From 6719a8e3d5d457a52b8cfe9ba392ecbf5ae89a7d Mon Sep 17 00:00:00 2001
From: Erik Hofman <erik@ehofman.com>
Date: Mon, 25 Apr 2022 10:48:07 +0200
Subject: [PATCH] Add functions to return the squared length of a vector:
 Comparing two squared values prevents two computionally heavy sqrt calls.

---
 simgear/math/SGVec2.hxx | 8 ++++++++
 simgear/math/SGVec3.hxx | 9 +++++++++
 simgear/math/SGVec4.hxx | 8 ++++++++
 3 files changed, 25 insertions(+)

diff --git a/simgear/math/SGVec2.hxx b/simgear/math/SGVec2.hxx
index d9e4439f..87c6fe2f 100644
--- a/simgear/math/SGVec2.hxx
+++ b/simgear/math/SGVec2.hxx
@@ -231,6 +231,14 @@ T
 norm(const SGVec2<T>& v)
 { return simd4::magnitude(v.simd2()); }
 
+/// The squared euclidean norm of the vector
+/// Comparing two squared values prevents two computionally heavy sqrt calls.
+template<typename T>
+inline
+T
+norm2(const SGVec2<T>& v)
+{ return simd4::magnitude2(v.simd2()); }
+
 /// The euclidean norm of the vector, that is what most people call length
 template<typename T>
 inline
diff --git a/simgear/math/SGVec3.hxx b/simgear/math/SGVec3.hxx
index 514f9575..aa1061b8 100644
--- a/simgear/math/SGVec3.hxx
+++ b/simgear/math/SGVec3.hxx
@@ -301,6 +301,15 @@ T
 norm(const SGVec3<T>& v)
 { return simd4::magnitude(v.simd3()); }
 
+/// The squared euclidean norm of the vector
+/// Comparing two squared values prevents two computionally heavy sqrt calls.
+template<typename T>
+inline
+T
+norm2(const SGVec3<T>& v)
+{ return simd4::magnitude2(v.simd3()); }
+
+
 /// The euclidean norm of the vector, that is what most people call length
 template<typename T>
 inline
diff --git a/simgear/math/SGVec4.hxx b/simgear/math/SGVec4.hxx
index b62561ab..bd66389f 100644
--- a/simgear/math/SGVec4.hxx
+++ b/simgear/math/SGVec4.hxx
@@ -249,6 +249,14 @@ T
 norm(const SGVec4<T>& v)
 { return simd4::magnitude(v.simd4()); }
 
+/// The squared euclidean norm of the vector
+/// Comparing two squared values prevents two computionally heavy sqrt calls.
+template<typename T>
+inline
+T
+norm2(const SGVec4<T>& v)
+{ return simd4::magnitude2(v.simd4()); }
+
 /// The euclidean norm of the vector, that is what most people call length
 template<typename T>
 inline