issues with small extents

[Yewondwossen Assefa]

Hi There,

I am having some trouble with a wms request using a small bbx 
(&BbOx=-0.0042,-0.0024,0.0042,0.0024), lat/long values.  What happens 
from what I can see is that there seems to be invalid values  set inside 
the projection objects and the points transformation (from layer 
projection to map projection) seem to give uncorrect values.  BTW both 
layer and map are set to epsg:4326 but at one point the 
msProjectionsDiffer call returns true ( Igues this is another issue).  
Following in the code, It seems that my points get corrupted in 
msProjectPoint.


if( out && out->gt.need_geotransform )
  {
      double x_out, y_out;

      x_out = out->gt.invgeotransform[0]
          + out->gt.invgeotransform[1] * point->x
          + out->gt.invgeotransform[2] * point->y;
      y_out = out->gt.invgeotransform[3]
          + out->gt.invgeotransform[4] * point->x
          + out->gt.invgeotransform[5] * point->y;

      point->x = x_out;
      point->y = y_out;
}

 The values inside the invgeotransform array seems to be  wrong but I am 
not sure

invgeotransform    0x00ec6850    double [6]
    [0]    84.000000000000000    double
    [1]    20119.760479041917    double
    [2]    0.00000000000000000    double
    [3]    47.999999999999993    double
    [4]    0.00000000000000000    double
    [5]    20210.526315789473    double

-    geotransform    0x00ec6820    double [6]
    [0]    -0.0041749999999999999    double
    [1]    4.9702380952380948e-005    double
    [2]    0.00000000000000000    double
    [3]    -0.0023749999999999999    double
    [4]    0.00000000000000000    double
    [5]    4.9479166666666665e-005    double


  before conversion
    point->x    0.00000000000000000    double
    point->y    -1.0000000000000000    double

 after conversion
    point->x    84.000000000000000    double
    point->y    -20162.526315789473    double


 At what point the invgeotransform   are set ?  I realise this e-mail is 
far from being clear but I am more looking general ideas on how to 
quickly  debug this.


 Thanks

-- 
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Assefa Yewondwossen           
Software Analyst   

Email: assefa at dmsolutions.ca    
http://www.dmsolutions.ca/

Phone: (613) 565-5056 (ext 14)
Fax:   (613) 565-0925
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