// Fetch a projection parameter value
func (sr SpatialReference) ProjectionParameter(name string, defaultValue float64) (float64, error) {
cName := C.CString(name)
defer C.free(unsafe.Pointer(cName))
var cErr C.OGRErr
value := C.OSRGetProjParm(sr.cval, cName, C.double(defaultValue), &cErr)
return float64(value), cErr.Err()
}
// Build a polygon / ring from a set of lines
func (geom Geometry) BuildPolygonFromEdges(autoClose bool, tolerance float64) (Geometry, error) {
var cErr C.OGRErr
newGeom := C.OGRBuildPolygonFromEdges(
geom.cval,
0,
BoolToCInt(autoClose),
C.double(tolerance),
&cErr,
)
return Geometry{newGeom}, cErr.Err()
}
// Get spheroid inverse flattening axis
func (sr SpatialReference) InverseFlattening() (float64, error) {
var cErr C.OGRErr
flat := C.OSRGetInvFlattening(sr.cval, &cErr)
return float64(flat), cErr.Err()
}
// Get spheroid semi-minor axis
func (sr SpatialReference) SemiMinorAxis() (float64, error) {
var cErr C.OGRErr
axis := C.OSRGetSemiMinor(sr.cval, &cErr)
return float64(axis), cErr.Err()
}