[Tilecache] help with gdal-wms-c driver

[Richard Duivenvoorde]

Hi List,
after reading
http://crschmidt.net/blog/282/openaerialmap-using-with-other-tools/
and
http://wiki.openaerialmap.org/Using_With_MapServer

I thought it would be nice to be able to have a wms-interface in front
of 'our' dutch openstreetmap development server
http://tile.openstreetmap.nl/

But failing to accomplish this (I thought because of the 'strange'
resolutions/scales), I seeded my own tilecache with very simple scales
and bboxes:
http://www.duif.net/osmtilecache/tilecache2.py/1.0.0/osmpostgis2/
and an OpenLayers-test with a TMS layer in front:
http://www.duif.net/osm/wmsct.html
getting tiles from the above mentioned tilecache.

But the main-goal was to be able to put a wms in front of it:

<GDAL_WMS>
     <Service name="WMS">
         <Version>1.1.1</Version>
<ServerUrl>http://www.duif.net/osmtilecache/tilecache2.py/</ServerUrl>
         <Layers>osmpostgis2</Layers>
         <SRS>EPSG:28992</SRS>
     </Service>
     <DataWindow>
         <UpperLeftX>0</UpperLeftX>
         <UpperLeftY>600000</UpperLeftY>
         <LowerRightX>300000</LowerRightX>
         <LowerRightY>300000</LowerRightY>
         <SizeX>524288</SizeX> <!-- ??? -->
         <SizeY>524288</SizeY>
         <TileLevel>11</TileLevel>
     </DataWindow>
     <Projection>EPSG:28992</Projection>
     <!--<OverviewCount>12</OverviewCount>-->
     <BlockSizeX>256</BlockSizeX>
     <BlockSizeY>256</BlockSizeY>
     <BandsCount>3</BandsCount>
</GDAL_WMS>

and a layer in a wms:

LAYER
     name  "osmnl"
     METADATA
       "wms_title" "osmnl"
       "wms_srs" "epsg:28992"
     END
     type raster
     status default
     data "/usr/lib/cgi-bin/osmpostgis2_cache.xml"
     projection "init=epsg:28992" end
     #offsite 0 0 0
END

and an openlayer demo page:
http://www.duif.net/osm/wmsc.html

But I keep failing in getting this to work. I'm not able to build a
configuration that requests the right tiles to tilecache. All request
from mapserver to the tilecache give errors like:

An error occurred: can't find resolution index for 1171.875000.
Available resolutions are:
[2048.0, 1024.0, 512.0, 256.0, 128.0, 64.0, 32.0, 16.0, 8.0, 4.0, 2.0]

Can somebody help me to explain HOW openlayers comes to url's like:
http://www.duif.net/cgi-bin/mapserv?map=osmpostgis2.map&TYPE=jpeg&LAYERS=osmnl&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&FORMAT=image%2Fjpeg&SRS=EPSG%3A28992&BBOX=0,300000,524288,824288&WIDTH=256&HEIGHT=256
giving rise to:
http://www.duif.net/osmtilecache/tilecache2.py/?request=GetMap&version=1.1.1&layers=osmpostgis2&styles=&srs=EPSG:28992&format=image/jpeg&width=256&height=256&bbox=0.00000000,300000.00000000,300000.00000000,600000.00000000
etc  etc

gdal info output from the xml:

Driver: WMS/OGC Web Map Service
Files: /usr/lib/cgi-bin/osmpostgis2_cache.xml
Size is 524288, 524288
Coordinate System is:
PROJCS["Amersfoort / RD New",
     GEOGCS["Amersfoort",
         DATUM["Amersfoort",
             SPHEROID["Bessel 1841",6377397.155,299.1528128,
                 AUTHORITY["EPSG","7004"]],
             AUTHORITY["EPSG","6289"]],
         PRIMEM["Greenwich",0,
             AUTHORITY["EPSG","8901"]],
         UNIT["degree",0.01745329251994328,
             AUTHORITY["EPSG","9122"]],
         AUTHORITY["EPSG","4289"]],
     UNIT["metre",1,
         AUTHORITY["EPSG","9001"]],
     PROJECTION["Oblique_Stereographic"],
     PARAMETER["latitude_of_origin",52.15616055555555],
     PARAMETER["central_meridian",5.38763888888889],
     PARAMETER["scale_factor",0.9999079],
     PARAMETER["false_easting",155000],
     PARAMETER["false_northing",463000],
     AUTHORITY["EPSG","28992"]]
Origin = (0.000000000000000,600000.000000000000000)
Pixel Size = (0.572204589843750,-0.572204589843750)
Corner Coordinates:
Upper Left  (       0.000,  600000.000) (  3d 3'31.41"E, 53d21'53.77"N)
Lower Left  (       0.000,  300000.000) (  3d11'41.21"E, 50d40'12.02"N)
Upper Right (  300000.000,  600000.000) (  7d33'59.07"E, 53d22'3.89"N)
Lower Right (  300000.000,  300000.000) (  7d26'20.80"E, 50d40'21.39"N)
Center      (  150000.000,  450000.000) (  5d18'53.12"E, 52d 2'21.41"N)
Band 1 Block=256x256 Type=Byte, ColorInterp=Undefined
   Overviews: 262144x262144, 131072x131072, 65536x65536, 32768x32768,
16384x16384, 8192x8192, 4096x4096, 2048x2048, 1024x1024, 512x512, 256x256
Band 2 Block=256x256 Type=Byte, ColorInterp=Undefined
   Overviews: 262144x262144, 131072x131072, 65536x65536, 32768x32768,
16384x16384, 8192x8192, 4096x4096, 2048x2048, 1024x1024, 512x512, 256x256
Band 3 Block=256x256 Type=Byte, ColorInterp=Undefined
   Overviews: 262144x262144, 131072x131072, 65536x65536, 32768x32768,
16384x16384, 8192x8192, 4096x4096, 2048x2048, 1024x1024, 512x512, 256x256

Any help VERY much appreciated,

Regards,

Richard Duivenvoorde