1berry/qtbase
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
qtbase/src/gui/opengl/qopenglframebufferobject.cpp
Sean Harmer fc41ee4c92 OpenGL: Use official glext.h and gl2ext.h headers 
The Khronos group makes the glext.h (Desktop OpenGL) and gl2ext.h
(OpenGL ES2) headers officially available nowadays. Most (all?)
Linux systems ship this by default. On Windows platforms the
glext.h file needs to be downloaded from

http://www.opengl.org/registry/api/glext.h

and placed alongside the system OpenGL header.

Making use of the official header reduces the maintenance
overhead for OpenGL support in Qt by removing the need to copy
and paste definitions into the Qt sources.

As the Khronos-provided headers are standardised and backwards and
forwards compatible we can utilise these for all platforms rather
than just for Windows. This means that all definitions required
by Qt will be present even if the system ships out-dated
equivalents.

Mac OS X needs special handling in that we should always use the
system-provided headers there. This is because Apple controls the
OpenGL driver and the headers that go along with it. As such there
is no possibility that the driver exposes additional functionality
compared with the system-provided OpenGL headers. Apple has also
decided to make different decisions about some OpenGL typedefs
compared to other implementations. For example, Apple typdefs
GLhandleARB to void* whereas other platforms use unsigned int.

The alternative, which is to use the system provided glext.h (or
gl2ext.h) header means that Qt code would need to check for the
availability of such definitions wherever it is not guaranteed
to be provided by core OpenGL/ES just to compile.

The proposed approach means that Qt can compile regardless of
the system's OpenGL extension support. We just need to be
rigourous in runtime checking of support for extensions but
that is already a requirement (and is missing in a few places,
see TODO's added in this commit).

The official Khronos headers are added to Qt as

qopenglext.h - Desktop OpenGL
qopengles2ext.h - OpenGL ES2

They need to be public but not part of QtGui module include, hence
the headers have been modified by adding

 #if 0
 #pragma qt_no_master_include
 #endif

to them.

This has been tested on:

Gentoo Linux with GCC 4.6.3
Windows 7 with MSVC 2010
Mac OSX 10.8 with Apple clang 4.0 (based on LLVM 3.1svn)
QNX with qcc (based on GCC 4.4)

A small change is needed to QtDeclarative when building for OpenGL
ES 2 after applying this commit. See
https://codereview.qt-project.org/#change,31794

Change-Id: I4b3d2b1680baf4c78be9a87b4d8de076d23e8f82
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
2012-08-20 11:58:16 +02:00

1321 lines
44 KiB
C++
Raw Blame History

/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** 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.
**
** 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.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qopenglframebufferobject.h"
#include "qopenglframebufferobject_p.h"
#include <qdebug.h>
#include <private/qopengl_p.h>
#include <private/qopenglcontext_p.h>
#include <private/qopenglextensions_p.h>
#include <private/qfont_p.h>
#include <qwindow.h>
#include <qlibrary.h>
#include <qimage.h>
QT_BEGIN_NAMESPACE
#ifndef QT_NO_DEBUG
#define QT_RESET_GLERROR() \
{ \
while (glGetError() != GL_NO_ERROR) {} \
}
#define QT_CHECK_GLERROR() \
{ \
GLenum err = glGetError(); \
if (err != GL_NO_ERROR) { \
qDebug("[%s line %d] OpenGL Error: %d", \
__FILE__, __LINE__, (int)err); \
} \
}
#else
#define QT_RESET_GLERROR() {}
#define QT_CHECK_GLERROR() {}
#endif
// ####TODO Properly #ifdef this class to use #define symbols actually defined
// by OpenGL/ES includes
#ifndef GL_MAX_SAMPLES
#define GL_MAX_SAMPLES 0x8D57
#endif
#ifndef GL_RENDERBUFFER_SAMPLES
#define GL_RENDERBUFFER_SAMPLES 0x8CAB
#endif
#ifndef GL_DEPTH24_STENCIL8
#define GL_DEPTH24_STENCIL8 0x88F0
#endif
#ifndef GL_DEPTH_COMPONENT24
#define GL_DEPTH_COMPONENT24 0x81A6
#endif
#ifndef GL_READ_FRAMEBUFFER
#define GL_READ_FRAMEBUFFER 0x8CA8
#endif
#ifndef GL_DRAW_FRAMEBUFFER
#define GL_DRAW_FRAMEBUFFER 0x8CA9
#endif
/*!
\class QOpenGLFramebufferObjectFormat
\brief The QOpenGLFramebufferObjectFormat class specifies the format of an OpenGL
framebuffer object.
\inmodule QtGui
\since 5.0
\ingroup painting-3D
A framebuffer object has several characteristics:
\list
\li \l{setSamples()}{Number of samples per pixels.}
\li \l{setAttachment()}{Depth and/or stencil attachments.}
\li \l{setTextureTarget()}{Texture target.}
\li \l{setInternalTextureFormat()}{Internal texture format.}
\endlist
Note that the desired attachments or number of samples per pixels might not
be supported by the hardware driver. Call QOpenGLFramebufferObject::format()
after creating a QOpenGLFramebufferObject to find the exact format that was
used to create the frame buffer object.
\sa QOpenGLFramebufferObject
*/
/*!
\internal
*/
void QOpenGLFramebufferObjectFormat::detach()
{
if (d->ref.load() != 1) {
QOpenGLFramebufferObjectFormatPrivate *newd
= new QOpenGLFramebufferObjectFormatPrivate(d);
if (!d->ref.deref())
delete d;
d = newd;
}
}
/*!
Creates a QOpenGLFramebufferObjectFormat object for specifying
the format of an OpenGL framebuffer object.
By default the format specifies a non-multisample framebuffer object with no
attachments, texture target \c GL_TEXTURE_2D, and internal format \c GL_RGBA8.
On OpenGL/ES systems, the default internal format is \c GL_RGBA.
\sa samples(), attachment(), internalTextureFormat()
*/
QOpenGLFramebufferObjectFormat::QOpenGLFramebufferObjectFormat()
{
d = new QOpenGLFramebufferObjectFormatPrivate;
}
/*!
Constructs a copy of \a other.
*/
QOpenGLFramebufferObjectFormat::QOpenGLFramebufferObjectFormat(const QOpenGLFramebufferObjectFormat &other)
{
d = other.d;
d->ref.ref();
}
/*!
Assigns \a other to this object.
*/
QOpenGLFramebufferObjectFormat &QOpenGLFramebufferObjectFormat::operator=(const QOpenGLFramebufferObjectFormat &other)
{
if (d != other.d) {
other.d->ref.ref();
if (!d->ref.deref())
delete d;
d = other.d;
}
return *this;
}
/*!
Destroys the QOpenGLFramebufferObjectFormat.
*/
QOpenGLFramebufferObjectFormat::~QOpenGLFramebufferObjectFormat()
{
if (!d->ref.deref())
delete d;
}
/*!
Sets the number of samples per pixel for a multisample framebuffer object
to \a samples. The default sample count of 0 represents a regular
non-multisample framebuffer object.
If the desired amount of samples per pixel is not supported by the hardware
then the maximum number of samples per pixel will be used. Note that
multisample framebuffer objects can not be bound as textures. Also, the
\c{GL_EXT_framebuffer_multisample} extension is required to create a
framebuffer with more than one sample per pixel.
\sa samples()
*/
void QOpenGLFramebufferObjectFormat::setSamples(int samples)
{
detach();
d->samples = samples;
}
/*!
Returns the number of samples per pixel if a framebuffer object
is a multisample framebuffer object. Otherwise, returns 0.
The default value is 0.
\sa setSamples()
*/
int QOpenGLFramebufferObjectFormat::samples() const
{
return d->samples;
}
/*!
Enables mipmapping if \a enabled is true; otherwise disables it.
Mipmapping is disabled by default.
If mipmapping is enabled, additional memory will be allocated for
the mipmap levels. The mipmap levels can be updated by binding the
texture and calling glGenerateMipmap(). Mipmapping cannot be enabled
for multisampled framebuffer objects.
\sa mipmap(), QOpenGLFramebufferObject::texture()
*/
void QOpenGLFramebufferObjectFormat::setMipmap(bool enabled)
{
detach();
d->mipmap = enabled;
}
/*!
Returns true if mipmapping is enabled.
\sa setMipmap()
*/
bool QOpenGLFramebufferObjectFormat::mipmap() const
{
return d->mipmap;
}
/*!
Sets the attachment configuration of a framebuffer object to \a attachment.
\sa attachment()
*/
void QOpenGLFramebufferObjectFormat::setAttachment(QOpenGLFramebufferObject::Attachment attachment)
{
detach();
d->attachment = attachment;
}
/*!
Returns the configuration of the depth and stencil buffers attached to
a framebuffer object. The default is QOpenGLFramebufferObject::NoAttachment.
\sa setAttachment()
*/
QOpenGLFramebufferObject::Attachment QOpenGLFramebufferObjectFormat::attachment() const
{
return d->attachment;
}
/*!
Sets the texture target of the texture attached to a framebuffer object to
\a target. Ignored for multisample framebuffer objects.
\sa textureTarget(), samples()
*/
void QOpenGLFramebufferObjectFormat::setTextureTarget(GLenum target)
{
detach();
d->target = target;
}
/*!
Returns the texture target of the texture attached to a framebuffer object.
Ignored for multisample framebuffer objects. The default is
\c GL_TEXTURE_2D.
\sa setTextureTarget(), samples()
*/
GLenum QOpenGLFramebufferObjectFormat::textureTarget() const
{
return d->target;
}
/*!
Sets the internal format of a framebuffer object's texture or
multisample framebuffer object's color buffer to
\a internalTextureFormat.
\sa internalTextureFormat()
*/
void QOpenGLFramebufferObjectFormat::setInternalTextureFormat(GLenum internalTextureFormat)
{
detach();
d->internal_format = internalTextureFormat;
}
/*!
Returns the internal format of a framebuffer object's texture or
multisample framebuffer object's color buffer. The default is
\c GL_RGBA8 on desktop OpenGL systems, and \c GL_RGBA on
OpenGL/ES systems.
\sa setInternalTextureFormat()
*/
GLenum QOpenGLFramebufferObjectFormat::internalTextureFormat() const
{
return d->internal_format;
}
/*!
Returns true if all the options of this framebuffer object format
are the same as \a other; otherwise returns false.
*/
bool QOpenGLFramebufferObjectFormat::operator==(const QOpenGLFramebufferObjectFormat& other) const
{
if (d == other.d)
return true;
else
return d->equals(other.d);
}
/*!
Returns false if all the options of this framebuffer object format
are the same as \a other; otherwise returns true.
*/
bool QOpenGLFramebufferObjectFormat::operator!=(const QOpenGLFramebufferObjectFormat& other) const
{
return !(*this == other);
}
bool QOpenGLFramebufferObjectPrivate::checkFramebufferStatus(QOpenGLContext *ctx) const
{
if (!ctx)
return false; // Context no longer exists.
GLenum status = ctx->functions()->glCheckFramebufferStatus(GL_FRAMEBUFFER);
switch(status) {
case GL_NO_ERROR:
case GL_FRAMEBUFFER_COMPLETE:
return true;
break;
case GL_FRAMEBUFFER_UNSUPPORTED:
qDebug("QOpenGLFramebufferObject: Unsupported framebuffer format.");
break;
case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
qDebug("QOpenGLFramebufferObject: Framebuffer incomplete attachment.");
break;
case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
qDebug("QOpenGLFramebufferObject: Framebuffer incomplete, missing attachment.");
break;
#ifdef GL_FRAMEBUFFER_INCOMPLETE_DUPLICATE_ATTACHMENT
case GL_FRAMEBUFFER_INCOMPLETE_DUPLICATE_ATTACHMENT:
qDebug("QOpenGLFramebufferObject: Framebuffer incomplete, duplicate attachment.");
break;
#endif
#ifdef GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS
case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS:
qDebug("QOpenGLFramebufferObject: Framebuffer incomplete, attached images must have same dimensions.");
break;
#endif
#ifdef GL_FRAMEBUFFER_INCOMPLETE_FORMATS
case GL_FRAMEBUFFER_INCOMPLETE_FORMATS:
qDebug("QOpenGLFramebufferObject: Framebuffer incomplete, attached images must have same format.");
break;
#endif
#ifdef GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER
case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER:
qDebug("QOpenGLFramebufferObject: Framebuffer incomplete, missing draw buffer.");
break;
#endif
#ifdef GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER
case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER:
qDebug("QOpenGLFramebufferObject: Framebuffer incomplete, missing read buffer.");
break;
#endif
#ifdef GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE
case GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE:
qDebug("QOpenGLFramebufferObject: Framebuffer incomplete, attachments must have same number of samples per pixel.");
break;
#endif
default:
qDebug() <<"QOpenGLFramebufferObject: An undefined error has occurred: "<< status;
break;
}
return false;
}
namespace
{
void freeFramebufferFunc(QOpenGLFunctions *funcs, GLuint id)
{
funcs->glDeleteFramebuffers(1, &id);
}
void freeRenderbufferFunc(QOpenGLFunctions *funcs, GLuint id)
{
funcs->glDeleteRenderbuffers(1, &id);
}
void freeTextureFunc(QOpenGLFunctions *, GLuint id)
{
glDeleteTextures(1, &id);
}
}
void QOpenGLFramebufferObjectPrivate::init(QOpenGLFramebufferObject *, const QSize &sz,
QOpenGLFramebufferObject::Attachment attachment,
GLenum texture_target, GLenum internal_format,
GLint samples, bool mipmap)
{
QOpenGLContext *ctx = QOpenGLContext::currentContext();
funcs.initializeOpenGLFunctions();
if (!funcs.hasOpenGLFeature(QOpenGLFunctions::Framebuffers))
return;
size = sz;
target = texture_target;
// texture dimensions
QT_RESET_GLERROR(); // reset error state
GLuint fbo = 0;
funcs.glGenFramebuffers(1, &fbo);
funcs.glBindFramebuffer(GL_FRAMEBUFFER, fbo);
GLuint texture = 0;
GLuint color_buffer = 0;
QT_CHECK_GLERROR();
// init texture
if (samples == 0) {
glGenTextures(1, &texture);
glBindTexture(target, texture);
glTexParameteri(target, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(target, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(target, 0, internal_format, size.width(), size.height(), 0,
GL_RGBA, GL_UNSIGNED_BYTE, NULL);
if (mipmap) {
int width = size.width();
int height = size.height();
int level = 0;
while (width > 1 || height > 1) {
width = qMax(1, width >> 1);
height = qMax(1, height >> 1);
++level;
glTexImage2D(target, level, internal_format, width, height, 0,
GL_RGBA, GL_UNSIGNED_BYTE, NULL);
}
}
funcs.glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
target, texture, 0);
QT_CHECK_GLERROR();
valid = checkFramebufferStatus(ctx);
glBindTexture(target, 0);
color_buffer = 0;
} else {
mipmap = false;
GLint maxSamples;
glGetIntegerv(GL_MAX_SAMPLES, &maxSamples);
samples = qBound(0, int(samples), int(maxSamples));
funcs.glGenRenderbuffers(1, &color_buffer);
funcs.glBindRenderbuffer(GL_RENDERBUFFER, color_buffer);
if (funcs.hasOpenGLExtension(QOpenGLExtensions::FramebufferMultisample) && samples > 0) {
funcs.glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples,
internal_format, size.width(), size.height());
} else {
samples = 0;
funcs.glRenderbufferStorage(GL_RENDERBUFFER, internal_format,
size.width(), size.height());
}
funcs.glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_RENDERBUFFER, color_buffer);
QT_CHECK_GLERROR();
valid = checkFramebufferStatus(ctx);
if (valid)
funcs.glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_SAMPLES, &samples);
}
format.setTextureTarget(target);
format.setSamples(int(samples));
format.setInternalTextureFormat(internal_format);
format.setMipmap(mipmap);
initAttachments(ctx, attachment);
funcs.glBindFramebuffer(GL_FRAMEBUFFER, ctx->d_func()->current_fbo);
if (valid) {
fbo_guard = new QOpenGLSharedResourceGuard(ctx, fbo, freeFramebufferFunc);
if (color_buffer)
color_buffer_guard = new QOpenGLSharedResourceGuard(ctx, color_buffer, freeRenderbufferFunc);
else
texture_guard = new QOpenGLSharedResourceGuard(ctx, texture, freeTextureFunc);
} else {
if (color_buffer)
funcs.glDeleteRenderbuffers(1, &color_buffer);
else
glDeleteTextures(1, &texture);
funcs.glDeleteFramebuffers(1, &fbo);
}
QT_CHECK_GLERROR();
}
void QOpenGLFramebufferObjectPrivate::initAttachments(QOpenGLContext *ctx, QOpenGLFramebufferObject::Attachment attachment)
{
int samples = format.samples();
// free existing attachments
if (depth_buffer_guard) {
funcs.glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, 0);
depth_buffer_guard->free();
}
if (stencil_buffer_guard) {
funcs.glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, 0);
if (stencil_buffer_guard != depth_buffer_guard)
stencil_buffer_guard->free();
}
depth_buffer_guard = 0;
stencil_buffer_guard = 0;
GLuint depth_buffer = 0;
GLuint stencil_buffer = 0;
// In practice, a combined depth-stencil buffer is supported by all desktop platforms, while a
// separate stencil buffer is not. On embedded devices however, a combined depth-stencil buffer
// might not be supported while separate buffers are, according to QTBUG-12861.
if (attachment == QOpenGLFramebufferObject::CombinedDepthStencil
&& funcs.hasOpenGLExtension(QOpenGLExtensions::PackedDepthStencil))
{
// depth and stencil buffer needs another extension
funcs.glGenRenderbuffers(1, &depth_buffer);
funcs.glBindRenderbuffer(GL_RENDERBUFFER, depth_buffer);
Q_ASSERT(funcs.glIsRenderbuffer(depth_buffer));
if (samples != 0 && funcs.hasOpenGLExtension(QOpenGLExtensions::FramebufferMultisample))
funcs.glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples,
GL_DEPTH24_STENCIL8, size.width(), size.height());
else
funcs.glRenderbufferStorage(GL_RENDERBUFFER,
GL_DEPTH24_STENCIL8, size.width(), size.height());
stencil_buffer = depth_buffer;
funcs.glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
GL_RENDERBUFFER, depth_buffer);
funcs.glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
GL_RENDERBUFFER, stencil_buffer);
valid = checkFramebufferStatus(ctx);
if (!valid) {
funcs.glDeleteRenderbuffers(1, &depth_buffer);
stencil_buffer = depth_buffer = 0;
}
}
if (depth_buffer == 0 && (attachment == QOpenGLFramebufferObject::CombinedDepthStencil
|| (attachment == QOpenGLFramebufferObject::Depth)))
{
funcs.glGenRenderbuffers(1, &depth_buffer);
funcs.glBindRenderbuffer(GL_RENDERBUFFER, depth_buffer);
Q_ASSERT(funcs.glIsRenderbuffer(depth_buffer));
if (samples != 0 && funcs.hasOpenGLExtension(QOpenGLExtensions::FramebufferMultisample)) {
#ifdef QT_OPENGL_ES
if (funcs.hasOpenGLExtension(QOpenGLExtensions::Depth24)) {
funcs.glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples,
GL_DEPTH_COMPONENT24, size.width(), size.height());
} else {
funcs.glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples,
GL_DEPTH_COMPONENT16, size.width(), size.height());
}
#else
funcs.glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples,
GL_DEPTH_COMPONENT, size.width(), size.height());
#endif
} else {
#ifdef QT_OPENGL_ES
if (funcs.hasOpenGLExtension(QOpenGLExtensions::Depth24)) {
funcs.glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24,
size.width(), size.height());
} else {
funcs.glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16,
size.width(), size.height());
}
#else
funcs.glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, size.width(), size.height());
#endif
}
funcs.glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
GL_RENDERBUFFER, depth_buffer);
valid = checkFramebufferStatus(ctx);
if (!valid) {
funcs.glDeleteRenderbuffers(1, &depth_buffer);
depth_buffer = 0;
}
}
if (stencil_buffer == 0 && (attachment == QOpenGLFramebufferObject::CombinedDepthStencil)) {
funcs.glGenRenderbuffers(1, &stencil_buffer);
funcs.glBindRenderbuffer(GL_RENDERBUFFER, stencil_buffer);
Q_ASSERT(funcs.glIsRenderbuffer(stencil_buffer));
if (samples != 0 && funcs.hasOpenGLExtension(QOpenGLExtensions::FramebufferMultisample)) {
#ifdef QT_OPENGL_ES
funcs.glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples,
GL_STENCIL_INDEX8, size.width(), size.height());
#else
funcs.glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples,
GL_STENCIL_INDEX, size.width(), size.height());
#endif
} else {
#ifdef QT_OPENGL_ES
funcs.glRenderbufferStorage(GL_RENDERBUFFER, GL_STENCIL_INDEX8,
size.width(), size.height());
#else
funcs.glRenderbufferStorage(GL_RENDERBUFFER, GL_STENCIL_INDEX,
size.width(), size.height());
#endif
}
funcs.glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
GL_RENDERBUFFER, stencil_buffer);
valid = checkFramebufferStatus(ctx);
if (!valid) {
funcs.glDeleteRenderbuffers(1, &stencil_buffer);
stencil_buffer = 0;
}
}
// The FBO might have become valid after removing the depth or stencil buffer.
valid = checkFramebufferStatus(ctx);
if (depth_buffer && stencil_buffer) {
fbo_attachment = QOpenGLFramebufferObject::CombinedDepthStencil;
} else if (depth_buffer) {
fbo_attachment = QOpenGLFramebufferObject::Depth;
} else {
fbo_attachment = QOpenGLFramebufferObject::NoAttachment;
}
if (valid) {
if (depth_buffer)
depth_buffer_guard = new QOpenGLSharedResourceGuard(ctx, depth_buffer, freeRenderbufferFunc);
if (stencil_buffer) {
if (stencil_buffer == depth_buffer)
stencil_buffer_guard = depth_buffer_guard;
else
stencil_buffer_guard = new QOpenGLSharedResourceGuard(ctx, stencil_buffer, freeRenderbufferFunc);
}
} else {
if (depth_buffer)
funcs.glDeleteRenderbuffers(1, &depth_buffer);
if (stencil_buffer && depth_buffer != stencil_buffer)
funcs.glDeleteRenderbuffers(1, &stencil_buffer);
}
QT_CHECK_GLERROR();
format.setAttachment(fbo_attachment);
}
/*!
\class QOpenGLFramebufferObject
\brief The QOpenGLFramebufferObject class encapsulates an OpenGL framebuffer object.
\since 5.0
\inmodule QtGui
\ingroup painting-3D
The QOpenGLFramebufferObject class encapsulates an OpenGL framebuffer
object, defined by the \c{GL_EXT_framebuffer_object} extension. In
addition it provides a rendering surface that can be painted on
with a QPainter, rendered to using native OpenGL calls, or both. This
surface can be bound and used as a regular texture in your own OpenGL
drawing code. By default, the QOpenGLFramebufferObject class
generates a 2D OpenGL texture (using the \c{GL_TEXTURE_2D} target),
which is used as the internal rendering target.
\b{It is important to have a current OpenGL context when creating a
QOpenGLFramebufferObject, otherwise initialization will fail.}
When using a QPainter to paint to a QOpenGLFramebufferObject you should take
care that the QOpenGLFramebufferObject is created with the CombinedDepthStencil
attachment for QPainter to be able to render correctly.
Note that you need to create a QOpenGLFramebufferObject with more than one
sample per pixel for primitives to be antialiased when drawing using a
QPainter. To create a multisample framebuffer object you should use one of
the constructors that take a QOpenGLFramebufferObject parameter, and set the
QOpenGLFramebufferObject::samples() property to a non-zero value.
For multisample framebuffer objects a color render buffer is created,
otherwise a texture with the specified texture target is created.
The color render buffer or texture will have the specified internal
format, and will be bound to the \c GL_COLOR_ATTACHMENT0
attachment in the framebuffer object.
If you want to use a framebuffer object with multisampling enabled
as a texture, you first need to copy from it to a regular framebuffer
object using QOpenGLContext::blitFramebuffer().
\section1 Threading
As of Qt 4.8, it's possible to draw into a QOpenGLFramebufferObject
using a QPainter in a separate thread. Note that OpenGL 2.0 or
OpenGL ES 2.0 is required for this to work.
*/
/*!
\enum QOpenGLFramebufferObject::Attachment
This enum type is used to configure the depth and stencil buffers
attached to the framebuffer object when it is created.
\value NoAttachment No attachment is added to the framebuffer object. Note that the
OpenGL depth and stencil tests won't work when rendering to a
framebuffer object without any depth or stencil buffers.
This is the default value.
\value CombinedDepthStencil If the \c GL_EXT_packed_depth_stencil extension is present,
a combined depth and stencil buffer is attached.
If the extension is not present, only a depth buffer is attached.
\value Depth A depth buffer is attached to the framebuffer object.
\sa attachment()
*/
/*! \fn QOpenGLFramebufferObject::QOpenGLFramebufferObject(const QSize &size, GLenum target)
Constructs an OpenGL framebuffer object and binds a 2D OpenGL texture
to the buffer of the size \a size. The texture is bound to the
\c GL_COLOR_ATTACHMENT0 target in the framebuffer object.
The \a target parameter is used to specify the OpenGL texture
target. The default target is \c GL_TEXTURE_2D. Keep in mind that
\c GL_TEXTURE_2D textures must have a power of 2 width and height
(e.g. 256x512), unless you are using OpenGL 2.0 or higher.
By default, no depth and stencil buffers are attached. This behavior
can be toggled using one of the overloaded constructors.
The default internal texture format is \c GL_RGBA8 for desktop
OpenGL, and \c GL_RGBA for OpenGL/ES.
It is important that you have a current OpenGL context set when
creating the QOpenGLFramebufferObject, otherwise the initialization
will fail.
\sa size(), texture(), attachment()
*/
QOpenGLFramebufferObject::QOpenGLFramebufferObject(const QSize &size, GLenum target)
: d_ptr(new QOpenGLFramebufferObjectPrivate)
{
Q_D(QOpenGLFramebufferObject);
d->init(this, size, NoAttachment, target, DEFAULT_FORMAT);
}
/*! \overload
Constructs an OpenGL framebuffer object and binds a 2D OpenGL texture
to the buffer of the given \a width and \a height.
\sa size(), texture()
*/
QOpenGLFramebufferObject::QOpenGLFramebufferObject(int width, int height, GLenum target)
: d_ptr(new QOpenGLFramebufferObjectPrivate)
{
Q_D(QOpenGLFramebufferObject);
d->init(this, QSize(width, height), NoAttachment, target, DEFAULT_FORMAT);
}
/*! \overload
Constructs an OpenGL framebuffer object of the given \a size based on the
supplied \a format.
*/
QOpenGLFramebufferObject::QOpenGLFramebufferObject(const QSize &size, const QOpenGLFramebufferObjectFormat &format)
: d_ptr(new QOpenGLFramebufferObjectPrivate)
{
Q_D(QOpenGLFramebufferObject);
d->init(this, size, format.attachment(), format.textureTarget(), format.internalTextureFormat(),
format.samples(), format.mipmap());
}
/*! \overload
Constructs an OpenGL framebuffer object of the given \a width and \a height
based on the supplied \a format.
*/
QOpenGLFramebufferObject::QOpenGLFramebufferObject(int width, int height, const QOpenGLFramebufferObjectFormat &format)
: d_ptr(new QOpenGLFramebufferObjectPrivate)
{
Q_D(QOpenGLFramebufferObject);
d->init(this, QSize(width, height), format.attachment(), format.textureTarget(),
format.internalTextureFormat(), format.samples(), format.mipmap());
}
/*! \overload
Constructs an OpenGL framebuffer object and binds a texture to the
buffer of the given \a width and \a height.
The \a attachment parameter describes the depth/stencil buffer
configuration, \a target the texture target and \a internal_format
the internal texture format. The default texture target is \c
GL_TEXTURE_2D, while the default internal format is \c GL_RGBA8
for desktop OpenGL and \c GL_RGBA for OpenGL/ES.
\sa size(), texture(), attachment()
*/
QOpenGLFramebufferObject::QOpenGLFramebufferObject(int width, int height, Attachment attachment,
GLenum target, GLenum internal_format)
: d_ptr(new QOpenGLFramebufferObjectPrivate)
{
Q_D(QOpenGLFramebufferObject);
d->init(this, QSize(width, height), attachment, target, internal_format);
}
/*! \overload
Constructs an OpenGL framebuffer object and binds a texture to the
buffer of the given \a size.
The \a attachment parameter describes the depth/stencil buffer
configuration, \a target the texture target and \a internal_format
the internal texture format. The default texture target is \c
GL_TEXTURE_2D, while the default internal format is \c GL_RGBA8
for desktop OpenGL and \c GL_RGBA for OpenGL/ES.
\sa size(), texture(), attachment()
*/
QOpenGLFramebufferObject::QOpenGLFramebufferObject(const QSize &size, Attachment attachment,
GLenum target, GLenum internal_format)
: d_ptr(new QOpenGLFramebufferObjectPrivate)
{
Q_D(QOpenGLFramebufferObject);
d->init(this, size, attachment, target, internal_format);
}
/*!
\fn QOpenGLFramebufferObject::~QOpenGLFramebufferObject()
Destroys the framebuffer object and frees any allocated resources.
*/
QOpenGLFramebufferObject::~QOpenGLFramebufferObject()
{
Q_D(QOpenGLFramebufferObject);
if (d->texture_guard)
d->texture_guard->free();
if (d->color_buffer_guard)
d->color_buffer_guard->free();
if (d->depth_buffer_guard)
d->depth_buffer_guard->free();
if (d->stencil_buffer_guard && d->stencil_buffer_guard != d->depth_buffer_guard)
d->stencil_buffer_guard->free();
if (d->fbo_guard)
d->fbo_guard->free();
}
/*!
\fn bool QOpenGLFramebufferObject::isValid() const
Returns true if the framebuffer object is valid.
The framebuffer can become invalid if the initialization process
fails, the user attaches an invalid buffer to the framebuffer
object, or a non-power of two width/height is specified as the
texture size if the texture target is \c{GL_TEXTURE_2D}.
The non-power of two limitation does not apply if the OpenGL version
is 2.0 or higher, or if the GL_ARB_texture_non_power_of_two extension
is present.
The framebuffer can also become invalid if the QOpenGLContext that
the framebuffer was created within is destroyed and there are
no other shared contexts that can take over ownership of the
framebuffer.
*/
bool QOpenGLFramebufferObject::isValid() const
{
Q_D(const QOpenGLFramebufferObject);
return d->valid && d->fbo_guard && d->fbo_guard->id();
}
/*!
\fn bool QOpenGLFramebufferObject::bind()
Switches rendering from the default, windowing system provided
framebuffer to this framebuffer object.
Returns true upon success, false otherwise.
\sa release()
*/
bool QOpenGLFramebufferObject::bind()
{
if (!isValid())
return false;
Q_D(QOpenGLFramebufferObject);
QOpenGLContext *current = QOpenGLContext::currentContext();
if (!current)
return false;
#ifdef QT_DEBUG
if (current->shareGroup() != d->fbo_guard->group())
qWarning("QOpenGLFramebufferObject::bind() called from incompatible context");
#endif
d->funcs.glBindFramebuffer(GL_FRAMEBUFFER, d->fbo());
d->valid = d->checkFramebufferStatus(current);
if (d->valid && current)
current->d_func()->current_fbo = d->fbo();
return d->valid;
}
/*!
\fn bool QOpenGLFramebufferObject::release()
Switches rendering back to the default, windowing system provided
framebuffer.
Returns true upon success, false otherwise.
\sa bind()
*/
bool QOpenGLFramebufferObject::release()
{
if (!isValid())
return false;
QOpenGLContext *current = QOpenGLContext::currentContext();
if (!current)
return false;
Q_D(QOpenGLFramebufferObject);
#ifdef QT_DEBUG
if (current->shareGroup() != d->fbo_guard->group())
qWarning("QOpenGLFramebufferObject::release() called from incompatible context");
#endif
if (current) {
current->d_func()->current_fbo = current->defaultFramebufferObject();
d->funcs.glBindFramebuffer(GL_FRAMEBUFFER, current->d_func()->current_fbo);
}
return true;
}
/*!
\fn GLuint QOpenGLFramebufferObject::texture() const
Returns the texture id for the texture attached as the default
rendering target in this framebuffer object. This texture id can
be bound as a normal texture in your own OpenGL code.
If a multisample framebuffer object is used then the value returned
from this function will be invalid.
*/
GLuint QOpenGLFramebufferObject::texture() const
{
Q_D(const QOpenGLFramebufferObject);
return d->texture_guard ? d->texture_guard->id() : 0;
}
/*!
\fn QSize QOpenGLFramebufferObject::size() const
Returns the size of the texture attached to this framebuffer
object.
*/
QSize QOpenGLFramebufferObject::size() const
{
Q_D(const QOpenGLFramebufferObject);
return d->size;
}
/*!
\fn int QOpenGLFramebufferObject::width() const
Returns the width of the framebuffer object attachments.
*/
/*!
\fn int QOpenGLFramebufferObject::height() const
Returns the height of the framebuffer object attachments.
*/
/*!
Returns the format of this framebuffer object.
*/
QOpenGLFramebufferObjectFormat QOpenGLFramebufferObject::format() const
{
Q_D(const QOpenGLFramebufferObject);
return d->format;
}
namespace {
/*
Read back the contents of the currently bound framebuffer, used in
QGLWidget::grabFrameBuffer(), QGLPixelbuffer::toImage() and
QGLFramebufferObject::toImage()
*/
void convertFromGLImage(QImage &img, int w, int h, bool alpha_format, bool include_alpha)
{
if (QSysInfo::ByteOrder == QSysInfo::BigEndian) {
// OpenGL gives RGBA; Qt wants ARGB
uint *p = (uint*)img.bits();
uint *end = p + w*h;
if (alpha_format && include_alpha) {
while (p < end) {
uint a = *p << 24;
*p = (*p >> 8) | a;
p++;
}
} else {
// This is an old legacy fix for PowerPC based Macs, which
// we shouldn't remove
while (p < end) {
*p = 0xff000000 | (*p>>8);
++p;
}
}
} else {
// OpenGL gives ABGR (i.e. RGBA backwards); Qt wants ARGB
for (int y = 0; y < h; y++) {
uint *q = (uint*)img.scanLine(y);
for (int x=0; x < w; ++x) {
const uint pixel = *q;
if (alpha_format && include_alpha) {
*q = ((pixel << 16) & 0xff0000) | ((pixel >> 16) & 0xff)
| (pixel & 0xff00ff00);
} else {
*q = 0xff000000 | ((pixel << 16) & 0xff0000)
| ((pixel >> 16) & 0xff) | (pixel & 0x00ff00);
}
q++;
}
}
}
img = img.mirrored();
}
}
Q_GUI_EXPORT QImage qt_gl_read_framebuffer(const QSize &size, bool alpha_format, bool include_alpha)
{
QImage img(size, (alpha_format && include_alpha) ? QImage::Format_ARGB32_Premultiplied
: QImage::Format_RGB32);
int w = size.width();
int h = size.height();
glReadPixels(0, 0, w, h, GL_RGBA, GL_UNSIGNED_BYTE, img.bits());
convertFromGLImage(img, w, h, alpha_format, include_alpha);
return img;
}
/*!
\fn QImage QOpenGLFramebufferObject::toImage() const
Returns the contents of this framebuffer object as a QImage.
*/
QImage QOpenGLFramebufferObject::toImage() const
{
Q_D(const QOpenGLFramebufferObject);
if (!d->valid)
return QImage();
// qt_gl_read_framebuffer doesn't work on a multisample FBO
if (format().samples() != 0) {
QOpenGLFramebufferObject temp(size(), QOpenGLFramebufferObjectFormat());
QRect rect(QPoint(0, 0), size());
blitFramebuffer(&temp, rect, const_cast<QOpenGLFramebufferObject *>(this), rect);
return temp.toImage();
}
bool wasBound = isBound();
if (!wasBound)
const_cast<QOpenGLFramebufferObject *>(this)->bind();
QImage image = qt_gl_read_framebuffer(d->size, format().internalTextureFormat() != GL_RGB, true);
if (!wasBound)
const_cast<QOpenGLFramebufferObject *>(this)->release();
return image;
}
/*!
\fn bool QOpenGLFramebufferObject::bindDefault()
\internal
Switches rendering back to the default, windowing system provided
framebuffer.
Returns true upon success, false otherwise.
\sa bind(), release()
*/
bool QOpenGLFramebufferObject::bindDefault()
{
QOpenGLContext *ctx = const_cast<QOpenGLContext *>(QOpenGLContext::currentContext());
QOpenGLFunctions functions(ctx);
if (ctx) {
ctx->d_func()->current_fbo = ctx->defaultFramebufferObject();
functions.glBindFramebuffer(GL_FRAMEBUFFER, ctx->d_func()->current_fbo);
#ifdef QT_DEBUG
} else {
qWarning("QOpenGLFramebufferObject::bindDefault() called without current context.");
#endif
}
return ctx != 0;
}
/*!
\fn bool QOpenGLFramebufferObject::hasOpenGLFramebufferObjects()
Returns true if the OpenGL \c{GL_EXT_framebuffer_object} extension
is present on this system; otherwise returns false.
*/
bool QOpenGLFramebufferObject::hasOpenGLFramebufferObjects()
{
return QOpenGLFunctions(QOpenGLContext::currentContext()).hasOpenGLFeature(QOpenGLFunctions::Framebuffers);
}
/*!
\fn GLuint QOpenGLFramebufferObject::handle() const
Returns the OpenGL framebuffer object handle for this framebuffer
object (returned by the \c{glGenFrameBuffersEXT()} function). This
handle can be used to attach new images or buffers to the
framebuffer. The user is responsible for cleaning up and
destroying these objects.
*/
GLuint QOpenGLFramebufferObject::handle() const
{
Q_D(const QOpenGLFramebufferObject);
return d->fbo();
}
/*!
Returns the status of the depth and stencil buffers attached to
this framebuffer object.
*/
QOpenGLFramebufferObject::Attachment QOpenGLFramebufferObject::attachment() const
{
Q_D(const QOpenGLFramebufferObject);
if (d->valid)
return d->fbo_attachment;
return NoAttachment;
}
/*!
Sets the attachments of the framebuffer object.
This can be used to free or reattach the depth and stencil buffer
attachments as needed.
*/
void QOpenGLFramebufferObject::setAttachment(QOpenGLFramebufferObject::Attachment attachment)
{
Q_D(QOpenGLFramebufferObject);
if (attachment == d->fbo_attachment || !isValid())
return;
QOpenGLContext *current = QOpenGLContext::currentContext();
if (!current)
return;
#ifdef QT_DEBUG
if (current->shareGroup() != d->fbo_guard->group())
qWarning("QOpenGLFramebufferObject::setAttachment() called from incompatible context");
#endif
d->funcs.glBindFramebuffer(GL_FRAMEBUFFER, d->fbo());
d->initAttachments(current, attachment);
if (current->d_func()->current_fbo != d->fbo())
d->funcs.glBindFramebuffer(GL_FRAMEBUFFER, current->d_func()->current_fbo);
}
/*!
Returns true if the framebuffer object is currently bound to a context,
otherwise false is returned.
*/
bool QOpenGLFramebufferObject::isBound() const
{
Q_D(const QOpenGLFramebufferObject);
QOpenGLContext *current = QOpenGLContext::currentContext();
return current ? current->d_func()->current_fbo == d->fbo() : false;
}
/*!
\fn bool QOpenGLFramebufferObject::hasOpenGLFramebufferBlit()
Returns true if the OpenGL \c{GL_EXT_framebuffer_blit} extension
is present on this system; otherwise returns false.
\sa blitFramebuffer()
*/
bool QOpenGLFramebufferObject::hasOpenGLFramebufferBlit()
{
return QOpenGLExtensions(QOpenGLContext::currentContext()).hasOpenGLExtension(QOpenGLExtensions::FramebufferBlit);
}
/*!
\overload
Convenience overload to blit between two framebuffer objects.
*/
void QOpenGLFramebufferObject::blitFramebuffer(QOpenGLFramebufferObject *target,
QOpenGLFramebufferObject *source,
GLbitfield buffers, GLenum filter)
{
if (!target && !source)
return;
QSize targetSize;
QSize sourceSize;
if (target)
targetSize = target->size();
if (source)
sourceSize = source->size();
if (targetSize.isEmpty())
targetSize = sourceSize;
else if (sourceSize.isEmpty())
sourceSize = targetSize;
blitFramebuffer(target, QRect(QPoint(0, 0), targetSize),
source, QRect(QPoint(0, 0), sourceSize),
buffers, filter);
}
/*!
Blits from the \a sourceRect rectangle in the \a source framebuffer
object to the \a targetRect rectangle in the \a target framebuffer object.
If \a source or \a target is 0, the default framebuffer will be used
instead of a framebuffer object as source or target respectively.
The \a buffers parameter should be a mask consisting of any combination of
\c GL_COLOR_BUFFER_BIT, \c GL_DEPTH_BUFFER_BIT, and
\c GL_STENCIL_BUFFER_BIT. Any buffer type that is not present both
in the source and target buffers is ignored.
The \a sourceRect and \a targetRect rectangles may have different sizes;
in this case \a buffers should not contain \c GL_DEPTH_BUFFER_BIT or
\c GL_STENCIL_BUFFER_BIT. The \a filter parameter should be set to
\c GL_LINEAR or \c GL_NEAREST, and specifies whether linear or nearest
interpolation should be used when scaling is performed.
If \a source equals \a target a copy is performed within the same buffer.
Results are undefined if the source and target rectangles overlap and
have different sizes. The sizes must also be the same if any of the
framebuffer objects are multisample framebuffers.
Note that the scissor test will restrict the blit area if enabled.
This function will have no effect unless hasOpenGLFramebufferBlit() returns
true.
\sa hasOpenGLFramebufferBlit()
*/
void QOpenGLFramebufferObject::blitFramebuffer(QOpenGLFramebufferObject *target, const QRect &targetRect,
QOpenGLFramebufferObject *source, const QRect &sourceRect,
GLbitfield buffers,
GLenum filter)
{
QOpenGLContext *ctx = QOpenGLContext::currentContext();
if (!ctx)
return;
QOpenGLExtensions extensions(ctx);
if (!extensions.hasOpenGLExtension(QOpenGLExtensions::FramebufferBlit))
return;
const int sx0 = sourceRect.left();
const int sx1 = sourceRect.left() + sourceRect.width();
const int sy0 = sourceRect.top();
const int sy1 = sourceRect.top() + sourceRect.height();
const int tx0 = targetRect.left();
const int tx1 = targetRect.left() + targetRect.width();
const int ty0 = targetRect.top();
const int ty1 = targetRect.top() + targetRect.height();
extensions.glBindFramebuffer(GL_READ_FRAMEBUFFER, source ? source->handle() : 0);
extensions.glBindFramebuffer(GL_DRAW_FRAMEBUFFER, target ? target->handle() : 0);
extensions.glBlitFramebuffer(sx0, sy0, sx1, sy1,
tx0, ty0, tx1, ty1,
buffers, filter);
extensions.glBindFramebuffer(GL_FRAMEBUFFER, ctx->d_func()->current_fbo);
}
QT_END_NAMESPACE
Reference in New Issue View Git Blame Copy Permalink