Merge #827

827: rstar::object for geo_types::Polygon r=rmanoka,lnicola a=michaelkirk

- [x] I agree to follow the project's [code of conduct](https://github.com/georust/geo/blob/main/CODE_OF_CONDUCT.md).
- [x] I added an entry to `CHANGES.md` if knowledge of this change could be valuable to users.
---
superesedes #351

Introduced an rstar::Object implementation for Polygon. This was originally proposed in #351,  but that PR has since grown stale because we now support two versions of rstar.

based on #351, this PR:
- merges in main
- update polygon impl to work with the multiple versions of rstar we now support


Co-authored-by: Stephan Hügel <[email protected]>
Co-authored-by: Michael Kirk <[email protected]>

geo-types/CHANGES.md

@@ -4,6 +4,8 @@
 
 * Add `split_x` and `split_y` methods on `Rect`
   * <https://github.com/georust/geo/pull/823>
+* Add support for `Polygon` in `RTree`
+  * <https://github.com/georust/geo/pull/351>
 
 ## 0.7.4
 

geo-types/src/polygon.rs

@@ -542,3 +542,25 @@ impl<T: AbsDiffEq<Epsilon = T> + CoordNum> AbsDiffEq for Polygon<T> {
         zipper.all(|(lhs, rhs)| lhs.abs_diff_eq(rhs, epsilon))
     }
 }
+
+#[cfg(any(feature = "rstar_0_8", feature = "rstar_0_9"))]
+macro_rules! impl_rstar_polygon {
+    ($rstar:ident) => {
+        impl<T> $rstar::RTreeObject for Polygon<T>
+        where
+            T: ::num_traits::Float + ::$rstar::RTreeNum,
+        {
+            type Envelope = ::$rstar::AABB<Point<T>>;
+
+            fn envelope(&self) -> Self::Envelope {
+                self.exterior.envelope()
+            }
+        }
+    };
+}
+
+#[cfg(feature = "rstar_0_8")]
+impl_rstar_polygon!(rstar_0_8);
+
+#[cfg(feature = "rstar_0_9")]
+impl_rstar_polygon!(rstar_0_9);