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Diffstat (limited to 'src/opengl/qopenglvertexarrayobject.cpp')
| -rw-r--r-- | src/opengl/qopenglvertexarrayobject.cpp | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/src/opengl/qopenglvertexarrayobject.cpp b/src/opengl/qopenglvertexarrayobject.cpp new file mode 100644 index 0000000000..a6ac282d4c --- /dev/null +++ b/src/opengl/qopenglvertexarrayobject.cpp @@ -0,0 +1,531 @@ +/**************************************************************************** +** +** Copyright (C) 2014 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Sean Harmer <sean.harmer@kdab.com> +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtOpenGL 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 "qopenglvertexarrayobject.h" + +#include <QtCore/private/qobject_p.h> +#include <QtCore/qthread.h> +#include <QtGui/qopenglcontext.h> +#include <QtGui/qoffscreensurface.h> +#include <QtGui/qguiapplication.h> + +#include <QtGui/qopenglfunctions_3_0.h> +#include <QtGui/qopenglfunctions_3_2_core.h> + +#include <private/qopenglextensions_p.h> +#include <private/qopenglvertexarrayobject_p.h> + +QT_BEGIN_NAMESPACE + +class QOpenGLFunctions_3_0; +class QOpenGLFunctions_3_2_Core; + +void qtInitializeVertexArrayObjectHelper(QOpenGLVertexArrayObjectHelper *helper, QOpenGLContext *context) +{ + Q_ASSERT(helper); + Q_ASSERT(context); + + bool tryARB = true; + + if (context->isOpenGLES()) { + if (context->format().majorVersion() >= 3) { + QOpenGLExtraFunctionsPrivate *extra = static_cast<QOpenGLExtensions *>(context->extraFunctions())->d(); + helper->GenVertexArrays = extra->f.GenVertexArrays; + helper->DeleteVertexArrays = extra->f.DeleteVertexArrays; + helper->BindVertexArray = extra->f.BindVertexArray; + helper->IsVertexArray = extra->f.IsVertexArray; + tryARB = false; + } else if (context->hasExtension(QByteArrayLiteral("GL_OES_vertex_array_object"))) { + helper->GenVertexArrays = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_GenVertexArrays_t>(context->getProcAddress("glGenVertexArraysOES")); + helper->DeleteVertexArrays = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_DeleteVertexArrays_t>(context->getProcAddress("glDeleteVertexArraysOES")); + helper->BindVertexArray = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_BindVertexArray_t>(context->getProcAddress("glBindVertexArrayOES")); + helper->IsVertexArray = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_IsVertexArray_t>(context->getProcAddress("glIsVertexArrayOES")); + tryARB = false; + } + } else if (context->hasExtension(QByteArrayLiteral("GL_APPLE_vertex_array_object")) && + !context->hasExtension(QByteArrayLiteral("GL_ARB_vertex_array_object"))) { + helper->GenVertexArrays = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_GenVertexArrays_t>(context->getProcAddress("glGenVertexArraysAPPLE")); + helper->DeleteVertexArrays = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_DeleteVertexArrays_t>(context->getProcAddress("glDeleteVertexArraysAPPLE")); + helper->BindVertexArray = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_BindVertexArray_t>(context->getProcAddress("glBindVertexArrayAPPLE")); + helper->IsVertexArray = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_IsVertexArray_t>(context->getProcAddress("glIsVertexArrayAPPLE")); + tryARB = false; + } + + if (tryARB && context->hasExtension(QByteArrayLiteral("GL_ARB_vertex_array_object"))) { + helper->GenVertexArrays = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_GenVertexArrays_t>(context->getProcAddress("glGenVertexArrays")); + helper->DeleteVertexArrays = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_DeleteVertexArrays_t>(context->getProcAddress("glDeleteVertexArrays")); + helper->BindVertexArray = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_BindVertexArray_t>(context->getProcAddress("glBindVertexArray")); + helper->IsVertexArray = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_IsVertexArray_t>(context->getProcAddress("glIsVertexArray")); + } +} + +class QOpenGLVertexArrayObjectPrivate : public QObjectPrivate +{ +public: + QOpenGLVertexArrayObjectPrivate() + : vao(0) + , vaoFuncsType(NotSupported) + , context(nullptr) + { + } + + ~QOpenGLVertexArrayObjectPrivate() + { + if (vaoFuncsType == ARB || vaoFuncsType == APPLE || vaoFuncsType == OES) + delete vaoFuncs.helper; + } + + bool create(); + void destroy(); + void bind(); + void release(); + void _q_contextAboutToBeDestroyed(); + + Q_DECLARE_PUBLIC(QOpenGLVertexArrayObject) + + GLuint vao; + + union { + QOpenGLFunctions_3_0 *core_3_0; + QOpenGLFunctions_3_2_Core *core_3_2; + QOpenGLVertexArrayObjectHelper *helper; + } vaoFuncs; + enum { + NotSupported, + Core_3_0, + Core_3_2, + ARB, + APPLE, + OES + } vaoFuncsType; + + QOpenGLContext *context; +}; + +bool QOpenGLVertexArrayObjectPrivate::create() +{ + if (vao) { + qWarning("QOpenGLVertexArrayObject::create() VAO is already created"); + return false; + } + + Q_Q(QOpenGLVertexArrayObject); + + QOpenGLContext *ctx = QOpenGLContext::currentContext(); + if (!ctx) { + qWarning("QOpenGLVertexArrayObject::create() requires a valid current OpenGL context"); + return false; + } + + //Fail early, if context is the same as ctx, it means we have tried to initialize for this context and failed + if (ctx == context) + return false; + + context = ctx; + QObject::connect(context, SIGNAL(aboutToBeDestroyed()), q, SLOT(_q_contextAboutToBeDestroyed())); + + if (ctx->isOpenGLES()) { + if (ctx->format().majorVersion() >= 3 || ctx->hasExtension(QByteArrayLiteral("GL_OES_vertex_array_object"))) { + vaoFuncs.helper = new QOpenGLVertexArrayObjectHelper(ctx); + vaoFuncsType = OES; + vaoFuncs.helper->glGenVertexArrays(1, &vao); + } + } else { + vaoFuncs.core_3_0 = nullptr; + vaoFuncsType = NotSupported; + QSurfaceFormat format = ctx->format(); +#ifndef QT_OPENGL_ES_2 + if (format.version() >= qMakePair<int, int>(3,2)) { + vaoFuncs.core_3_2 = ctx->versionFunctions<QOpenGLFunctions_3_2_Core>(); + vaoFuncsType = Core_3_2; + vaoFuncs.core_3_2->glGenVertexArrays(1, &vao); + } else if (format.majorVersion() >= 3) { + vaoFuncs.core_3_0 = ctx->versionFunctions<QOpenGLFunctions_3_0>(); + vaoFuncsType = Core_3_0; + vaoFuncs.core_3_0->glGenVertexArrays(1, &vao); + } else +#endif + if (ctx->hasExtension(QByteArrayLiteral("GL_ARB_vertex_array_object"))) { + vaoFuncs.helper = new QOpenGLVertexArrayObjectHelper(ctx); + vaoFuncsType = ARB; + vaoFuncs.helper->glGenVertexArrays(1, &vao); + } else if (ctx->hasExtension(QByteArrayLiteral("GL_APPLE_vertex_array_object"))) { + vaoFuncs.helper = new QOpenGLVertexArrayObjectHelper(ctx); + vaoFuncsType = APPLE; + vaoFuncs.helper->glGenVertexArrays(1, &vao); + } + } + + return (vao != 0); +} + +void QOpenGLVertexArrayObjectPrivate::destroy() +{ + Q_Q(QOpenGLVertexArrayObject); + + QOpenGLContext *ctx = QOpenGLContext::currentContext(); + QOpenGLContext *oldContext = nullptr; + QSurface *oldContextSurface = nullptr; + QScopedPointer<QOffscreenSurface> offscreenSurface; + if (context && context != ctx) { + oldContext = ctx; + oldContextSurface = ctx ? ctx->surface() : nullptr; + // Before going through the effort of creating an offscreen surface + // check that we are on the GUI thread because otherwise many platforms + // will not able to create that offscreen surface. + if (QThread::currentThread() != qGuiApp->thread()) { + ctx = nullptr; + } else { + // Cannot just make the current surface current again with another context. + // The format may be incompatible and some platforms (iOS) may impose + // restrictions on using a window with different contexts. Create an + // offscreen surface (a pbuffer or a hidden window) instead to be safe. + offscreenSurface.reset(new QOffscreenSurface); + offscreenSurface->setFormat(context->format()); + offscreenSurface->create(); + if (context->makeCurrent(offscreenSurface.data())) { + ctx = context; + } else { + qWarning("QOpenGLVertexArrayObject::destroy() failed to make VAO's context current"); + ctx = nullptr; + } + } + } + + if (context) { + QObject::disconnect(context, SIGNAL(aboutToBeDestroyed()), q, SLOT(_q_contextAboutToBeDestroyed())); + context = nullptr; + } + + if (vao && ctx) { + switch (vaoFuncsType) { +#ifndef QT_OPENGL_ES_2 + case Core_3_2: + vaoFuncs.core_3_2->glDeleteVertexArrays(1, &vao); + break; + case Core_3_0: + vaoFuncs.core_3_0->glDeleteVertexArrays(1, &vao); + break; +#endif + case ARB: + case APPLE: + case OES: + vaoFuncs.helper->glDeleteVertexArrays(1, &vao); + break; + default: + break; + } + + vao = 0; + } + + if (oldContext && oldContextSurface) { + if (!oldContext->makeCurrent(oldContextSurface)) + qWarning("QOpenGLVertexArrayObject::destroy() failed to restore current context"); + } +} + +/*! + \internal +*/ +void QOpenGLVertexArrayObjectPrivate::_q_contextAboutToBeDestroyed() +{ + destroy(); +} + +void QOpenGLVertexArrayObjectPrivate::bind() +{ + switch (vaoFuncsType) { +#ifndef QT_OPENGL_ES_2 + case Core_3_2: + vaoFuncs.core_3_2->glBindVertexArray(vao); + break; + case Core_3_0: + vaoFuncs.core_3_0->glBindVertexArray(vao); + break; +#endif + case ARB: + case APPLE: + case OES: + vaoFuncs.helper->glBindVertexArray(vao); + break; + default: + break; + } +} + +void QOpenGLVertexArrayObjectPrivate::release() +{ + switch (vaoFuncsType) { +#ifndef QT_OPENGL_ES_2 + case Core_3_2: + vaoFuncs.core_3_2->glBindVertexArray(0); + break; + case Core_3_0: + vaoFuncs.core_3_0->glBindVertexArray(0); + break; +#endif + case ARB: + case APPLE: + case OES: + vaoFuncs.helper->glBindVertexArray(0); + break; + default: + break; + } +} + + +/*! + \class QOpenGLVertexArrayObject + \brief The QOpenGLVertexArrayObject class wraps an OpenGL Vertex Array Object. + \inmodule QtOpenGL + \since 5.1 + \ingroup painting-3D + + A Vertex Array Object (VAO) is an OpenGL container object that encapsulates + the state needed to specify per-vertex attribute data to the OpenGL pipeline. + To put it another way, a VAO remembers the states of buffer objects (see + QOpenGLBuffer) and their associated state (e.g. vertex attribute divisors). + This allows a very easy and efficient method of switching between OpenGL buffer + states for rendering different "objects" in a scene. The QOpenGLVertexArrayObject + class is a thin wrapper around an OpenGL VAO. + + For the desktop, VAOs are supported as a core feature in OpenGL 3.0 or newer and by the + GL_ARB_vertex_array_object for older versions. On OpenGL ES 2, VAOs are provided by + the optional GL_OES_vertex_array_object extension. You can check the version of + OpenGL with QOpenGLContext::surfaceFormat() and check for the presence of extensions + with QOpenGLContext::hasExtension(). + + As with the other Qt OpenGL classes, QOpenGLVertexArrayObject has a create() + function to create the underlying OpenGL object. This is to allow the developer to + ensure that there is a valid current OpenGL context at the time. + + Once you have successfully created a VAO the typical usage pattern is: + + \list + \li In scene initialization function, for each visual object: + \list + \li Bind the VAO + \li Set vertex data state for this visual object (vertices, normals, texture coordinates etc.) + \li Unbind (release()) the VAO + \endlist + \li In render function, for each visual object: + \list + \li Bind the VAO (and shader program if needed) + \li Call a glDraw*() function + \li Unbind (release()) the VAO + \endlist + \endlist + + The act of binding the VAO in the render function has the effect of restoring + all of the vertex data state setup in the initialization phase. In this way we can + set a great deal of state when setting up a VAO and efficiently switch between + state sets of objects to be rendered. Using VAOs also allows the OpenGL driver + to amortise the validation checks of the vertex data. + + \note Vertex Array Objects, like all other OpenGL container objects, are specific + to the context for which they were created and cannot be shared amongst a + context group. + + \sa QOpenGLVertexArrayObject::Binder, QOpenGLBuffer +*/ + +/*! + Creates a QOpenGLVertexArrayObject with the given \a parent. You must call create() + with a valid OpenGL context before using. +*/ +QOpenGLVertexArrayObject::QOpenGLVertexArrayObject(QObject* parent) + : QObject(*new QOpenGLVertexArrayObjectPrivate, parent) +{ +} + +/*! + \internal +*/ +QOpenGLVertexArrayObject::QOpenGLVertexArrayObject(QOpenGLVertexArrayObjectPrivate &dd) + : QObject(dd) +{ +} + +/*! + Destroys the QOpenGLVertexArrayObject and the underlying OpenGL resource. +*/ +QOpenGLVertexArrayObject::~QOpenGLVertexArrayObject() +{ + destroy(); +} + +/*! + Creates the underlying OpenGL vertex array object. There must be a valid OpenGL context + that supports vertex array objects current for this function to succeed. + + Returns \c true if the OpenGL vertex array object was successfully created. + + When the return value is \c false, vertex array object support is not available. This + is not an error: on systems with OpenGL 2.x or OpenGL ES 2.0 vertex array objects may + not be supported. The application is free to continue execution in this case, but it + then has to be prepared to operate in a VAO-less manner too. This means that instead + of merely calling bind(), the value of isCreated() must be checked and the vertex + arrays has to be initialized in the traditional way when there is no vertex array + object present. + + \sa isCreated() +*/ +bool QOpenGLVertexArrayObject::create() +{ + Q_D(QOpenGLVertexArrayObject); + return d->create(); +} + +/*! + Destroys the underlying OpenGL vertex array object. There must be a valid OpenGL context + that supports vertex array objects current for this function to succeed. +*/ +void QOpenGLVertexArrayObject::destroy() +{ + Q_D(QOpenGLVertexArrayObject); + d->destroy(); +} + +/*! + Returns \c true is the underlying OpenGL vertex array object has been created. If this + returns \c true and the associated OpenGL context is current, then you are able to bind() + this object. +*/ +bool QOpenGLVertexArrayObject::isCreated() const +{ + Q_D(const QOpenGLVertexArrayObject); + return (d->vao != 0); +} + +/*! + Returns the id of the underlying OpenGL vertex array object. +*/ +GLuint QOpenGLVertexArrayObject::objectId() const +{ + Q_D(const QOpenGLVertexArrayObject); + return d->vao; +} + +/*! + Binds this vertex array object to the OpenGL binding point. From this point on + and until release() is called or another vertex array object is bound, any + modifications made to vertex data state are stored inside this vertex array object. + + If another vertex array object is then bound you can later restore the set of + state associated with this object by calling bind() on this object once again. + This allows efficient changes between vertex data states in rendering functions. +*/ +void QOpenGLVertexArrayObject::bind() +{ + Q_D(QOpenGLVertexArrayObject); + d->bind(); +} + +/*! + Unbinds this vertex array object by binding the default vertex array object (id = 0). +*/ +void QOpenGLVertexArrayObject::release() +{ + Q_D(QOpenGLVertexArrayObject); + d->release(); +} + + +/*! + \class QOpenGLVertexArrayObject::Binder + \brief The QOpenGLVertexArrayObject::Binder class is a convenience class to help + with the binding and releasing of OpenGL Vertex Array Objects. + \inmodule QtOpenGL + \reentrant + \since 5.1 + \ingroup painting-3D + + QOpenGLVertexArrayObject::Binder is a simple convenience class that can be used + to assist with the binding and releasing of QOpenGLVertexArrayObject instances. + This class is to QOpenGLVertexArrayObject as QMutexLocker is to QMutex. + + This class implements the RAII principle which helps to ensure behavior in + complex code or in the presence of exceptions. + + The constructor of this class accepts a QOpenGLVertexArrayObject (VAO) as an + argument and attempts to bind the VAO, calling QOpenGLVertexArrayObject::create() + if necessary. The destructor of this class calls QOpenGLVertexArrayObject::release() + which unbinds the VAO. + + If needed the VAO can be temporarily unbound with the release() function and bound + once more with rebind(). + + \sa QOpenGLVertexArrayObject +*/ + +/*! + \fn QOpenGLVertexArrayObject::Binder::Binder(QOpenGLVertexArrayObject *v) + + Creates a QOpenGLVertexArrayObject::Binder object and binds \a v by calling + QOpenGLVertexArrayObject::bind(). If necessary it first calls + QOpenGLVertexArrayObject::create(). +*/ + +/*! + \fn QOpenGLVertexArrayObject::Binder::~Binder() + + Destroys the QOpenGLVertexArrayObject::Binder and releases the associated vertex array object. +*/ + +/*! + \fn QOpenGLVertexArrayObject::Binder::release() + + Can be used to temporarily release the associated vertex array object. + + \sa rebind() +*/ + +/*! + \fn QOpenGLVertexArrayObject::Binder::rebind() + + Can be used to rebind the associated vertex array object. + + \sa release() +*/ + +QT_END_NAMESPACE + +#include "moc_qopenglvertexarrayobject.cpp" |