--- /dev/null
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
+<!-- saved from url=(0013)about:internet -->
+<?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>glXGetConfig</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glXGetConfig"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glXGetConfig — return information about GLX visuals</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">int <b class="fsfunc">glXGetConfig</b>(</code></td><td>Display * </td><td><var class="pdparam">dpy</var>, </td></tr><tr><td> </td><td>XVisualInfo * </td><td><var class="pdparam">vis</var>, </td></tr><tr><td> </td><td>int </td><td><var class="pdparam">attrib</var>, </td></tr><tr><td> </td><td>int * </td><td><var class="pdparam">value</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><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>vis</code></em></span></dt><dd><p>
+ Specifies the visual to be queried.
+ It is a pointer to an <code class="constant">XVisualInfo</code> structure,
+ not a visual ID or a pointer to a <code class="constant">Visual</code>.
+ </p></dd><dt><span class="term"><em class="parameter"><code>attrib</code></em></span></dt><dd><p>
+ Specifies the visual 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" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
+ <code class="function">glXGetConfig</code> sets <em class="parameter"><code>value</code></em> to the <em class="parameter"><code>attrib</code></em> value of windows or GLX pixmaps
+ created with respect to <em class="parameter"><code>vis</code></em>.
+ <code class="function">glXGetConfig</code> returns an error code if it fails for any reason.
+ Otherwise, zero is returned.
+ </p><p>
+ <em class="parameter"><code>attrib</code></em> is one of the following:
+ </p><p>
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GLX_USE_GL</code></span></dt><dd><p>
+ <code class="constant">True</code> if OpenGL rendering is supported by this visual,
+ <code class="constant">False</code> otherwise.
+ </p></dd><dt><span class="term"><code class="constant">GLX_BUFFER_SIZE</code></span></dt><dd><p>
+ Number of bits per color buffer.
+ For RGBA visuals, <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>.
+ For color index visuals, <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>
+ Frame buffer level of the visual.
+ 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 underlay the default
+ buffer.
+ </p></dd><dt><span class="term"><code class="constant">GLX_RGBA</code></span></dt><dd><p>
+ <code class="constant">True</code> if color buffers store red, green, blue, and alpha values.
+ <code class="constant">False</code> if they store color indexes.
+ </p></dd><dt><span class="term"><code class="constant">GLX_DOUBLEBUFFER</code></span></dt><dd><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>
+ <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>
+ 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>
+ Number of bits of red stored in each color buffer.
+ Undefined if <code class="constant">GLX_RGBA</code> is <code class="constant">False</code>.
+ </p></dd><dt><span class="term"><code class="constant">GLX_GREEN_SIZE</code></span></dt><dd><p>
+ Number of bits of green stored in each color buffer.
+ Undefined if <code class="constant">GLX_RGBA</code> is <code class="constant">False</code>.
+ </p></dd><dt><span class="term"><code class="constant">GLX_BLUE_SIZE</code></span></dt><dd><p>
+ Number of bits of blue stored in each color buffer.
+ Undefined if <code class="constant">GLX_RGBA</code> is <code class="constant">False</code>.
+ </p></dd><dt><span class="term"><code class="constant">GLX_ALPHA_SIZE</code></span></dt><dd><p>
+ Number of bits of alpha stored in each color buffer.
+ Undefined if <code class="constant">GLX_RGBA</code> is <code class="constant">False</code>.
+ </p></dd><dt><span class="term"><code class="constant">GLX_DEPTH_SIZE</code></span></dt><dd><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>
+ 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>
+ 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>
+ 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>
+ 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>
+ Number of bits of alpha stored in the accumulation buffer.
+ </p></dd></dl></div><p>
+ The X protocol allows a single visual ID to be instantiated with
+ different numbers of bits per pixel.
+ Windows or GLX pixmaps that will be rendered with OpenGL, however,
+ must be instantiated with a color buffer depth of <code class="constant">GLX_BUFFER_SIZE</code>.
+ </p><p>
+ Although a GLX implementation can export many visuals that support GL
+ rendering,
+ it must support
+ at least one RGBA visual. This visual must have at
+ least one color buffer,
+ a stencil buffer of at least 1 bit,
+ a depth buffer of at least 12 bits,
+ and an accumulation buffer.
+ Alpha bitplanes are optional in this visual.
+ However,
+ its color buffer size must be as great as that of the
+ deepest <code class="constant">TrueColor</code>, <code class="constant">DirectColor</code>,
+ <code class="constant">PseudoColor</code>, or <code class="constant">StaticColor</code> visual supported on level zero,
+ and it must itself be made available on level zero.
+ </p><p>
+ In addition, if the X server exports a <code class="constant">PseudoColor</code>
+ or <code class="constant">StaticColor</code> visual on framebuffer level 0, a color index
+ visual is also required on that level.
+ It must have
+ at least one color buffer,
+ a stencil buffer of at least 1 bit,
+ and a depth buffer of at least 12 bits.
+ This visual must
+ have as many
+ color bitplanes as the deepest
+ <code class="constant">PseudoColor</code> or <code class="constant">StaticColor</code> visual supported on level 0.
+ </p><p>
+ Applications are best written to select the visual that most closely
+ meets their requirements.
+ Creating windows or GLX pixmaps with unnecessary buffers can result in
+ reduced rendering performance as well as poor resource allocation.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
+ <code class="constant">XVisualInfo</code> is defined in <span class="emphasis"><em>Xutil.h.</em></span>
+ It is a structure that includes <span class="emphasis"><em>visual</em></span>, <span class="emphasis"><em>visualID</em></span>, <span class="emphasis"><em>screen</em></span>, and
+ <span class="emphasis"><em>depth</em></span> elements.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><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.
+ </p><p>
+ <code class="constant">GLX_BAD_SCREEN</code> is returned if the screen of <em class="parameter"><code>vis</code></em> does not correspond
+ to a screen.
+ </p><p>
+ <code class="constant">GLX_BAD_ATTRIBUTE</code> is returned if <em class="parameter"><code>attrib</code></em> is not a valid GLX attribute.
+ </p><p>
+ <code class="constant">GLX_BAD_VISUAL</code> is returned if <em class="parameter"><code>vis</code></em> doesn't support GLX and an
+ attribute other than <code class="constant">GLX_USE_GL</code> is requested.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
+ <a class="citerefentry" href="glXChooseVisual.xml"><span class="citerefentry"><span class="refentrytitle">glXChooseVisual</span></span></a>,
+ <a class="citerefentry" href="glXCreateContext.xml"><span class="citerefentry"><span class="refentrytitle">glXCreateContext</span></span></a>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><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>
HCoop / clinton / guile-figl.git / blobdiff