/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include "Quaternion.h" #include "Matrix.h" #include "Tools.h" #include <algorithm> #include <ostream> #include <math.h> using namespace std; namespace mozilla { namespace gfx { std::ostream& operator<<(std::ostream& aStream, const Quaternion& aQuat) { return aStream << "< " << aQuat.x << " " << aQuat.y << " " << aQuat.z << " " << aQuat.w << ">"; } void Quaternion::SetFromRotationMatrix(const Matrix4x4& m) { // see http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/index.htm const Float trace = m._11 + m._22 + m._33; if (trace > 0.0) { const Float s = 0.5f / sqrt(trace + 1.0f); w = 0.25f / s; x = (m._32 - m._23) * s; y = (m._13 - m._31) * s; z = (m._21 - m._12) * s; } else if (m._11 > m._22 && m._11 > m._33) { const Float s = 2.0f * sqrt(1.0f + m._11 - m._22 - m._33); w = (m._32 - m._23) / s; x = 0.25f * s; y = (m._12 + m._21) / s; z = (m._13 + m._31) / s; } else if (m._22 > m._33) { const Float s = 2.0 * sqrt(1.0f + m._22 - m._11 - m._33); w = (m._13 - m._31) / s; x = (m._12 + m._21) / s; y = 0.25f * s; z = (m._23 + m._32) / s; } else { const Float s = 2.0 * sqrt(1.0f + m._33 - m._11 - m._22); w = (m._21 - m._12) / s; x = (m._13 + m._31) / s; y = (m._23 + m._32) / s; z = 0.25f * s; } } } // namespace gfx } // namespace mozilla