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Diffstat (limited to 'src/gui/graphicsview/qgraphicstransform.cpp')
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diff --git a/src/gui/graphicsview/qgraphicstransform.cpp b/src/gui/graphicsview/qgraphicstransform.cpp new file mode 100644 index 000000000..890aff74a --- /dev/null +++ b/src/gui/graphicsview/qgraphicstransform.cpp @@ -0,0 +1,573 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the QtDeclarative 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 either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** 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 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \class QGraphicsTransform + \brief The QGraphicsTransform class is an abstract base class for building + advanced transformations on QGraphicsItems. + \since 4.6 + + As an alternative to QGraphicsItem::transform, QGraphicsTransform lets you + create and control advanced transformations that can be configured + independently using specialized properties. + + QGraphicsItem allows you to assign any number of QGraphicsTransform + instances to one QGraphicsItem. Each QGraphicsTransform is applied in + order, one at a time, to the QGraphicsItem it's assigned to. + + QGraphicsTransform is particularily useful for animations. Whereas + QGraphicsItem::setTransform() lets you assign any transform directly to an + item, there is no direct way to interpolate between two different + transformations (e.g., when transitioning between two states, each for + which the item has a different arbitrary transform assigned). Using + QGraphicsTransform you can interpolate the property values of each + independent transformation. The resulting operation is then combined into a + single transform which is applied to QGraphicsItem. + + If you want to create your own configurable transformation, you can create + a subclass of QGraphicsTransform (or any or the existing subclasses), and + reimplement the pure virtual applyTo() function, which takes a pointer to a + QTransform. Each operation you would like to apply should be exposed as + properties (e.g., customTransform->setVerticalShear(2.5)). Inside you + reimplementation of applyTo(), you can modify the provided transform + respectively. + + QGraphicsTransform can be used together with QGraphicsItem::setTransform(), + QGraphicsItem::setRotation(), and QGraphicsItem::setScale(). + + \sa QGraphicsItem::transform(), QGraphicsScale, QGraphicsRotation, QGraphicsRotation3D +*/ + +#include "qgraphicstransform.h" +#include "qgraphicsitem_p.h" +#include "qgraphicstransform_p.h" +#include <QDebug> + +#include <math.h> +#ifndef M_PI +#define M_PI 3.14159265358979323846 +#endif + +QT_BEGIN_NAMESPACE + +void QGraphicsTransformPrivate::setItem(QGraphicsItem *i) +{ + if (item == i) + return; + + if (item) { + Q_Q(QGraphicsTransform); + QGraphicsItemPrivate *d_ptr = item->d_ptr; + + item->prepareGeometryChange(); + Q_ASSERT(d_ptr->transformData); + d_ptr->transformData->graphicsTransforms.removeAll(q); + d_ptr->dirtySceneTransform = 1; + item = 0; + } + + item = i; +} + +void QGraphicsTransformPrivate::updateItem(QGraphicsItem *item) +{ + item->prepareGeometryChange(); + item->d_ptr->dirtySceneTransform = 1; +} + +/*! + Constructs a new QGraphicsTransform with the given \a parent. +*/ +QGraphicsTransform::QGraphicsTransform(QObject *parent) + : QObject(*new QGraphicsTransformPrivate, parent) +{ +} + +/*! + Destroys the graphics transform. +*/ +QGraphicsTransform::~QGraphicsTransform() +{ + Q_D(QGraphicsTransform); + d->setItem(0); +} + +/*! + \internal +*/ +QGraphicsTransform::QGraphicsTransform(QGraphicsTransformPrivate &p, QObject *parent) + : QObject(p, parent) +{ +} + +/*! + Applies this transformation to an identity transform, and returns the + resulting transform. + + This is equivalent to passing an identity transform to applyTo(). + + \sa applyTo() +*/ +QTransform QGraphicsTransform::transform() const +{ + QTransform t; + applyTo(&t); + return t; +} + +/*! + \fn void QGraphicsTransform::applyTo(QTransform *transform) const + + This pure virtual method has to be reimplemented in derived classes. + + It applies this transformation to \a transform. + + \sa QGraphicsItem::transform() +*/ + +/*! + Notifies that this transform operation has changed its parameters in such a + way that applyTo() will return a different result than before. + + When implementing you own custom graphics transform, you must call this + function every time you change a parameter, to let QGraphicsItem know that + its transformation needs to be updated. + + \sa applyTo() +*/ +void QGraphicsTransform::update() +{ + Q_D(QGraphicsTransform); + if (d->item) + d->updateItem(d->item); +} + +/*! + \class QGraphicsScale + \brief The QGraphicsScale class provides a scale transformation. + \since 4.6 + + QGraphicsScene provides certain parameters to help control how the scale + should be applied. + + The origin is the point that the item is scaled from (i.e., it stays fixed + relative to the parent as the rest of the item grows). By default the + origin is QPointF(0, 0). + + The two parameters xScale and yScale describe the scale factors to apply in + horizontal and vertical direction. They can take on any value, including 0 + (to collapse the item to a point) or negativate value. A negative xScale + value will mirror the item horizontally. A negative yScale value will flip + the item vertically. + + \sa QGraphicsTransform, QGraphicsItem::setScale(), QTransform::scale() +*/ + +class QGraphicsScalePrivate : public QGraphicsTransformPrivate +{ +public: + QGraphicsScalePrivate() + : xScale(1), yScale(1) {} + QPointF origin; + qreal xScale; + qreal yScale; +}; + +/*! + Constructs an empty QGraphicsScale object with the given \a parent. +*/ +QGraphicsScale::QGraphicsScale(QObject *parent) + : QGraphicsTransform(*new QGraphicsScalePrivate, parent) +{ +} + +/*! + Destroys the graphics scale. +*/ +QGraphicsScale::~QGraphicsScale() +{ +} + +/*! + \property QGraphicsScale::origin + \brief The QGraphicsScene class provides the origin of the scale. + + All scaling will be done relative to this point (i.e., this point + will stay fixed, relative to the parent, when the item is scaled). + + \sa xScale, yScale +*/ +QPointF QGraphicsScale::origin() const +{ + Q_D(const QGraphicsScale); + return d->origin; +} +void QGraphicsScale::setOrigin(const QPointF &point) +{ + Q_D(QGraphicsScale); + d->origin = point; + update(); + emit originChanged(); +} + +/*! + \property QGraphicsScale::xScale + \brief the horizontal scale factor. + + The scale factor can be any real number; the default value is 1.0. If you + set the factor to 0.0, the item will be collapsed to a single point. If you + provide a negative value, the item will be mirrored horizontally around its + origin. + + \sa yScale, origin +*/ +qreal QGraphicsScale::xScale() const +{ + Q_D(const QGraphicsScale); + return d->xScale; +} +void QGraphicsScale::setXScale(qreal scale) +{ + Q_D(QGraphicsScale); + if (d->xScale == scale) + return; + d->xScale = scale; + update(); + emit scaleChanged(); +} + +/*! + \property QGraphicsScale::yScale + \brief the vertical scale factor. + + The scale factor can be any real number; the default value is 1.0. If you + set the factor to 0.0, the item will be collapsed to a single point. If you + provide a negative value, the item will be flipped vertically around its + origin. + + \sa xScale, origin +*/ +qreal QGraphicsScale::yScale() const +{ + Q_D(const QGraphicsScale); + return d->yScale; +} +void QGraphicsScale::setYScale(qreal scale) +{ + Q_D(QGraphicsScale); + if (d->yScale == scale) + return; + d->yScale = scale; + update(); + emit scaleChanged(); +} + +/*! + \reimp +*/ +void QGraphicsScale::applyTo(QTransform *transform) const +{ + Q_D(const QGraphicsScale); + transform->translate(d->origin.x(), d->origin.y()); + transform->scale(d->xScale, d->yScale); + transform->translate(-d->origin.x(), -d->origin.y()); +} + +/*! + \fn QGraphicsScale::originChanged() + + QGraphicsScale emits this signal when its origin changes. + + \sa QGraphicsScale::origin +*/ + +/*! + \fn QGraphicsScale::scaleChanged() + + This signal is emitted whenever the xScale or yScale of the object + changes. + + \sa QGraphicsScale::xScale, QGraphicsScale::yScale +*/ + +/*! + \class QGraphicsRotation + \brief The QGraphicsRotation class provides a rotation transformation. + \since 4.6 + + QGraphicsRotation provides certain parameters to help control how the + rotation should be applied. + + The origin is the point that the item is rotated around (i.e., it stays + fixed relative to the parent as the rest of the item is rotated). By + default the origin is QPointF(0, 0). + + The angle property provides the number of degrees to rotate the item + clockwise around the origin. This value also be negative, indicating a + counter-clockwise rotation. For animation purposes it may also be useful to + provide rotation angles exceeding (-360, 360) degrees, for instance to + animate how an item rotates several times. + + \sa QGraphicsTransform, QGraphicsItem::setRotation(), QTransform::rotate() +*/ + +class QGraphicsRotationPrivate : public QGraphicsTransformPrivate +{ +public: + QGraphicsRotationPrivate() + : angle(0) {} + QPointF origin; + qreal originY; + qreal angle; +}; + +/*! + Constructs a new QGraphicsRotation with the given \a parent. +*/ +QGraphicsRotation::QGraphicsRotation(QObject *parent) + : QGraphicsTransform(*new QGraphicsRotationPrivate, parent) +{ +} + +/*! + \internal +*/ +QGraphicsRotation::QGraphicsRotation(QGraphicsRotationPrivate &p, QObject *parent) + : QGraphicsTransform(p, parent) +{ +} + +/*! + Destroys the graphics rotation. +*/ +QGraphicsRotation::~QGraphicsRotation() +{ +} + +/*! + \property QGraphicsRotation::origin + \brief the origin of the rotation. + + All rotations will be done relative to this point (i.e., this point + will stay fixed, relative to the parent, when the item is rotated). + + \sa angle +*/ +QPointF QGraphicsRotation::origin() const +{ + Q_D(const QGraphicsRotation); + return d->origin; +} +void QGraphicsRotation::setOrigin(const QPointF &point) +{ + Q_D(QGraphicsRotation); + d->origin = point; + update(); + emit originChanged(); +} + +/*! + \property QGraphicsRotation::angle + \brief the angle for clockwise rotation, in degrees. + + The angle can be any real number; the default value is 0.0. A value of 180 + will rotate 180 degrees, clockwise. If you provide a negative number, the + item will be rotated counter-clockwise. Normally the rotation angle will be + in the range (-360, 360), but you can also provide numbers outside of this + range (e.g., a angle of 370 degrees gives the same result as 10 degrees). + + \sa origin +*/ +qreal QGraphicsRotation::angle() const +{ + Q_D(const QGraphicsRotation); + return d->angle; +} +void QGraphicsRotation::setAngle(qreal angle) +{ + Q_D(QGraphicsRotation); + if (d->angle == angle) + return; + d->angle = angle; + update(); + emit angleChanged(); +} + +/*! + \reimp +*/ +void QGraphicsRotation::applyTo(QTransform *t) const +{ + Q_D(const QGraphicsRotation); + if (d->angle) { + t->translate(d->origin.x(), d->origin.y()); + t->rotate(d->angle); + t->translate(-d->origin.x(), -d->origin.y()); + } +} + +/*! + \fn QGraphicsRotation::originChanged() + + This signal is emitted whenever the origin has changed. + + \sa QGraphicsRotation::origin +*/ + +/*! + \fn void QGraphicsRotation::angleChanged() + + This signal is emitted whenever the angle has changed. + + \sa QGraphicsRotation::angle +*/ + +/*! + \class QGraphicsRotation3D + \brief The QGraphicsRotation3D class provides rotation in 3 dimensions. + \since 4.6 + + QGraphicsRotation3D extends QGraphicsRotation with the ability to rotate + around a given axis. + + You can provide the desired axis by assigning a QVector3D to the axis + property. The angle property, which is provided by QGraphicsRotation, now + describes the number of degrees to rotate around this axis. + + By default the axis is (0, 0, 1), giving QGraphicsRotation3D the same + default behavior as QGraphicsRotation (i.e., rotation around the Z axis). + + \sa QGraphicsTransform, QGraphicsItem::setRotation(), QTransform::rotate() +*/ + +class QGraphicsRotation3DPrivate : public QGraphicsRotationPrivate +{ +public: + QGraphicsRotation3DPrivate() {} + + QVector3D axis; +}; + +/*! + Constructs a new QGraphicsRotation3D with the given \a parent. +*/ +QGraphicsRotation3D::QGraphicsRotation3D(QObject *parent) + : QGraphicsRotation(*new QGraphicsRotation3DPrivate, parent) +{ +} + +/*! + Destroys the 3D graphics rotation. +*/ +QGraphicsRotation3D::~QGraphicsRotation3D() +{ +} + +/*! + \property QGraphicsRotation3D::axis + \brief a rotation axis, specified by a vector in 3D space. + + This can be any axis in 3D space. By default the axis is (0, 0, 1), + which is aligned with the Z axis and provides the same behavior + for the rotation angle as QGraphicsRotation. If you provide another + axis, QGraphicsRotation3D will provide a transformation that rotates + around this axis. For example, if you would like to rotate an item + around its X axis, you could pass (1, 0, 0) as the axis. + + \sa QTransform, QGraphicsRotation::angle +*/ +QVector3D QGraphicsRotation3D::axis() +{ + Q_D(QGraphicsRotation3D); + return d->axis; +} +void QGraphicsRotation3D::setAxis(const QVector3D &axis) +{ + Q_D(QGraphicsRotation3D); + d->axis = axis; + update(); +} + +static const qreal inv_dist_to_plane = 1. / 1024.; + +/*! + \reimp +*/ +void QGraphicsRotation3D::applyTo(QTransform *t) const +{ + Q_D(const QGraphicsRotation3D); + + if (d->angle == 0. || + (d->axis.z() == 0. && d->axis.y() == 0 && d->axis.x() == 0)) + return; + + qreal rad = d->angle * 2. * M_PI / 360.; + qreal c = ::cos(rad); + qreal s = ::sin(rad); + + qreal x = d->axis.x(); + qreal y = d->axis.y(); + qreal z = d->axis.z(); + + qreal len = x * x + y * y + z * z; + if (len != 1.) { + len = 1./::sqrt(len); + x *= len; + y *= len; + z *= len; + } + + t->translate(d->origin.x(), d->origin.y()); + *t = QTransform(x*x*(1-c)+c, x*y*(1-c)-z*s, x*z*(1-c)+y*s*inv_dist_to_plane, + y*x*(1-c)+z*s, y*y*(1-c)+c, y*z*(1-c)-x*s*inv_dist_to_plane, + 0, 0, 1) * *t; + t->translate(-d->origin.x(), -d->origin.y()); +} + +/*! + \fn void QGraphicsRotation3D::axisChanged() + + This signal is emitted whenever the axis of the object changes. +*/ + +#include "moc_qgraphicstransform.cpp" + +QT_END_NAMESPACE |