From 044496f65201355ead07dd166f0c74059fd1fe6c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Miku=C5=82a?= <oss@mateuszmikula.dev>
Date: Mon, 12 Jan 2026 23:38:03 +0100
Subject: [PATCH] Sort using more deterministic algorithm

`hypot` while useful for most of the cases, may break sorting
assumptions like deterministic comparison.
As seen in: https://github.com/pop-os/cosmic-launcher/issues/352

Add and use a new method that trades the performance for more
determinism.
---
 core/src/point.rs      | 12 ++++++++++++
 graphics/src/damage.rs |  4 ++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/core/src/point.rs b/core/src/point.rs
index 55872911..e2b51e04 100644
--- a/core/src/point.rs
+++ b/core/src/point.rs
@@ -34,6 +34,18 @@ impl<T: Num> Point<T> {
 
         a.hypot(b)
     }
+
+    /// Computes the distance to another [`Point`], using a slower but more deterministic algorithm.
+    /// Useful for sorting algorithms.
+    pub fn distance_slow(&self, to: Self) -> T
+    where
+        T: Float,
+    {
+        let a = self.x - to.x;
+        let b = self.y - to.y;
+
+        (a * a + b * b).sqrt()
+    }
 }
 
 impl<T> From<[T; 2]> for Point<T>
diff --git a/graphics/src/damage.rs b/graphics/src/damage.rs
index 8aa42798..6e2d1ab8 100644
--- a/graphics/src/damage.rs
+++ b/graphics/src/damage.rs
@@ -49,8 +49,8 @@ pub fn group(mut damage: Vec<Rectangle>, bounds: Rectangle) -> Vec<Rectangle> {
 
     damage.sort_by(|a, b| {
         a.center()
-            .distance(Point::ORIGIN)
-            .total_cmp(&b.center().distance(Point::ORIGIN))
+            .distance_slow(Point::ORIGIN)
+            .total_cmp(&b.center().distance_slow(Point::ORIGIN))
     });
 
     let mut output = Vec::new();