From 39a2f62e88f0976109b4442cef1f77eec3442107 Mon Sep 17 00:00:00 2001
From: Michael Kirk <michael.code@endoftheworl.de>
Date: Sat, 2 Nov 2024 13:35:33 -0700
Subject: [PATCH] WIP: add support for multipolygon

---
 geo-types/src/geometry/multi_polygon.rs | 39 +++++++++++++++++++++++++
 geo/src/algorithm/bool_ops/mod.rs       |  8 ++---
 geo/src/algorithm/bool_ops/tests.rs     | 14 +++++++--
 3 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/geo-types/src/geometry/multi_polygon.rs b/geo-types/src/geometry/multi_polygon.rs
index 8a0b7d2005..b42f926fa9 100644
--- a/geo-types/src/geometry/multi_polygon.rs
+++ b/geo-types/src/geometry/multi_polygon.rs
@@ -170,6 +170,45 @@ where
     }
 }
 
+#[cfg(any(
+    feature = "rstar_0_8",
+    feature = "rstar_0_9",
+    feature = "rstar_0_10",
+    feature = "rstar_0_11",
+    feature = "rstar_0_12"
+))]
+macro_rules! impl_rstar_multi_polygon {
+    ($rstar:ident) => {
+        impl<T> $rstar::RTreeObject for MultiPolygon<T>
+        where
+            T: ::num_traits::Float + ::$rstar::RTreeNum,
+        {
+            type Envelope = ::$rstar::AABB<$crate::Point<T>>;
+
+            fn envelope(&self) -> Self::Envelope {
+                use ::$rstar::Envelope;
+                self.iter()
+                    .map(|p| p.envelope())
+                    .fold(::$rstar::AABB::new_empty(), |a, b| a.merged(&b))
+            }
+        }
+    };
+}
+#[cfg(feature = "rstar_0_8")]
+impl_rstar_multi_polygon!(rstar_0_8);
+
+#[cfg(feature = "rstar_0_9")]
+impl_rstar_multi_polygon!(rstar_0_9);
+
+#[cfg(feature = "rstar_0_10")]
+impl_rstar_multi_polygon!(rstar_0_10);
+
+#[cfg(feature = "rstar_0_11")]
+impl_rstar_multi_polygon!(rstar_0_11);
+
+#[cfg(feature = "rstar_0_12")]
+impl_rstar_multi_polygon!(rstar_0_12);
+
 #[cfg(test)]
 mod test {
     use super::*;
diff --git a/geo/src/algorithm/bool_ops/mod.rs b/geo/src/algorithm/bool_ops/mod.rs
index 81d4b13081..c6e2dd0cbc 100644
--- a/geo/src/algorithm/bool_ops/mod.rs
+++ b/geo/src/algorithm/bool_ops/mod.rs
@@ -226,18 +226,18 @@ impl<T: BoolOpsNum> BooleanOps for MultiPolygon<T> {
 }
 
 /// Allows the unary union operation to be performed on any container which can produce items of type `Polygon<T>`
-impl<T, Container> UnaryUnion for Container
+impl<T, Boppable, BoppableCollection> UnaryUnion for BoppableCollection
 where
     T: BoolOpsNum,
-    Container: IntoIterator<Item = Polygon<T>> + Clone,
-    Polygon<T>: RTreeObject,
+    Boppable: BooleanOps<Scalar = T> + RTreeObject,
+    BoppableCollection: IntoIterator<Item = Boppable> + Clone,
 {
     type Scalar = T;
 
     fn unary_union(&self) -> MultiPolygon<Self::Scalar> {
         // these three functions drive the union operation
         let init = || MultiPolygon::<T>::new(vec![]);
-        let fold = |mut accum: MultiPolygon<T>, poly: &Polygon<T>| -> MultiPolygon<T> {
+        let fold = |mut accum: MultiPolygon<T>, poly: &Boppable| -> MultiPolygon<T> {
             accum = accum.union(poly);
             accum
         };
diff --git a/geo/src/algorithm/bool_ops/tests.rs b/geo/src/algorithm/bool_ops/tests.rs
index d125bc3f68..8d6abd62b6 100644
--- a/geo/src/algorithm/bool_ops/tests.rs
+++ b/geo/src/algorithm/bool_ops/tests.rs
@@ -7,9 +7,17 @@ fn test_unary_union() {
     let poly2: Polygon = wkt!(POLYGON((210.0 290.0,204.07584923592933 288.2701221108328,212.24082541367974 285.47846008552216,210.0 290.0)));
     let poly3: Polygon = wkt!(POLYGON((211.0 292.0,204.07584923592933 288.2701221108328,212.24082541367974 285.47846008552216,210.0 290.0)));
 
-    let polys = vec![poly1, poly2, poly3];
-    let res = polys.unary_union();
-    assert_eq!(res.0.len(), 1);
+    let polys = vec![poly1.clone(), poly2.clone(), poly3.clone()];
+    let poly_union = polys.unary_union();
+    assert_eq!(poly_union.0.len(), 1);
+
+    let multi_poly_1 = MultiPolygon::new(vec![poly1, poly2]);
+    let multi_poly_2 = MultiPolygon::new(vec![poly3]);
+    let multi_polys = vec![multi_poly_1, multi_poly_2];
+    let multi_poly_union = multi_polys.unary_union();
+    // FIXME: This should be 1, same as poly_union, right?
+    assert_eq!(multi_poly_union.0.len(), 1);
+    assert_eq!(poly_union, multi_poly_union);
 }
 
 #[test]