Abeeujah commented on issue #303:
URL: https://github.com/apache/sedona-db/issues/303#issuecomment-3536946790
About this, I did start the implementation using `geo-traits` but then
stopped midway as I felt the overhead for going to andfrom `Geometry` to `Wkb`
to be able to call the `geos` `boundary` library function, to using
`geo-traits` convenience methods looks quite expensive serialising and
deserialising from one format to another (IMO), here's what it looked like
```rust
fn calculate_boundary_geos(geos_geom: &geos::Geometry) -> Result<Geometry> {
if geos_geom.geometry_type() == GeometryTypes::GeometryCollection {
let wkb_bytes = geos_geom.to_wkb().map_err(|e| {
DataFusionError::Execution(format!("Failed to convert to WKB:
{e}"))
})?;
let wkb = wkb::reader::read_wkb(wkb_bytes.as_ref()).map_err(|e| {
DataFusionError::Execution(format!("Failed to read WKB: {e}"))
})?;
let factory = GEOSWkbFactory::new();
match wkb.as_type() {
geo_traits::GeometryType::GeometryCollection(geometry_collection) => {
let boundaries: Result<Vec<_>> = geometry_collection
.geometries()
.map(|geom| {
let geos_geom = factory.create(geom).map_err(|e| {
DataFusionError::Execution(format!("Failed to
create GEOS geometry: {e}"))
})?;
calculate_boundary_geos(&geos_geom)
})
.collect();
Geometry::create_geometry_collection(boundaries?).map_err(|e| {
DataFusionError::Execution(format!("Failed to create
geometry collection: {e}"))
})
}
_ => unreachable!(),
}
} else {
geos_geom.boundary().map_err(|e| {
DataFusionError::Execution(format!("Failed to calculate
boundary: {e}"))
})
}
}
```
Another reason why I didn't continue that path was the amount of edge cases
I kept discovering along the line with the way `POSTGIS` computes the boundary
of a `GEOMETRYCOLLECTION`.
I currently base my implementations currently on the `geos` crate library
functions and as much info I can get from the POSTGIS reference - which is
mostly Consumer/User toned, not for developers building the said functions;
I would try to consult OGC Simple Feature Standards more, better still, It
would be great if you can recommend a more better resource I can consult and
work with
@paleolimbot @petern48 @jiayuasu
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