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- <title>Mesa FAQ</title>
+ <title>Frequently Asked Questions</title>
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- <h1>The Mesa 3D Graphics Library</h1>
+ The Mesa 3D Graphics Library
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-<center>
-<h1>Mesa Frequently Asked Questions</h1>
-Last updated: 9 October 2012
-</center>
+<h1>Frequently Asked Questions</h1>
+Last updated: 19 September 2018
-<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>
+<h2 id="part1">1. High-level Questions and Answers</h2>
-
-<h1 id="part1">1. High-level Questions and Answers</h1>
-
-<h2>1.1 What is Mesa?</h2>
+<h3>1.1 What is Mesa?</h3>
<p>
Mesa is an open-source implementation of the OpenGL specification.
OpenGL is a programming library for writing interactive 3D applications.
-See the <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>
drivers for X.org.
</p>
<ul>
- <li>See the <a href="http://dri.freedesktop.org/">DRI website</a>
+ <li>See the <a href="https://dri.freedesktop.org/">DRI website</a>
for more information.</li>
- <li>See <a href="http://intellinuxgraphics.org">intellinuxgraphics.org</a>
+ <li>See <a href="https://01.org/linuxgraphics">01.org</a>
for more information about Intel drivers.</li>
- <li>See <a href="http://nouveau.freedesktop.org">nouveau.freedesktop.org</a>
+ <li>See <a href="https://nouveau.freedesktop.org">nouveau.freedesktop.org</a>
for more information about Nouveau drivers.</li>
- <li>See <a href="http://www.x.org/wiki/RadeonFeature">www.x.org/wiki/RadeonFeature</a>
+ <li>See <a href="https://www.x.org/wiki/RadeonFeature">www.x.org/wiki/RadeonFeature</a>
for more information about Radeon drivers.</li>
</ul>
<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, libGL.so, contains everything (the programming API,
- the GLX functions and all the rendering code).
+<li>The OpenGL library, <code>libGL.so</code>, contains everything (the
+ programming API, the GLX functions and all the rendering code).
</ul>
<p>
Alternately, Mesa acts as the core for a number of OpenGL hardware drivers
within the DRI (Direct Rendering Infrastructure):
<ul>
-<li>The libGL.so library provides the GL and GLX API functions, a GLX
- protocol encoder, and a device driver loader.
-<li>The device driver modules (such as r200_dri.so) contain a built-in
- copy of the core Mesa code.
+<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.
<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">
+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.
</p>
<p>
-<a href="http://sourceforge.net/projects/ogl-es/">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">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://bellard.org/TinyGL/">TinyGL</a>
</p>
<p>
-<a href="http://sourceforge.net/projects/softgl/">SoftGL</a>
+<a href="https://sourceforge.net/projects/softgl/">SoftGL</a>
is an OpenGL subset for mobile devices.
</p>
</p>
+<h2 id="part2">2. Compilation and Installation Problems</h2>
-<br>
-<br>
-
-
-<h1 id="part2">2. Compilation and Installation Problems</h1>
-
-
-<h2>2.1 What's the easiest way to install Mesa?</h2>
+<h3>2.1 What's the easiest way to install Mesa?</h3>
<p>
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.
</p>
-<h2>2.2 I get undefined symbols such as bgnpolygon, v3f, etc...</h2>
+<h3>2.2 I get undefined symbols such as bgnpolygon, v3f, etc...</h3>
<p>
You're application is written in IRIS GL, not OpenGL.
IRIS GL was the predecessor to OpenGL and is a different thing (almost)
</p>
-<h2>2.3 Where is the GLUT library?</h2>
+<h3>2.3 Where is the GLUT library?</h3>
<p>
-GLUT (OpenGL Utility Toolkit) is no longer in the separate MesaGLUT-x.y.z.tar.gz file.
+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>
-<h2>2.4 Where is the GLw library?</h2>
+<h3>2.4 Where is the GLw library?</h3>
<p>
-GLw (OpenGL widget library) is now available from a separate <a href="http://cgit.freedesktop.org/mesa/glw/">git repository</a>. Unless you're using very old Xt/Motif applications with OpenGL, you shouldn't need it.
+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>2.5 What's the proper place for the libraries and headers?</h2>
<p>
On Linux-based systems you'll want to follow the
-<a href="http://oss.sgi.com/projects/ogl-sample/ABI/index.html">Linux ABI</a> standard.
+<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></ul>
+</dd>
+</dl>
<p>
-When configuring Mesa, there are three autoconf options that affect the install
+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>--with-dri-driverdir</code>. To install Mesa
+<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>--with-dri-driverdir</code> to the directory
+<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>--with-dri-driverdir=/usr/lib64/dri</code>.
+then set <code>-D dri-drivers-path=/usr/lib64/dri</code>.
</p>
<p>
After determining the correct values for the install location, configure Mesa
-with <code>./configure --prefix=/usr --libdir=xxx --with-dri-driverdir=xxx</code>
-and then install with <code>sudo make install</code>.
+with <code>meson configure --prefix=/usr --libdir=xxx -D dri-drivers-path=xxx</code>
+and then install with <code>sudo ninja install</code>.
</p>
-<br>
-<br>
-<h1 id="part3">3. Runtime / Rendering Problems</h1>
+<h2 id="part3">3. Runtime / Rendering Problems</h2>
-<h2>3.1 Rendering is slow / why isn't my graphics hardware being used?</h2>
+<h3>3.1 Rendering is slow / why isn't my graphics hardware being used?</h3>
<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>
If your DRI-based driver isn't working, go to the
-<a href="http://dri.freedesktop.org/">DRI website</a> for trouble-shooting information.
+<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.opengl.org/resources/faq/technical/depthbuffer.htm#0040">here</a>
+<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>
-<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.
-</p>
-
-<h2>3.6 How can I change the maximum framebuffer size in Mesa's
-<tt>swrast</tt> backend?</h2>
+<h3>3.5 <code>GL_POINTS</code> and <code>GL_LINES</code> don't touch the
+right pixels</h3>
<p>
-These can be overridden by using the <tt>--with-max-width</tt> and
-<tt>--with-max-height</tt> options. The two need not be equal.
-</p><p>
-Do note that Mesa uses these values to size some internal buffers,
-so increasing these sizes will cause Mesa to require additional
-memory. Furthermore, increasing these limits beyond <tt>4096</tt>
-may introduce rasterization artifacts; see the leading comments in
-<tt>src/mesa/swrast/s_tritemp.h</tt>.
+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>
-
-<h1 id="part4">4. Developer Questions</h1>
+<h2 id="part4">4. Developer Questions</h2>
-<h2>4.1 How can I contribute?</h2>
+<h3>4.1 How can I contribute?</h3>
<p>
First, join the <a href="lists.html">mesa-dev mailing list</a>.
That's where Mesa development is discussed.
</p>
<p>
-The <a href="http://www.opengl.org/documentation">
+The <a href="https://www.opengl.org/documentation">
OpenGL Specification</a> is the bible for OpenGL implementation work.
You should read it.
</p>
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>
-<h2>4.3 Why isn't GL_EXT_texture_compression_s3tc implemented in Mesa?</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">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 unsuccessful 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>
-In the mean time, a 3rd party <a href="http://dri.freedesktop.org/wiki/S3TC">
-plug-in library</a> is available.
+In versions prior to this, a 3rd party <a href="https://dri.freedesktop.org/wiki/S3TC">
+plug-in library</a> was required.
</p>
</div>
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