qglcontext.html

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<p> <p>See also <a href="#chooseContext">chooseContext</a>(), <a href="#format">format</a>() and <a href="#isValid">isValid</a>().

<h3 class=fn>const&nbsp;<a href="qglcontext.html">QGLContext</a>&nbsp;* <a name="currentContext"></a>QGLContext::currentContext ()<tt> [static]</tt>
</h3>

<p> Returns the current context, i.e. the context to which any OpenGL
commands will currently be directed. Returns 0 if no context is
current.
<p> <p>See also <a href="#makeCurrent">makeCurrent</a>().

<h3 class=fn><a href="qpaintdevice.html">QPaintDevice</a>&nbsp;* <a name="device"></a>QGLContext::device () const
</h3>

<p> Returns the paint device set for this context.
<p> <p>See also <a href="#QGLContext">QGLContext::QGLContext</a>().

<h3 class=fn>bool <a name="deviceIsPixmap"></a>QGLContext::deviceIsPixmap () const<tt> [protected]</tt>
</h3>

<p> Returns TRUE if the paint device of this context is a pixmap;
otherwise returns FALSE.

<h3 class=fn>void <a name="doneCurrent"></a>QGLContext::doneCurrent ()<tt> [virtual protected]</tt>
</h3>

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

<h3 class=fn><a href="qglformat.html">QGLFormat</a> <a name="format"></a>QGLContext::format () const
</h3>

Returns the frame buffer format that was obtained (this may be a
subset of what was requested).
<p> <p>See also <a href="#requestedFormat">requestedFormat</a>().

<h3 class=fn>bool <a name="initialized"></a>QGLContext::initialized () const<tt> [protected]</tt>
</h3>

<p> Returns TRUE if this context has been initialized, i.e. if
<a href="qglwidget.html#initializeGL">QGLWidget::initializeGL</a>() has been performed on it; otherwise returns
FALSE.
<p> <p>See also <a href="#setInitialized">setInitialized</a>().

<h3 class=fn>bool <a name="isSharing"></a>QGLContext::isSharing () const
</h3>

<p> Returns TRUE if display list sharing with another context was
requested in the <a href="#create">create</a>() call and the GL system was able to
fulfill this request; otherwise returns FALSE. Note that display list
sharing might not be supported between contexts with different
formats.

<h3 class=fn>bool <a name="isValid"></a>QGLContext::isValid () const
</h3>

Returns TRUE if a GL rendering context has been successfully created;
otherwise returns FALSE.

<h3 class=fn>void <a name="makeCurrent"></a>QGLContext::makeCurrent ()<tt> [virtual]</tt>
</h3>

<p> Makes this context the current OpenGL rendering context.  All GL
functions you call operate on this context until another context is
made current.
<p> Note that under special circumstances the underlying call may fail,
in which case this will not be reported back to the caller. However,
a message is printed to stderr stating this.

<h3 class=fn><a href="qcolor.html">QColor</a> <a name="overlayTransparentColor"></a>QGLContext::overlayTransparentColor () const
</h3>

<p> If this context is a valid context in an overlay plane, returns the
plane's transparent color. Otherwise returns an <a href="qcolor.html#isValid">invalid</a> color.
<p> The returned color's <a href="qcolor.html#pixel">pixel</a> value is
the index of the transparent color in the colormap of the overlay
plane. (Naturally, the color's RGB values are meaningless.)
<p> The returned <a href="qcolor.html">QColor</a> object will generally work as expected only when
passed as the argument to <a href="qglwidget.html#qglColor">QGLWidget::qglColor</a>() or
<a href="qglwidget.html#qglClearColor">QGLWidget::qglClearColor</a>(). Under certain circumstances it can also
be used to draw transparent graphics with a <a href="qpainter.html">QPainter</a>. See the
examples/opengl/overlay_x11 example for details.

<h3 class=fn><a href="qglformat.html">QGLFormat</a> <a name="requestedFormat"></a>QGLContext::requestedFormat () const
</h3>

<p> Returns the frame buffer format that was originally requested in the
constructor or <a href="#setFormat">setFormat</a>().
<p> <p>See also <a href="#format">format</a>().

<h3 class=fn>void <a name="reset"></a>QGLContext::reset ()<tt> [virtual]</tt>
</h3>

<p> Resets the context and makes it invalid.
<p>See also <a href="#create">create</a>() and <a href="#isValid">isValid</a>().

<h3 class=fn>void <a name="setFormat"></a>QGLContext::setFormat ( const&nbsp;<a href="qglformat.html">QGLFormat</a>&nbsp;&amp;&nbsp;format )<tt> [virtual]</tt>
</h3>
Sets a <em>format</em> for this context. The context is <a href="#reset">reset</a>.
<p> Call <a href="#create">create</a>() to create a new GL context that tries to match the new
format.
<p> <pre>
    QGLContext *cx;
    //  ...
    <a href="qglformat.html">QGLFormat</a> f;
    f.<a href="qglformat.html#setStereo">setStereo</a>( TRUE );
    cx-&gt;<a href="#setFormat">setFormat</a>( f );
    if ( !cx-&gt;<a href="#create">create</a>() )
        exit(); // no OpenGL support, or cannot render on the specified paintdevice
    if ( !cx-&gt;<a href="#format">format</a>().stereo() )
        exit(); // could not create stereo context
  </pre>
 
<p> <p>See also <a href="#format">format</a>(), <a href="#reset">reset</a>() and <a href="#create">create</a>().

<h3 class=fn>void <a name="setInitialized"></a>QGLContext::setInitialized ( bool&nbsp;on )<tt> [protected]</tt>
</h3>

<p> If <em>on</em> is TRUE the context has been initialized, i.e.
<a href="#setInitialized">QGLContext::setInitialized</a>() has been called on it. If <em>on</em> is
FALSE the context has not been initialized.
<p> <p>See also <a href="#initialized">initialized</a>().

<h3 class=fn>void <a name="setWindowCreated"></a>QGLContext::setWindowCreated ( bool&nbsp;on )<tt> [protected]</tt>
</h3>

<p> If <em>on</em> is TRUE the context has had a window created for it. If <em>on</em> is FALSE no window has been created for the context.
<p> <p>See also <a href="#windowCreated">windowCreated</a>().

<h3 class=fn>void <a name="swapBuffers"></a>QGLContext::swapBuffers () const<tt> [virtual]</tt>
</h3>

<p> Swaps the screen contents with an off-screen buffer. Works only if
the context is in double buffer mode.
<p>See also <a href="qglformat.html#setDoubleBuffer">QGLFormat::setDoubleBuffer</a>().

<h3 class=fn>bool <a name="windowCreated"></a>QGLContext::windowCreated () const<tt> [protected]</tt>
</h3>

<p> Returns TRUE if a window has been created for this context;
otherwise returns FALSE.
<p> <p>See also <a href="#setWindowCreated">setWindowCreated</a>().

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