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<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>glXGetFBConfigAttrib</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1" /></head><body><div class="refentry"><a id="glXGetFBConfigAttrib"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glXGetFBConfigAttrib — return information about a GLX frame buffer configuration</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <strong class="fsfunc">glXGetFBConfigAttrib</strong>(</code></td><td>Display * <var class="pdparam">dpy</var>, </td></tr><tr><td> </td><td>GLXFBConfig <var class="pdparam">config</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">attribute</var>, </td></tr><tr><td> </td><td>int * <var class="pdparam">value</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>dpy</code></em></span></dt><dd><p>
                    Specifies the connection to the X server.
                </p></dd><dt><span class="term"><em class="parameter"><code>config</code></em></span></dt><dd><p>
                    Specifies the GLX frame buffer configuration to be queried.
                </p></dd><dt><span class="term"><em class="parameter"><code>attribute</code></em></span></dt><dd><p>
                    Specifies the attribute to be returned.
                </p></dd><dt><span class="term"><em class="parameter"><code>value</code></em></span></dt><dd><p>
                    Returns the requested value.
                </p></dd></dl></div></div><div class="refsect1"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glXGetFBConfigAttrib</code> sets <em class="parameter"><code>value</code></em> to the <em class="parameter"><code>attribute</code></em> value of GLX drawables
            created with respect to <em class="parameter"><code>config</code></em>.
            <code class="function">glXGetFBConfigAttrib</code> returns an error code if it fails for any reason.
            Otherwise, <code class="constant">Success</code> is returned.
        </p><p>
            <em class="parameter"><code>attribute</code></em> is one of the following:
        </p><p>
        </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="constant">GLX_FBCONFIG_ID</code></span></dt><dd><p>
                        XID of the given GLXFBConfig.
                    </p></dd><dt><span class="term"><code class="constant">GLX_BUFFER_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits per color buffer.
                        If the frame buffer configuration supports RGBA contexts, then
                        <code class="constant">GLX_BUFFER_SIZE</code> is the sum of
                        <code class="constant">GLX_RED_SIZE</code>,
                        <code class="constant">GLX_GREEN_SIZE</code>,
                        <code class="constant">GLX_BLUE_SIZE</code>, and
                        <code class="constant">GLX_ALPHA_SIZE</code>.
                        If the frame buffer configuration supports only color index contexts,
                        <code class="constant">GLX_BUFFER_SIZE</code> is the size of the
                        color indexes.
                    </p></dd><dt><span class="term"><code class="constant">GLX_LEVEL</code></span></dt><dd><p>
                    </p><p>
                        Frame buffer level of the configuration.
                        Level zero is the default frame buffer.
                        Positive levels correspond to frame buffers that overlay the default buffer,
                        and negative levels correspond to frame buffers that underlie the default
                        buffer.
                    </p></dd><dt><span class="term"><code class="constant">GLX_DOUBLEBUFFER</code></span></dt><dd><p>
                    </p><p>
                        <code class="constant">True</code> if color buffers exist in front/back pairs that can be swapped,
                        <code class="constant">False</code> otherwise.
                    </p></dd><dt><span class="term"><code class="constant">GLX_STEREO</code></span></dt><dd><p>
                    </p><p>
                        <code class="constant">True</code> if color buffers exist in left/right pairs,
                        <code class="constant">False</code> otherwise.
                    </p></dd><dt><span class="term"><code class="constant">GLX_AUX_BUFFERS</code></span></dt><dd><p>
                    </p><p>
                        Number of auxiliary color buffers that are available.
                        Zero indicates that no auxiliary color buffers exist.
                    </p></dd><dt><span class="term"><code class="constant">GLX_RED_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits of red stored in each color buffer.
                        Undefined if RGBA contexts are not supported by the frame buffer configuration.
                    </p></dd><dt><span class="term"><code class="constant">GLX_GREEN_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits of green stored in each color buffer.
                        Undefined if RGBA contexts are not supported by the frame buffer configuration.
                    </p></dd><dt><span class="term"><code class="constant">GLX_BLUE_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits of blue stored in each color buffer.
                        Undefined if RGBA contexts are not supported by the frame buffer configuration.
                    </p></dd><dt><span class="term"><code class="constant">GLX_ALPHA_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits of alpha stored in each color buffer.
                        Undefined if RGBA contexts are not supported by the frame buffer configuration.
                    </p></dd><dt><span class="term"><code class="constant">GLX_DEPTH_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits in the depth buffer.
                    </p></dd><dt><span class="term"><code class="constant">GLX_STENCIL_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits in the stencil buffer.
                    </p></dd><dt><span class="term"><code class="constant">GLX_ACCUM_RED_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits of red stored in the accumulation buffer.
                    </p></dd><dt><span class="term"><code class="constant">GLX_ACCUM_GREEN_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits of green stored in the accumulation buffer.
                    </p></dd><dt><span class="term"><code class="constant">GLX_ACCUM_BLUE_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits of blue stored in the accumulation buffer.
                    </p></dd><dt><span class="term"><code class="constant">GLX_ACCUM_ALPHA_SIZE</code></span></dt><dd><p>
                    </p><p>
                        Number of bits of alpha stored in the accumulation buffer.
                    </p></dd><dt><span class="term"><code class="constant">GLX_RENDER_TYPE</code></span></dt><dd><p>
                    </p><p>
                        Mask indicating what type of GLX contexts can be made
                        current to the frame buffer configuration. Valid bits are 
                        <code class="constant">GLX_RGBA_BIT</code> and
                        <code class="constant">GLX_COLOR_INDEX_BIT</code>.
                    </p></dd><dt><span class="term"><code class="constant">GLX_DRAWABLE_TYPE</code></span></dt><dd><p>
                    </p><p>
                        Mask indicating what drawable types the frame buffer configuration
                        supports. Valid bits are <code class="constant">GLX_WINDOW_BIT</code>,
                        <code class="constant">GLX_PIXMAP_BIT</code>, and <code class="constant">GLX_PBUFFER_BIT</code>.
                    </p></dd><dt><span class="term"><code class="constant">GLX_X_RENDERABLE</code></span></dt><dd><p>
                    </p><p>
                        <code class="constant">True</code> if drawables created with the 
                        frame buffer configuration can be rendered to by X.
                    </p></dd><dt><span class="term"><code class="constant">GLX_VISUAL_ID</code></span></dt><dd><p>
                    </p><p>
                        XID of the corresponding visual, or zero 
                        if there is no associated visual (i.e., if
                        <code class="constant">GLX_X_RENDERABLE</code> is <code class="constant">False</code> or
                        <code class="constant">GLX_DRAWABLE_TYPE</code> does not have the
                        <code class="constant">GLX_WINDOW_BIT</code> bit set).
                    </p></dd><dt><span class="term"><code class="constant">GLX_X_VISUAL_TYPE</code></span></dt><dd><p>
                    </p><p>
                        Visual type of associated visual. The returned value will be one of:
                        <code class="constant">GLX_TRUE_COLOR</code>, <code class="constant">GLX_DIRECT_COLOR</code>, <code class="constant">GLX_PSEUDO_COLOR</code>,
                        <code class="constant">GLX_STATIC_COLOR</code>, <code class="constant">GLX_GRAY_SCALE</code>, <code class="constant">GLX_STATIC_GRAY</code>,
                        or <code class="constant">GLX_NONE</code>, if there is no associated visual (i.e., if
                        <code class="constant">GLX_X_RENDERABLE</code> is <code class="constant">False</code> or
                        <code class="constant">GLX_DRAWABLE_TYPE</code> does not have the
                        <code class="constant">GLX_WINDOW_BIT</code> bit set).
                    </p></dd><dt><span class="term"><code class="constant">GLX_CONFIG_CAVEAT</code></span></dt><dd><p>
                    </p><p>
                        One of <code class="constant">GLX_NONE</code>,
                        <code class="constant">GLX_SLOW_CONFIG</code>, or 
                        <code class="constant">GLX_NON_CONFORMANT_CONFIG</code>, indicating
                        that the frame buffer configuration has no caveats,
                        some aspect of the frame buffer configuration runs slower
                        than other frame buffer configurations, or some aspect of the
                        frame buffer configuration is nonconformant, respectively.
                    </p></dd><dt><span class="term"><code class="constant">GLX_TRANSPARENT_TYPE</code></span></dt><dd><p>
                    </p><p>
                        One of <code class="constant">GLX_NONE</code>,
                        <code class="constant">GLX_TRANSPARENT_RGB</code>,
                        <code class="constant">GLX_TRANSPARENT_INDEX</code>, indicating that 
                        the frame buffer configuration is opaque, is transparent for particular
                        values of red, green, and blue, or is transparent for
                        particular index values, respectively.
                    </p></dd><dt><span class="term"><code class="constant">GLX_TRANSPARENT_INDEX_VALUE</code></span></dt><dd><p>
                    </p><p>
                        Integer value between 0 and the maximum
                        frame buffer value for indices, indicating the transparent
                        index value for the frame buffer configuration. 
                        Undefined if <code class="constant">GLX_TRANSPARENT_TYPE</code>
                        is not <code class="constant">GLX_TRANSPARENT_INDEX</code>.
                    </p></dd><dt><span class="term"><code class="constant">GLX_TRANSPARENT_RED_VALUE</code></span></dt><dd><p>
                    </p><p>
                        Integer value between 0 and the maximum
                        frame buffer value for red, indicating the transparent
                        red value for the frame buffer configuration. 
                        Undefined if <code class="constant">GLX_TRANSPARENT_TYPE</code>
                        is not <code class="constant">GLX_TRANSPARENT_RGB</code>.
                    </p></dd><dt><span class="term"><code class="constant">GLX_TRANSPARENT_GREEN_VALUE</code></span></dt><dd><p>
                    </p><p>
                        Integer value between 0 and the maximum
                        frame buffer value for green, indicating the transparent
                        green value for the frame buffer configuration. 
                        Undefined if <code class="constant">GLX_TRANSPARENT_TYPE</code>
                        is not <code class="constant">GLX_TRANSPARENT_RGB</code>.
                    </p></dd><dt><span class="term"><code class="constant">GLX_TRANSPARENT_BLUE_VALUE</code></span></dt><dd><p>
                    </p><p>
                        Integer value between 0 and the maximum
                        frame buffer value for blue, indicating the transparent
                        blue value for the frame buffer configuration. 
                        Undefined if <code class="constant">GLX_TRANSPARENT_TYPE</code>
                        is not <code class="constant">GLX_TRANSPARENT_RGB</code>.
                    </p></dd><dt><span class="term"><code class="constant">GLX_TRANSPARENT_ALPHA_VALUE</code></span></dt><dd><p>
                    </p><p>
                        Integer value between 0 and the maximum
                        frame buffer value for alpha, indicating the transparent
                        blue value for the frame buffer configuration. 
                        Undefined if <code class="constant">GLX_TRANSPARENT_TYPE</code>
                        is not <code class="constant">GLX_TRANSPARENT_RGB</code>.
                    </p></dd><dt><span class="term"><code class="constant">GLX_MAX_PBUFFER_WIDTH</code></span></dt><dd><p>
                    </p><p>
                        The maximum width that can be specified to 
                        <a class="citerefentry" href="glXCreatePbuffer.xml"><span class="citerefentry"><span class="refentrytitle">glXCreatePbuffer</span></span></a>.
                    </p></dd><dt><span class="term"><code class="constant">GLX_MAX_PBUFFER_HEIGHT</code></span></dt><dd><p>
                    </p><p>
                        The maximum height that can be specified to 
                        <a class="citerefentry" href="glXCreatePbuffer.xml"><span class="citerefentry"><span class="refentrytitle">glXCreatePbuffer</span></span></a>.
                    </p></dd><dt><span class="term"><code class="constant">GLX_MAX_PBUFFER_PIXELS</code></span></dt><dd><p>
                    </p><p>
                        The maximum number of pixels (width times height) for a 
                        pixel buffer. Note that this value may be less than
                        <code class="constant">GLX_MAX_PBUFFER_WIDTH</code> times
                        <code class="constant">GLX_MAX_PBUFFER_HEIGHT</code>. Also, this
                        value is static and assumes that no other pixel buffers 
                        or X resources are contending for the frame buffer memory. 
                        As a result, it may not be possible to allocate a pixel buffer of
                        the size given by <code class="constant">GLX_MAX_PBUFFER_PIXELS</code>.
                    </p></dd></dl></div><p>
            Applications should choose the frame buffer configuration that most closely
            meets their requirements.
            Creating windows, GLX pixmaps, or GLX pixel buffers with unnecessary buffers 
            can result in
            reduced rendering performance as well as poor resource allocation.
        </p></div><div class="refsect1"><a id="notes"></a><h2>Notes</h2><p>
            <code class="function">glXGetFBConfigAttrib</code> is available only if the GLX version is 1.3 or greater.
        </p><p>
            If the GLX version is 1.1 or 1.0, the GL version must be 1.0.
            If the GLX version is 1.2, then the GL version must be 1.1.
            If the GLX version is 1.3, then the GL version must be 1.2.
        </p></div><div class="refsect1"><a id="errors"></a><h2>Errors</h2><p>
            <code class="constant">GLX_NO_EXTENSION</code> is returned if <em class="parameter"><code>dpy</code></em> does not support the GLX
            extension.
            <code class="constant">GLX_BAD_ATTRIBUTE</code> is returned if <em class="parameter"><code>attribute</code></em> is not a valid GLX attribute.
        </p></div><div class="refsect1"><a id="seealso"></a><h2>See Also</h2><p>
            <a class="citerefentry" href="glXGetFBConfigs.xml"><span class="citerefentry"><span class="refentrytitle">glXGetFBConfigs</span></span></a>,
            <a class="citerefentry" href="glXChooseFBConfig.xml"><span class="citerefentry"><span class="refentrytitle">glXChooseFBConfig</span></span></a>,
            <a class="citerefentry" href="glXGetVisualFromFBConfig.xml"><span class="citerefentry"><span class="refentrytitle">glXGetVisualFromFBConfig</span></span></a>,
            <a class="citerefentry" href="glXGetConfig.xml"><span class="citerefentry"><span class="refentrytitle">glXGetConfig</span></span></a>
        </p></div><div class="refsect1"><a id="Copyright"></a><h2>Copyright</h2><p>
            Copyright <span class="trademark"></span>© 1991-2006
            Silicon Graphics, Inc. This document is licensed under the SGI
            Free Software B License. For details, see
            <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
        </p></div></div></body></html>