[Gdal-dev] Problem in Coordinate Transformation

[bargi]

Hi to all,

I am working on a project in which I have to project shapefiles on our
Application.

I am facing problem in transforming coordinate from one system to another
................

I googled a lot and found some code and try to run it.........but Its not
working properly..............

The code is as follow:

[code]
    if ( !__GOOGRFeatureSourceDriversRegistered ) {
        OGRRegisterAll();
        __GOOGRFeatureSourceDriversRegistered = true;
    }

     OGRDataSource *ogrDataSource = OGRSFDriverRegistrar::Open( qPrintable(
file ));

   
     if ( !ogrDataSource ) {
         return false;
     }


const int nLayers = ogrDataSource->GetLayerCount();
     
     OGRLayer *layer = ogrDataSource->GetLayer( 0 );
     m_displayName   = layer->GetLayerDefn()->GetName();
     m_path          = file;
     m_driverName    = ogrDataSource->GetDriver()->GetName();
     
     for ( int i = 0; i < nLayers; ++i ) {
         layer = ogrDataSource->GetLayer( i );
         OGRSpatialReference*    pSourceSRS = layer->GetSpatialRef();
         OGRSpatialReference*    pTargetSRS = pSourceSRS->Clone();
         pTargetSRS->SetProjCS("TM");
         pTargetSRS->SetTM(0,0,1,0,0);
         OGRGeometry*  poGeometry;
         double x,y;
         

        OGRCoordinateTransformation* poCT =
OGRCreateCoordinateTransformation(pSourceSRS,pTargetSRS);
       
          layer->ResetReading();  

         OGRFeature *ogrFeature = 0;
         
         while ( (ogrFeature = layer->GetNextFeature()) ) {
                 
               poGeometry = ogrFeature->GetGeometryRef();
                if (poGeometry !=NULL)  {
             if (wkbFlatten(poGeometry->getGeometryType()) == wkbLineString)
{
                 OGRPoint *poPoint = (OGRPoint *) poGeometry;
                 x = poPoint->getX();
                 y = poPoint->getY();
               if (poCT!= NULL || !poCT->Transform(1,&x,&y)) {
                   poPoint->setX(x);    //Set coordinate
                   poPoint->setY(y);
                   qDebug()<< poCT;  
                   printf( "(\n%f,%f) ->
(%f,%f)\n",poPoint->getX(),poPoint->getY(),x, y );
                     
                   GOFeature *feature = new GOFeature( ogrFeature );
                   features.push_back( feature );
                 
                }
             }
         }
     }
  }
[/code]

But it is not changing the coordinate............

The output is as follow when printf statement run......

(0.000000,0.000000) -> (0.000000,0.000000)

I am not able to understand where is the problem ?????

I this forum I found a post in which there was given suggestion for
Transformation  which is as follow:

[code]

 o Create a new layer for the output.
 o Make sure you pass the altered OGRSpatialReference to the
    CreateLayer() call.
 o You might as well just call transform() on the geometry
    instead of extracting the point and transforming that.

[/code]

When I try to use CreateLayer("MyFile",pTargetSRS,wkbunknow,null) function
,It gives error that ABC.shp file open in readonly ,MyFile cannot be
created........

The following line

 features.push_back( feature );

Is for adding features to a list from which we can extract features to
draw................

Also please tell me how can I stored changed coordinate of features and
retrieve them later..........

Any queries are welcome.........


Please help me to resolve the problem and please give steps of
implementation.....


Thanks 
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