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diff --git a/src/gui/painting/qtransform.cpp b/src/gui/painting/qtransform.cpp new file mode 100644 index 0000000..c2e2a80 --- /dev/null +++ b/src/gui/painting/qtransform.cpp @@ -0,0 +1,2078 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (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 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. +** $QT_END_LICENSE$ +** +****************************************************************************/ +#include "qtransform.h" + +#include "qdatastream.h" +#include "qdebug.h" +#include "qmatrix.h" +#include "qregion.h" +#include "qpainterpath.h" +#include "qvariant.h" +#include <qmath.h> + +QT_BEGIN_NAMESPACE + +#define Q_NEAR_CLIP 0.000001 + + +#define MAP(x, y, nx, ny) \ + do { \ + qreal FX_ = x; \ + qreal FY_ = y; \ + switch(t) { \ + case TxNone: \ + nx = FX_; \ + ny = FY_; \ + break; \ + case TxTranslate: \ + nx = FX_ + affine._dx; \ + ny = FY_ + affine._dy; \ + break; \ + case TxScale: \ + nx = affine._m11 * FX_ + affine._dx; \ + ny = affine._m22 * FY_ + affine._dy; \ + break; \ + case TxRotate: \ + case TxShear: \ + case TxProject: \ + nx = affine._m11 * FX_ + affine._m21 * FY_ + affine._dx; \ + ny = affine._m12 * FX_ + affine._m22 * FY_ + affine._dy; \ + if (t == TxProject) { \ + qreal w = 1./(m_13 * FX_ + m_23 * FY_ + m_33); \ + nx *= w; \ + ny *= w; \ + } \ + } \ + } while (0) + +/*! + \class QTransform + \brief The QTransform class specifies 2D transformations of a coordinate system. + \since 4.3 + \ingroup multimedia + + A transformation specifies how to translate, scale, shear, rotate + or project the coordinate system, and is typically used when + rendering graphics. + + QTransform differs from QMatrix in that it is a true 3x3 matrix, + allowing perspective transformations. QTransform's toAffine() + method allows casting QTransform to QMatrix. If a perspective + transformation has been specified on the matrix, then the + conversion to an affine QMatrix will cause loss of data. + + QTransform is the recommended transformation class in Qt. + + A QTransform object can be built using the setMatrix(), scale(), + rotate(), translate() and shear() functions. Alternatively, it + can be built by applying \l {QTransform#Basic Matrix + Operations}{basic matrix operations}. The matrix can also be + defined when constructed, and it can be reset to the identity + matrix (the default) using the reset() function. + + The QTransform class supports mapping of graphic primitives: A given + point, line, polygon, region, or painter path can be mapped to the + coordinate system defined by \e this matrix using the map() + function. In case of a rectangle, its coordinates can be + transformed using the mapRect() function. A rectangle can also be + transformed into a \e polygon (mapped to the coordinate system + defined by \e this matrix), using the mapToPolygon() function. + + QTransform provides the isIdentity() function which returns true if + the matrix is the identity matrix, and the isInvertible() function + which returns true if the matrix is non-singular (i.e. AB = BA = + I). The inverted() function returns an inverted copy of \e this + matrix if it is invertible (otherwise it returns the identity + matrix). In addition, QTransform provides the det() function + returning the matrix's determinant. + + Finally, the QTransform class supports matrix multiplication, and + objects of the class can be streamed as well as compared. + + \tableofcontents + + \section1 Rendering Graphics + + When rendering graphics, the matrix defines the transformations + but the actual transformation is performed by the drawing routines + in QPainter. + + By default, QPainter operates on the associated device's own + coordinate system. The standard coordinate system of a + QPaintDevice has its origin located at the top-left position. The + \e x values increase to the right; \e y values increase + downward. For a complete description, see the \l {The Coordinate + System}{coordinate system} documentation. + + QPainter has functions to translate, scale, shear and rotate the + coordinate system without using a QTransform. For example: + + \table 100% + \row + \o \inlineimage qtransform-simpletransformation.png + \o + \snippet doc/src/snippets/transform/main.cpp 0 + \endtable + + Although these functions are very convenient, it can be more + efficient to build a QTransform and call QPainter::setTransform() if you + want to perform more than a single transform operation. For + example: + + \table 100% + \row + \o \inlineimage qtransform-combinedtransformation.png + \o + \snippet doc/src/snippets/transform/main.cpp 1 + \endtable + + \section1 Basic Matrix Operations + + \image qtransform-representation.png + + A QTransform object contains a 3 x 3 matrix. The \c dx and \c dy + elements specify horizontal and vertical translation. The \c m11 + and \c m22 elements specify horizontal and vertical scaling. The + \c m21 and \c m12 elements specify horizontal and vertical \e shearing. + And finally, the \c m13 and \c m23 elements specify horizontal and vertical + projection, with \c m33 as an additional projection factor. + + QTransform transforms a point in the plane to another point using the + following formulas: + + \snippet doc/src/snippets/code/src_gui_painting_qtransform.cpp 0 + + The point \e (x, y) is the original point, and \e (x', y') is the + transformed point. \e (x', y') can be transformed back to \e (x, + y) by performing the same operation on the inverted() matrix. + + The various matrix elements can be set when constructing the + matrix, or by using the setMatrix() function later on. They can also + be manipulated using the translate(), rotate(), scale() and + shear() convenience functions, The currently set values can be + retrieved using the m11(), m12(), m13(), m21(), m22(), m23(), + m31(), m32(), m33(), dx() and dy() functions. + + Translation is the simplest transformation. Setting \c dx and \c + dy will move the coordinate system \c dx units along the X axis + and \c dy units along the Y axis. Scaling can be done by setting + \c m11 and \c m22. For example, setting \c m11 to 2 and \c m22 to + 1.5 will double the height and increase the width by 50%. The + identity matrix has \c m11, \c m22, and \c m33 set to 1 (all others are set + to 0) mapping a point to itself. Shearing is controlled by \c m12 + and \c m21. Setting these elements to values different from zero + will twist the coordinate system. Rotation is achieved by + carefully setting both the shearing factors and the scaling + factors. Perspective transformation is achieved by carefully setting + both the projection factors and the scaling factors. + + Here's the combined transformations example using basic matrix + operations: + + \table 100% + \row + \o \inlineimage qtransform-combinedtransformation2.png + \o + \snippet doc/src/snippets/transform/main.cpp 2 + \endtable + + \sa QPainter, {The Coordinate System}, {demos/affine}{Affine + Transformations Demo}, {Transformations Example} +*/ + +/*! + \enum QTransform::TransformationType + + \value TxNone + \value TxTranslate + \value TxScale + \value TxRotate + \value TxShear + \value TxProject +*/ + +/*! + Constructs an identity matrix. + + All elements are set to zero except \c m11 and \c m22 (specifying + the scale) and \c m13 which are set to 1. + + \sa reset() +*/ +QTransform::QTransform() + : m_13(0), m_23(0), m_33(1) + , m_type(TxNone) + , m_dirty(TxNone) +{ + +} + +/*! + Constructs a matrix with the elements, \a h11, \a h12, \a h13, + \a h21, \a h22, \a h23, \a h31, \a h32, \a h33. + + \sa setMatrix() +*/ +QTransform::QTransform(qreal h11, qreal h12, qreal h13, + qreal h21, qreal h22, qreal h23, + qreal h31, qreal h32, qreal h33) + : affine(h11, h12, h21, h22, h31, h32), + m_13(h13), m_23(h23), m_33(h33) + , m_type(TxNone) + , m_dirty(TxProject) +{ + +} + +/*! + Constructs a matrix with the elements, \a h11, \a h12, \a h21, \a + h22, \a dx and \a dy. + + \sa setMatrix() +*/ +QTransform::QTransform(qreal h11, qreal h12, qreal h21, + qreal h22, qreal dx, qreal dy) + : affine(h11, h12, h21, h22, dx, dy), + m_13(0), m_23(0), m_33(1) + , m_type(TxNone) + , m_dirty(TxShear) +{ + +} + +/*! + \fn QTransform::QTransform(const QMatrix &matrix) + + Constructs a matrix that is a copy of the given \a matrix. + Note that the \c m13, \c m23, and \c m33 elements are set to 0, 0, + and 1 respectively. + */ +QTransform::QTransform(const QMatrix &mtx) + : affine(mtx), + m_13(0), m_23(0), m_33(1) + , m_type(TxNone) + , m_dirty(TxShear) +{ + +} + +/*! + Returns the adjoint of this matrix. +*/ +QTransform QTransform::adjoint() const +{ + qreal h11, h12, h13, + h21, h22, h23, + h31, h32, h33; + h11 = affine._m22*m_33 - m_23*affine._dy; + h21 = m_23*affine._dx - affine._m21*m_33; + h31 = affine._m21*affine._dy - affine._m22*affine._dx; + h12 = m_13*affine._dy - affine._m12*m_33; + h22 = affine._m11*m_33 - m_13*affine._dx; + h32 = affine._m12*affine._dx - affine._m11*affine._dy; + h13 = affine._m12*m_23 - m_13*affine._m22; + h23 = m_13*affine._m21 - affine._m11*m_23; + h33 = affine._m11*affine._m22 - affine._m12*affine._m21; + + return QTransform(h11, h12, h13, + h21, h22, h23, + h31, h32, h33); +} + +/*! + Returns the transpose of this matrix. +*/ +QTransform QTransform::transposed() const +{ + QTransform t(affine._m11, affine._m21, affine._dx, + affine._m12, affine._m22, affine._dy, + m_13, m_23, m_33); + t.m_type = m_type; + t.m_dirty = m_dirty; + return t; +} + +/*! + Returns an inverted copy of this matrix. + + If the matrix is singular (not invertible), the returned matrix is + the identity matrix. If \a invertible is valid (i.e. not 0), its + value is set to true if the matrix is invertible, otherwise it is + set to false. + + \sa isInvertible() +*/ +QTransform QTransform::inverted(bool *invertible) const +{ + QTransform invert; + bool inv = true; + qreal det; + + switch(type()) { + case TxNone: + break; + case TxTranslate: + invert.affine._dx = -affine._dx; + invert.affine._dy = -affine._dy; + break; + case TxScale: + inv = !qFuzzyCompare(affine._m11 + 1, 1); + inv &= !qFuzzyCompare(affine._m22 + 1, 1); + if (inv) { + invert.affine._m11 = 1 / affine._m11; + invert.affine._m22 = 1 / affine._m22; + invert.affine._dx = -affine._dx * invert.affine._m11; + invert.affine._dy = -affine._dy * invert.affine._m22; + } + break; + case TxRotate: + case TxShear: + invert.affine = affine.inverted(&inv); + break; + default: + // general case + det = determinant(); + inv = !qFuzzyCompare(det + 1, 1); + if (inv) + invert = adjoint() / det; + break; + } + + if (invertible) + *invertible = inv; + + if (inv) { + // inverting doesn't change the type + invert.m_type = m_type; + invert.m_dirty = m_dirty; + } + + return invert; +} + +/*! + Moves the coordinate system \a dx along the x axis and \a dy along + the y axis, and returns a reference to the matrix. + + \sa setMatrix() +*/ +QTransform & QTransform::translate(qreal dx, qreal dy) +{ + switch(type()) { + case TxNone: + affine._dx = dx; + affine._dy = dy; + break; + case TxTranslate: + affine._dx += dx; + affine._dy += dy; + break; + case TxScale: + affine._dx += dx*affine._m11; + affine._dy += dy*affine._m22; + break; + case TxProject: + m_33 += dx*m_13 + dy*m_23; + // Fall through + case TxShear: + case TxRotate: + affine._dx += dx*affine._m11 + dy*affine._m21; + affine._dy += dy*affine._m22 + dx*affine._m12; + break; + } + m_dirty |= TxTranslate; + return *this; +} + +/*! + Creates a matrix which corresponds to a translation of \a dx along + the x axis and \a dy along the y axis. This is the same as + QTransform().translate(dx, dy) but slightly faster. + + \since 4.5 +*/ +QTransform QTransform::fromTranslate(qreal dx, qreal dy) +{ + QTransform transform(1, 0, 0, 1, dx, dy); + transform.m_dirty = TxTranslate; + return transform; +} + +/*! + Scales the coordinate system by \a sx horizontally and \a sy + vertically, and returns a reference to the matrix. + + \sa setMatrix() +*/ +QTransform & QTransform::scale(qreal sx, qreal sy) +{ + switch(type()) { + case TxNone: + case TxTranslate: + affine._m11 = sx; + affine._m22 = sy; + break; + case TxProject: + m_13 *= sx; + m_23 *= sy; + // fall through + case TxRotate: + case TxShear: + affine._m12 *= sx; + affine._m21 *= sy; + // fall through + case TxScale: + affine._m11 *= sx; + affine._m22 *= sy; + break; + } + m_dirty |= TxScale; + return *this; +} + +/*! + Creates a matrix which corresponds to a scaling of + \a sx horizontally and \a sy vertically. + This is the same as QTransform().scale(sx, sy) but slightly faster. + + \since 4.5 +*/ +QTransform QTransform::fromScale(qreal sx, qreal sy) +{ + QTransform transform(sx, 0, 0, sy, 0, 0); + transform.m_dirty = TxScale; + return transform; +} + +/*! + Shears the coordinate system by \a sh horizontally and \a sv + vertically, and returns a reference to the matrix. + + \sa setMatrix() +*/ +QTransform & QTransform::shear(qreal sh, qreal sv) +{ + switch(type()) { + case TxNone: + case TxTranslate: + affine._m12 = sv; + affine._m21 = sh; + break; + case TxScale: + affine._m12 = sv*affine._m22; + affine._m21 = sh*affine._m11; + break; + case TxProject: { + qreal tm13 = sv*m_23; + qreal tm23 = sh*m_13; + m_13 += tm13; + m_23 += tm23; + } + // fall through + case TxRotate: + case TxShear: { + qreal tm11 = sv*affine._m21; + qreal tm22 = sh*affine._m12; + qreal tm12 = sv*affine._m22; + qreal tm21 = sh*affine._m11; + affine._m11 += tm11; affine._m12 += tm12; + affine._m21 += tm21; affine._m22 += tm22; + break; + } + } + m_dirty |= TxShear; + return *this; +} + +const qreal deg2rad = qreal(0.017453292519943295769); // pi/180 +const qreal inv_dist_to_plane = 1. / 1024.; + +/*! + \fn QTransform &QTransform::rotate(qreal angle, Qt::Axis axis) + + Rotates the coordinate system counterclockwise by the given \a angle + about the specified \a axis and returns a reference to the matrix. + + Note that if you apply a QTransform to a point defined in widget + coordinates, the direction of the rotation will be clockwise + because the y-axis points downwards. + + The angle is specified in degrees. + + \sa setMatrix() +*/ +QTransform & QTransform::rotate(qreal a, Qt::Axis axis) +{ + qreal sina = 0; + qreal cosa = 0; + if (a == 90. || a == -270.) + sina = 1.; + else if (a == 270. || a == -90.) + sina = -1.; + else if (a == 180.) + cosa = -1.; + else{ + qreal b = deg2rad*a; // convert to radians + sina = qSin(b); // fast and convenient + cosa = qCos(b); + } + + if (axis == Qt::ZAxis) { + switch(type()) { + case TxNone: + case TxTranslate: + affine._m11 = cosa; + affine._m12 = sina; + affine._m21 = -sina; + affine._m22 = cosa; + break; + case TxScale: { + qreal tm11 = cosa*affine._m11; + qreal tm12 = sina*affine._m22; + qreal tm21 = -sina*affine._m11; + qreal tm22 = cosa*affine._m22; + affine._m11 = tm11; affine._m12 = tm12; + affine._m21 = tm21; affine._m22 = tm22; + break; + } + case TxProject: { + qreal tm13 = cosa*m_13 + sina*m_23; + qreal tm23 = -sina*m_13 + cosa*m_23; + m_13 = tm13; + m_23 = tm23; + // fall through + } + case TxRotate: + case TxShear: { + qreal tm11 = cosa*affine._m11 + sina*affine._m21; + qreal tm12 = cosa*affine._m12 + sina*affine._m22; + qreal tm21 = -sina*affine._m11 + cosa*affine._m21; + qreal tm22 = -sina*affine._m12 + cosa*affine._m22; + affine._m11 = tm11; affine._m12 = tm12; + affine._m21 = tm21; affine._m22 = tm22; + break; + } + } + m_dirty |= TxRotate; + } else { + QTransform result; + if (axis == Qt::YAxis) { + result.affine._m11 = cosa; + result.m_13 = -sina * inv_dist_to_plane; + } else { + result.affine._m22 = cosa; + result.m_23 = -sina * inv_dist_to_plane; + } + result.m_type = TxProject; + *this = result * *this; + } + + return *this; +} + +/*! + \fn QTransform & QTransform::rotateRadians(qreal angle, Qt::Axis axis) + + Rotates the coordinate system counterclockwise by the given \a angle + about the specified \a axis and returns a reference to the matrix. + + Note that if you apply a QTransform to a point defined in widget + coordinates, the direction of the rotation will be clockwise + because the y-axis points downwards. + + The angle is specified in radians. + + \sa setMatrix() +*/ +QTransform & QTransform::rotateRadians(qreal a, Qt::Axis axis) +{ + qreal sina = qSin(a); + qreal cosa = qCos(a); + + if (axis == Qt::ZAxis) { + switch(type()) { + case TxNone: + case TxTranslate: + affine._m11 = cosa; + affine._m12 = sina; + affine._m21 = -sina; + affine._m22 = cosa; + break; + case TxScale: { + qreal tm11 = cosa*affine._m11; + qreal tm12 = sina*affine._m22; + qreal tm21 = -sina*affine._m11; + qreal tm22 = cosa*affine._m22; + affine._m11 = tm11; affine._m12 = tm12; + affine._m21 = tm21; affine._m22 = tm22; + break; + } + case TxProject: { + qreal tm13 = cosa*m_13 + sina*m_23; + qreal tm23 = -sina*m_13 + cosa*m_23; + m_13 = tm13; + m_23 = tm23; + // fall through + } + case TxRotate: + case TxShear: { + qreal tm11 = cosa*affine._m11 + sina*affine._m21; + qreal tm12 = cosa*affine._m12 + sina*affine._m22; + qreal tm21 = -sina*affine._m11 + cosa*affine._m21; + qreal tm22 = -sina*affine._m12 + cosa*affine._m22; + affine._m11 = tm11; affine._m12 = tm12; + affine._m21 = tm21; affine._m22 = tm22; + break; + } + } + m_dirty |= TxRotate; + } else { + QTransform result; + if (axis == Qt::YAxis) { + result.affine._m11 = cosa; + result.m_13 = -sina * inv_dist_to_plane; + } else { + result.affine._m22 = cosa; + result.m_23 = -sina * inv_dist_to_plane; + } + result.m_type = TxProject; + *this = result * *this; + } + return *this; +} + +/*! + \fn bool QTransform::operator==(const QTransform &matrix) const + Returns true if this matrix is equal to the given \a matrix, + otherwise returns false. +*/ +bool QTransform::operator==(const QTransform &o) const +{ +#define qFZ qFuzzyCompare + return qFZ(affine._m11, o.affine._m11) && qFZ(affine._m12, o.affine._m12) && qFZ(m_13, o.m_13) + && qFZ(affine._m21, o.affine._m21) && qFZ(affine._m22, o.affine._m22) && qFZ(m_23, o.m_23) + && qFZ(affine._dx, o.affine._dx) && qFZ(affine._dy, o.affine._dy) && qFZ(m_33, o.m_33); +#undef qFZ +} + +/*! + \fn bool QTransform::operator!=(const QTransform &matrix) const + Returns true if this matrix is not equal to the given \a matrix, + otherwise returns false. +*/ +bool QTransform::operator!=(const QTransform &o) const +{ + return !operator==(o); +} + +/*! + \fn QTransform & QTransform::operator*=(const QTransform &matrix) + \overload + + Returns the result of multiplying this matrix by the given \a + matrix. +*/ +QTransform & QTransform::operator*=(const QTransform &o) +{ + TransformationType t = qMax(type(), o.type()); + switch(t) { + case TxNone: + break; + case TxTranslate: + affine._dx += o.affine._dx; + affine._dy += o.affine._dy; + break; + case TxScale: + { + qreal m11 = affine._m11*o.affine._m11; + qreal m22 = affine._m22*o.affine._m22; + + qreal m31 = affine._dx*o.affine._m11 + o.affine._dx; + qreal m32 = affine._dy*o.affine._m22 + o.affine._dy; + + affine._m11 = m11; + affine._m22 = m22; + affine._dx = m31; affine._dy = m32; + break; + } + case TxRotate: + case TxShear: + { + qreal m11 = affine._m11*o.affine._m11 + affine._m12*o.affine._m21; + qreal m12 = affine._m11*o.affine._m12 + affine._m12*o.affine._m22; + + qreal m21 = affine._m21*o.affine._m11 + affine._m22*o.affine._m21; + qreal m22 = affine._m21*o.affine._m12 + affine._m22*o.affine._m22; + + qreal m31 = affine._dx*o.affine._m11 + affine._dy*o.affine._m21 + o.affine._dx; + qreal m32 = affine._dx*o.affine._m12 + affine._dy*o.affine._m22 + o.affine._dy; + + affine._m11 = m11; affine._m12 = m12; + affine._m21 = m21; affine._m22 = m22; + affine._dx = m31; affine._dy = m32; + break; + } + case TxProject: + { + qreal m11 = affine._m11*o.affine._m11 + affine._m12*o.affine._m21 + m_13*o.affine._dx; + qreal m12 = affine._m11*o.affine._m12 + affine._m12*o.affine._m22 + m_13*o.affine._dy; + qreal m13 = affine._m11*o.m_13 + affine._m12*o.m_23 + m_13*o.m_33; + + qreal m21 = affine._m21*o.affine._m11 + affine._m22*o.affine._m21 + m_23*o.affine._dx; + qreal m22 = affine._m21*o.affine._m12 + affine._m22*o.affine._m22 + m_23*o.affine._dy; + qreal m23 = affine._m21*o.m_13 + affine._m22*o.m_23 + m_23*o.m_33; + + qreal m31 = affine._dx*o.affine._m11 + affine._dy*o.affine._m21 + m_33*o.affine._dx; + qreal m32 = affine._dx*o.affine._m12 + affine._dy*o.affine._m22 + m_33*o.affine._dy; + qreal m33 = affine._dx*o.m_13 + affine._dy*o.m_23 + m_33*o.m_33; + + affine._m11 = m11; affine._m12 = m12; m_13 = m13; + affine._m21 = m21; affine._m22 = m22; m_23 = m23; + affine._dx = m31; affine._dy = m32; m_33 = m33; + } + } + + m_dirty = t; + m_type = t; + + return *this; +} + +/*! + \fn QTransform QTransform::operator*(const QTransform &matrix) const + Returns the result of multiplying this matrix by the given \a + matrix. + + Note that matrix multiplication is not commutative, i.e. a*b != + b*a. +*/ +QTransform QTransform::operator*(const QTransform &m) const +{ + QTransform result = *this; + result *= m; + return result; +} + +/*! + \fn QTransform & QTransform::operator*=(qreal scalar) + \overload + + Returns the result of performing an element-wise multiplication of this + matrix with the given \a scalar. +*/ + +/*! + \fn QTransform & QTransform::operator/=(qreal scalar) + \overload + + Returns the result of performing an element-wise division of this + matrix by the given \a scalar. +*/ + +/*! + \fn QTransform & QTransform::operator+=(qreal scalar) + \overload + + Returns the matrix obtained by adding the given \a scalar to each + element of this matrix. +*/ + +/*! + \fn QTransform & QTransform::operator-=(qreal scalar) + \overload + + Returns the matrix obtained by subtracting the given \a scalar from each + element of this matrix. +*/ + +/*! + Assigns the given \a matrix's values to this matrix. +*/ +QTransform & QTransform::operator=(const QTransform &matrix) +{ + affine._m11 = matrix.affine._m11; + affine._m12 = matrix.affine._m12; + affine._m21 = matrix.affine._m21; + affine._m22 = matrix.affine._m22; + affine._dx = matrix.affine._dx; + affine._dy = matrix.affine._dy; + m_13 = matrix.m_13; + m_23 = matrix.m_23; + m_33 = matrix.m_33; + m_type = matrix.m_type; + m_dirty = matrix.m_dirty; + + return *this; +} + +/*! + Resets the matrix to an identity matrix, i.e. all elements are set + to zero, except \c m11 and \c m22 (specifying the scale) which are + set to 1. + + \sa QTransform(), isIdentity(), {QTransform#Basic Matrix + Operations}{Basic Matrix Operations} +*/ +void QTransform::reset() +{ + affine._m11 = affine._m22 = m_33 = 1.0; + affine._m12 = m_13 = affine._m21 = m_23 = affine._dx = affine._dy = 0; + m_type = TxNone; + m_dirty = TxNone; +} + +#ifndef QT_NO_DATASTREAM +/*! + \fn QDataStream &operator<<(QDataStream &stream, const QTransform &matrix) + \since 4.3 + \relates QTransform + + Writes the given \a matrix to the given \a stream and returns a + reference to the stream. + + \sa {Format of the QDataStream Operators} +*/ +QDataStream & operator<<(QDataStream &s, const QTransform &m) +{ + s << double(m.m11()) + << double(m.m12()) + << double(m.m13()) + << double(m.m21()) + << double(m.m22()) + << double(m.m23()) + << double(m.m31()) + << double(m.m32()) + << double(m.m33()); + return s; +} + +/*! + \fn QDataStream &operator>>(QDataStream &stream, QTransform &matrix) + \since 4.3 + \relates QTransform + + Reads the given \a matrix from the given \a stream and returns a + reference to the stream. + + \sa {Format of the QDataStream Operators} +*/ +QDataStream & operator>>(QDataStream &s, QTransform &t) +{ + double m11, m12, m13, + m21, m22, m23, + m31, m32, m33; + + s >> m11; + s >> m12; + s >> m13; + s >> m21; + s >> m22; + s >> m23; + s >> m31; + s >> m32; + s >> m33; + t.setMatrix(m11, m12, m13, + m21, m22, m23, + m31, m32, m33); + return s; +} + +#endif // QT_NO_DATASTREAM + +#ifndef QT_NO_DEBUG_STREAM +QDebug operator<<(QDebug dbg, const QTransform &m) +{ + dbg.nospace() << "QTransform(" + << "11=" << m.m11() + << " 12=" << m.m12() + << " 13=" << m.m13() + << " 21=" << m.m21() + << " 22=" << m.m22() + << " 23=" << m.m23() + << " 31=" << m.m31() + << " 32=" << m.m32() + << " 33=" << m.m33() + << ")"; + return dbg.space(); +} +#endif + +/*! + \fn QPoint operator*(const QPoint &point, const QTransform &matrix) + \relates QTransform + + This is the same as \a{matrix}.map(\a{point}). + + \sa QTransform::map() +*/ +QPoint QTransform::map(const QPoint &p) const +{ + qreal fx = p.x(); + qreal fy = p.y(); + + qreal x = 0, y = 0; + + TransformationType t = type(); + switch(t) { + case TxNone: + x = fx; + y = fy; + break; + case TxTranslate: + x = fx + affine._dx; + y = fy + affine._dy; + break; + case TxScale: + x = affine._m11 * fx + affine._dx; + y = affine._m22 * fy + affine._dy; + break; + case TxRotate: + case TxShear: + case TxProject: + x = affine._m11 * fx + affine._m21 * fy + affine._dx; + y = affine._m12 * fx + affine._m22 * fy + affine._dy; + if (t == TxProject) { + qreal w = 1./(m_13 * fx + m_23 * fy + m_33); + x *= w; + y *= w; + } + } + return QPoint(qRound(x), qRound(y)); +} + + +/*! + \fn QPointF operator*(const QPointF &point, const QTransform &matrix) + \relates QTransform + + Same as \a{matrix}.map(\a{point}). + + \sa QTransform::map() +*/ + +/*! + \overload + + Creates and returns a QPointF object that is a copy of the given point, + \a p, mapped into the coordinate system defined by this matrix. +*/ +QPointF QTransform::map(const QPointF &p) const +{ + qreal fx = p.x(); + qreal fy = p.y(); + + qreal x = 0, y = 0; + + TransformationType t = type(); + switch(t) { + case TxNone: + x = fx; + y = fy; + break; + case TxTranslate: + x = fx + affine._dx; + y = fy + affine._dy; + break; + case TxScale: + x = affine._m11 * fx + affine._dx; + y = affine._m22 * fy + affine._dy; + break; + case TxRotate: + case TxShear: + case TxProject: + x = affine._m11 * fx + affine._m21 * fy + affine._dx; + y = affine._m12 * fx + affine._m22 * fy + affine._dy; + if (t == TxProject) { + qreal w = 1./(m_13 * fx + m_23 * fy + m_33); + x *= w; + y *= w; + } + } + return QPointF(x, y); +} + +/*! + \fn QPoint QTransform::map(const QPoint &point) const + \overload + + Creates and returns a QPoint object that is a copy of the given \a + point, mapped into the coordinate system defined by this + matrix. Note that the transformed coordinates are rounded to the + nearest integer. +*/ + +/*! + \fn QLineF operator*(const QLineF &line, const QTransform &matrix) + \relates QTransform + + This is the same as \a{matrix}.map(\a{line}). + + \sa QTransform::map() +*/ + +/*! + \fn QLine operator*(const QLine &line, const QTransform &matrix) + \relates QTransform + + This is the same as \a{matrix}.map(\a{line}). + + \sa QTransform::map() +*/ + +/*! + \overload + + Creates and returns a QLineF object that is a copy of the given line, + \a l, mapped into the coordinate system defined by this matrix. +*/ +QLine QTransform::map(const QLine &l) const +{ + qreal fx1 = l.x1(); + qreal fy1 = l.y1(); + qreal fx2 = l.x2(); + qreal fy2 = l.y2(); + + qreal x1 = 0, y1 = 0, x2 = 0, y2 = 0; + + TransformationType t = type(); + switch(t) { + case TxNone: + x1 = fx1; + y1 = fy1; + x2 = fx2; + y2 = fy2; + break; + case TxTranslate: + x1 = fx1 + affine._dx; + y1 = fy1 + affine._dy; + x2 = fx2 + affine._dx; + y2 = fy2 + affine._dy; + break; + case TxScale: + x1 = affine._m11 * fx1 + affine._dx; + y1 = affine._m22 * fy1 + affine._dy; + x2 = affine._m11 * fx2 + affine._dx; + y2 = affine._m22 * fy2 + affine._dy; + break; + case TxRotate: + case TxShear: + case TxProject: + x1 = affine._m11 * fx1 + affine._m21 * fy1 + affine._dx; + y1 = affine._m12 * fx1 + affine._m22 * fy1 + affine._dy; + x2 = affine._m11 * fx2 + affine._m21 * fy2 + affine._dx; + y2 = affine._m12 * fx2 + affine._m22 * fy2 + affine._dy; + if (t == TxProject) { + qreal w = 1./(m_13 * fx1 + m_23 * fy1 + m_33); + x1 *= w; + y1 *= w; + w = 1./(m_13 * fx2 + m_23 * fy2 + m_33); + x2 *= w; + y2 *= w; + } + } + return QLine(qRound(x1), qRound(y1), qRound(x2), qRound(y2)); +} + +/*! + \overload + + \fn QLineF QTransform::map(const QLineF &line) const + + Creates and returns a QLine object that is a copy of the given \a + line, mapped into the coordinate system defined by this matrix. + Note that the transformed coordinates are rounded to the nearest + integer. +*/ + +QLineF QTransform::map(const QLineF &l) const +{ + qreal fx1 = l.x1(); + qreal fy1 = l.y1(); + qreal fx2 = l.x2(); + qreal fy2 = l.y2(); + + qreal x1 = 0, y1 = 0, x2 = 0, y2 = 0; + + TransformationType t = type(); + switch(t) { + case TxNone: + x1 = fx1; + y1 = fy1; + x2 = fx2; + y2 = fy2; + break; + case TxTranslate: + x1 = fx1 + affine._dx; + y1 = fy1 + affine._dy; + x2 = fx2 + affine._dx; + y2 = fy2 + affine._dy; + break; + case TxScale: + x1 = affine._m11 * fx1 + affine._dx; + y1 = affine._m22 * fy1 + affine._dy; + x2 = affine._m11 * fx2 + affine._dx; + y2 = affine._m22 * fy2 + affine._dy; + break; + case TxRotate: + case TxShear: + case TxProject: + x1 = affine._m11 * fx1 + affine._m21 * fy1 + affine._dx; + y1 = affine._m12 * fx1 + affine._m22 * fy1 + affine._dy; + x2 = affine._m11 * fx2 + affine._m21 * fy2 + affine._dx; + y2 = affine._m12 * fx2 + affine._m22 * fy2 + affine._dy; + if (t == TxProject) { + qreal w = 1./(m_13 * fx1 + m_23 * fy1 + m_33); + x1 *= w; + y1 *= w; + w = 1./(m_13 * fx2 + m_23 * fy2 + m_33); + x2 *= w; + y2 *= w; + } + } + return QLineF(x1, y1, x2, y2); +} + +static QPolygonF mapProjective(const QTransform &transform, const QPolygonF &poly) +{ + if (poly.size() == 0) + return poly; + + if (poly.size() == 1) + return QPolygonF() << transform.map(poly.at(0)); + + QPainterPath path; + path.addPolygon(poly); + + path = transform.map(path); + + QPolygonF result; + for (int i = 0; i < path.elementCount(); ++i) + result << path.elementAt(i); + return result; +} + + +/*! + \fn QPolygonF operator *(const QPolygonF &polygon, const QTransform &matrix) + \since 4.3 + \relates QTransform + + This is the same as \a{matrix}.map(\a{polygon}). + + \sa QTransform::map() +*/ + +/*! + \fn QPolygon operator*(const QPolygon &polygon, const QTransform &matrix) + \relates QTransform + + This is the same as \a{matrix}.map(\a{polygon}). + + \sa QTransform::map() +*/ + +/*! + \fn QPolygonF QTransform::map(const QPolygonF &polygon) const + \overload + + Creates and returns a QPolygonF object that is a copy of the given + \a polygon, mapped into the coordinate system defined by this + matrix. +*/ +QPolygonF QTransform::map(const QPolygonF &a) const +{ + if (type() >= QTransform::TxProject) + return mapProjective(*this, a); + + int size = a.size(); + int i; + QPolygonF p(size); + const QPointF *da = a.constData(); + QPointF *dp = p.data(); + + TransformationType t = type(); + for(i = 0; i < size; ++i) { + MAP(da[i].xp, da[i].yp, dp[i].xp, dp[i].yp); + } + return p; +} + +/*! + \fn QPolygon QTransform::map(const QPolygon &polygon) const + \overload + + Creates and returns a QPolygon object that is a copy of the given + \a polygon, mapped into the coordinate system defined by this + matrix. Note that the transformed coordinates are rounded to the + nearest integer. +*/ +QPolygon QTransform::map(const QPolygon &a) const +{ + if (type() >= QTransform::TxProject) + return mapProjective(*this, QPolygonF(a)).toPolygon(); + + int size = a.size(); + int i; + QPolygon p(size); + const QPoint *da = a.constData(); + QPoint *dp = p.data(); + + TransformationType t = type(); + for(i = 0; i < size; ++i) { + qreal nx = 0, ny = 0; + MAP(da[i].xp, da[i].yp, nx, ny); + dp[i].xp = qRound(nx); + dp[i].yp = qRound(ny); + } + return p; +} + +/*! + \fn QRegion operator*(const QRegion ®ion, const QTransform &matrix) + \relates QTransform + + This is the same as \a{matrix}.map(\a{region}). + + \sa QTransform::map() +*/ + +/*! + \fn QRegion QTransform::map(const QRegion ®ion) const + \overload + + Creates and returns a QRegion object that is a copy of the given + \a region, mapped into the coordinate system defined by this matrix. + + Calling this method can be rather expensive if rotations or + shearing are used. +*/ +QRegion QTransform::map(const QRegion &r) const +{ + TransformationType t = type(); + if (t == TxNone) + return r; + if (t == TxTranslate) { + QRegion copy(r); + copy.translate(qRound(affine._dx), qRound(affine._dy)); + return copy; + } + + extern QPainterPath qt_regionToPath(const QRegion ®ion); + QPainterPath p = map(qt_regionToPath(r)); + return p.toFillPolygon(QTransform()).toPolygon(); +} + +struct QHomogeneousCoordinate +{ + qreal x; + qreal y; + qreal w; + + QHomogeneousCoordinate() {} + QHomogeneousCoordinate(qreal x_, qreal y_, qreal w_) : x(x_), y(y_), w(w_) {} + + const QPointF toPoint() const { + qreal iw = 1 / w; + return QPointF(x * iw, y * iw); + } +}; + +static inline QHomogeneousCoordinate mapHomogeneous(const QTransform &transform, const QPointF &p) +{ + QHomogeneousCoordinate c; + c.x = transform.m11() * p.x() + transform.m21() * p.y() + transform.m31(); + c.y = transform.m12() * p.x() + transform.m22() * p.y() + transform.m32(); + c.w = transform.m13() * p.x() + transform.m23() * p.y() + transform.m33(); + return c; +} + +static inline bool lineTo_clipped(QPainterPath &path, const QTransform &transform, const QPointF &a, const QPointF &b, bool needsMoveTo) +{ + QHomogeneousCoordinate ha = mapHomogeneous(transform, a); + QHomogeneousCoordinate hb = mapHomogeneous(transform, b); + + if (ha.w < Q_NEAR_CLIP && hb.w < Q_NEAR_CLIP) + return false; + + if (hb.w < Q_NEAR_CLIP) { + const qreal t = (Q_NEAR_CLIP - hb.w) / (ha.w - hb.w); + + hb.x += (ha.x - hb.x) * t; + hb.y += (ha.y - hb.y) * t; + hb.w = qreal(Q_NEAR_CLIP); + } else if (ha.w < Q_NEAR_CLIP) { + const qreal t = (Q_NEAR_CLIP - ha.w) / (hb.w - ha.w); + + ha.x += (hb.x - ha.x) * t; + ha.y += (hb.y - ha.y) * t; + ha.w = qreal(Q_NEAR_CLIP); + + const QPointF p = ha.toPoint(); + if (needsMoveTo) { + path.moveTo(p); + needsMoveTo = false; + } else { + path.lineTo(p); + } + } + + if (needsMoveTo) + path.moveTo(ha.toPoint()); + + path.lineTo(hb.toPoint()); + + return true; +} + +static inline bool cubicTo_clipped(QPainterPath &path, const QTransform &transform, const QPointF &a, const QPointF &b, const QPointF &c, const QPointF &d, bool needsMoveTo) +{ + const QHomogeneousCoordinate ha = mapHomogeneous(transform, a); + const QHomogeneousCoordinate hb = mapHomogeneous(transform, b); + const QHomogeneousCoordinate hc = mapHomogeneous(transform, c); + const QHomogeneousCoordinate hd = mapHomogeneous(transform, d); + + if (ha.w < Q_NEAR_CLIP && hb.w < Q_NEAR_CLIP && hc.w < Q_NEAR_CLIP && hd.w < Q_NEAR_CLIP) + return false; + + if (ha.w >= Q_NEAR_CLIP && hb.w >= Q_NEAR_CLIP && hc.w >= Q_NEAR_CLIP && hd.w >= Q_NEAR_CLIP) { + if (needsMoveTo) + path.moveTo(ha.toPoint()); + + path.cubicTo(hb.toPoint(), hc.toPoint(), hd.toPoint()); + return true; + } + + if (lineTo_clipped(path, transform, a, b, needsMoveTo)) + needsMoveTo = false; + if (lineTo_clipped(path, transform, b, c, needsMoveTo)) + needsMoveTo = false; + if (lineTo_clipped(path, transform, c, d, needsMoveTo)) + needsMoveTo = false; + + return !needsMoveTo; +} + +static QPainterPath mapProjective(const QTransform &transform, const QPainterPath &path) +{ + QPainterPath result; + + QPointF last; + QPointF lastMoveTo; + bool needsMoveTo = true; + for (int i = 0; i < path.elementCount(); ++i) { + switch (path.elementAt(i).type) { + case QPainterPath::MoveToElement: + if (i > 0 && lastMoveTo != last) + lineTo_clipped(result, transform, last, lastMoveTo, needsMoveTo); + + lastMoveTo = path.elementAt(i); + last = path.elementAt(i); + needsMoveTo = true; + break; + case QPainterPath::LineToElement: + if (lineTo_clipped(result, transform, last, path.elementAt(i), needsMoveTo)) + needsMoveTo = false; + last = path.elementAt(i); + break; + case QPainterPath::CurveToElement: + if (cubicTo_clipped(result, transform, last, path.elementAt(i), path.elementAt(i+1), path.elementAt(i+2), needsMoveTo)) + needsMoveTo = false; + i += 2; + last = path.elementAt(i); + break; + default: + Q_ASSERT(false); + } + } + + if (path.elementCount() > 0 && lastMoveTo != last) + lineTo_clipped(result, transform, last, lastMoveTo, needsMoveTo); + + return result; +} + +/*! + \fn QPainterPath operator *(const QPainterPath &path, const QTransform &matrix) + \since 4.3 + \relates QTransform + + This is the same as \a{matrix}.map(\a{path}). + + \sa QTransform::map() +*/ + +/*! + \overload + + Creates and returns a QPainterPath object that is a copy of the + given \a path, mapped into the coordinate system defined by this + matrix. +*/ +QPainterPath QTransform::map(const QPainterPath &path) const +{ + TransformationType t = type(); + if (t == TxNone || path.isEmpty()) + return path; + + if (t >= TxProject) + return mapProjective(*this, path); + + QPainterPath copy = path; + copy.detach(); + + if (t == TxTranslate) { + for (int i=0; i<path.elementCount(); ++i) { + QPainterPath::Element &e = copy.d_ptr->elements[i]; + e.x += affine._dx; + e.y += affine._dy; + } + } else { + // Full xform + for (int i=0; i<path.elementCount(); ++i) { + QPainterPath::Element &e = copy.d_ptr->elements[i]; + MAP(e.x, e.y, e.x, e.y); + } + } + + return copy; +} + +/*! + \fn QPolygon QTransform::mapToPolygon(const QRect &rectangle) const + + Creates and returns a QPolygon representation of the given \a + rectangle, mapped into the coordinate system defined by this + matrix. + + The rectangle's coordinates are transformed using the following + formulas: + + \snippet doc/src/snippets/code/src_gui_painting_qtransform.cpp 1 + + Polygons and rectangles behave slightly differently when + transformed (due to integer rounding), so + \c{matrix.map(QPolygon(rectangle))} is not always the same as + \c{matrix.mapToPolygon(rectangle)}. + + \sa mapRect(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ +QPolygon QTransform::mapToPolygon(const QRect &rect) const +{ + TransformationType t = type(); + + QPolygon a(4); + qreal x[4] = { 0, 0, 0, 0 }, y[4] = { 0, 0, 0, 0 }; + if (t <= TxScale) { + x[0] = affine._m11*rect.x() + affine._dx; + y[0] = affine._m22*rect.y() + affine._dy; + qreal w = affine._m11*rect.width(); + qreal h = affine._m22*rect.height(); + if (w < 0) { + w = -w; + x[0] -= w; + } + if (h < 0) { + h = -h; + y[0] -= h; + } + x[1] = x[0]+w; + x[2] = x[1]; + x[3] = x[0]; + y[1] = y[0]; + y[2] = y[0]+h; + y[3] = y[2]; + } else { + qreal right = rect.x() + rect.width(); + qreal bottom = rect.y() + rect.height(); + MAP(rect.x(), rect.y(), x[0], y[0]); + MAP(right, rect.y(), x[1], y[1]); + MAP(right, bottom, x[2], y[2]); + MAP(rect.x(), bottom, x[3], y[3]); + } + + // all coordinates are correctly, tranform to a pointarray + // (rounding to the next integer) + a.setPoints(4, qRound(x[0]), qRound(y[0]), + qRound(x[1]), qRound(y[1]), + qRound(x[2]), qRound(y[2]), + qRound(x[3]), qRound(y[3])); + return a; +} + +/*! + Creates a transformation matrix, \a trans, that maps a unit square + to a four-sided polygon, \a quad. Returns true if the transformation + is constructed or false if such a transformation does not exist. + + \sa quadToSquare(), quadToQuad() +*/ +bool QTransform::squareToQuad(const QPolygonF &quad, QTransform &trans) +{ + if (quad.count() != 4) + return false; + + qreal dx0 = quad[0].x(); + qreal dx1 = quad[1].x(); + qreal dx2 = quad[2].x(); + qreal dx3 = quad[3].x(); + + qreal dy0 = quad[0].y(); + qreal dy1 = quad[1].y(); + qreal dy2 = quad[2].y(); + qreal dy3 = quad[3].y(); + + double ax = dx0 - dx1 + dx2 - dx3; + double ay = dy0 - dy1 + dy2 - dy3; + + if (!ax && !ay) { //afine transform + trans.setMatrix(dx1 - dx0, dy1 - dy0, 0, + dx2 - dx1, dy2 - dy1, 0, + dx0, dy0, 1); + } else { + double ax1 = dx1 - dx2; + double ax2 = dx3 - dx2; + double ay1 = dy1 - dy2; + double ay2 = dy3 - dy2; + + /*determinants */ + double gtop = ax * ay2 - ax2 * ay; + double htop = ax1 * ay - ax * ay1; + double bottom = ax1 * ay2 - ax2 * ay1; + + double a, b, c, d, e, f, g, h; /*i is always 1*/ + + if (!bottom) + return false; + + g = gtop/bottom; + h = htop/bottom; + + a = dx1 - dx0 + g * dx1; + b = dx3 - dx0 + h * dx3; + c = dx0; + d = dy1 - dy0 + g * dy1; + e = dy3 - dy0 + h * dy3; + f = dy0; + + trans.setMatrix(a, d, g, + b, e, h, + c, f, 1.0); + } + + return true; +} + +/*! + \fn bool QTransform::quadToSquare(const QPolygonF &quad, QTransform &trans) + + Creates a transformation matrix, \a trans, that maps a four-sided polygon, + \a quad, to a unit square. Returns true if the transformation is constructed + or false if such a transformation does not exist. + + \sa squareToQuad(), quadToQuad() +*/ +bool QTransform::quadToSquare(const QPolygonF &quad, QTransform &trans) +{ + if (!squareToQuad(quad, trans)) + return false; + + bool invertible = false; + trans = trans.inverted(&invertible); + + return invertible; +} + +/*! + Creates a transformation matrix, \a trans, that maps a four-sided + polygon, \a one, to another four-sided polygon, \a two. + Returns true if the transformation is possible; otherwise returns + false. + + This is a convenience method combining quadToSquare() and + squareToQuad() methods. It allows the input quad to be + transformed into any other quad. + + \sa squareToQuad(), quadToSquare() +*/ +bool QTransform::quadToQuad(const QPolygonF &one, + const QPolygonF &two, + QTransform &trans) +{ + QTransform stq; + if (!quadToSquare(one, trans)) + return false; + if (!squareToQuad(two, stq)) + return false; + trans *= stq; + //qDebug()<<"Final = "<<trans; + return true; +} + +/*! + Sets the matrix elements to the specified values, \a m11, + \a m12, \a m13 \a m21, \a m22, \a m23 \a m31, \a m32 and + \a m33. Note that this function replaces the previous values. + QMatrix provides the translate(), rotate(), scale() and shear() + convenience functions to manipulate the various matrix elements + based on the currently defined coordinate system. + + \sa QTransform() +*/ + +void QTransform::setMatrix(qreal m11, qreal m12, qreal m13, + qreal m21, qreal m22, qreal m23, + qreal m31, qreal m32, qreal m33) +{ + affine._m11 = m11; affine._m12 = m12; m_13 = m13; + affine._m21 = m21; affine._m22 = m22; m_23 = m23; + affine._dx = m31; affine._dy = m32; m_33 = m33; + m_type = TxNone; + m_dirty = TxProject; +} + +QRect QTransform::mapRect(const QRect &rect) const +{ + TransformationType t = type(); + if (t <= TxScale) { + int x = qRound(affine._m11*rect.x() + affine._dx); + int y = qRound(affine._m22*rect.y() + affine._dy); + int w = qRound(affine._m11*rect.width()); + int h = qRound(affine._m22*rect.height()); + if (w < 0) { + w = -w; + x -= w; + } + if (h < 0) { + h = -h; + y -= h; + } + return QRect(x, y, w, h); + } else if (t < TxProject) { + // see mapToPolygon for explanations of the algorithm. + qreal x0 = 0, y0 = 0; + qreal x, y; + MAP(rect.left(), rect.top(), x0, y0); + qreal xmin = x0; + qreal ymin = y0; + qreal xmax = x0; + qreal ymax = y0; + MAP(rect.right() + 1, rect.top(), x, y); + xmin = qMin(xmin, x); + ymin = qMin(ymin, y); + xmax = qMax(xmax, x); + ymax = qMax(ymax, y); + MAP(rect.right() + 1, rect.bottom() + 1, x, y); + xmin = qMin(xmin, x); + ymin = qMin(ymin, y); + xmax = qMax(xmax, x); + ymax = qMax(ymax, y); + MAP(rect.left(), rect.bottom() + 1, x, y); + xmin = qMin(xmin, x); + ymin = qMin(ymin, y); + xmax = qMax(xmax, x); + ymax = qMax(ymax, y); + return QRect(qRound(xmin), qRound(ymin), qRound(xmax)-qRound(xmin), qRound(ymax)-qRound(ymin)); + } else { + QPainterPath path; + path.addRect(rect); + return map(path).boundingRect().toRect(); + } +} + +/*! + \fn QRectF QTransform::mapRect(const QRectF &rectangle) const + + Creates and returns a QRectF object that is a copy of the given \a + rectangle, mapped into the coordinate system defined by this + matrix. + + The rectangle's coordinates are transformed using the following + formulas: + + \snippet doc/src/snippets/code/src_gui_painting_qtransform.cpp 2 + + If rotation or shearing has been specified, this function returns + the \e bounding rectangle. To retrieve the exact region the given + \a rectangle maps to, use the mapToPolygon() function instead. + + \sa mapToPolygon(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ +QRectF QTransform::mapRect(const QRectF &rect) const +{ + TransformationType t = type(); + if (t <= TxScale) { + qreal x = affine._m11*rect.x() + affine._dx; + qreal y = affine._m22*rect.y() + affine._dy; + qreal w = affine._m11*rect.width(); + qreal h = affine._m22*rect.height(); + if (w < 0) { + w = -w; + x -= w; + } + if (h < 0) { + h = -h; + y -= h; + } + return QRectF(x, y, w, h); + } else if (t < TxProject) { + qreal x0 = 0, y0 = 0; + qreal x, y; + MAP(rect.x(), rect.y(), x0, y0); + qreal xmin = x0; + qreal ymin = y0; + qreal xmax = x0; + qreal ymax = y0; + MAP(rect.x() + rect.width(), rect.y(), x, y); + xmin = qMin(xmin, x); + ymin = qMin(ymin, y); + xmax = qMax(xmax, x); + ymax = qMax(ymax, y); + MAP(rect.x() + rect.width(), rect.y() + rect.height(), x, y); + xmin = qMin(xmin, x); + ymin = qMin(ymin, y); + xmax = qMax(xmax, x); + ymax = qMax(ymax, y); + MAP(rect.x(), rect.y() + rect.height(), x, y); + xmin = qMin(xmin, x); + ymin = qMin(ymin, y); + xmax = qMax(xmax, x); + ymax = qMax(ymax, y); + return QRectF(xmin, ymin, xmax-xmin, ymax - ymin); + } else { + QPainterPath path; + path.addRect(rect); + return map(path).boundingRect(); + } +} + +/*! + \fn QRect QTransform::mapRect(const QRect &rectangle) const + \overload + + Creates and returns a QRect object that is a copy of the given \a + rectangle, mapped into the coordinate system defined by this + matrix. Note that the transformed coordinates are rounded to the + nearest integer. +*/ + +/*! + Maps the given coordinates \a x and \a y into the coordinate + system defined by this matrix. The resulting values are put in *\a + tx and *\a ty, respectively. + + The coordinates are transformed using the following formulas: + + \snippet doc/src/snippets/code/src_gui_painting_qtransform.cpp 3 + + The point (x, y) is the original point, and (x', y') is the + transformed point. + + \sa {QTransform#Basic Matrix Operations}{Basic Matrix Operations} +*/ +void QTransform::map(qreal x, qreal y, qreal *tx, qreal *ty) const +{ + TransformationType t = type(); + MAP(x, y, *tx, *ty); +} + +/*! + \overload + + Maps the given coordinates \a x and \a y into the coordinate + system defined by this matrix. The resulting values are put in *\a + tx and *\a ty, respectively. Note that the transformed coordinates + are rounded to the nearest integer. +*/ +void QTransform::map(int x, int y, int *tx, int *ty) const +{ + TransformationType t = type(); + qreal fx = 0, fy = 0; + MAP(x, y, fx, fy); + *tx = qRound(fx); + *ty = qRound(fy); +} + +/*! + Returns the QTransform cast to a QMatrix. + */ +const QMatrix &QTransform::toAffine() const +{ + return affine; +} + +/*! + Returns the transformation type of this matrix. + + The transformation type is the highest enumeration value + capturing all of the matrix's transformations. For example, + if the matrix both scales and shears, the type would be \c TxShear, + because \c TxShear has a higher enumeration value than \c TxScale. + + Knowing the transformation type of a matrix is useful for optimization: + you can often handle specific types more optimally than handling + the generic case. + */ +QTransform::TransformationType QTransform::type() const +{ + if (m_dirty >= m_type) { + if (m_dirty > TxShear && (!qFuzzyCompare(m_13 + 1, 1) || !qFuzzyCompare(m_23 + 1, 1))) + m_type = TxProject; + else if (m_dirty > TxScale && (!qFuzzyCompare(affine._m12 + 1, 1) || !qFuzzyCompare(affine._m21 + 1, 1))) { + const qreal dot = affine._m11 * affine._m12 + affine._m21 * affine._m22; + if (qFuzzyCompare(dot + 1, 1)) + m_type = TxRotate; + else + m_type = TxShear; + } else if (m_dirty > TxTranslate && (!qFuzzyCompare(affine._m11, 1) || !qFuzzyCompare(affine._m22, 1) || !qFuzzyCompare(m_33, 1))) + m_type = TxScale; + else if (m_dirty > TxNone && (!qFuzzyCompare(affine._dx + 1, 1) || !qFuzzyCompare(affine._dy + 1, 1))) + m_type = TxTranslate; + else + m_type = TxNone; + + m_dirty = TxNone; + } + + return static_cast<TransformationType>(m_type); +} + +/*! + + Returns the transform as a QVariant. +*/ +QTransform::operator QVariant() const +{ + return QVariant(QVariant::Transform, this); +} + + +/*! + \fn bool QTransform::isInvertible() const + + Returns true if the matrix is invertible, otherwise returns false. + + \sa inverted() +*/ + +/*! + \fn qreal QTransform::det() const + + Returns the matrix's determinant. +*/ + + +/*! + \fn qreal QTransform::m11() const + + Returns the horizontal scaling factor. + + \sa scale(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + +/*! + \fn qreal QTransform::m12() const + + Returns the vertical shearing factor. + + \sa shear(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + +/*! + \fn qreal QTransform::m21() const + + Returns the horizontal shearing factor. + + \sa shear(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + +/*! + \fn qreal QTransform::m22() const + + Returns the vertical scaling factor. + + \sa scale(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + +/*! + \fn qreal QTransform::dx() const + + Returns the horizontal translation factor. + + \sa m31(), translate(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + +/*! + \fn qreal QTransform::dy() const + + Returns the vertical translation factor. + + \sa translate(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + + +/*! + \fn qreal QTransform::m13() const + + Returns the horizontal projection factor. + + \sa translate(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + + +/*! + \fn qreal QTransform::m23() const + + Returns the vertical projection factor. + + \sa translate(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + +/*! + \fn qreal QTransform::m31() const + + Returns the horizontal translation factor. + + \sa dx(), translate(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + +/*! + \fn qreal QTransform::m32() const + + Returns the vertical translation factor. + + \sa dy(), translate(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + +/*! + \fn qreal QTransform::m33() const + + Returns the division factor. + + \sa translate(), {QTransform#Basic Matrix Operations}{Basic Matrix + Operations} +*/ + +/*! + \fn qreal QTransform::determinant() const + + Returns the matrix's determinant. +*/ + +/*! + \fn bool QTransform::isIdentity() const + + Returns true if the matrix is the identity matrix, otherwise + returns false. + + \sa reset() +*/ + +/*! + \fn bool QTransform::isAffine() const + + Returns true if the matrix represent an affine transformation, + otherwise returns false. +*/ + +/*! + \fn bool QTransform::isScaling() const + + Returns true if the matrix represents a scaling + transformation, otherwise returns false. + + \sa reset() +*/ + +/*! + \fn bool QTransform::isRotating() const + + Returns true if the matrix represents some kind of a + rotating transformation, otherwise returns false. + + \sa reset() +*/ + +/*! + \fn bool QTransform::isTranslating() const + + Returns true if the matrix represents a translating + transformation, otherwise returns false. + + \sa reset() +*/ + +// returns true if the transform is uniformly scaling +// (same scale in x and y direction) +// scale is set to the max of x and y scaling factors +Q_GUI_EXPORT +bool qt_scaleForTransform(const QTransform &transform, qreal *scale) +{ + if (transform.type() <= QTransform::TxTranslate) { + *scale = 1; + return true; + } else if (transform.type() == QTransform::TxScale) { + const qreal xScale = qAbs(transform.m11()); + const qreal yScale = qAbs(transform.m22()); + *scale = qMax(xScale, yScale); + return qFuzzyCompare(xScale, yScale); + } + + const qreal xScale = transform.m11() * transform.m11() + + transform.m21() * transform.m21(); + const qreal yScale = transform.m12() * transform.m12() + + transform.m22() * transform.m22(); + *scale = qSqrt(qMax(xScale, yScale)); + return transform.type() == QTransform::TxRotate && qFuzzyCompare(xScale, yScale); +} + +QT_END_NAMESPACE |