-<html>
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html lang="en">
+<head>
+ <meta http-equiv="content-type" content="text/html; charset=utf-8">
+ <title>Frequently Asked Questions</title>
+ <link rel="stylesheet" type="text/css" href="mesa.css">
+</head>
+<body>
-<head><title>Mesa FAQ</title></head>
+<div class="header">
+ The Mesa 3D Graphics Library
+</div>
-<BODY text="#000000" bgcolor="#55bbff" link="#111188">
+<iframe src="contents.html"></iframe>
+<div class="content">
+<h1>Frequently Asked Questions</h1>
+Last updated: 19 September 2018
-<center>
-<h1>Mesa Frequently Asked Questions</h1>
-Last updated: 27 April 2004
-</center>
-
-<br>
-<br>
<h2>Index</h2>
-<a href="#part1">1. High-level Questions and Answers</a>
-<br>
-<a href="#part2">2. Compilation and Installation Problems</a>
-<br>
-<a href="#part3">3. Runtime / Rendering Problems</a>
-<br>
-<a href="#part4">4. Developer Questions</a>
-<br>
-<br>
-<br>
-
-
+<ol>
+ <li><a href="#part1">High-level Questions and Answers</a></li>
+ <li><a href="#part2">Compilation and Installation Problems</a></li>
+ <li><a href="#part3">Runtime / Rendering Problems</a></li>
+ <li><a href="#part4">Developer Questions</a></li>
+</ol>
-<a name="part1">
-</a><h1><a name="part1">1. High-level Questions and Answers</a></h1>
+<h2 id="part1">1. High-level Questions and Answers</h2>
-<h2><a name="part1">1.1 What is Mesa?</a></h2>
+<h3>1.1 What is Mesa?</h3>
<p>
-<a name="part1">Mesa is an open-source implementation of the OpenGL specification.
+Mesa is an open-source implementation of the OpenGL specification.
OpenGL is a programming library for writing interactive 3D applications.
-See the </a><a href="http://www.opengl.org/">OpenGL website</a> for more
+See the <a href="https://www.opengl.org/">OpenGL website</a> for more
information.
</p>
<p>
-Mesa 5.x supports the OpenGL 1.4 specification.
+Mesa 9.x supports the OpenGL 3.1 specification.
</p>
<h2>1.2 Does Mesa support/use graphics hardware?</h2>
<p>
-Yes. Specifically, Mesa serves as the OpenGL core for the open-source
-XFree86/DRI OpenGL drivers. See the <a href="http://dri.sf.net/">DRI
-website</a> for more information.
-</p>
-<p>
-There have been other hardware drivers for Mesa over the years (such as
-the 3Dfx Glide/Voodoo driver, an old S3 driver, etc) but the DRI drivers
-are the modern ones.
+Yes. Specifically, Mesa serves as the OpenGL core for the open-source DRI
+drivers for X.org.
</p>
+<ul>
+ <li>See the <a href="https://dri.freedesktop.org/">DRI website</a>
+ for more information.</li>
+ <li>See <a href="https://01.org/linuxgraphics">01.org</a>
+ for more information about Intel drivers.</li>
+ <li>See <a href="https://nouveau.freedesktop.org">nouveau.freedesktop.org</a>
+ for more information about Nouveau drivers.</li>
+ <li>See <a href="https://www.x.org/wiki/RadeonFeature">www.x.org/wiki/RadeonFeature</a>
+ for more information about Radeon drivers.</li>
+</ul>
-<h2>1.3 What purpose does Mesa (software-based rendering) serve today?</h2>
+<h2>1.3 What purpose does Mesa serve today?</h2>
<p>
Hardware-accelerated OpenGL implementations are available for most popular
operating systems today.
Still, Mesa serves at least these purposes:
</p>
<ul>
-<li>Mesa is used as the core of the open-source XFree86/DRI hardware drivers.
+<li>Mesa is used as the core of the open-source X.org DRI
+ hardware drivers.
</li>
<li>Mesa is quite portable and allows OpenGL to be used on systems
that have no other OpenGL solution.
</li>
</ul>
-<h2>1.4 How do I upgrade my DRI installation to use a new Mesa release?</h2>
+
+<h2>1.4 What's the difference between "Stand-Alone" Mesa and the DRI drivers?</h2>
<p>
-You don't! A copy of the Mesa source code lives inside the XFree86/DRI source
-tree and gets compiled into the individual DRI driver modules.
-If you try to install Mesa over an XFree86/DRI installation, you'll lose
-hardware rendering (because stand-alone Mesa's libGL.so is different than
-the XFree86 libGL.so).
+<em>Stand-alone Mesa</em> is the original incarnation of Mesa.
+On systems running the X Window System it does all its rendering through
+the Xlib API:
</p>
+<ul>
+<li>The GLX API is supported, but it's really just an emulation of the
+ real thing.
+<li>The GLX wire protocol is not supported and there's no OpenGL extension
+ loaded by the X server.
+<li>There is no hardware acceleration.
+<li>The OpenGL library, <code>libGL.so</code>, contains everything (the
+ programming API, the GLX functions and all the rendering code).
+</ul>
<p>
-The DRI developers will incorporate the latest release of Mesa into the
-DRI drivers when the time is right.
-</p>
+Alternately, Mesa acts as the core for a number of OpenGL hardware drivers
+within the DRI (Direct Rendering Infrastructure):
+<ul>
+<li>The <code>libGL.so</code> library provides the GL and GLX API functions,
+ a GLX protocol encoder, and a device driver loader.
+<li>The device driver modules (such as <code>r200_dri.so</code>) contain
+ a built-in copy of the core Mesa code.
+<li>The X server loads the GLX module.
+ The GLX module decodes incoming GLX protocol and dispatches the commands
+ to a rendering module.
+ For the DRI, this module is basically a software Mesa renderer.
+</ul>
+
+
+
+<h2>1.5 How do I upgrade my DRI installation to use a new Mesa release?</h2>
<p>
-To upgrade, either look for a new release of <a href="http://www.xfree86.org"
-target="_parent">XFree86</a> or visit the
-<a href="http://dri.sf.net" target="_parent">DRI website</a> to see
-if there's newer drivers.
+This wasn't easy in the past.
+Now, the DRI drivers are included in the Mesa tree and can be compiled
+separately from the X server.
+Just follow the Mesa <a href="install.html">compilation instructions</a>.
</p>
-<h2>1.5 Are there other open-source implementations of OpenGL?</h2>
+<h2>1.6 Are there other open-source implementations of OpenGL?</h2>
<p>
-Yes, SGI's <a href="http://oss.sgi.com/projects/ogl-sample/index.html"
-target="_parent">
-OpenGL Sample Implemenation (SI)</a> is available.
+Yes, SGI's <a href="http://web.archive.org/web/20171010115110_/http://oss.sgi.com/projects/ogl-sample/index.html">
+OpenGL Sample Implementation (SI)</a> is available.
The SI was written during the time that OpenGL was originally designed.
Unfortunately, development of the SI has stagnated.
Mesa is much more up to date with modern features and extensions.
</p>
<p>
-<a href="http://ogl-es.sourceforge.net" target="_parent">Vincent</a> is
+<a href="https://sourceforge.net/projects/ogl-es/">Vincent</a> is
an open-source implementation of OpenGL ES for mobile devices.
<p>
-<a href="http://www.dsbox.com/minigl.html" target="_parent">miniGL</a>
-is a subset of OpenGL for PalmOS devices.
+<a href="http://web.archive.org/web/20130830162848/http://www.dsbox.com/minigl.html">miniGL</a>
+is a subset of OpenGL for PalmOS devices. The website is gone, but the source
+code can still be found on <a href="https://sourceforge.net/projects/minigl/">sourceforge.net</a>.
<p>
-<a href="http://fabrice.bellard.free.fr/TinyGL/"
-target="_parent">TinyGL</a> is a subset of OpenGL.
+<a href="http://bellard.org/TinyGL/">TinyGL</a>
+is a subset of OpenGL.
</p>
<p>
-<a href="http://softgl.studierstube.org/" target="_parent">SoftGL</a>
+<a href="https://sourceforge.net/projects/softgl/">SoftGL</a>
is an OpenGL subset for mobile devices.
</p>
<p>
-<a href="http://chromium.sourceforge.net/" target="_parent">Chromium</a>
+<a href="http://chromium.sourceforge.net/">Chromium</a>
isn't a conventional OpenGL implementation (it's layered upon OpenGL),
but it does export the OpenGL API. It allows tiled rendering, sort-last
rendering, etc.
</p>
+<p>
+<a href="http://www.ticalc.org/archives/files/fileinfo/361/36173.html">ClosedGL</a>
+is an OpenGL subset library for TI graphing calculators.
+</p>
<p>
There may be other open OpenGL implementations, but Mesa is the most
popular and feature-complete.
</p>
-<br>
-<br>
-
-
-<a name="part2">
-</a><h1><a name="part2">2. Compilation and Installation Problems</a></h1>
+<h2 id="part2">2. Compilation and Installation Problems</h2>
-<h2><a name="part2">2.1 What's the easiest way to install Mesa?</a></h2>
+<h3>2.1 What's the easiest way to install Mesa?</h3>
<p>
-<a name="part2">If you're using a Linux-based system, your distro CD most likely already
+If you're using a Linux-based system, your distro CD most likely already
has Mesa packages (like RPM or DEB) which you can easily install.
-</a></p>
-
-
-<h2><a name="part2">2.2 Running <code>configure; make</code> Doesn't Work</a></h2>
-<p>
-<a name="part2">Unfortunately, the GNU autoconf/automake/libtool system doesn't seem to work
-too well on non GNU/Linux systems, even after installing gmake, gcc, etc.
-For that reason, Mesa's <b>old-style</b> makefile system is still included.
-The old-style system uses good old traditional Makefiles. Try the following:
-</a></p><pre><a name="part2"> cd Mesa-x.y.z
- cp Makefile.X11 Makefile
- make
-</a></pre>
-<a name="part2">You'll see a list of system configurations from which to choose.
-For example:
-</a><pre><a name="part2"> make linux-x86
-</a></pre>
-<p>
-<a name="part2">If you're experienced with GNU autoconf/automake/libtool and think you can help
-with maintence, contact the Mesa developers.
-FYI, the Mesa developers generally don't use the autoconf/automake system.
-We're especially annoyed with the fact that a +5000-line script (libtool)
-is needed to make shared libraries (ugh).
-</a></p>
-
-<h2><a name="part2">2.3 Mesa still doesn't compile</a></h2>
-<p>
-<a name="part2">If the old-style Makefile system doesn't work either, make sure you have
-the most recent version of Mesa.
-Otherwise, file a bug report or post to the Mesa3d-users mailing list.
-Give as much info as possible when describing your problem.
-</a></p>
+</p>
-<h2><a name="part2">2.4 I get undefined symbols such as bgnpolygon, v3f, etc...</a></h2>
+<h3>2.2 I get undefined symbols such as bgnpolygon, v3f, etc...</h3>
<p>
-<a name="part2">You're application is written in IRIS GL, not OpenGL.
+You're application is written in IRIS GL, not OpenGL.
IRIS GL was the predecessor to OpenGL and is a different thing (almost)
entirely.
Mesa's not the solution.
-</a></p>
+</p>
-<h2><a name="part2">2.5 Where is the GLUT library?</a></h2>
+<h3>2.3 Where is the GLUT library?</h3>
<p>
-<a name="part2">GLUT (OpenGL Utility Toolkit) is in the separate MesaDemos-x.y.z.tar.gz file.
-If you don't already have GLUT installed, you should grab the MesaDemos
-package and unpack it before compiling Mesa.
-</a></p>
+GLUT (OpenGL Utility Toolkit) is no longer in the separate
+<code>MesaGLUT-x.y.z.tar.gz</code> file.
+If you don't already have GLUT installed, you should grab
+<a href="http://freeglut.sourceforge.net/">freeglut</a>.
+</p>
+<h3>2.4 Where is the GLw library?</h3>
+<p>
+GLw (OpenGL widget library) is now available from a separate <a href="https://gitlab.freedesktop.org/mesa/glw">git repository</a>. Unless you're using very old Xt/Motif applications with OpenGL, you shouldn't need it.
+</p>
-<h2><a name="part2">2.6 What's the proper place for the libraries and headers?</a></h2>
+
+<h2>2.5 What's the proper place for the libraries and headers?</h2>
<p>
-<a name="part2">On Linux-based systems you'll want to follow the
-</a><a href="http://oss.sgi.com/projects/ogl-sample/ABI/index.html"
-target="_parent">Linux ABI</a> standard.
+On Linux-based systems you'll want to follow the
+<a href="https://www.khronos.org/registry/OpenGL/ABI/">Linux ABI</a> standard.
Basically you'll want the following:
</p>
-<ul>
-<li>/usr/include/GL/gl.h - the main OpenGL header
-</li><li>/usr/include/GL/glu.h - the OpenGL GLU (utility) header
-</li><li>/usr/include/GL/glx.h - the OpenGL GLX header
-</li><li>/usr/include/GL/glext.h - the OpenGL extensions header
-</li><li>/usr/include/GL/glxext.h - the OpenGL GLX extensions header
-</li><li>/usr/include/GL/osmesa.h - the Mesa off-screen rendering header
-</li><li>/usr/lib/libGL.so - a symlink to libGL.so.1
-</li><li>/usr/lib/libGL.so.1 - a symlink to libGL.so.1.xyz
-</li><li>/usr/lib/libGL.so.xyz - the actual OpenGL/Mesa library. xyz denotes the
+<dl>
+<dt><code>/usr/include/GL/gl.h</code></dt>
+<dd>the main OpenGL header</dd>
+<dt><code>/usr/include/GL/glu.h</code></dt>
+<dd>the OpenGL GLU (utility) header</dd>
+<dt><code>/usr/include/GL/glx.h</code></dt>
+<dd>the OpenGL GLX header</dd>
+<dt><code>/usr/include/GL/glext.h</code></dt>
+<dd>the OpenGL extensions header</dd>
+<dt><code>/usr/include/GL/glxext.h</code></dt>
+<dd>the OpenGL GLX extensions header</dd>
+<dt><code>/usr/include/GL/osmesa.h</code></dt>
+<dd>the Mesa off-screen rendering header</dd>
+<dt><code>/usr/lib/libGL.so</code></dt>
+<dd>a symlink to <code>libGL.so.1</code></dd>
+<dt><code>/usr/lib/libGL.so.1</code></dt>
+<dd>a symlink to <code>libGL.so.1.xyz</code></dd>
+<dt><code>/usr/lib/libGL.so.xyz</code></dt>
+<dd>the actual OpenGL/Mesa library. xyz denotes the
Mesa version number.
-</li><li>/usr/lib/libGLU.so - a symlink to libGLU.so.1
-</li><li>/usr/lib/libGLU.so.1 - a symlink to libGLU.so.1.3.xyz
-</li><li>/usr/lib/libGLU.so.xyz - the OpenGL Utility library. xyz denotes the Mesa
-version number.
-</li></ul>
+</dd>
+</dl>
<p>
-After installing XFree86 and the DRI drivers, some of these files
-may be symlinks into the /usr/X11R6/ tree.
+When configuring Mesa, there are three meson options that affect the install
+location that you should take care with: <code>--prefix</code>,
+<code>--libdir</code>, and <code>-D dri-drivers-path</code>. To install Mesa
+into the system location where it will be available for all programs to use, set
+<code>--prefix=/usr</code>. Set <code>--libdir</code> to where your Linux
+distribution installs system libraries, usually either <code>/usr/lib</code> or
+<code>/usr/lib64</code>. Set <code>-D dri-drivers-path</code> to the directory
+where your Linux distribution installs DRI drivers. To find your system's DRI
+driver directory, try executing <code>find /usr -type d -name dri</code>. For
+example, if the <code>find</code> command listed <code>/usr/lib64/dri</code>,
+then set <code>-D dri-drivers-path=/usr/lib64/dri</code>.
</p>
<p>
-The old-style Makefile system doesn't install the Mesa libraries; it's
-up to you to copy them (and the headers) to the right place.
+After determining the correct values for the install location, configure Mesa
+with <code>meson configure --prefix=/usr --libdir=xxx -D dri-drivers-path=xxx</code>
+and then install with <code>sudo ninja install</code>.
</p>
-<p>
-The GLUT header and library should go in the same directories.
-</p>
-<br>
-<br>
-<a name="part3">
-</a><h1><a name="part3">3. Runtime / Rendering Problems</a></h1>
+<h2 id="part3">3. Runtime / Rendering Problems</h2>
-<h2><a name="part3">3.1 Rendering is slow / why isn't my graphics hardware being used?</a></h2>
-<p>
-<a name="part3">Stand-alone Mesa (downloaded as MesaLib-x.y.z.tar.gz) doesn't have any
-support for hardware acceleration (with the exception of the 3DFX Voodoo
-driver).
-</a></p>
+<h3>3.1 Rendering is slow / why isn't my graphics hardware being used?</h3>
<p>
-<a name="part3">What you really want is a DRI or NVIDIA (or another vendor's OpenGL) driver
-for your particular hardware.
-</a></p>
+If Mesa can't use its hardware accelerated drivers it falls back on one of its software renderers.
+(eg. classic swrast, softpipe or llvmpipe)
+</p>
<p>
-<a name="part3">You can run the <code>glxinfo</code> program to learn about your OpenGL
+You can run the <code>glxinfo</code> program to learn about your OpenGL
library.
-Look for the GL_VENDOR and GL_RENDERER values.
-That will identify who's OpenGL library you're using and what sort of
+Look for the <code>OpenGL vendor</code> and <code>OpenGL renderer</code> values.
+That will identify who's OpenGL library with which driver you're using and what sort of
hardware it has detected.
-</a></p>
+</p>
<p>
-<a name="part3">If your DRI-based driver isn't working, go to the
-</a><a href="http://dri.sf.net/" target="_parent">DRI website</a> for trouble-shooting information.
+If you're using a hardware accelerated driver you want <code>direct rendering: Yes</code>.
+</p>
+<p>
+If your DRI-based driver isn't working, go to the
+<a href="https://dri.freedesktop.org/">DRI website</a> for trouble-shooting information.
</p>
-<h2>3.2 I'm seeing errors in depth (Z) buffering. Why?</h2>
+<h3>3.2 I'm seeing errors in depth (Z) buffering. Why?</h3>
<p>
Make sure the ratio of the far to near clipping planes isn't too great.
Look
-<a href="http://www.sgi.com/software/opengl/advanced97/notes/node18.html"
-target="_parent">
-here</a> for details.
+<a href="https://www.opengl.org/archives/resources/faq/technical/depthbuffer.htm#0040">here</a>
+for details.
</p>
<p>
Mesa uses a 16-bit depth buffer by default which is smaller and faster
to clear than a 32-bit buffer but not as accurate.
If you need a deeper you can modify the parameters to
-<code> glXChooseVisual</code> in your code.
+<code>glXChooseVisual</code> in your code.
</p>
-<h2>3.3 Why Isn't depth buffering working at all?</h2>
+<h3>3.3 Why Isn't depth buffering working at all?</h3>
<p>
-Be sure you're requesting a depth buffered-visual. If you set the MESA_DEBUG
-environment variable it will warn you about trying to enable depth testing
-when you don't have a depth buffer.
+Be sure you're requesting a depth buffered-visual. If you set the
+<code>MESA_DEBUG</code> environment variable it will warn you about trying
+to enable depth testing when you don't have a depth buffer.
</p>
<p>Specifically, make sure <code>glutInitDisplayMode</code> is being called
with <code>GLUT_DEPTH</code> or <code>glXChooseVisual</code> is being
-called with a non-zero value for GLX_DEPTH_SIZE.
+called with a non-zero value for <code>GLX_DEPTH_SIZE</code>.
</p>
<p>This discussion applies to stencil buffers, accumulation buffers and
alpha channels too.
</p>
-<h2>3.4 Why does glGetString() always return NULL?</h2>
+<h3>3.4 Why does <code>glGetString()</code> always return <code>NULL</code>?</h3>
<p>
Be sure you have an active/current OpenGL rendering context before
-calling glGetString.
+calling <code>glGetString</code>.
</p>
-<h2>3.5 GL_POINTS and GL_LINES don't touch the right pixels</h2>
+<h3>3.5 <code>GL_POINTS</code> and <code>GL_LINES</code> don't touch the
+right pixels</h3>
<p>
-If you're trying to draw a filled region by using GL_POINTS or GL_LINES
-and seeing holes or gaps it's because of a float-to-int rounding problem.
-But this is not a bug.
-See Appendix H of the OpenGL Programming Guide - "OpenGL Correctness Tips".
-Basically, applying a translation of (0.375, 0.375, 0.0) to your coordinates
-will fix the problem.
+If you're trying to draw a filled region by using <code>GL_POINTS</code> or
+<code>GL_LINES</code> and seeing holes or gaps it's because of a float-to-int
+rounding problem. But this is not a bug. See Appendix H of the OpenGL
+Programming Guide - "OpenGL Correctness Tips". Basically, applying a
+translation of (0.375, 0.375, 0.0) to your coordinates will fix the problem.
</p>
-<br>
-<br>
-
-<a name="part4">
-</a><h1><a name="part4">4. Developer Questions</a></h1>
+<h2 id="part4">4. Developer Questions</h2>
-<h2><a name="part4">4.1 How can I contribute?</a></h2>
+<h3>4.1 How can I contribute?</h3>
<p>
-<a name="part4">First, join the Mesa3d-dev mailing list. That's where Mesa development
-is discussed.
-</a></p>
+First, join the <a href="lists.html">mesa-dev mailing list</a>.
+That's where Mesa development is discussed.
+</p>
<p>
-<a name="part4">The </a><a href="http://www.opengl.org/developers/documentation/specs.html" target="_parent">
-OpenGL Specification</a> is the bible for OpenGL implemention work.
+The <a href="https://www.opengl.org/documentation">
+OpenGL Specification</a> is the bible for OpenGL implementation work.
You should read it.
</p>
<p>Most of the Mesa development work involves implementing new OpenGL
extensions, writing hardware drivers (for the DRI), and code optimization.
</p>
-<h2>4.2 How do I write a new device driver?</h2>
+<h3>4.2 How do I write a new device driver?</h3>
<p>
Unfortunately, writing a device driver isn't easy.
It requires detailed understanding of OpenGL, the Mesa code, and your
<p>
The best way to get started is to use an existing driver as your starting
point.
-For a software driver, the X11 and OSMesa drivers are good examples.
-For a hardware driver, the Radeon and R200 DRI drivers are good examples.
+For a classic hardware driver, the i965 driver is a good example.
+For a Gallium3D hardware driver, the r300g, r600g and the i915g are good examples.
</p>
<p>The DRI website has more information about writing hardware drivers.
The process isn't well document because the Mesa driver interface changes
-over time, and we seldome have spare time for writing documentation.
+over time, and we seldom have spare time for writing documentation.
That being said, many people have managed to figure out the process.
</p>
<p>
</p>
-<h2>4.3 Why isn't GL_EXT_texture_compression_s3tc implemented in Mesa and/or the DRI drivers?</h2>
+<h3>4.3 Why isn't <code>GL_EXT_texture_compression_s3tc</code> implemented in
+Mesa?</h3>
<p>
-The <a href="http://oss.sgi.com/projects/ogl-sample/registry/EXT/texture_compression_s3tc.txt" target="_parent">specification for the extension</a>
-indicates that there are intellectual property (IP) and/or patent issues
-to be dealt with.
+Oh but it is! Prior to 2nd October 2017, the Mesa project did not include s3tc
+support due to intellectual property (IP) and/or patent issues around the s3tc
+algorithm.
</p>
-<p>We've been unsucessful in getting a response from S3 (or whoever owns
-the IP nowadays) to indicate whether or not an open source project can
-implement the extension (specifically the compression/decompression
-algorithms).
+<p>
+As of Mesa 17.3.0, Mesa now officially supports s3tc, as the patent has expired.
</p>
<p>
-Until we can get official permission to do so, this extension will not
-be implemented in Mesa.
+In versions prior to this, a 3rd party <a href="https://dri.freedesktop.org/wiki/S3TC">
+plug-in library</a> was required.
</p>
-
+</div>
</body>
</html>
projects / mesa.git / blobdiff