Clean up QVector2D/3D/4D

In random order:

* Remove code marked for removal in Qt 6.

* Inline as much as possible. This should give us a massive
speed boost in some simple operations where the function call
overhead as much as the cost of body of the function itself
(lengthSquared, dotProduct, etc.).

* Plaster constexpr and noexcept, as much as possible; follow
Lakos' rule.

* Unexport the classes; selectively export only the symbols
still defined out of line.

* Add [[nodiscard]] to any non-trivial mathematical operation
(e.g. calculate the length).

* To avoid circular dependencies, centralize their implementation
in one file. Leave the existing headers for compatibility with
existing #include statements.

* Change all the signatures of the classes' members to take
QVectorND, QPointF, etc. objects by value, not by const ref.
Usage in other classes (e.g. QMatrix4x4) has not been adjusted.

Change-Id: Iaf5a4b5289fcdf704e77656793390b8e772e94a5
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

1 files changed, 0 insertions, 639 deletions

diff --git a/src/gui/math3d/qvector4d.cpp b/src/gui/math3d/qvector4d.cpp
deleted file mode 100644
index a9d57156f9..0000000000
--- a/src/gui/math3d/qvector4d.cpp
+++ /dev/null
@@ -1,639 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtGui module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qvector4d.h"
-#include "qvector3d.h"
-#include "qvector2d.h"
-#include <QtCore/qdatastream.h>
-#include <QtCore/qdebug.h>
-#include <QtCore/qvariant.h>
-#include <QtCore/qmath.h>
-
-QT_BEGIN_NAMESPACE
-
-#ifndef QT_NO_VECTOR4D
-
-static_assert(std::is_standard_layout<QVector4D>::value, "QVector4D is supposed to be standard layout");
-static_assert(sizeof(QVector4D) == sizeof(float) * 4, "QVector4D is not supposed to have padding at the end");
-
-/*!
-    \class QVector4D
-    \brief The QVector4D class represents a vector or vertex in 4D space.
-    \since 4.6
-    \ingroup painting-3D
-    \inmodule QtGui
-
-    The QVector4D class can also be used to represent vertices in 4D space.
-    We therefore do not need to provide a separate vertex class.
-
-    \sa QQuaternion, QVector2D, QVector3D
-*/
-
-/*!
-    \fn QVector4D::QVector4D()
-
-    Constructs a null vector, i.e. with coordinates (0, 0, 0, 0).
-*/
-
-/*!
-    \fn QVector4D::QVector4D(Qt::Initialization)
-    \since 5.5
-    \internal
-
-    Constructs a vector without initializing the contents.
-*/
-
-/*!
-    \fn QVector4D::QVector4D(float xpos, float ypos, float zpos, float wpos)
-
-    Constructs a vector with coordinates (\a xpos, \a ypos, \a zpos, \a wpos).
-*/
-
-/*!
-    \fn QVector4D::QVector4D(const QPoint& point)
-
-    Constructs a vector with x and y coordinates from a 2D \a point, and
-    z and w coordinates of 0.
-*/
-
-/*!
-    \fn QVector4D::QVector4D(const QPointF& point)
-
-    Constructs a vector with x and y coordinates from a 2D \a point, and
-    z and w coordinates of 0.
-*/
-
-#ifndef QT_NO_VECTOR2D
-
-/*!
-    Constructs a 4D vector from the specified 2D \a vector.  The z
-    and w coordinates are set to zero.
-
-    \sa toVector2D()
-*/
-QVector4D::QVector4D(const QVector2D& vector)
-{
-    v[0] = vector.v[0];
-    v[1] = vector.v[1];
-    v[2] = 0.0f;
-    v[3] = 0.0f;
-}
-
-/*!
-    Constructs a 4D vector from the specified 2D \a vector.  The z
-    and w coordinates are set to \a zpos and \a wpos respectively.
-
-    \sa toVector2D()
-*/
-QVector4D::QVector4D(const QVector2D& vector, float zpos, float wpos)
-{
-    v[0] = vector.v[0];
-    v[1] = vector.v[1];
-    v[2] = zpos;
-    v[3] = wpos;
-}
-
-#endif
-
-#ifndef QT_NO_VECTOR3D
-
-/*!
-    Constructs a 4D vector from the specified 3D \a vector.  The w
-    coordinate is set to zero.
-
-    \sa toVector3D()
-*/
-QVector4D::QVector4D(const QVector3D& vector)
-{
-    v[0] = vector.v[0];
-    v[1] = vector.v[1];
-    v[2] = vector.v[2];
-    v[3] = 0.0f;
-}
-
-/*!
-    Constructs a 4D vector from the specified 3D \a vector.  The w
-    coordinate is set to \a wpos.
-
-    \sa toVector3D()
-*/
-QVector4D::QVector4D(const QVector3D& vector, float wpos)
-{
-    v[0] = vector.v[0];
-    v[1] = vector.v[1];
-    v[2] = vector.v[2];
-    v[3] = wpos;
-}
-
-#endif
-
-/*!
-    \fn bool QVector4D::isNull() const
-
-    Returns \c true if the x, y, z, and w coordinates are set to 0.0,
-    otherwise returns \c false.
-*/
-
-/*!
-    \fn float QVector4D::x() const
-
-    Returns the x coordinate of this point.
-
-    \sa setX(), y(), z(), w()
-*/
-
-/*!
-    \fn float QVector4D::y() const
-
-    Returns the y coordinate of this point.
-
-    \sa setY(), x(), z(), w()
-*/
-
-/*!
-    \fn float QVector4D::z() const
-
-    Returns the z coordinate of this point.
-
-    \sa setZ(), x(), y(), w()
-*/
-
-/*!
-    \fn float QVector4D::w() const
-
-    Returns the w coordinate of this point.
-
-    \sa setW(), x(), y(), z()
-*/
-
-/*!
-    \fn void QVector4D::setX(float x)
-
-    Sets the x coordinate of this point to the given \a x coordinate.
-
-    \sa x(), setY(), setZ(), setW()
-*/
-
-/*!
-    \fn void QVector4D::setY(float y)
-
-    Sets the y coordinate of this point to the given \a y coordinate.
-
-    \sa y(), setX(), setZ(), setW()
-*/
-
-/*!
-    \fn void QVector4D::setZ(float z)
-
-    Sets the z coordinate of this point to the given \a z coordinate.
-
-    \sa z(), setX(), setY(), setW()
-*/
-
-/*!
-    \fn void QVector4D::setW(float w)
-
-    Sets the w coordinate of this point to the given \a w coordinate.
-
-    \sa w(), setX(), setY(), setZ()
-*/
-
-/*! \fn float &QVector4D::operator[](int i)
-    \since 5.2
-
-    Returns the component of the vector at index position \a i
-    as a modifiable reference.
-
-    \a i must be a valid index position in the vector (i.e., 0 <= \a i
-    < 4).
-*/
-
-/*! \fn float QVector4D::operator[](int i) const
-    \since 5.2
-
-    Returns the component of the vector at index position \a i.
-
-    \a i must be a valid index position in the vector (i.e., 0 <= \a i
-    < 4).
-*/
-
-/*!
-    Returns the length of the vector from the origin.
-
-    \sa lengthSquared(), normalized()
-*/
-float QVector4D::length() const
-{
-    // Need some extra precision if the length is very small.
-    double len = double(v[0]) * double(v[0]) +
-                 double(v[1]) * double(v[1]) +
-                 double(v[2]) * double(v[2]) +
-                 double(v[3]) * double(v[3]);
-    return float(std::sqrt(len));
-}
-
-/*!
-    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()
-*/
-float QVector4D::lengthSquared() const
-{
-    return v[0] * v[0] + v[1] * v[1] + v[2] * v[2] + v[3] * v[3];
-}
-
-/*!
-    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()
-*/
-QVector4D QVector4D::normalized() const
-{
-    // Need some extra precision if the length is very small.
-    double len = double(v[0]) * double(v[0]) +
-                 double(v[1]) * double(v[1]) +
-                 double(v[2]) * double(v[2]) +
-                 double(v[3]) * double(v[3]);
-    if (qFuzzyIsNull(len - 1.0f)) {
-        return *this;
-    } else if (!qFuzzyIsNull(len)) {
-        double sqrtLen = std::sqrt(len);
-        return QVector4D(float(double(v[0]) / sqrtLen),
-                         float(double(v[1]) / sqrtLen),
-                         float(double(v[2]) / sqrtLen),
-                         float(double(v[3]) / sqrtLen));
-    } else {
-        return QVector4D();
-    }
-}
-
-/*!
-    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 QVector4D::normalize()
-{
-    // Need some extra precision if the length is very small.
-    double len = double(v[0]) * double(v[0]) +
-                 double(v[1]) * double(v[1]) +
-                 double(v[2]) * double(v[2]) +
-                 double(v[3]) * double(v[3]);
-    if (qFuzzyIsNull(len - 1.0f) || qFuzzyIsNull(len))
-        return;
-
-    len = std::sqrt(len);
-
-    v[0] = float(double(v[0]) / len);
-    v[1] = float(double(v[1]) / len);
-    v[2] = float(double(v[2]) / len);
-    v[3] = float(double(v[3]) / len);
-}
-
-/*!
-    \fn QVector4D &QVector4D::operator+=(const QVector4D &vector)
-
-    Adds the given \a vector to this vector and returns a reference to
-    this vector.
-
-    \sa operator-=()
-*/
-
-/*!
-    \fn QVector4D &QVector4D::operator-=(const QVector4D &vector)
-
-    Subtracts the given \a vector from this vector and returns a reference to
-    this vector.
-
-    \sa operator+=()
-*/
-
-/*!
-    \fn QVector4D &QVector4D::operator*=(float factor)
-
-    Multiplies this vector's coordinates by the given \a factor, and
-    returns a reference to this vector.
-
-    \sa operator/=()
-*/
-
-/*!
-    \fn QVector4D &QVector4D::operator*=(const QVector4D &vector)
-
-    Multiplies the components of this vector by the corresponding
-    components in \a vector.
-*/
-
-/*!
-    \fn QVector4D &QVector4D::operator/=(float divisor)
-
-    Divides this vector's coordinates by the given \a divisor, and
-    returns a reference to this vector.
-
-    \sa operator*=()
-*/
-
-/*!
-    \fn QVector4D &QVector4D::operator/=(const QVector4D &vector)
-    \since 5.5
-
-    Divides the components of this vector by the corresponding
-    components in \a vector.
-
-    \sa operator*=()
-*/
-
-/*!
-    Returns the dot product of \a v1 and \a v2.
-*/
-float QVector4D::dotProduct(const QVector4D& v1, const QVector4D& v2)
-{
-    return v1.v[0] * v2.v[0] + v1.v[1] * v2.v[1] + v1.v[2] * v2.v[2] + v1.v[3] * v2.v[3];
-}
-
-/*!
-    \fn bool QVector4D::operator==(const QVector4D &v1, const QVector4D &v2)
-
-    Returns \c true if \a v1 is equal to \a v2; otherwise returns \c false.
-    This operator uses an exact floating-point comparison.
-*/
-
-/*!
-    \fn bool QVector4D::operator!=(const QVector4D &v1, const QVector4D &v2)
-
-    Returns \c true if \a v1 is not equal to \a v2; otherwise returns \c false.
-    This operator uses an exact floating-point comparison.
-*/
-
-/*!
-    \fn const QVector4D operator+(const QVector4D &v1, const QVector4D &v2)
-    \relates QVector4D
-
-    Returns a QVector4D object that is the sum of the given vectors, \a v1
-    and \a v2; each component is added separately.
-
-    \sa QVector4D::operator+=()
-*/
-
-/*!
-    \fn const QVector4D operator-(const QVector4D &v1, const QVector4D &v2)
-    \relates QVector4D
-
-    Returns a QVector4D object that is formed by subtracting \a v2 from \a v1;
-    each component is subtracted separately.
-
-    \sa QVector4D::operator-=()
-*/
-
-/*!
-    \fn const QVector4D operator*(float factor, const QVector4D &vector)
-    \relates QVector4D
-
-    Returns a copy of the given \a vector,  multiplied by the given \a factor.
-
-    \sa QVector4D::operator*=()
-*/
-
-/*!
-    \fn const QVector4D operator*(const QVector4D &vector, float factor)
-    \relates QVector4D
-
-    Returns a copy of the given \a vector,  multiplied by the given \a factor.
-
-    \sa QVector4D::operator*=()
-*/
-
-/*!
-    \fn const QVector4D operator*(const QVector4D &v1, const QVector4D& v2)
-    \relates QVector4D
-
-    Returns the vector consisting of the multiplication of the
-    components from \a v1 and \a v2.
-
-    \sa QVector4D::operator*=()
-*/
-
-/*!
-    \fn const QVector4D operator-(const QVector4D &vector)
-    \relates QVector4D
-    \overload
-
-    Returns a QVector4D object that is formed by changing the sign of
-    all three components of the given \a vector.
-
-    Equivalent to \c {QVector4D(0,0,0,0) - vector}.
-*/
-
-/*!
-    \fn const QVector4D operator/(const QVector4D &vector, float divisor)
-    \relates QVector4D
-
-    Returns the QVector4D object formed by dividing all four components of
-    the given \a vector by the given \a divisor.
-
-    \sa QVector4D::operator/=()
-*/
-
-/*!
-    \fn const QVector4D operator/(const QVector4D &vector, const QVector4D &divisor)
-    \relates QVector4D
-    \since 5.5
-
-    Returns the QVector4D object formed by dividing components of the given
-    \a vector by a respective components of the given \a divisor.
-
-    \sa QVector4D::operator/=()
-*/
-
-/*!
-    \fn bool qFuzzyCompare(const QVector4D& v1, const QVector4D& v2)
-    \relates QVector4D
-
-    Returns \c true if \a v1 and \a v2 are equal, allowing for a small
-    fuzziness factor for floating-point comparisons; false otherwise.
-*/
-
-#ifndef QT_NO_VECTOR2D
-
-/*!
-    Returns the 2D vector form of this 4D vector, dropping the z and w coordinates.
-
-    \sa toVector2DAffine(), toVector3D(), toPoint()
-*/
-QVector2D QVector4D::toVector2D() const
-{
-    return QVector2D(v[0], v[1]);
-}
-
-/*!
-    Returns the 2D vector form of this 4D vector, dividing the x and y
-    coordinates by the w coordinate and dropping the z coordinate.
-    Returns a null vector if w is zero.
-
-    \sa toVector2D(), toVector3DAffine(), toPoint()
-*/
-QVector2D QVector4D::toVector2DAffine() const
-{
-    if (qIsNull(v[3]))
-        return QVector2D();
-    return QVector2D(v[0] / v[3], v[1] / v[3]);
-}
-
-#endif
-
-#ifndef QT_NO_VECTOR3D
-
-/*!
-    Returns the 3D vector form of this 4D vector, dropping the w coordinate.
-
-    \sa toVector3DAffine(), toVector2D(), toPoint()
-*/
-QVector3D QVector4D::toVector3D() const
-{
-    return QVector3D(v[0], v[1], v[2]);
-}
-
-/*!
-    Returns the 3D vector form of this 4D vector, dividing the x, y, and
-    z coordinates by the w coordinate.  Returns a null vector if w is zero.
-
-    \sa toVector3D(), toVector2DAffine(), toPoint()
-*/
-QVector3D QVector4D::toVector3DAffine() const
-{
-    if (qIsNull(v[3]))
-        return QVector3D();
-    return QVector3D(v[0] / v[3], v[1] / v[3], v[2] / v[3]);
-}
-
-#endif
-
-/*!
-    \fn QPoint QVector4D::toPoint() const
-
-    Returns the QPoint form of this 4D vector. The z and w coordinates
-    are dropped.
-
-    \sa toPointF(), toVector2D()
-*/
-
-/*!
-    \fn QPointF QVector4D::toPointF() const
-
-    Returns the QPointF form of this 4D vector. The z and w coordinates
-    are dropped.
-
-    \sa toPoint(), toVector2D()
-*/
-
-/*!
-    Returns the 4D vector as a QVariant.
-*/
-QVector4D::operator QVariant() const
-{
-    return QVariant::fromValue(*this);
-}
-
-#ifndef QT_NO_DEBUG_STREAM
-
-QDebug operator<<(QDebug dbg, const QVector4D &vector)
-{
-    QDebugStateSaver saver(dbg);
-    dbg.nospace() << "QVector4D("
-        << vector.x() << ", " << vector.y() << ", "
-        << vector.z() << ", " << vector.w() << ')';
-    return dbg;
-}
-
-#endif
-
-#ifndef QT_NO_DATASTREAM
-
-/*!
-    \fn QDataStream &operator<<(QDataStream &stream, const QVector4D &vector)
-    \relates QVector4D
-
-    Writes the given \a vector to the given \a stream and returns a
-    reference to the stream.
-
-    \sa {Serializing Qt Data Types}
-*/
-
-QDataStream &operator<<(QDataStream &stream, const QVector4D &vector)
-{
-    stream << vector.x() << vector.y()
-           << vector.z() << vector.w();
-    return stream;
-}
-
-/*!
-    \fn QDataStream &operator>>(QDataStream &stream, QVector4D &vector)
-    \relates QVector4D
-
-    Reads a 4D vector from the given \a stream into the given \a vector
-    and returns a reference to the stream.
-
-    \sa {Serializing Qt Data Types}
-*/
-
-QDataStream &operator>>(QDataStream &stream, QVector4D &vector)
-{
-    float x, y, z, w;
-    stream >> x;
-    stream >> y;
-    stream >> z;
-    stream >> w;
-    vector.setX(x);
-    vector.setY(y);
-    vector.setZ(z);
-    vector.setW(w);
-    return stream;
-}
-
-#endif // QT_NO_DATASTREAM
-
-#endif // QT_NO_VECTOR4D
-
-QT_END_NAMESPACE