From 2f1e2f94d7fe0100091a4cf47734c6624a8e757d Mon Sep 17 00:00:00 2001
From: SirLynix <lynix680@gmail.com>
Date: Fri, 23 Jun 2023 13:23:26 +0200
Subject: [PATCH] Math/Plane: Fix construction from 3 points

---
 include/Nazara/Math/Frustum.inl | 2 +-
 include/Nazara/Math/Plane.hpp   | 2 ++
 include/Nazara/Math/Plane.inl   | 4 ++--
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/include/Nazara/Math/Frustum.inl b/include/Nazara/Math/Frustum.inl
index 99e6519cf..6bddf1fe4 100644
--- a/include/Nazara/Math/Frustum.inl
+++ b/include/Nazara/Math/Frustum.inl
@@ -460,7 +460,7 @@ namespace Nz
 		T farW = farH * ratio;
 
 		Vector3<T> f = Vector3<T>::Normalize(target - eye);
-		Vector3<T> u(up.GetNormal());
+		Vector3<T> u = Vector3<T>::Normalize(up);
 		Vector3<T> s = Vector3<T>::Normalize(f.CrossProduct(u));
 		u = s.CrossProduct(f);
 
diff --git a/include/Nazara/Math/Plane.hpp b/include/Nazara/Math/Plane.hpp
index 13ca6a311..e804dbc82 100644
--- a/include/Nazara/Math/Plane.hpp
+++ b/include/Nazara/Math/Plane.hpp
@@ -17,6 +17,8 @@ namespace Nz
 	template<typename T>
 	class Plane
 	{
+		// Note: this class follows the ax + by + cz + d = 0 equation, which means d is the distance from origin
+
 		public:
 			constexpr Plane() = default;
 			constexpr Plane(T normalX, T normalY, T normalZ, T Distance);
diff --git a/include/Nazara/Math/Plane.inl b/include/Nazara/Math/Plane.inl
index e3455820c..bb971899a 100644
--- a/include/Nazara/Math/Plane.inl
+++ b/include/Nazara/Math/Plane.inl
@@ -88,7 +88,7 @@ namespace Nz
 		normal = edge1.CrossProduct(edge2);
 		normal.Normalize();
 
-		distance = normal.DotProduct(point3);
+		distance = -normal.DotProduct(point3);
 	}
 
 	/*!
@@ -139,7 +139,7 @@ namespace Nz
 	template<typename T>
 	constexpr T Plane<T>::SignedDistance(const Vector3<T>& point) const
 	{
-		return normal.DotProduct(point) + distance; // ax + by + cz + d = 0.
+		return normal.DotProduct(point) + distance; // ax + by + cz + d = 0
 	}
 
 	/*!