From cfb15613b19a1b5109a5d9668d784909519b0a18 Mon Sep 17 00:00:00 2001
From: Danny McGee <dannymcgee@gmail.com>
Date: Wed, 18 Oct 2023 00:59:37 -0400
Subject: [PATCH] Allow specified tolerance for `NearlyEq` checks

---
 studio/src/interaction/gizmos/controller.rs |  2 +-
 studio/src/math/util.rs                     | 30 ++++++++++++++++-----
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/studio/src/interaction/gizmos/controller.rs b/studio/src/interaction/gizmos/controller.rs
index 15cd881..5657574 100644
--- a/studio/src/interaction/gizmos/controller.rs
+++ b/studio/src/interaction/gizmos/controller.rs
@@ -161,7 +161,7 @@ impl From<Vec3> for SphericalCoords {
         }
 
         let pitch = f32::asin(-y / radius);
-        let heading = if (pitch - 90_f32.to_radians()).abs() < 1e-3_f32 {
+        let heading = if pitch.nearly_eq_within(90_f32.to_radians(), 1e-3) {
             0.
         } else {
             f32::atan2(x, z)
diff --git a/studio/src/math/util.rs b/studio/src/math/util.rs
index c7dafe2..c7a5e19 100644
--- a/studio/src/math/util.rs
+++ b/studio/src/math/util.rs
@@ -1,17 +1,33 @@
 use bevy::prelude::Vec3;
 
-pub trait NearlyEq<Rhs> {
-    fn nearly_eq(self, rhs: Rhs) -> bool;
+pub trait NearlyEq<Rhs, Tolerance = Rhs> {
+    const DEFAULT_TOLERANCE: Tolerance;
+
+    #[inline]
+    fn nearly_eq(self, rhs: Rhs) -> bool
+    where
+        Self: Sized,
+    {
+        self.nearly_eq_within(rhs, Self::DEFAULT_TOLERANCE)
+    }
+
+    fn nearly_eq_within(self, rhs: Rhs, tolerance: Tolerance) -> bool;
 }
 
 impl NearlyEq<f32> for f32 {
-    fn nearly_eq(self, rhs: f32) -> bool {
-        (self - rhs).abs() < Self::EPSILON
+    const DEFAULT_TOLERANCE: f32 = f32::EPSILON;
+
+    fn nearly_eq_within(self, rhs: f32, tolerance: f32) -> bool {
+        (self - rhs).abs() < tolerance
     }
 }
 
-impl NearlyEq<Vec3> for Vec3 {
-    fn nearly_eq(self, rhs: Vec3) -> bool {
-        self.x.nearly_eq(rhs.x) && self.y.nearly_eq(rhs.y) && self.z.nearly_eq(rhs.z)
+impl NearlyEq<Vec3, f32> for Vec3 {
+    const DEFAULT_TOLERANCE: f32 = <f32 as NearlyEq<f32>>::DEFAULT_TOLERANCE;
+
+    fn nearly_eq_within(self, rhs: Vec3, tolerance: f32) -> bool {
+        self.x.nearly_eq_within(rhs.x, tolerance)
+            && self.y.nearly_eq_within(rhs.y, tolerance)
+            && self.z.nearly_eq_within(rhs.z, tolerance)
     }
 }