Added small optimisation and comments

src/game/darkness.rs

@@ -318,6 +318,8 @@ fn get_light_geometry(
         true
     });
 
+    // FIXME: light source may not always be at bounding box center
+    // for example: optimal spot light bounding box
     let center = aabb.center();
     points.sort_unstable_by(|a, b| {
         f32::atan2(a.y - center.y, a.x - center.x)
@@ -328,12 +330,14 @@ fn get_light_geometry(
     // Build visibility polygon
     let mut polygon: Vec<_> = vec![];
     for point in points.drain(..) {
-        // We shoot 2 rays offset by this angle from the point.
+        /// We shoot 2 rays offset by this angle from the edge to catch what is beyond it.
         const ANGLE_OFFSET: f32 = 0.0001;
+        /// Multiplier for hypotenuse when the other two sides are the same length. Or sqrt(2).
+        const HYPOTENUSE_MULT: f32 = 1.4142135623730951;
         offset_cast(
             aabb.center(),
             (point - aabb.center()).normalize_or_zero(),
-            aabb.size().max_element(),
+            aabb.half_size().max_element() * HYPOTENUSE_MULT,
             true,
             filter,
             ANGLE_OFFSET,