[Gdal-dev] GDAL WMS Questions..

[Adam Nowacki]

Fodder wrote:
> mchapman wrote:
>> I think you just pass the file path of the XML file to the GDALOpen
>> method.
>> That's how the WMS client works.  Then just call RasterIO() and work with
>> it
>> the same way you would any other raster.  That is my guess anyway.
>>
>> Martin
>>
> 
> Thanks, I tried this at first but when I pass the filepath to the GDALOpen
> method I just get a nil object back (the code works for other images). I'm
> just using the demo xml from the gdal.org site:
> 
> <GDAL_WMS>
>     <Service name="TileService">
>         <Version>1</Version>
>        
> <ServerUrl>http://s0.tileservice.worldwindcentral.com/getTile?</ServerUrl>
>         <Dataset>za.johannesburg_2006_20cm</Dataset>
>     </Service>
>     <DataWindow>
>         <UpperLeftX>-180.0</UpperLeftX>
>         <UpperLeftY>90.0</UpperLeftY>
>         <LowerRightX>180.0</LowerRightX>
>         <LowerRightY>-90.0</LowerRightY>
>         <SizeX>268435456</SizeX>
>         <SizeY>134217728</SizeY>
>         <TileLevel>19</TileLevel>
>     </DataWindow>
>     <Projection>EPSG:4326</Projection>
>     <OverviewCount>16</OverviewCount>
>     <BlockSizeX>512</BlockSizeX>
>     <BlockSizeY>512</BlockSizeY>
>     <BandsCount>3</BandsCount>
> </GDAL_WMS>

If you're getting null (0) and no error message then either you have no 
wms driver built in or the xml doesnt start with <GDAL_WMS>.