will ogr get coordinates in geographic coordinate system or projected coordinate system when using getPoint(int,OGRPoint*)

Question

Consider the code that I have written in the stackoverflow question How to extract vertexes of geometries in ESRI shapefiles using ogr library with c++, I have used the code to show shapefiles on an OpenGL window and 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.

for a layer, like this:

are the vertex coordinates stored in Geographic coordinate system or projected 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:

I come to the point that coordinates are stored in the PCS not GCS, but why my layer is stretched.
In fact I'm not sure what's the problem to start to solve. So just tell me:

• Are the coordinates fetched when we use the above functions in geographic coordinate system or in projected coordinate system?

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Edited section based on the Andre Joost's comment
I have downloaded Country Regions dataset here, you see its coordinate system and bounding box here:
and the data stored is:

that you see is in decimal degrees. Now in ArcCatalog I change the coordinate system:
As you see the bounding box is not projected to the new coordinate system and they are the same number just their unit is in meters. Which is obviously not true:

and the data stored with for the same point in my program is:

So I think the projection is not done automatically and I should do the calculations with PROJ.4 library!

Answer 1

Your problem is an openGL logic problem. The interaction between your viewport command and projection command is such that the coordinates are being graphed in a coordinate system that fills the viewport that you have defined. You can see this by grabbing the right edge of your openGL window and resizing. The entire display rubber-bands with the shape of the screen.

I'm not that familiar with the structure of openGL programs, but your problem lies in the interaction of the viewport with the projection (glOrtho in this case). You need to get these coordinated so that shape is preserved. I would start with a very simple program- plotting a square - and make sure that no matter how you resize the window, it remains square. Once you get this understood, apply that logic to setting the viewport and projection for your shapefile program.

Answer 2

The verticers are stored in the coordinate system given in the .prj file. You can open that with any text editor.

The extent of the shapefile is in the same coordinate system.

The central meridian is the only value in degrees, all others are in meters when using UTM.