From 3ee83a15ef776cd9db9af29d3426bb9d7c39e6a2 Mon Sep 17 00:00:00 2001
From: CaptainCarrot <CaptainCarrot@users.noreply.github.com>
Date: Sat, 22 Jul 2017 17:09:21 +0200
Subject: [PATCH] Add files via upload

---
 glm/gtx/quaternion.hpp | 28 ++++++++++++++++++++++++++++
 glm/gtx/quaternion.inl | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/glm/gtx/quaternion.hpp b/glm/gtx/quaternion.hpp
index ad298dae..401f22c0 100644
--- a/glm/gtx/quaternion.hpp
+++ b/glm/gtx/quaternion.hpp
@@ -177,6 +177,34 @@ namespace glm
 		vec<3, T, P> const & orig, 
 		vec<3, T, P> const & dest);
 
+		/// Build a look at quaternion based on the default handedness.
+	///
+	/// @param direction Desired direction of the camera.
+	/// @param up Up vector, how the camera is oriented.. Typically (0, 0, 1).
+	template<typename T, precision P>
+	GLM_FUNC_DECL tquat<T, P> quatLookAt(
+		tvec3<T, P> const & direction,
+		tvec3<T, P> const & up);
+
+	/// Build a right-handed look at quaternion.
+	///
+	/// @param direction Desired direction of the camera.
+	/// @param up Up vector, how the camera is oriented. Typically (0, 0, 1).
+	template<typename T, precision P>
+	GLM_FUNC_DECL tquat<T, P> quatLookAtRH(
+		tvec3<T, P> const & direction,
+		tvec3<T, P> const & up);
+
+	/// Build a left-handed look at quaternion.
+	///
+	/// @param eye Position of the camera
+	/// @param direction Desired direction onto which the +z-axis gets mapped
+	/// @param up Up vector, how the camera is oriented. Typically (0, 0, 1).
+	template <typename T, precision P>
+	GLM_FUNC_DECL tquat<T, P> quatLookAtLH(
+		tvec3<T, P> const & direction,
+		tvec3<T, P> const & up);
+	
 	/// Returns the squared length of x.
 	/// 
 	/// @see gtx_quaternion
diff --git a/glm/gtx/quaternion.inl b/glm/gtx/quaternion.inl
index 7bdcdf60..c69426bb 100644
--- a/glm/gtx/quaternion.inl
+++ b/glm/gtx/quaternion.inl
@@ -208,5 +208,39 @@ namespace glm
 			rotationAxis.y * invs,
 			rotationAxis.z * invs);
 	}
+	
+	template<typename T, precision P>
+	GLM_FUNC_QUALIFIER tquat<T, P> quatLookAt(tvec3<T, P> const& direction, tvec3<T, P> const& up)
+	{
+#		if GLM_COORDINATE_SYSTEM == GLM_LEFT_HANDED
+			return quatLookAtLH(direction, up);
+#		else
+			return quatLookAtRH(direction, up);
+# 		endif
+	}
+
+	template<typename T, precision P>
+	GLM_FUNC_QUALIFIER tquat<T, P> quatLookAtRH(tvec3<T, P> const& direction, tvec3<T, P> const& up)
+	{
+		tmat3x3<T, P> Result(uninitialize);
+
+		Result[2] = -normalize(direction);
+		Result[0] = normalize(cross(up, Result[2]));
+		Result[1] = cross(Result[2], Result[0]);
+
+		return quat_cast(Result);
+	}
+
+	template<typename T, precision P>
+	GLM_FUNC_QUALIFIER tquat<T, P> quatLookAtLH(tvec3<T, P> const& direction, tvec3<T, P> const& up)
+	{
+		tmat3x3<T, P> Result(uninitialize);
+
+		Result[2] = normalize(direction);
+		Result[0] = normalize(cross(up, Result[2]));
+		Result[1] = cross(Result[2], Result[0]);
+
+		return quat_cast(Result);
+	}
 
 }//namespace glm