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Diffstat (limited to 'src/declarative/scenegraph/coreapi/qsgmatrix4x4stack.cpp')
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diff --git a/src/declarative/scenegraph/coreapi/qsgmatrix4x4stack.cpp b/src/declarative/scenegraph/coreapi/qsgmatrix4x4stack.cpp new file mode 100644 index 0000000000..07ba21d17c --- /dev/null +++ b/src/declarative/scenegraph/coreapi/qsgmatrix4x4stack.cpp @@ -0,0 +1,380 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (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 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 "qsgmatrix4x4stack.h" +#include "qsgmatrix4x4stack_p.h" + +QT_BEGIN_NAMESPACE + +/*! + \class QSGMatrix4x4Stack + \brief The QSGMatrix4x4Stack class manages stacks of transformation matrices in GL applications. + \since 4.8 + \ingroup qt3d + \ingroup qt3d::enablers + + Transformation matrices are one of the basic building blocks of + 3D applications, allowing object models to be positioned, scaled, + rotated, and projected onto the screen. + + GL systems support several standard kinds of matrices, particularly + modelview and projection matrices. These matrices are typically + organized into stacks, which allow the current matrix state to be + saved with push() and restored later with pop(). + + QSGMatrix4x4Stack assists QGLPainter with the management of matrix + stacks, providing operations to set and modify transformation + matrices in each of the standard matrix stacks. + + In the following example, a standard orthographic projection matrix for a + view is set via the QGLPainter::projectionMatrix() stack, and + then a modelview matrix is set via the QGLPainter::modelViewMatrix() + stack to scale and translate an object prior to drawing: + + \code + QGLPainter painter(this); + + QMatrix4x4 projm; + projm.ortho(window->rect()); + painter.projectionMatrix() = projm; + + painter.modelViewMatrix().setToIdentity(); + painter.modelViewMatrix().translate(-1.0f, 2.0f, 0.0f); + painter.modelViewMatrix().scale(0.5f); + \endcode + + Later, the application can save the current modelview matrix state + and draw a different object with a different modelview matrix: + + \code + painter.modelViewMatrix().push(); + painter.modelViewMatrix().setToIdentity(); + painter.modelViewMatrix().scale(2.0f); + \endcode + + For efficiency, the matrix values are kept client-side until they + are needed by a QGLPainter::draw() operation. Until then, changes + to the matrix will not be reflected in the GL server. The application + can force the GL server to update the server with a call to + QGLPainter::update(). + + QSGMatrix4x4Stack is supported on all GL platforms, including OpenGL/ES 2.0 + which doesn't support matrix stacks natively. On that platform, the + matrix stack is simulated in client memory. When the application + selects a shader program to draw under OpenGL/ES 2.0, it calls + top() to obtain the actual value to be set on the shader program. + + \sa QGLPainter +*/ + +/*! + Creates a matrix stack. +*/ +QSGMatrix4x4Stack::QSGMatrix4x4Stack() + : d_ptr(new QSGMatrix4x4StackPrivate) +{ +} + +/*! + Destroy this matrix stack. +*/ +QSGMatrix4x4Stack::~QSGMatrix4x4Stack() +{ +} + +/*! + Pushes the current matrix onto the matrix stack. The matrix can + be restored with pop(). The new top of stack will have the + same value as the previous top of stack. + + The depths of the traditional \c{GL_MODELVIEW} and \c{GL_PROJECTION} + matrix stacks in the GL server are system-dependent and easy to + overflow in nested rendering code using \c{glPushMatrix()}. + By contrast, the push() function provides an arbitrary-sized stack + in client memory. + + \sa pop(), top() +*/ +void QSGMatrix4x4Stack::push() +{ + Q_D(QSGMatrix4x4Stack); + d->stack.push(d->matrix); +} + +/*! + Pops the top-most matrix from this matrix stack and sets the + current matrix to the next value down. Does nothing if the + matrix stack contains a single entry. + + \sa push() +*/ +void QSGMatrix4x4Stack::pop() +{ + Q_D(QSGMatrix4x4Stack); + if (!d->stack.isEmpty()) + d->matrix = d->stack.pop(); + d->isDirty = true; +} + +/*! + Set the matrix at the top of this matrix stack to the identity matrix. + + \sa operator=() +*/ +void QSGMatrix4x4Stack::setToIdentity() +{ + Q_D(QSGMatrix4x4Stack); + d->matrix.setToIdentity(); + d->isDirty = true; +} + +/*! + Returns a const reference to the current matrix at the top of this + matrix stack. This is typically used to fetch the matrix so it can + be set on user-defined shader programs. + + \sa operator=() +*/ +const QMatrix4x4 &QSGMatrix4x4Stack::top() const +{ + Q_D(const QSGMatrix4x4Stack); + return d->matrix; +} + +/*! + \fn QSGMatrix4x4Stack::operator const QMatrix4x4 &() const + + Returns a const reference to the current matrix at the top of + this matrix stack. + + \sa top() +*/ + +/*! + Assigns \a matrix to the matrix at the top of this matrix stack. + + \sa top() +*/ +QSGMatrix4x4Stack& QSGMatrix4x4Stack::operator=(const QMatrix4x4& matrix) +{ + Q_D(QSGMatrix4x4Stack); + d->matrix = matrix; + d->isDirty = true; + return *this; +} + +/*! + Multiplies the matrix at the top of this matrix stack by \a matrix. + + \sa top() +*/ +QSGMatrix4x4Stack& QSGMatrix4x4Stack::operator*=(const QMatrix4x4& matrix) +{ + Q_D(QSGMatrix4x4Stack); + d->matrix *= matrix; + d->isDirty = true; + return *this; +} + +/*! + Multiplies the current matrix at the top of this matrix stack by another + that translates coordinates by (\a x, \a y, \a z). The following example + translates the modelview matrix by (1, -3, 0): + + \code + QGLPainter painter(this); + painter.modelViewMatrix().translate(1.0f, -3.0f, 0.0f); + \endcode + + \sa scale(), rotate() +*/ +void QSGMatrix4x4Stack::translate(qreal x, qreal y, qreal z) +{ + Q_D(QSGMatrix4x4Stack); + d->matrix.translate(x, y, z); + d->isDirty = true; +} + +/*! + Multiplies the current matrix at the top of this matrix statck by another + that translates coordinates by the components of \a vector. + + \sa scale(), rotate() +*/ +void QSGMatrix4x4Stack::translate(const QVector3D& vector) +{ + Q_D(QSGMatrix4x4Stack); + d->matrix.translate(vector); + d->isDirty = true; +} + +/*! + Multiplies the current matrix at the top of this matrix stack by another + that scales coordinates by the components \a x, \a y, and \a z. + The following example scales the modelview matrix by (1, 2, 1): + + \code + QGLPainter painter(this); + painter.modelViewMatrix().scale(1.0f, 2.0f, 1.0f); + \endcode + + \sa translate(), rotate() +*/ +void QSGMatrix4x4Stack::scale(qreal x, qreal y, qreal z) +{ + Q_D(QSGMatrix4x4Stack); + d->matrix.scale(x, y, z); + d->isDirty = true; +} + +/*! + Multiplies the current matrix at the top of this matrix stack by another + that scales coordinates by the given \a factor. The following example + scales the modelview matrix by a factor of 2: + + \code + QGLPainter painter(this); + painter.modelViewMatrix().scale(2.0f); + \endcode + + \sa translate(), rotate() +*/ +void QSGMatrix4x4Stack::scale(qreal factor) +{ + Q_D(QSGMatrix4x4Stack); + d->matrix.scale(factor); + d->isDirty = true; +} + +/*! + Multiplies the current matrix at the top of this matrix stack by another + that scales coordinates by the components of \a vector. + + \sa translate(), rotate() +*/ +void QSGMatrix4x4Stack::scale(const QVector3D& vector) +{ + Q_D(QSGMatrix4x4Stack); + d->matrix.scale(vector); + d->isDirty = true; +} + +/*! + Multiplies the current matrix at the top of this matrix stack by another + that rotates coordinates through \a angle degrees about the vector + (\a x, \a y, \a z). The following example rotates the modelview + matrix by 45 degress about the vector (1, -3, 0): + + \code + QGLPainter painter(this); + painter.modelViewMatrix().rotate(45.0f, 1.0f, -3.0f, 0.0f); + \endcode + + \sa scale(), translate() +*/ +void QSGMatrix4x4Stack::rotate(qreal angle, qreal x, qreal y, qreal z) +{ + Q_D(QSGMatrix4x4Stack); + d->matrix.rotate(angle, x, y, z); + d->isDirty = true; +} + +/*! + Multiplies the current matrix at the top of this matrix stack by another + that rotates coordinates through \a angle degrees about \a vector. + + \sa scale(), translate() +*/ +void QSGMatrix4x4Stack::rotate(qreal angle, const QVector3D& vector) +{ + Q_D(QSGMatrix4x4Stack); + d->matrix.rotate(angle, vector); + d->isDirty = true; +} + +/*! + Multiplies the current matrix at the top of this matrix stack by the + \a quaternion. Thus \c {painter->modelViewMatrix().rotate(quaternion)} + is equivalent to the following code: + \code + QMatrix4x4 mat; + mat.rotate(quaternion); + painter->modelViewMatrix() *= mat; + \endcode + which rotates coordinates according to the given \a quaternion. + + \sa scale(), translate() +*/ +void QSGMatrix4x4Stack::rotate(const QQuaternion &quaternion) +{ + Q_D(QSGMatrix4x4Stack); + d->matrix.rotate(quaternion); + d->isDirty = true; +} + +/*! + Returns true if the top of this matrix stack has been modified; + false otherwise. + + \sa setDirty() +*/ +bool QSGMatrix4x4Stack::isDirty() const +{ + Q_D(const QSGMatrix4x4Stack); + return d->isDirty; +} + +/*! + Sets the \a dirty flag on this matrix stack, which indicates + if it has been modified. + + A matrix stack may also be set to dirty by translate(), + scale(), operator*(), etc. + + \sa isDirty() +*/ +void QSGMatrix4x4Stack::setDirty(bool dirty) +{ + Q_D(QSGMatrix4x4Stack); + d->isDirty = dirty; +} + +QT_END_NAMESPACE |