From f36f80537f7ae709d1994d654f2ba078eb56f565 Mon Sep 17 00:00:00 2001
From: Mikolaj Wielgus <wielgusmikolaj@gmail.com>
Date: Tue, 19 Sep 2023 15:40:26 +0200
Subject: [PATCH] layout: Add invariant testing R-tree envelope invariance

---
 src/layout.rs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/layout.rs b/src/layout.rs
index 33e7644..e12c67c 100644
--- a/src/layout.rs
+++ b/src/layout.rs
@@ -24,6 +24,7 @@ pub struct Layout {
 }
 
 #[debug_invariant(self.graph.node_count() == self.rtree.size())]
+#[debug_invariant(self.test_envelopes())]
 impl Layout {
     pub fn new() -> Self {
         Layout {
@@ -224,6 +225,7 @@ impl Layout {
     }
 }
 
+#[debug_invariant(self.test_envelopes())]
 impl Layout {
     #[debug_ensures(self.graph.node_count() == old(self.graph.node_count()))]
     #[debug_ensures(self.graph.edge_count() == old(self.graph.edge_count()))]
@@ -310,3 +312,14 @@ impl Layout {
             .is_some());
     }
 }
+
+impl Layout {
+    fn test_envelopes(&self) -> bool {
+        !self.rtree.iter().any(|wrapper| {
+            !self
+                .rtree
+                .locate_in_envelope(&wrapper.geom().envelope())
+                .any(|w| w == wrapper)
+        })
+    }
+}