From 85e491b30c09c833aa1afb618a4f945740a2e0fe Mon Sep 17 00:00:00 2001
From: Christophe Riccio <christophe.riccio@unity3d.com>
Date: Sun, 5 Jan 2020 20:41:51 +0100
Subject: [PATCH] Tentative fix of GLM_FORCE_QUAT_DATA_WXYZ on Clang with tests

---
 glm/detail/type_quat.inl           | 39 +++++++++++++++++++++++-------
 test/core/CMakeLists.txt           |  1 +
 test/core/core_force_quat_wxyz.cpp | 13 ++++++++++
 3 files changed, 44 insertions(+), 9 deletions(-)
 create mode 100644 test/core/core_force_quat_wxyz.cpp

diff --git a/glm/detail/type_quat.inl b/glm/detail/type_quat.inl
index c1824e0c..692f434d 100644
--- a/glm/detail/type_quat.inl
+++ b/glm/detail/type_quat.inl
@@ -90,32 +90,52 @@ namespace detail
 		template<typename T, qualifier Q>
 		GLM_FUNC_QUALIFIER GLM_CONSTEXPR qua<T, Q>::qua()
 #			if GLM_CONFIG_CTOR_INIT != GLM_CTOR_INIT_DISABLE
-			: x(0), y(0), z(0), w(1)
+#				ifdef GLM_FORCE_QUAT_DATA_WXYZ
+					: w(1), x(0), y(0), z(0)
+#				else
+					: x(0), y(0), z(0), w(1)
+#				endif
 #			endif
 		{}
 
 		template<typename T, qualifier Q>
 		GLM_FUNC_QUALIFIER GLM_CONSTEXPR qua<T, Q>::qua(qua<T, Q> const& q)
-			: x(q.x), y(q.y), z(q.z), w(q.w)
+#			ifdef GLM_FORCE_QUAT_DATA_WXYZ
+				: w(q.w), x(q.x), y(q.y), z(q.z)
+#			else
+				: x(q.x), y(q.y), z(q.z), w(q.w)
+#			endif
 		{}
 #	endif
 
 	template<typename T, qualifier Q>
 	template<qualifier P>
 	GLM_FUNC_QUALIFIER GLM_CONSTEXPR qua<T, Q>::qua(qua<T, P> const& q)
-		: x(q.x), y(q.y), z(q.z), w(q.w)
+#		ifdef GLM_FORCE_QUAT_DATA_WXYZ
+			: w(q.w), x(q.x), y(q.y), z(q.z)
+#		else
+			: x(q.x), y(q.y), z(q.z), w(q.w)
+#		endif
 	{}
 
 	// -- Explicit basic constructors --
 
 	template<typename T, qualifier Q>
 	GLM_FUNC_QUALIFIER GLM_CONSTEXPR qua<T, Q>::qua(T s, vec<3, T, Q> const& v)
-		: x(v.x), y(v.y), z(v.z), w(s)
+#		ifdef GLM_FORCE_QUAT_DATA_WXYZ
+			: w(s), x(v.x), y(v.y), z(v.z)
+#		else
+			: x(v.x), y(v.y), z(v.z), w(s)
+#		endif
 	{}
 
 	template <typename T, qualifier Q>
 	GLM_FUNC_QUALIFIER GLM_CONSTEXPR qua<T, Q>::qua(T _w, T _x, T _y, T _z)
-		: x(_x), y(_y), z(_z), w(_w)
+#		ifdef GLM_FORCE_QUAT_DATA_WXYZ
+			: y(_y), z(_z), w(_w), x(_x)
+#		else
+			: x(_x), y(_y), z(_z), w(_w)
+#		endif
 	{}
 
 	// -- Conversion constructors --
@@ -123,10 +143,11 @@ namespace detail
 	template<typename T, qualifier Q>
 	template<typename U, qualifier P>
 	GLM_FUNC_QUALIFIER GLM_CONSTEXPR qua<T, Q>::qua(qua<U, P> const& q)
-		: x(static_cast<T>(q.x))
-		, y(static_cast<T>(q.y))
-		, z(static_cast<T>(q.z))
-		, w(static_cast<T>(q.w))
+#		ifdef GLM_FORCE_QUAT_DATA_WXYZ
+			: w(static_cast<T>(q.w)), x(static_cast<T>(q.x)), y(static_cast<T>(q.y)), z(static_cast<T>(q.z))
+#		else
+			: x(static_cast<T>(q.x)), y(static_cast<T>(q.y)), z(static_cast<T>(q.z)), w(static_cast<T>(q.w))
+#		endif
 	{}
 
 	//template<typename valType>
diff --git a/test/core/CMakeLists.txt b/test/core/CMakeLists.txt
index a1f1d0ff..935792b9 100644
--- a/test/core/CMakeLists.txt
+++ b/test/core/CMakeLists.txt
@@ -7,6 +7,7 @@ glmCreateTestGTC(core_force_inline)
 glmCreateTestGTC(core_force_pure)
 glmCreateTestGTC(core_force_unrestricted_gentype)
 glmCreateTestGTC(core_force_xyzw_only)
+glmCreateTestGTC(core_force_quat_wxyz)
 glmCreateTestGTC(core_type_aligned)
 glmCreateTestGTC(core_type_cast)
 glmCreateTestGTC(core_type_ctor)
diff --git a/test/core/core_force_quat_wxyz.cpp b/test/core/core_force_quat_wxyz.cpp
new file mode 100644
index 00000000..bcb57394
--- /dev/null
+++ b/test/core/core_force_quat_wxyz.cpp
@@ -0,0 +1,13 @@
+#define GLM_FORCE_QUAT_DATA_WXYZ
+#define GLM_FORCE_INLINE
+
+#include <glm/glm.hpp>
+#include <glm/ext.hpp>
+
+int main()
+{
+	int Error = 0;
+
+	return Error;
+}
+