qgl.cpp

奇趣公司比较新的qt/emd版本

}

/*! \overload

    Generates and binds a 2D GL texture based on \a pixmap.
*/
GLuint QGLContext::bindTexture(const QPixmap &pixmap, GLenum target, GLint format)
{
    Q_D(QGLContext);
    return d->bindTexture(pixmap, target, format, false);
}

/*!
    Removes the texture identified by \a id from the texture cache. If
    the context is not shared by any other QGLContext,
    glDeleteTextures() will be called to delete the texture from the
    context.

    \sa bindTexture()
*/
void QGLContext::deleteTexture(GLuint id)
{
    if (!qt_tex_cache)
        return;

    QList<QString> keys = qt_tex_cache->keys();
    for (int i = 0; i < keys.size(); ++i) {
        QGLTexture *tex = qt_tex_cache->object(keys.at(i));
        if (tex->id == id && tex->context == this) {
            qt_tex_cache->remove(keys.at(i));
            break;
        }
    }
}

/*!
    This function sets the limit for the texture cache to \a size,
    expressed in kilobytes.

    By default, the cache limit is approximately 64 MB.

    \sa textureCacheLimit()
*/
void QGLContext::setTextureCacheLimit(int size)
{
    qt_tex_cache_limit = size;
    if (qt_tex_cache)
        qt_tex_cache->setMaxCost(qt_tex_cache_limit);
}

/*!
    Returns the current texture cache limit in kilobytes.

    \sa setTextureCacheLimit()
*/
int QGLContext::textureCacheLimit()
{
    return qt_tex_cache_limit;
}


/*!
    \fn QGLFormat QGLContext::format() const

    Returns the frame buffer format that was obtained (this may be a
    subset of what was requested).

    \sa requestedFormat()
*/

/*!
    \fn QGLFormat QGLContext::requestedFormat() const

    Returns the frame buffer format that was originally requested in
    the constructor or setFormat().

    \sa format()
*/

/*!
    Sets a \a format for this context. The context is \link reset()
    reset\endlink.

    Call create() to create a new GL context that tries to match the
    new format.

    \code
    QGLContext *cx;
    //  ...
    QGLFormat f;
    f.setStereo(true);
    cx->setFormat(f);
    if (!cx->create())
        exit(); // no OpenGL support, or cannot render on the specified paintdevice
    if (!cx->format().stereo())
        exit(); // could not create stereo context
    \endcode

    \sa format(), reset(), create()
*/

void QGLContext::setFormat(const QGLFormat &format)
{
    Q_D(QGLContext);
    reset();
    d->glFormat = d->reqFormat = format;
}

/*!
    \internal
*/
void QGLContext::setDevice(QPaintDevice *pDev)
{
    Q_D(QGLContext);
    if (isValid())
        reset();
    d->paintDevice = pDev;
    if (d->paintDevice && (d->paintDevice->devType() != QInternal::Widget
                           && d->paintDevice->devType() != QInternal::Pixmap
                           && d->paintDevice->devType() != QInternal::Pbuffer)) {
        qWarning("QGLContext: Unsupported paint device type");
    }
}

/*!
    \fn bool QGLContext::isValid() const

    Returns true if a GL rendering context has been successfully
    created; otherwise returns false.
*/

/*!
    \fn void QGLContext::setValid(bool valid)
    \internal

    Forces the GL rendering context to be valid.
*/

/*!
    \fn bool QGLContext::isSharing() const

    Returns true if this context is sharing its GL context with
    another QGLContext, otherwise false is returned. Note that context
    sharing might not be supported between contexts with different
    formats.
*/

/*!
    \fn bool QGLContext::deviceIsPixmap() const

    Returns true if the paint device of this context is a pixmap;
    otherwise returns false.
*/

/*!
    \fn bool QGLContext::windowCreated() const

    Returns true if a window has been created for this context;
    otherwise returns false.

    \sa setWindowCreated()
*/

/*!
    \fn void QGLContext::setWindowCreated(bool on)

    If \a on is true the context has had a window created for it. If
    \a on is false no window has been created for the context.

    \sa windowCreated()
*/

/*!
    \fn uint QGLContext::colorIndex(const QColor& c) const

    \internal

    Returns a colormap index for the color c, in ColorIndex mode. Used
    by qglColor() and qglClearColor().
*/


/*!
    \fn bool QGLContext::initialized() const

    Returns true if this context has been initialized, i.e. if
    QGLWidget::initializeGL() has been performed on it; otherwise
    returns false.

    \sa setInitialized()
*/

/*!
    \fn void QGLContext::setInitialized(bool on)

    If \a on is true the context has been initialized, i.e.
    QGLContext::setInitialized() has been called on it. If \a on is
    false the context has not been initialized.

    \sa initialized()
*/

/*!
    \fn const QGLContext* QGLContext::currentContext()

    Returns the current context, i.e. the context to which any OpenGL
    commands will currently be directed. Returns 0 if no context is
    current.

    \sa makeCurrent()
*/

/*!
    \fn QColor QGLContext::overlayTransparentColor() const

    If this context is a valid context in an overlay plane, returns
    the plane's transparent color. Otherwise returns an \link
    QColor::isValid() invalid \endlink color.

    The returned color's \link QColor::pixel() pixel \endlink value is
    the index of the transparent color in the colormap of the overlay
    plane. (Naturally, the color's RGB values are meaningless.)

    The returned QColor object will generally work as expected only
    when passed as the argument to QGLWidget::qglColor() or
    QGLWidget::qglClearColor(). Under certain circumstances it can
    also be used to draw transparent graphics with a QPainter. See the
    examples/opengl/overlay_x11 example for details.
*/


/*!
    Creates the GL context. Returns true if it was successful in
    creating a valid GL rendering context on the paint device
    specified in the constructor; otherwise returns false (i.e. the
    context is invalid).

    After successful creation, format() returns the set of features of
    the created GL rendering context.

    If \a shareContext points to a valid QGLContext, this method will
    try to establish OpenGL display list and texture object sharing
    between this context and the \a shareContext. Note that this may
    fail if the two contexts have different \l {format()} {formats}.
    Use isSharing() to see if sharing is in effect.

    \warning Implementation note: initialization of C++ class
    members usually takes place in the class constructor. QGLContext
    is an exception because it must be simple to customize. The
    virtual functions chooseContext() (and chooseVisual() for X11) can
    be reimplemented in a subclass to select a particular context. The
    problem is that virtual functions are not properly called during
    construction (even though this is correct C++) because C++
    constructs class hierarchies from the bottom up. For this reason
    we need a create() function.

    \sa chooseContext(), format(), isValid()
*/

bool QGLContext::create(const QGLContext* shareContext)
{
    Q_D(QGLContext);
    reset();
    d->valid = chooseContext(shareContext);
    if (d->sharing)  // ok, we managed to share
        qgl_share_reg()->addShare(this, shareContext);
    return d->valid;
}

bool QGLContext::isValid() const
{
    Q_D(const QGLContext);
    return d->valid;
}

void QGLContext::setValid(bool valid)
{
    Q_D(QGLContext);
    d->valid = valid;
}

bool QGLContext::isSharing() const
{
    Q_D(const QGLContext);
    return d->sharing;
}

QGLFormat QGLContext::format() const
{
    Q_D(const QGLContext);
    return d->glFormat;
}

QGLFormat QGLContext::requestedFormat() const
{
    Q_D(const QGLContext);
    return d->reqFormat;
}

 QPaintDevice* QGLContext::device() const
{
    Q_D(const QGLContext);
    return d->paintDevice;
}

bool QGLContext::deviceIsPixmap() const
{
    Q_D(const QGLContext);
    return d->paintDevice->devType() == QInternal::Pixmap;
}


bool QGLContext::windowCreated() const
{
    Q_D(const QGLContext);
    return d->crWin;
}


void QGLContext::setWindowCreated(bool on)
{
    Q_D(QGLContext);
    d->crWin = on;
}

bool QGLContext::initialized() const
{
    Q_D(const QGLContext);
    return d->initDone;
}

void QGLContext::setInitialized(bool on)
{
    Q_D(QGLContext);
    d->initDone = on;
}

const QGLContext* QGLContext::currentContext()
{
    if (qgl_context_storage.hasLocalData())
        return qgl_context_storage.localData()->context;
    return 0;
}

/*!
    \fn bool QGLContext::chooseContext(const QGLContext* shareContext = 0)

    This semi-internal function is called by create(). It creates a
    system-dependent OpenGL handle that matches the format() of \a
    shareContext as closely as possible, returning true if successful
    or false if a suitable handle could not be found.

    On Windows, it calls the virtual function choosePixelFormat(),
    which finds a matching pixel format identifier. On X11, it calls
    the virtual function chooseVisual() which finds an appropriate X
    visual. On other platforms it may work differently.
*/


/*!
    \fn void QGLContext::reset()

    Resets the context and makes it invalid.

    \sa create(), isValid()
*/


/*!
    \fn void QGLContext::makeCurrent()

    Makes this context the current OpenGL rendering context. All GL
    functions you call operate on this context until another context
    is made current.

    In some very rare cases the underlying call may fail. If this
    occurs an error message is output to stderr.
*/


/*!
    \fn void QGLContext::swapBuffers() const

    Swaps the screen contents with an off-screen buffer. Only works if
    the context is in double buffer mode.

    \sa QGLFormat::setDoubleBuffer()
*/


/*!
    \fn void QGLContext::doneCurrent()

    Makes no GL context the current context. Normally, you do not need
    to call this function; QGLContext calls it as necessary.
*/


/*!
    \fn QPaintDevice* QGLContext::device() const

    Returns the paint device set for this context.

    \sa QGLContext::QGLContext()
*/

/*!
    \obsolete
    \fn void QGLContext::generateFontDisplayLists(const QFont& font, int listBase)

    Generates a set of 256 display lists for the 256 first characters
    in the font \a font. The first list will start at index \a listBase.

    \sa QGLWidget::renderText()
*/


/*****************************************************************************
  QGLWidget implementation
 *****************************************************************************/


/*!
    \class QGLWidget
    \brief The QGLWidget class is a widget for rendering OpenGL graphics.

    \ingroup multimedia
    \mainclass

    QGLWidget provides functionality for displaying OpenGL graphics
    integrated into a Qt application. It is very simple to use. You
    inherit from it and use the subclass like any other QWidget,
    except that you have the choice between using QPainter and
    standard OpenGL rendering commands.

    QGLWidget provides three convenient virtual functions that you can
    reimplement in your subclass to perform the typical OpenGL tasks:

    \list
    \i paintGL() - Renders the OpenGL scene. Gets called whenever the widget
    needs to be updated.
    \i resizeGL() - Sets up the OpenGL viewport, projection, etc. Gets
    called whenever the the widget has been resized (and also when it
    is shown for the first time because all newly created widgets get a
    resize event automatically).
    \i initializeGL() - Sets up the OpenGL rendering context, defines display
    lists, etc. Gets called once before the first time resizeGL() or
    paintGL() is called.
    \endlist

    Here is a rough outline of how a QGLWidget subclass might look:

    \code
    class MyGLDrawer : public QGLWidget
    {
        Q_OBJECT        // must include this if you use Qt signals/slots

    public:
        MyGLDrawer(QWidget *parent)
            : QGLWidget(