git subrepo clone --branch=sono6good https://github.com/essej/JUCE.git deps/juce

subrepo:
  subdir:   "deps/juce"
  merged:   "b13f9084e"
upstream:
  origin:   "https://github.com/essej/JUCE.git"
  branch:   "sono6good"
  commit:   "b13f9084e"
git-subrepo:
  version:  "0.4.3"
  origin:   "https://github.com/ingydotnet/git-subrepo.git"
  commit:   "2f68596"

deps/juce/modules/juce_opengl/geometry/juce_Quaternion.h

@@ -0,0 +1,98 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2020 - Raw Material Software Limited
+
+   JUCE is an open source library subject to commercial or open-source
+   licensing.
+
+   By using JUCE, you agree to the terms of both the JUCE 6 End-User License
+   Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
+
+   End User License Agreement: www.juce.com/juce-6-licence
+   Privacy Policy: www.juce.com/juce-privacy-policy
+
+   Or: You may also use this code under the terms of the GPL v3 (see
+   www.gnu.org/licenses).
+
+   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
+   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
+   DISCLAIMED.
+
+  ==============================================================================
+*/
+
+namespace juce
+{
+
+//==============================================================================
+/**
+    Holds a quaternion (a 3D vector and a scalar value).
+
+    @tags{OpenGL}
+*/
+template <typename Type>
+class Quaternion
+{
+public:
+    Quaternion() noexcept                                               : scalar() {}
+    Quaternion (const Quaternion& other) noexcept                       : vector (other.vector), scalar (other.scalar) {}
+    Quaternion (Vector3D<Type> vectorPart, Type scalarPart) noexcept    : vector (vectorPart), scalar (scalarPart) {}
+    Quaternion (Type x, Type y, Type z, Type w) noexcept                : vector (x, y, z), scalar (w) {}
+
+    /** Creates a quaternion from an angle and an axis. */
+    static Quaternion fromAngle (Type angle, Vector3D<Type> axis) noexcept
+    {
+        return Quaternion (axis.normalised() * std::sin (angle / (Type) 2), std::cos (angle / (Type) 2));
+    }
+
+    Quaternion& operator= (Quaternion other) noexcept
+    {
+        vector = other.vector;
+        scalar = other.scalar;
+        return *this;
+    }
+
+    Quaternion& operator*= (Quaternion other) noexcept
+    {
+        const Type oldScalar (scalar);
+        scalar = (scalar * other.scalar) - (vector * other.vector);
+        vector = (other.vector * oldScalar) + (vector * other.scalar) + (vector ^ other.vector);
+        return *this;
+    }
+
+    Type length() const noexcept        { return std::sqrt (normal()); }
+    Type normal() const noexcept        { return scalar * scalar + vector.lengthSquared(); }
+
+    Quaternion normalised() const noexcept
+    {
+        const Type len (length());
+        jassert (len > 0);
+        return Quaternion (vector / len, scalar / len);
+    }
+
+    /** Returns the matrix that will perform the rotation specified by this quaternion. */
+    Matrix3D<Type> getRotationMatrix() const noexcept
+    {
+        const Type norm (normal());
+        const Type s (norm > 0 ? ((Type) 2) / norm : 0);
+        const Type xs (s * vector.x),  ys (s * vector.y),  zs (s * vector.z);
+        const Type wx (xs * scalar),   wy (ys * scalar),   wz (zs * scalar);
+        const Type xx (xs * vector.x), xy (ys * vector.x), xz (zs * vector.x);
+        const Type yy (ys * vector.y), yz (zs * vector.y), zz (zs * vector.z);
+
+        return Matrix3D<Type> (((Type) 1) - (yy + zz), xy - wz, xz + wy, 0,
+                               xy + wz, ((Type) 1) - (xx+ zz),  yz - wx, 0,
+                               xz - wy, yz + wx, ((Type) 1) - (xx + yy), 0,
+                               0, 0, 0, (Type) 1);
+    }
+
+    /** The vector part of the quaternion. */
+    Vector3D<Type> vector;
+
+    /** The scalar part of the quaternion. */
+    Type scalar;
+};
+
+} // namespace juce