On Tue, Nov 13, 2007 at 05:21:29PM +0100, Trond Michelsen wrote: > I'm using mapserver 4.10.0 and I've noticed that mapserver changes the > bbox of incoming WMS-requests. At first I thought there was some > inconsistencies with my proj-definitions that caused a small > correction when mapserver fetched external WMS-layers. But now I've > noticed that mapserver always reduces the width and height of the > bounding box with the equivialent of a single pixel, then recenters > it.
Hang on... I should probably have looked harder at the source before posting. I just found this in mapwms.c: /* ** WMS extents are edge to edge while MapServer extents are center of ** pixel to center of pixel. Here we try to adjust the WMS extents ** in by half a pixel. We wait till here because we want to ensure we ** are doing this in terms of the correct WIDTH and HEIGHT. */ So, I assume mapserver actually plots everything to the edge of the original BBOX. In that case, I still think it's a bug that the adjusted BBOX is used when fetching layers from remote WMS-servers. I haven't tested with mapserver 5.0 yet, though, but I've looked at the source, and there doesn't seem to be any changes in how mapserver adjusts the extents. -- Trond Michelsen
