[Benchmarking] Comparing GeoServer and MapServer styling

[Andrea Aime]

Hi,
I've just added the sample styling requests for GeoServer on the wiki:
http://wiki.osgeo.org/wiki/Benchmarking_2010#Live_Benchmark_WMS_GetMap_Requests

Comparing the first two requests:
http://12.189.158.78:8081/cgi-bin/mapserv?MAP=/benchmarking/mapserver/spain-shapefiles.map&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&LAYERS=vector_benchmarking_2010&STYLES=&BBOX=1.8,41,2.4,42&WIDTH=800&HEIGHT=600&srs=EPSG:4326&FORMAT=image/png
http://12.189.158.78:8080/geoserver/wms?SRS=EPSG%3A4326&LAYERS=shp_alllayers_label&STYLES=&FORMAT=image/png&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&BBOX=1.8,41,2.4,42&WIDTH=800&HEIGHT=600

I see that MapServer styles are not limiting the scales of the point
layers labels. Is this intended?

Comparing the labeled contours one:
http://12.189.158.78:8081/cgi-bin/mapserv_label?MAP=/benchmarking/mapserver/spain-shapefiles.map&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&LAYERS=vector_benchmarking_2010&STYLES=&BBOX=2.1076723642349,41.407828508849,2.1178733654021,41.414271246429&width=800&height=600&srs=EPSG:4326&FORMAT=image/png
http://12.189.158.78:8080/geoserver/wms?SRS=EPSG%3A4326&LAYERS=shp_alllayers_label&STYLES=&FORMAT=image/png&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&BBOX=2.1076723642349,41.407828508849,2.1178733654021,41.414271246429&width=800&height=600

I first noticed that GeoServer was not using round joins, so modified GS
  style to follow suit.

The lines in GeoServer are thicker. My guess is that is due to Java2D
antialiasing more heavily the line widths compared to AGG.
Not sure what to do here, I can try to hand tune the GS widths until
I match MapServer outputs (thinner lines should correspond to less work
both drawing and compression wise, though I have no idea of how
significant the difference would be).

I also added a new request against the same region, but using a slightly
larger area:
http://12.189.158.78:8081/cgi-bin/mapserv_label?MAP=/benchmarking/mapserver/spain-shapefiles.map&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&LAYERS=vector_benchmarking_2010&STYLES=&BBOX=2.1048033326566,41.405072728518,2.1207423969804,41.41702702676&width=800&height=600&srs=EPSG:4326&FORMAT=image/png
http://12.189.158.78:8080/geoserver/wms?EXCEPTIONS=application%2Fvnd.ogc.se_inimage&LAYERS=shp_alllayers_label&STYLES=&FORMAT=image%2Fpng&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&SRS=EPSG%3A4326&BBOX=2.1048033326566,41.405072728518,2.1207423969804,41.41702702676&WIDTH=800&HEIGHT=600

Oddly it seems MS and GS are placing the point labels in different
spots. I can understand the line labels, there are a lot of heuristics
going on there, but the point labels are odd.
Will be interesting to see where the other servers place those
labels.

Ah, the larger request shows MapServer curved labels overlapping on the
top (above the "Sierra de Vilavana" label for example)
and some odd label positioning at the bottom (see that 150? barely
readable).

Cheers
Andrea