[mapserver-users] Getting an image scaled to pixels

[Stuart]

Hi,

I have a csharp application using map_script that I am using to cut up
an ECW file into tiles for display on a Bing map. The issue I am
having is that each tile slightly overlaps others above and below it.
The procedure I am using is as follows:

I load the basic map file below add the projection and units from
within a csharp application:

   mapserverMap = new mapObj(mapOutputPath + mapFileName);
   mapserverMap.setWKTProjection("+proj=merc +a=6378137 +b=6378137
+lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null
+no_defs ");
   mapserverMap.setSize(256, 256);
   mapserverMap.units = MS_UNITS.MS_DD ;


I then use the csharp application to add a single RASTER layer

   layerObj layer = new layerObj(mapserverMap);
   Console.WriteLine(mapserverMap.layerorder);
   layer.name = ecwName;
   layer.type = MS_LAYER_TYPE.MS_LAYER_RASTER;
   layer.status = mapscript.MS_ON;
   layer.sizeunits = (int)MS_UNITS.MS_PIXELS;

   var extentdoubles = GetPlanExtentFromDB(ecwName, planConnectionString);
   layer.setExtent(extentdoubles[0], extentdoubles[1],
extentdoubles[2], extentdoubles[3]);

   layer.data = mapOutputPath + ecwName + ".ecw";

I have identified the issue is when for each quadKey I set the
mapserverMap extent to the bounding box of the quadKey MapServer
changes the latitudes of its extent to fit the map size (256 x 256)

e.g. for quadKey 31121320312020 i set the MapServer extent to:

   maxX
   152.95166015625
   maxY
   -30.334953881988554
   minX
   152.9296875
   minY
   -30.353916372297036

Then after setting the extent if I ask MapServer for its extent it returns:

   mapserverMap.extent
   {OSGeo.MapServer.rectObj}
       maxx: 152.95166015625
       maxy: -30.333448799017795
       minx: 152.9296875
       miny: -30.355421455267795

Notice the Longitudes are the same but the Latitudes (minY, maxY) have
been stretched.

So my question is that when I set mapserverMap object to the bounding
box I want it to be set to the latitude and longitude given and
stretched to fit the map size (256 x 256) rather than MapServer
modifying the latitudes to fit the map size.

Any help would be appreciated.

Stuart

--

Here is the starting map file

MAP
       NAME MyMap

       DEBUG ON
       IMAGECOLOR 128 155 155

       UNITS DD
       RESOLUTION 96
       TRANSPARENT OFF
       CONFIG   "PROJ_LIB"  "/ms4w/proj/nad/"
       CONFIG "CPL_DEBUG" "ON"
       SYMBOLSET ./etc/symbols.sym
       IMAGETYPE png
       FONTSET ./etc/fonts.txt

END