[gdal-dev] will ogr get coordinates in geographic coordinate system or projected coordinate system when using getPoint function

sepideh sepideh.abadpour87 at gmail.com
Sun Sep 15 02:39:37 PDT 2013


showShapefile.rar
<http://osgeo-org.1560.x6.nabble.com/file/n5077897/showShapefile.rar>    
In the uploaded file, I have included a program that shows a polygon
shapefile on an opengl window. My problem is it seems the layer is stretched
comparing to what is shown when we render it in ArcGIS, QGIS and etc that I
think it is maybe because of not using the correct projection.  

As you see we set up an orthographic projection for opengl with the use of
the layer's bounding box and glOrtho.  
The question is for a layer, like this:  
<http://osgeo-org.1560.x6.nabble.com/file/n5077897/Capture1.jpg>   
<http://osgeo-org.1560.x6.nabble.com/file/n5077897/Capture2.jpg>   
are the vertex coordinates stored in Geographic coordinate system or
projectected coordinate system when we use functions like:  

OGRLineString::getPoint(int,OGRPoint*);
OGRPoint::getX();
OGRPoint::getY();  

when  I debug my code and see the vectors stored:  
<http://osgeo-org.1560.x6.nabble.com/file/n5077897/Capture.jpg>   
I come to the point that coordinates are stored in the *PCS* not *GCS*, but
why my layer is stretched.  

Is it because I show GCS coordinates in a glOrtho projection or do you think
the problem is something else?



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