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authorQt by Nokia <qt-info@nokia.com>2011-04-27 12:05:43 +0200
committeraxis <qt-info@nokia.com>2011-04-27 12:05:43 +0200
commit38be0d13830efd2d98281c645c3a60afe05ffece (patch)
tree6ea73f3ec77f7d153333779883e8120f82820abe /src/gui/math3d/qquaternion.cpp
Initial import from the monolithic Qt.
This is the beginning of revision history for this module. If you want to look at revision history older than this, please refer to the Qt Git wiki for how to use Git history grafting. At the time of writing, this wiki is located here: http://qt.gitorious.org/qt/pages/GitIntroductionWithQt If you have already performed the grafting and you don't see any history beyond this commit, try running "git log" with the "--follow" argument. Branched from the monolithic repo, Qt master branch, at commit 896db169ea224deb96c59ce8af800d019de63f12
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+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qquaternion.h"
+#include <QtCore/qmath.h>
+#include <QtCore/qvariant.h>
+#include <QtCore/qdebug.h>
+
+QT_BEGIN_NAMESPACE
+
+#ifndef QT_NO_QUATERNION
+
+/*!
+ \class QQuaternion
+ \brief The QQuaternion class represents a quaternion consisting of a vector and scalar.
+ \since 4.6
+ \ingroup painting-3D
+
+ Quaternions are used to represent rotations in 3D space, and
+ consist of a 3D rotation axis specified by the x, y, and z
+ coordinates, and a scalar representing the rotation angle.
+*/
+
+/*!
+ \fn QQuaternion::QQuaternion()
+
+ Constructs an identity quaternion, i.e. with coordinates (1, 0, 0, 0).
+*/
+
+/*!
+ \fn QQuaternion::QQuaternion(qreal scalar, qreal xpos, qreal ypos, qreal zpos)
+
+ Constructs a quaternion with the vector (\a xpos, \a ypos, \a zpos)
+ and \a scalar.
+*/
+
+#ifndef QT_NO_VECTOR3D
+
+/*!
+ \fn QQuaternion::QQuaternion(qreal scalar, const QVector3D& vector)
+
+ Constructs a quaternion vector from the specified \a vector and
+ \a scalar.
+
+ \sa vector(), scalar()
+*/
+
+/*!
+ \fn QVector3D QQuaternion::vector() const
+
+ Returns the vector component of this quaternion.
+
+ \sa setVector(), scalar()
+*/
+
+/*!
+ \fn void QQuaternion::setVector(const QVector3D& vector)
+
+ Sets the vector component of this quaternion to \a vector.
+
+ \sa vector(), setScalar()
+*/
+
+#endif
+
+/*!
+ \fn void QQuaternion::setVector(qreal x, qreal y, qreal z)
+
+ Sets the vector component of this quaternion to (\a x, \a y, \a z).
+
+ \sa vector(), setScalar()
+*/
+
+#ifndef QT_NO_VECTOR4D
+
+/*!
+ \fn QQuaternion::QQuaternion(const QVector4D& vector)
+
+ Constructs a quaternion from the components of \a vector.
+*/
+
+/*!
+ \fn QVector4D QQuaternion::toVector4D() const
+
+ Returns this quaternion as a 4D vector.
+*/
+
+#endif
+
+/*!
+ \fn bool QQuaternion::isNull() const
+
+ Returns true if the x, y, z, and scalar components of this
+ quaternion are set to 0.0; otherwise returns false.
+*/
+
+/*!
+ \fn bool QQuaternion::isIdentity() const
+
+ Returns true if the x, y, and z components of this
+ quaternion are set to 0.0, and the scalar component is set
+ to 1.0; otherwise returns false.
+*/
+
+/*!
+ \fn qreal QQuaternion::x() const
+
+ Returns the x coordinate of this quaternion's vector.
+
+ \sa setX(), y(), z(), scalar()
+*/
+
+/*!
+ \fn qreal QQuaternion::y() const
+
+ Returns the y coordinate of this quaternion's vector.
+
+ \sa setY(), x(), z(), scalar()
+*/
+
+/*!
+ \fn qreal QQuaternion::z() const
+
+ Returns the z coordinate of this quaternion's vector.
+
+ \sa setZ(), x(), y(), scalar()
+*/
+
+/*!
+ \fn qreal QQuaternion::scalar() const
+
+ Returns the scalar component of this quaternion.
+
+ \sa setScalar(), x(), y(), z()
+*/
+
+/*!
+ \fn void QQuaternion::setX(qreal x)
+
+ Sets the x coordinate of this quaternion's vector to the given
+ \a x coordinate.
+
+ \sa x(), setY(), setZ(), setScalar()
+*/
+
+/*!
+ \fn void QQuaternion::setY(qreal y)
+
+ Sets the y coordinate of this quaternion's vector to the given
+ \a y coordinate.
+
+ \sa y(), setX(), setZ(), setScalar()
+*/
+
+/*!
+ \fn void QQuaternion::setZ(qreal z)
+
+ Sets the z coordinate of this quaternion's vector to the given
+ \a z coordinate.
+
+ \sa z(), setX(), setY(), setScalar()
+*/
+
+/*!
+ \fn void QQuaternion::setScalar(qreal scalar)
+
+ Sets the scalar component of this quaternion to \a scalar.
+
+ \sa scalar(), setX(), setY(), setZ()
+*/
+
+/*!
+ Returns the length of the quaternion. This is also called the "norm".
+
+ \sa lengthSquared(), normalized()
+*/
+qreal QQuaternion::length() const
+{
+ return qSqrt(xp * xp + yp * yp + zp * zp + wp * wp);
+}
+
+/*!
+ Returns the squared length of the quaternion.
+
+ \sa length()
+*/
+qreal QQuaternion::lengthSquared() const
+{
+ return xp * xp + yp * yp + zp * zp + wp * wp;
+}
+
+/*!
+ Returns the normalized unit form of this quaternion.
+
+ If this quaternion is null, then a null quaternion is returned.
+ If the length of the quaternion is very close to 1, then the quaternion
+ will be returned as-is. Otherwise the normalized form of the
+ quaternion of length 1 will be returned.
+
+ \sa length(), normalize()
+*/
+QQuaternion QQuaternion::normalized() const
+{
+ // Need some extra precision if the length is very small.
+ double len = double(xp) * double(xp) +
+ double(yp) * double(yp) +
+ double(zp) * double(zp) +
+ double(wp) * double(wp);
+ if (qFuzzyIsNull(len - 1.0f))
+ return *this;
+ else if (!qFuzzyIsNull(len))
+ return *this / qSqrt(len);
+ else
+ return QQuaternion(0.0f, 0.0f, 0.0f, 0.0f);
+}
+
+/*!
+ Normalizes the currect quaternion in place. Nothing happens if this
+ is a null quaternion or the length of the quaternion is very close to 1.
+
+ \sa length(), normalized()
+*/
+void QQuaternion::normalize()
+{
+ // Need some extra precision if the length is very small.
+ double len = double(xp) * double(xp) +
+ double(yp) * double(yp) +
+ double(zp) * double(zp) +
+ double(wp) * double(wp);
+ if (qFuzzyIsNull(len - 1.0f) || qFuzzyIsNull(len))
+ return;
+
+ len = qSqrt(len);
+
+ xp /= len;
+ yp /= len;
+ zp /= len;
+ wp /= len;
+}
+
+/*!
+ \fn QQuaternion QQuaternion::conjugate() const
+
+ Returns the conjugate of this quaternion, which is
+ (-x, -y, -z, scalar).
+*/
+
+/*!
+ Rotates \a vector with this quaternion to produce a new vector
+ in 3D space. The following code:
+
+ \code
+ QVector3D result = q.rotatedVector(vector);
+ \endcode
+
+ is equivalent to the following:
+
+ \code
+ QVector3D result = (q * QQuaternion(0, vector) * q.conjugate()).vector();
+ \endcode
+*/
+QVector3D QQuaternion::rotatedVector(const QVector3D& vector) const
+{
+ return (*this * QQuaternion(0, vector) * conjugate()).vector();
+}
+
+/*!
+ \fn QQuaternion &QQuaternion::operator+=(const QQuaternion &quaternion)
+
+ Adds the given \a quaternion to this quaternion and returns a reference to
+ this quaternion.
+
+ \sa operator-=()
+*/
+
+/*!
+ \fn QQuaternion &QQuaternion::operator-=(const QQuaternion &quaternion)
+
+ Subtracts the given \a quaternion from this quaternion and returns a
+ reference to this quaternion.
+
+ \sa operator+=()
+*/
+
+/*!
+ \fn QQuaternion &QQuaternion::operator*=(qreal factor)
+
+ Multiplies this quaternion's components by the given \a factor, and
+ returns a reference to this quaternion.
+
+ \sa operator/=()
+*/
+
+/*!
+ \fn QQuaternion &QQuaternion::operator*=(const QQuaternion &quaternion)
+
+ Multiplies this quaternion by \a quaternion and returns a reference
+ to this quaternion.
+*/
+
+/*!
+ \fn QQuaternion &QQuaternion::operator/=(qreal divisor)
+
+ Divides this quaternion's components by the given \a divisor, and
+ returns a reference to this quaternion.
+
+ \sa operator*=()
+*/
+
+#ifndef QT_NO_VECTOR3D
+
+/*!
+ Creates a normalized quaternion that corresponds to rotating through
+ \a angle degrees about the specified 3D \a axis.
+*/
+QQuaternion QQuaternion::fromAxisAndAngle(const QVector3D& axis, qreal angle)
+{
+ // Algorithm from:
+ // http://www.j3d.org/matrix_faq/matrfaq_latest.html#Q56
+ // We normalize the result just in case the values are close
+ // to zero, as suggested in the above FAQ.
+ qreal a = (angle / 2.0f) * M_PI / 180.0f;
+ qreal s = qSin(a);
+ qreal c = qCos(a);
+ QVector3D ax = axis.normalized();
+ return QQuaternion(c, ax.x() * s, ax.y() * s, ax.z() * s).normalized();
+}
+
+#endif
+
+/*!
+ Creates a normalized quaternion that corresponds to rotating through
+ \a angle degrees about the 3D axis (\a x, \a y, \a z).
+*/
+QQuaternion QQuaternion::fromAxisAndAngle
+ (qreal x, qreal y, qreal z, qreal angle)
+{
+ qreal length = qSqrt(x * x + y * y + z * z);
+ if (!qFuzzyIsNull(length - 1.0f) && !qFuzzyIsNull(length)) {
+ x /= length;
+ y /= length;
+ z /= length;
+ }
+ qreal a = (angle / 2.0f) * M_PI / 180.0f;
+ qreal s = qSin(a);
+ qreal c = qCos(a);
+ return QQuaternion(c, x * s, y * s, z * s).normalized();
+}
+
+/*!
+ \fn bool operator==(const QQuaternion &q1, const QQuaternion &q2)
+ \relates QQuaternion
+
+ Returns true if \a q1 is equal to \a q2; otherwise returns false.
+ This operator uses an exact floating-point comparison.
+*/
+
+/*!
+ \fn bool operator!=(const QQuaternion &q1, const QQuaternion &q2)
+ \relates QQuaternion
+
+ Returns true if \a q1 is not equal to \a q2; otherwise returns false.
+ This operator uses an exact floating-point comparison.
+*/
+
+/*!
+ \fn const QQuaternion operator+(const QQuaternion &q1, const QQuaternion &q2)
+ \relates QQuaternion
+
+ Returns a QQuaternion object that is the sum of the given quaternions,
+ \a q1 and \a q2; each component is added separately.
+
+ \sa QQuaternion::operator+=()
+*/
+
+/*!
+ \fn const QQuaternion operator-(const QQuaternion &q1, const QQuaternion &q2)
+ \relates QQuaternion
+
+ Returns a QQuaternion object that is formed by subtracting
+ \a q2 from \a q1; each component is subtracted separately.
+
+ \sa QQuaternion::operator-=()
+*/
+
+/*!
+ \fn const QQuaternion operator*(qreal factor, const QQuaternion &quaternion)
+ \relates QQuaternion
+
+ Returns a copy of the given \a quaternion, multiplied by the
+ given \a factor.
+
+ \sa QQuaternion::operator*=()
+*/
+
+/*!
+ \fn const QQuaternion operator*(const QQuaternion &quaternion, qreal factor)
+ \relates QQuaternion
+
+ Returns a copy of the given \a quaternion, multiplied by the
+ given \a factor.
+
+ \sa QQuaternion::operator*=()
+*/
+
+/*!
+ \fn const QQuaternion operator*(const QQuaternion &q1, const QQuaternion& q2)
+ \relates QQuaternion
+
+ Multiplies \a q1 and \a q2 using quaternion multiplication.
+ The result corresponds to applying both of the rotations specified
+ by \a q1 and \a q2.
+
+ \sa QQuaternion::operator*=()
+*/
+
+/*!
+ \fn const QQuaternion operator-(const QQuaternion &quaternion)
+ \relates QQuaternion
+ \overload
+
+ Returns a QQuaternion object that is formed by changing the sign of
+ all three components of the given \a quaternion.
+
+ Equivalent to \c {QQuaternion(0,0,0,0) - quaternion}.
+*/
+
+/*!
+ \fn const QQuaternion operator/(const QQuaternion &quaternion, qreal divisor)
+ \relates QQuaternion
+
+ Returns the QQuaternion object formed by dividing all components of
+ the given \a quaternion by the given \a divisor.
+
+ \sa QQuaternion::operator/=()
+*/
+
+/*!
+ \fn bool qFuzzyCompare(const QQuaternion& q1, const QQuaternion& q2)
+ \relates QQuaternion
+
+ Returns true if \a q1 and \a q2 are equal, allowing for a small
+ fuzziness factor for floating-point comparisons; false otherwise.
+*/
+
+/*!
+ Interpolates along the shortest spherical path between the
+ rotational positions \a q1 and \a q2. The value \a t should
+ be between 0 and 1, indicating the spherical distance to travel
+ between \a q1 and \a q2.
+
+ If \a t is less than or equal to 0, then \a q1 will be returned.
+ If \a t is greater than or equal to 1, then \a q2 will be returned.
+
+ \sa nlerp()
+*/
+QQuaternion QQuaternion::slerp
+ (const QQuaternion& q1, const QQuaternion& q2, qreal t)
+{
+ // Handle the easy cases first.
+ if (t <= 0.0f)
+ return q1;
+ else if (t >= 1.0f)
+ return q2;
+
+ // Determine the angle between the two quaternions.
+ QQuaternion q2b;
+ qreal dot;
+ dot = q1.xp * q2.xp + q1.yp * q2.yp + q1.zp * q2.zp + q1.wp * q2.wp;
+ if (dot >= 0.0f) {
+ q2b = q2;
+ } else {
+ q2b = -q2;
+ dot = -dot;
+ }
+
+ // Get the scale factors. If they are too small,
+ // then revert to simple linear interpolation.
+ qreal factor1 = 1.0f - t;
+ qreal factor2 = t;
+ if ((1.0f - dot) > 0.0000001) {
+ qreal angle = qreal(qAcos(dot));
+ qreal sinOfAngle = qreal(qSin(angle));
+ if (sinOfAngle > 0.0000001) {
+ factor1 = qreal(qSin((1.0f - t) * angle)) / sinOfAngle;
+ factor2 = qreal(qSin(t * angle)) / sinOfAngle;
+ }
+ }
+
+ // Construct the result quaternion.
+ return q1 * factor1 + q2b * factor2;
+}
+
+/*!
+ Interpolates along the shortest linear path between the rotational
+ positions \a q1 and \a q2. The value \a t should be between 0 and 1,
+ indicating the distance to travel between \a q1 and \a q2.
+ The result will be normalized().
+
+ If \a t is less than or equal to 0, then \a q1 will be returned.
+ If \a t is greater than or equal to 1, then \a q2 will be returned.
+
+ The nlerp() function is typically faster than slerp() and will
+ give approximate results to spherical interpolation that are
+ good enough for some applications.
+
+ \sa slerp()
+*/
+QQuaternion QQuaternion::nlerp
+ (const QQuaternion& q1, const QQuaternion& q2, qreal t)
+{
+ // Handle the easy cases first.
+ if (t <= 0.0f)
+ return q1;
+ else if (t >= 1.0f)
+ return q2;
+
+ // Determine the angle between the two quaternions.
+ QQuaternion q2b;
+ qreal dot;
+ dot = q1.xp * q2.xp + q1.yp * q2.yp + q1.zp * q2.zp + q1.wp * q2.wp;
+ if (dot >= 0.0f)
+ q2b = q2;
+ else
+ q2b = -q2;
+
+ // Perform the linear interpolation.
+ return (q1 * (1.0f - t) + q2b * t).normalized();
+}
+
+/*!
+ Returns the quaternion as a QVariant.
+*/
+QQuaternion::operator QVariant() const
+{
+ return QVariant(QVariant::Quaternion, this);
+}
+
+#ifndef QT_NO_DEBUG_STREAM
+
+QDebug operator<<(QDebug dbg, const QQuaternion &q)
+{
+ dbg.nospace() << "QQuaternion(scalar:" << q.scalar()
+ << ", vector:(" << q.x() << ", "
+ << q.y() << ", " << q.z() << "))";
+ return dbg.space();
+}
+
+#endif
+
+#ifndef QT_NO_DATASTREAM
+
+/*!
+ \fn QDataStream &operator<<(QDataStream &stream, const QQuaternion &quaternion)
+ \relates QQuaternion
+
+ Writes the given \a quaternion to the given \a stream and returns a
+ reference to the stream.
+
+ \sa {Serializing Qt Data Types}
+*/
+
+QDataStream &operator<<(QDataStream &stream, const QQuaternion &quaternion)
+{
+ stream << double(quaternion.scalar()) << double(quaternion.x())
+ << double(quaternion.y()) << double(quaternion.z());
+ return stream;
+}
+
+/*!
+ \fn QDataStream &operator>>(QDataStream &stream, QQuaternion &quaternion)
+ \relates QQuaternion
+
+ Reads a quaternion from the given \a stream into the given \a quaternion
+ and returns a reference to the stream.
+
+ \sa {Serializing Qt Data Types}
+*/
+
+QDataStream &operator>>(QDataStream &stream, QQuaternion &quaternion)
+{
+ double scalar, x, y, z;
+ stream >> scalar;
+ stream >> x;
+ stream >> y;
+ stream >> z;
+ quaternion.setScalar(qreal(scalar));
+ quaternion.setX(qreal(x));
+ quaternion.setY(qreal(y));
+ quaternion.setZ(qreal(z));
+ return stream;
+}
+
+#endif // QT_NO_DATASTREAM
+
+#endif
+
+QT_END_NAMESPACE