src/gui/math3d/qvector2d.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/gui/math3d/qvector2d.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,470 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 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 "qvector2d.h"
+#include "qvector3d.h"
+#include "qvector4d.h"
+#include <QtCore/qdebug.h>
+#include <QtCore/qvariant.h>
+#include <QtCore/qmath.h>
+
+QT_BEGIN_NAMESPACE
+
+#ifndef QT_NO_VECTOR2D
+
+/*!
+    \class QVector2D
+    \brief The QVector2D class represents a vector or vertex in 2D space.
+    \since 4.6
+    \ingroup painting
+    \ingroup painting-3D
+
+    The QVector2D class can also be used to represent vertices in 2D space.
+    We therefore do not need to provide a separate vertex class.
+
+    \sa QVector3D, QVector4D, QQuaternion
+*/
+
+/*!
+    \fn QVector2D::QVector2D()
+
+    Constructs a null vector, i.e. with coordinates (0, 0, 0).
+*/
+
+/*!
+    \fn QVector2D::QVector2D(qreal xpos, qreal ypos)
+
+    Constructs a vector with coordinates (\a xpos, \a ypos).
+*/
+
+/*!
+    \fn QVector2D::QVector2D(const QPoint& point)
+
+    Constructs a vector with x and y coordinates from a 2D \a point.
+*/
+
+/*!
+    \fn QVector2D::QVector2D(const QPointF& point)
+
+    Constructs a vector with x and y coordinates from a 2D \a point.
+*/
+
+#ifndef QT_NO_VECTOR3D
+
+/*!
+    Constructs a vector with x and y coordinates from a 3D \a vector.
+    The z coordinate of \a vector is dropped.
+
+    \sa toVector3D()
+*/
+QVector2D::QVector2D(const QVector3D& vector)
+{
+    xp = vector.xp;
+    yp = vector.yp;
+}
+
+#endif
+
+#ifndef QT_NO_VECTOR4D
+
+/*!
+    Constructs a vector with x and y coordinates from a 3D \a vector.
+    The z and w coordinates of \a vector are dropped.
+
+    \sa toVector4D()
+*/
+QVector2D::QVector2D(const QVector4D& vector)
+{
+    xp = vector.xp;
+    yp = vector.yp;
+}
+
+#endif
+
+/*!
+    \fn bool QVector2D::isNull() const
+
+    Returns true if the x and y coordinates are set to 0.0,
+    otherwise returns false.
+*/
+
+/*!
+    \fn qreal QVector2D::x() const
+
+    Returns the x coordinate of this point.
+
+    \sa setX(), y()
+*/
+
+/*!
+    \fn qreal QVector2D::y() const
+
+    Returns the y coordinate of this point.
+
+    \sa setY(), x()
+*/
+
+/*!
+    \fn void QVector2D::setX(qreal x)
+
+    Sets the x coordinate of this point to the given \a x coordinate.
+
+    \sa x(), setY()
+*/
+
+/*!
+    \fn void QVector2D::setY(qreal y)
+
+    Sets the y coordinate of this point to the given \a y coordinate.
+
+    \sa y(), setX()
+*/
+
+/*!
+    Returns the length of the vector from the origin.
+
+    \sa lengthSquared(), normalized()
+*/
+qreal QVector2D::length() const
+{
+    return qSqrt(xp * xp + yp * yp);
+}
+
+/*!
+    Returns the squared length of the vector from the origin.
+    This is equivalent to the dot product of the vector with itself.
+
+    \sa length(), dotProduct()
+*/
+qreal QVector2D::lengthSquared() const
+{
+    return xp * xp + yp * yp;
+}
+
+/*!
+    Returns the normalized unit vector form of this vector.
+
+    If this vector is null, then a null vector is returned.  If the length
+    of the vector is very close to 1, then the vector will be returned as-is.
+    Otherwise the normalized form of the vector of length 1 will be returned.
+
+    \sa length(), normalize()
+*/
+QVector2D QVector2D::normalized() const
+{
+    // Need some extra precision if the length is very small.
+    double len = double(xp) * double(xp) +
+                 double(yp) * double(yp);
+    if (qFuzzyIsNull(len - 1.0f))
+        return *this;
+    else if (!qFuzzyIsNull(len))
+        return *this / qSqrt(len);
+    else
+        return QVector2D();
+}
+
+/*!
+    Normalizes the currect vector in place.  Nothing happens if this
+    vector is a null vector or the length of the vector is very close to 1.
+
+    \sa length(), normalized()
+*/
+void QVector2D::normalize()
+{
+    // Need some extra precision if the length is very small.
+    double len = double(xp) * double(xp) +
+                 double(yp) * double(yp);
+    if (qFuzzyIsNull(len - 1.0f) || qFuzzyIsNull(len))
+        return;
+
+    len = qSqrt(len);
+
+    xp /= len;
+    yp /= len;
+}
+
+/*!
+    \fn QVector2D &QVector2D::operator+=(const QVector2D &vector)
+
+    Adds the given \a vector to this vector and returns a reference to
+    this vector.
+
+    \sa operator-=()
+*/
+
+/*!
+    \fn QVector2D &QVector2D::operator-=(const QVector2D &vector)
+
+    Subtracts the given \a vector from this vector and returns a reference to
+    this vector.
+
+    \sa operator+=()
+*/
+
+/*!
+    \fn QVector2D &QVector2D::operator*=(qreal factor)
+
+    Multiplies this vector's coordinates by the given \a factor, and
+    returns a reference to this vector.
+
+    \sa operator/=()
+*/
+
+/*!
+    \fn QVector2D &QVector2D::operator*=(const QVector2D &vector)
+
+    Multiplies the components of this vector by the corresponding
+    components in \a vector.
+*/
+
+/*!
+    \fn QVector2D &QVector2D::operator/=(qreal divisor)
+
+    Divides this vector's coordinates by the given \a divisor, and
+    returns a reference to this vector.
+
+    \sa operator*=()
+*/
+
+/*!
+    Returns the dot product of \a v1 and \a v2.
+*/
+qreal QVector2D::dotProduct(const QVector2D& v1, const QVector2D& v2)
+{
+    return v1.xp * v2.xp + v1.yp * v2.yp;
+}
+
+/*!
+    \fn bool operator==(const QVector2D &v1, const QVector2D &v2)
+    \relates QVector2D
+
+    Returns true if \a v1 is equal to \a v2; otherwise returns false.
+    This operator uses an exact floating-point comparison.
+*/
+
+/*!
+    \fn bool operator!=(const QVector2D &v1, const QVector2D &v2)
+    \relates QVector2D
+
+    Returns true if \a v1 is not equal to \a v2; otherwise returns false.
+    This operator uses an exact floating-point comparison.
+*/
+
+/*!
+    \fn const QVector2D operator+(const QVector2D &v1, const QVector2D &v2)
+    \relates QVector2D
+
+    Returns a QVector2D object that is the sum of the given vectors, \a v1
+    and \a v2; each component is added separately.
+
+    \sa QVector2D::operator+=()
+*/
+
+/*!
+    \fn const QVector2D operator-(const QVector2D &v1, const QVector2D &v2)
+    \relates QVector2D
+
+    Returns a QVector2D object that is formed by subtracting \a v2 from \a v1;
+    each component is subtracted separately.
+
+    \sa QVector2D::operator-=()
+*/
+
+/*!
+    \fn const QVector2D operator*(qreal factor, const QVector2D &vector)
+    \relates QVector2D
+
+    Returns a copy of the given \a vector,  multiplied by the given \a factor.
+
+    \sa QVector2D::operator*=()
+*/
+
+/*!
+    \fn const QVector2D operator*(const QVector2D &vector, qreal factor)
+    \relates QVector2D
+
+    Returns a copy of the given \a vector,  multiplied by the given \a factor.
+
+    \sa QVector2D::operator*=()
+*/
+
+/*!
+    \fn const QVector2D operator*(const QVector2D &v1, const QVector2D &v2)
+    \relates QVector2D
+
+    Multiplies the components of \a v1 by the corresponding
+    components in \a v2.
+*/
+
+/*!
+    \fn const QVector2D operator-(const QVector2D &vector)
+    \relates QVector2D
+    \overload
+
+    Returns a QVector2D object that is formed by changing the sign of
+    the components of the given \a vector.
+
+    Equivalent to \c {QVector2D(0,0) - vector}.
+*/
+
+/*!
+    \fn const QVector2D operator/(const QVector2D &vector, qreal divisor)
+    \relates QVector2D
+
+    Returns the QVector2D object formed by dividing all three components of
+    the given \a vector by the given \a divisor.
+
+    \sa QVector2D::operator/=()
+*/
+
+/*!
+    \fn bool qFuzzyCompare(const QVector2D& v1, const QVector2D& v2)
+    \relates QVector2D
+
+    Returns true if \a v1 and \a v2 are equal, allowing for a small
+    fuzziness factor for floating-point comparisons; false otherwise.
+*/
+
+#ifndef QT_NO_VECTOR3D
+
+/*!
+    Returns the 3D form of this 2D vector, with the z coordinate set to zero.
+
+    \sa toVector4D(), toPoint()
+*/
+QVector3D QVector2D::toVector3D() const
+{
+    return QVector3D(xp, yp, 0.0f, 1);
+}
+
+#endif
+
+#ifndef QT_NO_VECTOR4D
+
+/*!
+    Returns the 4D form of this 2D vector, with the z and w coordinates set to zero.
+
+    \sa toVector3D(), toPoint()
+*/
+QVector4D QVector2D::toVector4D() const
+{
+    return QVector4D(xp, yp, 0.0f, 0.0f, 1);
+}
+
+#endif
+
+/*!
+    \fn QPoint QVector2D::toPoint() const
+
+    Returns the QPoint form of this 2D vector.
+
+    \sa toPointF(), toVector3D()
+*/
+
+/*!
+    \fn QPointF QVector2D::toPointF() const
+
+    Returns the QPointF form of this 2D vector.
+
+    \sa toPoint(), toVector3D()
+*/
+
+/*!
+    Returns the 2D vector as a QVariant.
+*/
+QVector2D::operator QVariant() const
+{
+    return QVariant(QVariant::Vector2D, this);
+}
+
+#ifndef QT_NO_DEBUG_STREAM
+
+QDebug operator<<(QDebug dbg, const QVector2D &vector)
+{
+    dbg.nospace() << "QVector2D(" << vector.x() << ", " << vector.y() << ')';
+    return dbg.space();
+}
+
+#endif
+
+#ifndef QT_NO_DATASTREAM
+
+/*!
+    \fn QDataStream &operator<<(QDataStream &stream, const QVector2D &vector)
+    \relates QVector2D
+
+    Writes the given \a vector to the given \a stream and returns a
+    reference to the stream.
+
+    \sa {Format of the QDataStream Operators}
+*/
+
+QDataStream &operator<<(QDataStream &stream, const QVector2D &vector)
+{
+    stream << double(vector.x()) << double(vector.y());
+    return stream;
+}
+
+/*!
+    \fn QDataStream &operator>>(QDataStream &stream, QVector2D &vector)
+    \relates QVector2D
+
+    Reads a 2D vector from the given \a stream into the given \a vector
+    and returns a reference to the stream.
+
+    \sa {Format of the QDataStream Operators}
+*/
+
+QDataStream &operator>>(QDataStream &stream, QVector2D &vector)
+{
+    double x, y;
+    stream >> x;
+    stream >> y;
+    vector.setX(qreal(x));
+    vector.setY(qreal(y));
+    return stream;
+}
+
+#endif // QT_NO_DATASTREAM
+
+#endif // QT_NO_VECTOR2D
+
+QT_END_NAMESPACE