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Diffstat (limited to 'src/opengl/qglbuffer.cpp')
| -rw-r--r-- | src/opengl/qglbuffer.cpp | 454 |
1 files changed, 454 insertions, 0 deletions
diff --git a/src/opengl/qglbuffer.cpp b/src/opengl/qglbuffer.cpp new file mode 100644 index 0000000..7022a53 --- /dev/null +++ b/src/opengl/qglbuffer.cpp @@ -0,0 +1,454 @@ +/**************************************************************************** +** +** 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 QtOpenGL 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 <QtOpenGL/qgl.h> +#include <QtOpenGL/private/qgl_p.h> +#include <QtOpenGL/private/qglextensions_p.h> +#include "qglbuffer.h" + +QT_BEGIN_NAMESPACE + +/*! + \class QGLBuffer + \brief The QGLBuffer class provides functions for creating and managing GL buffer objects. + \since 4.7 + \ingroup painting-3D + + Buffer objects are created in the GL server so that the + client application can avoid uploading vertices, indices, + texture image data, etc every time they are needed. +*/ + +/*! + \enum QGLBuffer::Type + This enum defines the type of GL buffer object to create with QGLBuffer. + + \value VertexBuffer Vertex buffer object for use when specifying + vertex arrays. + \value IndexBuffer Index buffer object for use with \c{glDrawElements()}. + \value PixelPackBuffer Pixel pack buffer object for reading pixel + data from the GL server (for example, with \c{glReadPixels()}). + Not supported under OpenGL/ES. + \value PixelUnpackBuffer Pixel unpack buffer object for writing pixel + data to the GL server (for example, with \c{glTexImage2D()}). + Not supported under OpenGL/ES. +*/ + +/*! + \enum QGLBuffer::UsagePattern + This enum defines the usage pattern of a QGLBuffer object. + + \value StreamDraw The data will be set once and used a few times + for drawing operations. Under OpenGL/ES 1.1 this is identical + to StaticDraw. + \value StreamRead The data will be set once and used a few times + for reading data back from the GL server. Not supported + under OpenGL/ES. + \value StreamCopy The data will be set once and used a few times + for reading data back from the GL server for use in further + drawing operations. Not supported under OpenGL/ES. + \value StaticDraw The data will be set once and used many times + for drawing operations. + \value StaticRead The data will be set once and used many times + for reading data back from the GL server. Not supported + under OpenGL/ES. + \value StaticCopy The data will be set once and used many times + for reading data back from the GL server for use in further + drawing operations. Not supported under OpenGL/ES. + \value DynamicDraw The data will be modified repeatedly and used + many times for drawing operations. + \value DynamicRead The data will be modified repeatedly and used + many times for reading data back from the GL server. + Not supported under OpenGL/ES. + \value DynamicCopy The data will be modified repeatedly and used + many times for reading data back from the GL server for + use in further drawing operations. Not supported under OpenGL/ES. +*/ + +/*! + \enum QGLBuffer::Access + This enum defines the access mode for QGLBuffer::map(). + + \value ReadOnly The buffer will be mapped for reading only. + \value WriteOnly The buffer will be mapped for writing only. + \value ReadWrite The buffer will be mapped for reading and writing. +*/ + +class QGLBufferPrivate +{ +public: + QGLBufferPrivate(QGLBuffer::Type t) + : type(t), + guard(0), + usagePattern(QGLBuffer::StaticDraw), + actualUsagePattern(QGLBuffer::StaticDraw) + { + } + + QGLBuffer::Type type; + QGLSharedResourceGuard guard; + QGLBuffer::UsagePattern usagePattern; + QGLBuffer::UsagePattern actualUsagePattern; +}; + +/*! + Constructs a new buffer object of \a type. + + Note: this constructor just creates the QGLBuffer instance. The actual + buffer object in the GL server is not created until create() is called. + + \sa create() +*/ +QGLBuffer::QGLBuffer(QGLBuffer::Type type) + : d_ptr(new QGLBufferPrivate(type)) +{ +} + +#define ctx d->guard.context() + +/*! + Destroys this buffer object, including the storage being + used in the GL server. +*/ +QGLBuffer::~QGLBuffer() +{ + Q_D(QGLBuffer); + GLuint bufferId = d->guard.id(); + if (bufferId) { + // Switch to the original creating context to destroy it. + QGLShareContextScope scope(d->guard.context()); + glDeleteBuffers(1, &bufferId); + } +} + +/*! + Returns the type of buffer represented by this object. +*/ +QGLBuffer::Type QGLBuffer::type() const +{ + Q_D(const QGLBuffer); + return d->type; +} + +/*! + Returns the usage pattern for this buffer object. + The default value is StaticDraw. + + \sa setUsagePattern() +*/ +QGLBuffer::UsagePattern QGLBuffer::usagePattern() const +{ + Q_D(const QGLBuffer); + return d->usagePattern; +} + +/*! + Sets the usage pattern for this buffer object to \a value. + This function must be called before allocate() or write(). + + \sa usagePattern(), allocate(), write() +*/ +void QGLBuffer::setUsagePattern(QGLBuffer::UsagePattern value) +{ + Q_D(QGLBuffer); +#if defined(QT_OPENGL_ES_1) + // OpenGL/ES 1.1 does not support GL_STREAM_DRAW, so use GL_STATIC_DRAW. + // OpenGL/ES 2.0 does support GL_STREAM_DRAW. + d->usagePattern = value; + if (value == StreamDraw) + d->actualUsagePattern = StaticDraw; + else + d->actualUsagePattern = value; +#else + d->usagePattern = d->actualUsagePattern = value; +#endif +} + +#undef ctx + +/*! + Creates the buffer object in the GL server. Returns true if + the object was created; false otherwise. + + This function must be called with a current QGLContext. + The buffer will be bound to and can only be used in + that context (or any other context that is shared with it). + + This function will return false if the GL implementation + does not support buffers, or there is no current QGLContext. + + \sa isCreated(), allocate(), write() +*/ +bool QGLBuffer::create() +{ + Q_D(QGLBuffer); + if (d->guard.id()) + return true; + const QGLContext *ctx = QGLContext::currentContext(); + if (ctx) { + if (!qt_resolve_buffer_extensions(const_cast<QGLContext *>(ctx))) + return false; + GLuint bufferId = 0; + glGenBuffers(1, &bufferId); + if (bufferId) { + d->guard.setContext(ctx); + d->guard.setId(bufferId); + return true; + } + } + return false; +} + +#define ctx d->guard.context() + +/*! + Returns true if this buffer has been created; false otherwise. + + \sa create() +*/ +bool QGLBuffer::isCreated() const +{ + Q_D(const QGLBuffer); + return d->guard.id() != 0; +} + +/*! + Reads the \a count bytes in this buffer starting at \a offset + into \a data. Returns true on success; false if reading from + the buffer is not supported. Buffer reading is not supported + under OpenGL/ES. + + It is assumed that this buffer has been bound to the current context. + + \sa write(), bind() +*/ +bool QGLBuffer::read(int offset, void *data, int count) +{ +#if !defined(QT_OPENGL_ES) + Q_D(QGLBuffer); + if (!glGetBufferSubData || !d->guard.id()) + return false; + while (glGetError() != GL_NO_ERROR) ; // Clear error state. + glGetBufferSubData(d->type, offset, count, data); + return glGetError() == GL_NO_ERROR; +#else + Q_UNUSED(offset); + Q_UNUSED(data); + Q_UNUSED(count); + return false; +#endif +} + +/*! + Replaces the \a count bytes of this buffer starting at \a offset + with the contents of \a data. Any other bytes in the buffer + will be left unmodified. + + It is assumed that create() has been called on this buffer and that + it has been bound to the current context. + + \sa create(), read(), allocate() +*/ +void QGLBuffer::write(int offset, const void *data, int count) +{ + Q_D(QGLBuffer); + if (d->guard.id()) + glBufferSubData(d->type, offset, count, data); +} + +/*! + Allocates \a count bytes of space to the buffer, initialized to + the contents of \a data. Any previous contents will be removed. + + It is assumed that create() has been called on this buffer and that + it has been bound to the current context. + + \sa create(), read(), write() +*/ +void QGLBuffer::allocate(const void *data, int count) +{ + Q_D(QGLBuffer); + if (d->guard.id()) + glBufferData(d->type, count, data, d->actualUsagePattern); +} + +/*! + \fn void QGLBuffer::allocate(int count) + \overload + + Allocates \a count bytes of space to the buffer. Any previous + contents will be removed. + + It is assumed that create() has been called on this buffer and that + it has been bound to the current context. + + \sa create(), write() +*/ + +/*! + Binds the buffer associated with this object to the current + GL context. Returns false if binding was not possible, usually because + type() is not supported on this GL implementation. + + The buffer must be bound to the same QGLContext current when create() + was called, or to another QGLContext that is sharing with it. + Otherwise, false will be returned from this function. + + \sa release(), create() +*/ +bool QGLBuffer::bind() const +{ + Q_D(const QGLBuffer); + GLuint bufferId = d->guard.id(); + if (bufferId) { + if (!QGLContext::areSharing(QGLContext::currentContext(), + d->guard.context())) { +#ifndef QT_NO_DEBUG + qWarning("QGLBuffer::bind: buffer is not valid in the current context"); +#endif + return false; + } + glBindBuffer(d->type, bufferId); + return true; + } else { + return false; + } +} + +/*! + Releases the buffer associated with this object from the + current GL context. + + This function must be called with the same QGLContext current + as when bind() was called on the buffer. + + \sa bind() +*/ +void QGLBuffer::release() const +{ + Q_D(const QGLBuffer); + if (d->guard.id()) + glBindBuffer(d->type, 0); +} + +/*! + Returns the GL identifier associated with this buffer; zero if + the buffer has not been created. + + \sa isCreated() +*/ +uint QGLBuffer::bufferId() const +{ + Q_D(const QGLBuffer); + return d->guard.id(); +} + +#ifndef GL_BUFFER_SIZE +#define GL_BUFFER_SIZE 0x8764 +#endif + +/*! + Returns the size of the data in this buffer, for reading operations. + Returns -1 if fetching the buffer size is not supported, or the + buffer has not been created. + + It is assumed that this buffer has been bound to the current context. + + \sa isCreated(), bind() +*/ +int QGLBuffer::size() const +{ + Q_D(const QGLBuffer); + if (!d->guard.id()) + return -1; + GLint value = -1; + glGetBufferParameteriv(d->type, GL_BUFFER_SIZE, &value); + return value; +} + +/*! + Maps the contents of this buffer into the application's memory + space and returns a pointer to it. Returns null if memory + mapping is not possible. The \a access parameter indicates the + type of access to be performed. + + It is assumed that create() has been called on this buffer and that + it has been bound to the current context. + + This function is only supported under OpenGL/ES if the + \c{GL_OES_mapbuffer} extension is present. + + \sa unmap(), create(), bind() +*/ +void *QGLBuffer::map(QGLBuffer::Access access) +{ + Q_D(QGLBuffer); + if (!d->guard.id()) + return 0; + if (!glMapBufferARB) + return 0; + return glMapBufferARB(d->type, access); +} + +/*! + Unmaps the buffer after it was mapped into the application's + memory space with a previous call to map(). Returns true if + the unmap succeeded; false otherwise. + + It is assumed that this buffer has been bound to the current context, + and that it was previously mapped with map(). + + This function is only supported under OpenGL/ES if the + \c{GL_OES_mapbuffer} extension is present. + + \sa map() +*/ +bool QGLBuffer::unmap() +{ + Q_D(QGLBuffer); + if (!d->guard.id()) + return false; + if (!glUnmapBufferARB) + return false; + return glUnmapBufferARB(d->type) == GL_TRUE; +} + +QT_END_NAMESPACE |