From 4c95ddf296d66d2a0316631bd521e4eeab98c87a Mon Sep 17 00:00:00 2001
From: Nolan Darilek <nolan@thewordnerd.info>
Date: Sun, 23 Feb 2025 08:17:30 -0600
Subject: [PATCH] Attempt to work around crash when creating direction.

---
 src/visibility.rs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/visibility.rs b/src/visibility.rs
index 2e26ca1..097f4c2 100644
--- a/src/visibility.rs
+++ b/src/visibility.rs
@@ -80,13 +80,14 @@ impl Viewshed {
                 // println!("Checking {coord:?}");
                 if let Some((_, entities)) = opacity_map.get(&coord) {
                     for e in entities {
-                        if entities.len() == 1 || sensors.contains(*e) {
+                        let coord = Vec2::new(coord.x as f32 + 0.5, coord.y as f32 + 0.5);
+                        let dir = (coord - *start).normalize_or_zero();
+                        if dir == Vec2::ZERO || entities.len() == 1 || sensors.contains(*e) {
                             // println!("Spotted {e:?}");
                             new_visible_entities.insert(*e);
                         } else {
                             let should_push = std::cell::RefCell::new(true);
-                            let coord = Vec2::new(coord.x as f32 + 0.5, coord.y as f32 + 0.5);
-                            let dir = Dir2::new_unchecked((coord - *start).normalize_or_zero());
+                            let dir = Dir2::new_unchecked(dir);
                             // println!("Casting from {coord} to {dir:?}");
                             spatial_query.cast_ray_predicate(
                                 *start,