From bcc10a1ee29e0767745979e03b913574b4eda769 Mon Sep 17 00:00:00 2001
From: Lynix <lynix680@gmail.com>
Date: Tue, 10 Dec 2019 09:49:52 +0100
Subject: [PATCH] Math/Matrix4: Add Decompose

---
 ChangeLog.md                    |  1 +
 include/Nazara/Math/Matrix4.hpp |  2 ++
 include/Nazara/Math/Matrix4.inl | 19 +++++++++++++++++++
 3 files changed, 22 insertions(+)

diff --git a/ChangeLog.md b/ChangeLog.md
index 5a7a81ea1..fe438cc97 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -202,6 +202,7 @@ Nazara Engine:
 - Add Flags<E>::Set(Flags) helper method, to enable flags
 - ⚠ Constraint2D are no longer managed by references and are now handled objects
 - ⚠ Removed all Set methods from math classes taking their own type (e.g. Box::Set(Box))
+- Added Matrix4::Decompose
 
 Nazara Development Kit:
 - Added ImageWidget (#139)
diff --git a/include/Nazara/Math/Matrix4.hpp b/include/Nazara/Math/Matrix4.hpp
index 5a0e1808f..3ed2cd717 100644
--- a/include/Nazara/Math/Matrix4.hpp
+++ b/include/Nazara/Math/Matrix4.hpp
@@ -44,6 +44,8 @@ namespace Nz
 			Matrix4& Concatenate(const Matrix4& matrix);
 			Matrix4& ConcatenateAffine(const Matrix4& matrix);
 
+			void Decompose(Vector3<T>& translation, Quaternion<T>& rotation, Vector3<T>& scale);
+
 			Vector4<T> GetColumn(unsigned int column) const;
 			T GetDeterminant() const;
 			T GetDeterminantAffine() const;
diff --git a/include/Nazara/Math/Matrix4.inl b/include/Nazara/Math/Matrix4.inl
index 48d99f21e..1f2f58a17 100644
--- a/include/Nazara/Math/Matrix4.inl
+++ b/include/Nazara/Math/Matrix4.inl
@@ -220,6 +220,25 @@ namespace Nz
 		           F(1.0));
 	}
 
+	template<typename T>
+	void Matrix4<T>::Decompose(Vector3<T>& translation, Quaternion<T>& rotation, Vector3<T>& scale)
+	{
+		Matrix4f localMat(*this);
+
+		translation = localMat.GetTranslation();
+		scale = localMat.GetScale();
+
+		Vector3<T> invScale;
+		invScale.x = T(1) / scale.x;
+		invScale.y = T(1) / scale.y;
+		invScale.z = T(1) / scale.z;
+
+		localMat.ApplyScale(invScale);
+
+		rotation = localMat.GetRotation();
+	}
+
+
 	/*!
 	* \brief Gets the ith column of the matrix
 	* \return Vector4 which is the transformation of this axis