CreateOGRPolygon.cpp

void OGRLayer::SetSpatialFilterRect( double dfMinX, double dfMinY,
                                      double dfMaxX, double dfMaxY )

{
     OGRLinearRing  oRing;
     OGRPolygon oPoly;

     oRing.addPoint( dfMinX, dfMinY );
     oRing.addPoint( dfMinX, dfMaxY );
     oRing.addPoint( dfMaxX, dfMaxY );
     oRing.addPoint( dfMaxX, dfMinY );
     oRing.addPoint( dfMinX, dfMinY );

     oPoly.addRing( &oRing );

     SetSpatialFilter( &oPoly );
}