earlier here.
If you use a singleTile layer that is gridded, *eventully* the user is going to pan the map such that the corners of the grid are in the viewbox. At that point, the only option is to load 4 tiles, at which point, we're back to gridded, in which case you might as well just use a normal gridded layer with a very big tilesize and a buffer:0 Alternatively, One could imagine a tile layer which is double-tiled and that would avoid this problem, but seems like a horrible implementation nightmare. On 10/4/07, David William Bitner <[EMAIL PROTECTED]> wrote: > Ducky! > > Great to see you here -- don't be a stranger. > > The problem with aligning singleTile to a grid is that as soon as you have > the corner of the grid on the screen, all the sudden you are in a tiled mode > only with larger tiles. It strikes me that for any use case that would > require any kind of grid alignment at all, really you should be using a > tiled mode only with perhaps larger tiles and smaller buffers. The use case > that I see for single tile is for dynamic data -- data that is dynamic > enough that you wouldn't want it cached at all, ever. > > David > > > On 10/4/07, Dan Little <[EMAIL PROTECTED]> wrote: > > > > > > > > Yikes, first time poster! > > > > I think the speed to generate a single tile is wholely dependent on the > map-rendering engine and the dataset. > > > > For example, here at the City of Saint Paul, our streets layer is entirely > vector. I can generate a very very large tile with highly detailed streets > for the entire city using Mapserver in less than 1/3 of a second. Given the > nature of MapServer, and the size of the shapefile which stores our streets > layer, multiple tiles is much much slower (as the shapefile needs to be read > from disk and loaded to memory for each rendered tile). It would be nice to > have some of the effects of tiling without the high-cost it currently > presents in rendering performance. > > > > Dan "Ducky" Little > > City of Saint Paul / Public Works / GIS > > > > > > > > > > ----- Original Message ---- > > From: Stephen Woodbridge <[EMAIL PROTECTED]> > > To: [EMAIL PROTECTED] > > Cc: [email protected] > > Sent: Wednesday, October 3, 2007 9:37:29 PM > > Subject: Re: [OpenLayers-Dev] singleTile optimization > > > > > > [EMAIL PROTECTED] wrote: > > > What do you think about aligning singleTile bounds to the grid to > > > promote cacheability in the client? > > > > I think that this should be an option in the layer definition if it gets > > done. I can see some benefits to doing this, but the down side is that > > all images generated will be larger and slower to generate and the > > singleTile option needs to support more than one use case in my mind > anyway. > > > > -Steve > > _______________________________________________ > > Dev mailing list > > [email protected] > > http://openlayers.org/mailman/listinfo/dev > > > > > > ________________________________ > Luggage? GPS? Comic books? > > Check out fitting gifts for grads at Yahoo! Search. > > _______________________________________________ > > Dev mailing list > > [email protected] > > http://openlayers.org/mailman/listinfo/dev > > > > > > > > -- > ************************************ > David William Bitner > _______________________________________________ > Dev mailing list > [email protected] > http://openlayers.org/mailman/listinfo/dev > > _______________________________________________ Dev mailing list [email protected] http://openlayers.org/mailman/listinfo/dev
