<body>
<div class="header">
- <h1>The Mesa 3D Graphics Library</h1>
+ The Mesa 3D Graphics Library
</div>
<iframe src="contents.html"></iframe>
<ul>
-<li><a href="#style">Coding Style</a>
-<li><a href="#submitting">Submitting Patches</a>
-<li><a href="#release">Making a New Mesa Release</a>
<li><a href="#extensions">Adding Extensions</a>
</ul>
-
-<h2 id="style">Coding Style</h2>
-
-<p>
-Mesa is over 20 years old and the coding style has evolved over time.
-Some old parts use a style that's a bit out of date.
-If the guidelines below don't cover something, try following the format of
-existing, neighboring code.
-</p>
-
-<p>
-Basic formatting guidelines
-</p>
-
-<ul>
-<li>3-space indentation, no tabs.
-<li>Limit lines to 78 or fewer characters. The idea is to prevent line
-wrapping in 80-column editors and terminals. There are exceptions, such
-as if you're defining a large, static table of information.
-<li>Opening braces go on the same line as the if/for/while statement.
-For example:
-<pre>
- if (condition) {
- foo;
- } else {
- bar;
- }
-</pre>
-
-<li>Put a space before/after operators. For example, <tt>a = b + c;</tt>
-and not <tt>a=b+c;</tt>
-
-<li>This GNU indent command generally does the right thing for formatting:
-<pre>
- indent -br -i3 -npcs --no-tabs infile.c -o outfile.c
-</pre>
-
-<li>Use comments wherever you think it would be helpful for other developers.
-Several specific cases and style examples follow. Note that we roughly
-follow <a href="http://www.stack.nl/~dimitri/doxygen/">Doxygen</a> conventions.
-<br>
-<br>
-Single-line comments:
-<pre>
- /* null-out pointer to prevent dangling reference below */
- bufferObj = NULL;
-</pre>
-Or,
-<pre>
- bufferObj = NULL; /* prevent dangling reference below */
-</pre>
-Multi-line comment:
-<pre>
- /* If this is a new buffer object id, or one which was generated but
- * never used before, allocate a buffer object now.
- */
-</pre>
-We try to quote the OpenGL specification where prudent:
-<pre>
- /* Page 38 of the PDF of the OpenGL ES 3.0 spec says:
- *
- * "An INVALID_OPERATION error is generated for any of the following
- * conditions:
- *
- * * <length> is zero."
- *
- * Additionally, page 94 of the PDF of the OpenGL 4.5 core spec
- * (30.10.2014) also says this, so it's no longer allowed for desktop GL,
- * either.
- */
-</pre>
-Function comment example:
-<pre>
- /**
- * Create and initialize a new buffer object. Called via the
- * ctx->Driver.CreateObject() driver callback function.
- * \param name integer name of the object
- * \param type one of GL_FOO, GL_BAR, etc.
- * \return pointer to new object or NULL if error
- */
- struct gl_object *
- _mesa_create_object(GLuint name, GLenum type)
- {
- /* function body */
- }
-</pre>
-
-<li>Put the function return type and qualifiers on one line and the function
-name and parameters on the next, as seen above. This makes it easy to use
-<code>grep ^function_name dir/*</code> to find function definitions. Also,
-the opening brace goes on the next line by itself (see above.)
-
-<li>Function names follow various conventions depending on the type of function:
-<pre>
- glFooBar() - a public GL entry point (in glapi_dispatch.c)
- _mesa_FooBar() - the internal immediate mode function
- save_FooBar() - retained mode (display list) function in dlist.c
- foo_bar() - a static (private) function
- _mesa_foo_bar() - an internal non-static Mesa function
-</pre>
-
-<li>Constants, macros and enumerant names are ALL_UPPERCASE, with _ between
-words.
-<li>Mesa usually uses camel case for local variables (Ex: "localVarname")
-while gallium typically uses underscores (Ex: "local_var_name").
-<li>Global variables are almost never used because Mesa should be thread-safe.
-
-<li>Booleans. Places that are not directly visible to the GL API
-should prefer the use of <tt>bool</tt>, <tt>true</tt>, and
-<tt>false</tt> over <tt>GLboolean</tt>, <tt>GL_TRUE</tt>, and
-<tt>GL_FALSE</tt>. In C code, this may mean that
-<tt>#include <stdbool.h></tt> needs to be added. The
-<tt>try_emit_</tt>* methods in src/mesa/program/ir_to_mesa.cpp and
-src/mesa/state_tracker/st_glsl_to_tgsi.cpp can serve as examples.
-
-</ul>
-
-
-<h2 id="submitting">Submitting patches</h2>
-
-<p>
-The basic guidelines for submitting patches are:
-</p>
-
-<ul>
-<li>Patches should be sufficiently tested before submitting.
-<li>Code patches should follow Mesa coding conventions.
-<li>Whenever possible, patches should only effect individual Mesa/Gallium
-components.
-<li>Patches should never introduce build breaks and should be bisectable (see
-<code>git bisect</code>.)
-<li>Patches should be properly formatted (see below).
-<li>Patches should be submitted to mesa-dev for review using
-<code>git send-email</code>.
-<li>Patches should not mix code changes with code formatting changes (except,
-perhaps, in very trivial cases.)
-</ul>
-
-<h3>Patch formatting</h3>
-
-<p>
-The basic rules for patch formatting are:
-</p>
-
-<ul>
-<li>Lines should be limited to 75 characters or less so that git logs
-displayed in 80-column terminals avoid line wrapping. Note that git
-log uses 4 spaces of indentation (4 + 75 < 80).
-<li>The first line should be a short, concise summary of the change prefixed
-with a module name. Examples:
-<pre>
- mesa: Add support for querying GL_VERTEX_ATTRIB_ARRAY_LONG
-
- gallium: add PIPE_CAP_DEVICE_RESET_STATUS_QUERY
-
- i965: Fix missing type in local variable declaration.
-</pre>
-<li>Subsequent patch comments should describe the change in more detail,
-if needed. For example:
-<pre>
- i965: Remove end-of-thread SEND alignment code.
-
- This was present in Eric's initial implementation of the compaction code
- for Sandybridge (commit 077d01b6). There is no documentation saying this
- is necessary, and removing it causes no regressions in piglit on any
- platform.
-</pre>
-<li>A "Signed-off-by:" line is not required, but not discouraged either.
-<li>If a patch address a bugzilla issue, that should be noted in the
-patch comment. For example:
-<pre>
- Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89689
-</pre>
-<li>If there have been several revisions to a patch during the review
-process, they should be noted such as in this example:
-<pre>
- st/mesa: add ARB_texture_stencil8 support (v4)
-
- if we support stencil texturing, enable texture_stencil8
- there is no requirement to support native S8 for this,
- the texture can be converted to x24s8 fine.
-
- v2: fold fixes from Marek in:
- a) put S8 last in the list
- b) fix renderable to always test for d/s renderable
- fixup the texture case to use a stencil only format
- for picking the format for the texture view.
- v3: hit fallback for getteximage
- v4: put s8 back in front, it shouldn't get picked now (Ilia)
-</pre>
-<li>If someone tested your patch, document it with a line like this:
-<pre>
- Tested-by: Joe Hacker <jhacker@foo.com>
-</pre>
-<li>If the patch was reviewed (usually the case) or acked by someone,
-that should be documented with:
-<pre>
- Reviewed-by: Joe Hacker <jhacker@foo.com>
- Acked-by: Joe Hacker <jhacker@foo.com>
-</pre>
-</ul>
-
-
-
-<h3>Testing Patches</h3>
-
-<p>
-It should go without saying that patches must be tested. In general,
-do whatever testing is prudent.
-</p>
-
-<p>
-You should always run the Mesa test suite before submitting patches.
-The test suite can be run using the 'make check' command. All tests
-must pass before patches will be accepted, this may mean you have
-to update the tests themselves.
-</p>
-
-<p>
-Whenever possible and applicable, test the patch with
-<a href="http://piglit.freedesktop.org">Piglit</a> to
-check for regressions.
-</p>
-
-
-<h3>Mailing Patches</h3>
-
-<p>
-Patches should be sent to the Mesa mailing list for review.
-When submitting a patch make sure to use git send-email rather than attaching
-patches to emails. Sending patches as attachments prevents people from being
-able to provide in-line review comments.
-</p>
-
-<p>
-When submitting follow-up patches you can use --in-reply-to to make v2, v3,
-etc patches show up as replies to the originals. This usually works well
-when you're sending out updates to individual patches (as opposed to
-re-sending the whole series). Using --in-reply-to makes
-it harder for reviewers to accidentally review old patches.
-</p>
-
-<p>
-When submitting follow-up patches you should also login to
-<a href="https://patchwork.freedesktop.org">patchwork</a> and change the
-state of your old patches to Superseded.
-</p>
-
-<h3>Reviewing Patches</h3>
-
-<p>
-When you've reviewed a patch on the mailing list, please be unambiguous
-about your review. That is, state either
-<pre>
- Reviewed-by: Joe Hacker <jhacker@foo.com>
-</pre>
-or
-<pre>
- Acked-by: Joe Hacker <jhacker@foo.com>
-</pre>
-Rather than saying just "LGTM" or "Seems OK".
-</p>
-
-<p>
-If small changes are suggested, it's OK to say something like:
-<pre>
- With the above fixes, Reviewed-by: Joe Hacker <jhacker@foo.com>
-</pre>
-which tells the patch author that the patch can be committed, as long
-as the issues are resolved first.
-</p>
-
-
-<h3>Marking a commit as a candidate for a stable branch</h3>
-
-<p>
-If you want a commit to be applied to a stable branch,
-you should add an appropriate note to the commit message.
-</p>
-
-<p>
-Here are some examples of such a note:
-</p>
-<ul>
- <li>CC: <mesa-stable@lists.freedesktop.org></li>
- <li>CC: "9.2 10.0" <mesa-stable@lists.freedesktop.org></li>
- <li>CC: "10.0" <mesa-stable@lists.freedesktop.org></li>
-</ul>
-
-Simply adding the CC to the mesa-stable list address is adequate to nominate
-the commit for the most-recently-created stable branch. It is only necessary
-to specify a specific branch name, (such as "9.2 10.0" or "10.0" in the
-examples above), if you want to nominate the commit for an older stable
-branch. And, as in these examples, you can nominate the commit for the older
-branch in addition to the more recent branch, or nominate the commit
-exclusively for the older branch.
-
-This "CC" syntax for patch nomination will cause patches to automatically be
-copied to the mesa-stable@ mailing list when you use "git send-email" to send
-patches to the mesa-dev@ mailing list. Also, if you realize that a commit
-should be nominated for the stable branch after it has already been committed,
-you can send a note directly to the mesa-stable@lists.freedesktop.org where
-the Mesa stable-branch maintainers will receive it. Be sure to mention the
-commit ID of the commit of interest (as it appears in the mesa master branch).
-
-The latest set of patches that have been nominated, accepted, or rejected for
-the upcoming stable release can always be seen on the
-<a href="http://cworth.org/~cworth/mesa-stable-queue/">Mesa Stable Queue</a>
-page.
-
-<h3>Criteria for accepting patches to the stable branch</h3>
-
-Mesa has a designated release manager for each stable branch, and the release
-manager is the only developer that should be pushing changes to these
-branches. Everyone else should simply nominate patches using the mechanism
-described above.
-
-The stable-release manager will work with the list of nominated patches, and
-for each patch that meets the crtieria below will cherry-pick the patch with:
-<code>git cherry-pick -x <commit></code>. The <code>-x</code> option is
-important so that the picked patch references the comit ID of the original
-patch.
-
-The stable-release manager may at times need to force-push changes to the
-stable branches, for example, to drop a previously-picked patch that was later
-identified as causing a regression). These force-pushes may cause changes to
-be lost from the stable branch if developers push things directly. Consider
-yourself warned.
-
-The stable-release manager is also given broad discretion in rejecting patches
-that have been nominated for the stable branch. The most basic rule is that
-the stable branch is for bug fixes only, (no new features, no
-regressions). Here is a non-exhaustive list of some reasons that a patch may
-be rejected:
-
-<ul>
- <li>Patch introduces a regression. Any reported build breakage or other
- regression caused by a particular patch, (game no longer work, piglit test
- changes from PASS to FAIL), is justification for rejecting a patch.</li>
-
- <li>Patch is too large, (say, larger than 100 lines)</li>
-
- <li>Patch is not a fix. For example, a commit that moves code around with no
- functional change should be rejected.</li>
-
- <li>Patch fix is not clearly described. For example, a commit message
- of only a single line, no description of the bug, no mention of bugzilla,
- etc.</li>
-
- <li>Patch has not obviously been reviewed, For example, the commit message
- has no Reviewed-by, Signed-off-by, nor Tested-by tags from anyone but the
- author.</li>
-
- <li>Patch has not already been merged to the master branch. As a rule, bug
- fixes should never be applied first to a stable branch. Patches should land
- first on the master branch and then be cherry-picked to a stable
- branch. (This is to avoid future releases causing regressions if the patch
- is not also applied to master.) The only things that might look like
- exceptions would be backports of patches from master that happen to look
- significantly different.</li>
-
- <li>Patch depends on too many other patches. Ideally, all stable-branch
- patches should be self-contained. It sometimes occurs that a single, logical
- bug-fix occurs as two separate patches on master, (such as an original
- patch, then a subsequent fix-up to that patch). In such a case, these two
- patches should be squashed into a single, self-contained patch for the
- stable branch. (Of course, if the squashing makes the patch too large, then
- that could be a reason to reject the patch.)</li>
-
- <li>Patch includes new feature development, not bug fixes. New OpenGL
- features, extensions, etc. should be applied to Mesa master and included in
- the next major release. Stable releases are intended only for bug fixes.
-
- Note: As an exception to this rule, the stable-release manager may accept
- hardware-enabling "features". For example, backports of new code to support
- a newly-developed hardware product can be accepted if they can be reasonably
- determined to not have effects on other hardware.</li>
-
- <li>Patch is a performance optimization. As a rule, performance patches are
- not candidates for the stable branch. The only exception might be a case
- where an application's performance was recently severely impacted so as to
- become unusable. The fix for this performance regression could then be
- considered for a stable branch. The optimization must also be
- non-controversial and the patches still need to meet the other criteria of
- being simple and self-contained</li>
-
- <li>Patch introduces a new failure mode (such as an assert). While the new
- assert might technically be correct, for example to make Mesa more
- conformant, this is not the kind of "bug fix" we want in a stable
- release. The potential problem here is that an OpenGL program that was
- previously working, (even if technically non-compliant with the
- specification), could stop working after this patch. So that would be a
- regression that is unaacceptable for the stable branch.</li>
-</ul>
-
-
-<h2 id="release">Making a New Mesa Release</h2>
-
-<p>
-These are the instructions for making a new Mesa release.
-</p>
-
-<h3>Get latest source files</h3>
-<p>
-Use git to get the latest Mesa files from the git repository, from whatever
-branch is relevant. This document uses the convention X.Y.Z for the release
-being created, which should be created from a branch named X.Y.
-</p>
-
-<h3>Perform basic testing</h3>
-<p>
-The release manager should, at the very least, test the code by compiling it,
-installing it, and running the latest piglit to ensure that no piglit tests
-have regressed since the previous release.
-</p>
-
-<p>
-The release manager should do this testing with at least one hardware driver,
-(say, whatever is contained in the local development machine), as well as on
-both Gallium and non-Gallium software drivers. The software testing can be
-performed by running piglit with the following environment-variable set:
-</p>
-
-<pre>
-LIBGL_ALWAYS_SOFTWARE=1
-</pre>
-
-And Gallium vs. non-Gallium software drivers can be obtained by using the
-following configure flags on separate builds:
-
-<pre>
---with-dri-drivers=swrast
---with-gallium-drivers=swrast
-</pre>
-
-<p>
-Note: If both options are given in one build, both swrast_dri.so drivers will
-be compiled, but only one will be installed. The following command can be used
-to ensure the correct driver is being tested:
-</p>
-
-<pre>
-LIBGL_ALWAYS_SOFTWARE=1 glxinfo | grep "renderer string"
-</pre>
-
-If any regressions are found in this testing with piglit, stop here, and do
-not perform a release until regressions are fixed.
-
-<h3>Update version in file VERSION</h3>
-
-<p>
-Increment the version contained in the file VERSION at Mesa's top-level, then
-commit this change.
-</p>
-
-<h3>Create release notes for the new release</h3>
-
-<p>
-Create a new file docs/relnotes/X.Y.Z.html, (follow the style of the previous
-release notes). Note that the sha256sums section of the release notes should
-be empty at this point.
-</p>
-
-<p>
-Two scripts are available to help generate portions of the release notes:
-
-<pre>
- ./bin/bugzilla_mesa.sh
- ./bin/shortlog_mesa.sh
-</pre>
-
-<p>
-The first script identifies commits that reference bugzilla bugs and obtains
-the descriptions of those bugs from bugzilla. The second script generates a
-log of all commits. In both cases, HTML-formatted lists are printed to stdout
-to be included in the release notes.
-</p>
-
-<p>
-Commit these changes
-</p>
-
-<h3>Make the release archives, signatures, and the release tag</h3>
-<p>
-From inside the Mesa directory:
-<pre>
- ./autogen.sh
- make -j1 tarballs
-</pre>
-
-<p>
-After the tarballs are created, the sha256 checksums for the files will
-be computed and printed. These will be used in a step below.
-</p>
-
-<p>
-It's important at this point to also verify that the constructed tar file
-actually builds:
-</p>
-
-<pre>
- tar xjf MesaLib-X.Y.Z.tar.bz2
- cd Mesa-X.Y.Z
- ./configure --enable-gallium-llvm
- make -j6
- make install
-</pre>
-
-<p>
-Some touch testing should also be performed at this point, (run glxgears or
-more involved OpenGL programs against the installed Mesa).
-</p>
-
-<p>
-Create detached GPG signatures for each of the archive files created above:
-</p>
-
-<pre>
- gpg --sign --detach MesaLib-X.Y.Z.tar.gz
- gpg --sign --detach MesaLib-X.Y.Z.tar.bz2
- gpg --sign --detach MesaLib-X.Y.Z.zip
-</pre>
-
-<p>
-Tag the commit used for the build:
-</p>
-
-<pre>
- git tag -s mesa-X.Y.X -m "Mesa X.Y.Z release"
-</pre>
-
-<p>
-Note: It would be nice to investigate and fix the issue that causes the
-tarballs target to fail with multiple build process, such as with "-j4". It
-would also be nice to incorporate all of the above commands into a single
-makefile target. And instead of a custom "tarballs" target, we should
-incorporate things into the standard "make dist" and "make distcheck" targets.
-</p>
-
-<h3>Add the sha256sums to the release notes</h3>
-
-<p>
-Edit docs/relnotes/X.Y.Z.html to add the sha256sums printed as part of "make
-tarballs" in the previous step. Commit this change.
-</p>
-
-<h3>Push all commits and the tag created above</h3>
-
-<p>
-This is the first step that cannot easily be undone. The release is going
-forward from this point:
-</p>
-
-<pre>
- git push origin X.Y --tags
-</pre>
-
-<h3>Install the release files and signatures on the distribution server</h3>
-
-<p>
-The following commands can be used to copy the release archive files and
-signatures to the freedesktop.org server:
-</p>
-
-<pre>
- scp MesaLib-X.Y.Z* people.freedesktop.org:
- ssh people.freedesktop.org
- cd /srv/ftp.freedesktop.org/pub/mesa
- mkdir X.Y.Z
- cd X.Y.Z
- mv ~/MesaLib-X.Y.Z* .
-</pre>
-
-<h3>Back on mesa master, add the new release notes into the tree</h3>
-
-<p>
-Something like the following steps will do the trick:
-</p>
-
-<pre>
- cp docs/relnotes/X.Y.Z.html /tmp
- git checkout master
- cp /tmp/X.Y.Z.html docs/relnotes
- git add docs/relnotes/X.Y.Z.html
-</pre>
-
-<p>
-Also, edit docs/relnotes.html to add a link to the new release notes, and edit
-docs/index.html to add a news entry. Then commit and push:
-</p>
-
-<pre>
- git commit -a -m "docs: Import X.Y.Z release notes, add news item."
- git push origin
-</pre>
-
-<h3>Update the mesa3d.org website</h3>
-
-<p>
-NOTE: The recent release managers have not been performing this step
-themselves, but leaving this to Brian Paul, (who has access to the
-sourceforge.net hosting for mesa3d.org). Brian is more than willing to grant
-the permission necessary to future release managers to do this step on their
-own.
-</p>
-
-<p>
-Update the web site by copying the docs/ directory's files to
-/home/users/b/br/brianp/mesa-www/htdocs/ with:
-<br>
-<code>
-sftp USERNAME,mesa3d@web.sourceforge.net
-</code>
-</p>
-
-
-<h3>Announce the release</h3>
-<p>
-Make an announcement on the mailing lists:
-
-<em>mesa-dev@lists.freedesktop.org</em>,
-and
-<em>mesa-announce@lists.freedesktop.org</em>
-
-Follow the template of previously-sent release announcements. The following
-command can be used to generate the log of changes to be included in the
-release announcement:
-
-<pre>
- git shortlog mesa-X.Y.Z-1..mesa-X.Y.Z
-</pre>
-</p>
-
-
<h2 id="extensions">Adding Extensions</h2>
<p>
To add a new GL extension to Mesa you have to do at least the following.
+</p>
<ul>
<li>
- If glext.h doesn't define the extension, edit include/GL/gl.h and add
- code like this:
+ If <code>glext.h</code> doesn't define the extension, edit
+ <code>include/GL/gl.h</code> and add code like this:
<pre>
#ifndef GL_EXT_the_extension_name
#define GL_EXT_the_extension_name 1
</pre>
</li>
<li>
- In the src/mapi/glapi/gen/ directory, add the new extension functions and
- enums to the gl_API.xml file.
+ In the <code>src/mapi/glapi/gen/</code> directory, add the new extension
+ functions and enums to the <code>gl_API.xml</code> file.
Then, a bunch of source files must be regenerated by executing the
corresponding Python scripts.
</li>
<li>
- Add a new entry to the <code>gl_extensions</code> struct in mtypes.h
+ Add a new entry to the <code>gl_extensions</code> struct in
+ <code>mtypes.h</code> if the extension requires driver capabilities not
+ already exposed by another extension.
</li>
<li>
- Update the <code>extensions.c</code> file.
+ Add a new entry to the <code>src/mesa/main/extensions_table.h</code> file.
</li>
<li>
From this point, the best way to proceed is to find another extension,
as an example.
</li>
<li>
- If the new extension adds new GL state, the functions in get.c, enable.c
- and attrib.c will most likely require new code.
+ If the new extension adds new GL state, the functions in
+ <code>get.c</code>, <code>enable.c</code> and <code>attrib.c</code>
+ will most likely require new code.
+</li>
+<li>
+ To determine if the new extension is active in the current context,
+ use the auto-generated <code>_mesa_has_##name_str()</code> function
+ defined in <code>src/mesa/main/extensions.h</code>.
</li>
<li>
- The dispatch tests check_table.cpp and dispatch_sanity.cpp
- should be updated with details about the new extensions functions. These
- tests are run using 'make check'
+ The dispatch tests <code>check_table.cpp</code> and
+ <code>dispatch_sanity.cpp</code> should be updated with details about
+ the new extensions functions. These tests are run using
+ <code>meson test</code>.
</li>
</ul>
projects / mesa.git / blobdiff