docs/devinfo.html

   1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
   2 <html lang="en">
   3 <head>
   4   <meta http-equiv="content-type" content="text/html; charset=utf-8">
   5   <title>Development Notes</title>
   6   <link rel="stylesheet" type="text/css" href="mesa.css">
   7 </head>
   8 <body>
   9
  10 <div class="header">
  11   <h1>The Mesa 3D Graphics Library</h1>
  12 </div>
  13
  14 <iframe src="contents.html"></iframe>
  15 <div class="content">
  16
  17 <h1>Development Notes</h1>
  18
  19
  20 <ul>
  21 <li><a href="#style">Coding Style</a>
  22 <li><a href="#submitting">Submitting Patches</a>
  23 <li><a href="#release">Making a New Mesa Release</a>
  24 <li><a href="#extensions">Adding Extensions</a>
  25 </ul>
  26
  27
  28 <h2 id="style">Coding Style</h2>
  29
  30 <p>
  31 Mesa is over 20 years old and the coding style has evolved over time.
  32 Some old parts use a style that's a bit out of date.
  33 If the guidelines below don't cover something, try following the format of
  34 existing, neighboring code.
  35 </p>
  36
  37 <p>
  38 Basic formatting guidelines
  39 </p>
  40
  41 <ul>
  42 <li>3-space indentation, no tabs.
  43 <li>Limit lines to 78 or fewer characters.  The idea is to prevent line
  44 wrapping in 80-column editors and terminals.  There are exceptions, such
  45 as if you're defining a large, static table of information.
  46 <li>Opening braces go on the same line as the if/for/while statement.
  47 For example:
  48 <pre>
  49    if (condition) {
  50       foo;
  51    } else {
  52       bar;
  53    }
  54 </pre>
  55
  56 <li>Put a space before/after operators.  For example, <tt>a = b + c;</tt>
  57 and not <tt>a=b+c;</tt>
  58
  59 <li>This GNU indent command generally does the right thing for formatting:
  60 <pre>
  61    indent -br -i3 -npcs --no-tabs infile.c -o outfile.c
  62 </pre>
  63
  64 <li>Use comments wherever you think it would be helpful for other developers.
  65 Several specific cases and style examples follow.  Note that we roughly
  66 follow <a href="http://www.stack.nl/~dimitri/doxygen/">Doxygen</a> conventions.
  67 <br>
  68 <br>
  69 Single-line comments:
  70 <pre>
  71    /* null-out pointer to prevent dangling reference below */
  72    bufferObj = NULL;
  73 </pre>
  74 Or,
  75 <pre>
  76    bufferObj = NULL;  /* prevent dangling reference below */
  77 </pre>
  78 Multi-line comment:
  79 <pre>
  80    /* If this is a new buffer object id, or one which was generated but
  81     * never used before, allocate a buffer object now.
  82     */
  83 </pre>
  84 We try to quote the OpenGL specification where prudent:
  85 <pre>
  86    /* Page 38 of the PDF of the OpenGL ES 3.0 spec says:
  87     *
  88     *     "An INVALID_OPERATION error is generated for any of the following
  89     *     conditions:
  90     *
  91     *     * <length> is zero."
  92     *
  93     * Additionally, page 94 of the PDF of the OpenGL 4.5 core spec
  94     * (30.10.2014) also says this, so it's no longer allowed for desktop GL,
  95     * either.
  96     */
  97 </pre>
  98 Function comment example:
  99 <pre>
 100    /**
 101     * Create and initialize a new buffer object.  Called via the
 102     * ctx->Driver.CreateObject() driver callback function.
 103     * \param  name  integer name of the object
 104     * \param  type  one of GL_FOO, GL_BAR, etc.
 105     * \return  pointer to new object or NULL if error
 106     */
 107    struct gl_object *
 108    _mesa_create_object(GLuint name, GLenum type)
 109    {
 110       /* function body */
 111    }
 112 </pre>
 113
 114 <li>Put the function return type and qualifiers on one line and the function
 115 name and parameters on the next, as seen above.  This makes it easy to use
 116 <code>grep ^function_name dir/*</code> to find function definitions.  Also,
 117 the opening brace goes on the next line by itself (see above.)
 118
 119 <li>Function names follow various conventions depending on the type of function:
 120 <pre>
 121    glFooBar()       - a public GL entry point (in glapi_dispatch.c)
 122    _mesa_FooBar()   - the internal immediate mode function
 123    save_FooBar()    - retained mode (display list) function in dlist.c
 124    foo_bar()        - a static (private) function
 125    _mesa_foo_bar()  - an internal non-static Mesa function
 126 </pre>
 127
 128 <li>Constants, macros and enumerant names are ALL_UPPERCASE, with _ between
 129 words.
 130 <li>Mesa usually uses camel case for local variables (Ex: "localVarname")
 131 while gallium typically uses underscores (Ex: "local_var_name").
 132 <li>Global variables are almost never used because Mesa should be thread-safe.
 133
 134 <li>Booleans.  Places that are not directly visible to the GL API
 135 should prefer the use of <tt>bool</tt>, <tt>true</tt>, and
 136 <tt>false</tt> over <tt>GLboolean</tt>, <tt>GL_TRUE</tt>, and
 137 <tt>GL_FALSE</tt>.  In C code, this may mean that
 138 <tt>#include &lt;stdbool.h&gt;</tt> needs to be added.  The
 139 <tt>try_emit_</tt>* methods in src/mesa/program/ir_to_mesa.cpp and
 140 src/mesa/state_tracker/st_glsl_to_tgsi.cpp can serve as examples.
 141
 142 </ul>
 143
 144
 145 <h2 id="submitting">Submitting patches</h2>
 146
 147 <p>
 148 The basic guidelines for submitting patches are:
 149 </p>
 150
 151 <ul>
 152 <li>Patches should be sufficiently tested before submitting.
 153 <li>Code patches should follow Mesa coding conventions.
 154 <li>Whenever possible, patches should only effect individual Mesa/Gallium
 155 components.
 156 <li>Patches should never introduce build breaks and should be bisectable (see
 157 <code>git bisect</code>.)
 158 <li>Patches should be properly formatted (see below).
 159 <li>Patches should be submitted to mesa-dev for review using
 160 <code>git send-email</code>.
 161 <li>Patches should not mix code changes with code formatting changes (except,
 162 perhaps, in very trivial cases.)
 163 </ul>
 164
 165 <h3>Patch formatting</h3>
 166
 167 <p>
 168 The basic rules for patch formatting are:
 169 </p>
 170
 171 <ul>
 172 <li>Lines should be limited to 75 characters or less so that git logs
 173 displayed in 80-column terminals avoid line wrapping.  Note that git
 174 log uses 4 spaces of indentation (4 + 75 &lt; 80).
 175 <li>The first line should be a short, concise summary of the change prefixed
 176 with a module name.  Examples:
 177 <pre>
 178     mesa: Add support for querying GL_VERTEX_ATTRIB_ARRAY_LONG
 179
 180     gallium: add PIPE_CAP_DEVICE_RESET_STATUS_QUERY
 181
 182     i965: Fix missing type in local variable declaration.
 183 </pre>
 184 <li>Subsequent patch comments should describe the change in more detail,
 185 if needed.  For example:
 186 <pre>
 187     i965: Remove end-of-thread SEND alignment code.
 188
 189     This was present in Eric's initial implementation of the compaction code
 190     for Sandybridge (commit 077d01b6). There is no documentation saying this
 191     is necessary, and removing it causes no regressions in piglit on any
 192     platform.
 193 </pre>
 194 <li>A "Signed-off-by:" line is not required, but not discouraged either.
 195 <li>If a patch address a bugzilla issue, that should be noted in the
 196 patch comment.  For example:
 197 <pre>
 198    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89689
 199 </pre>
 200 <li>If there have been several revisions to a patch during the review
 201 process, they should be noted such as in this example:
 202 <pre>
 203     st/mesa: add ARB_texture_stencil8 support (v4)
 204
 205     if we support stencil texturing, enable texture_stencil8
 206     there is no requirement to support native S8 for this,
 207     the texture can be converted to x24s8 fine.
 208
 209     v2: fold fixes from Marek in:
 210        a) put S8 last in the list
 211        b) fix renderable to always test for d/s renderable
 212         fixup the texture case to use a stencil only format
 213         for picking the format for the texture view.
 214     v3: hit fallback for getteximage
 215     v4: put s8 back in front, it shouldn't get picked now (Ilia)
 216 </pre>
 217 <li>If someone tested your patch, document it with a line like this:
 218 <pre>
 219     Tested-by: Joe Hacker &lt;jhacker@foo.com&gt;
 220 </pre>
 221 <li>If the patch was reviewed (usually the case) or acked by someone,
 222 that should be documented with:
 223 <pre>
 224     Reviewed-by: Joe Hacker &lt;jhacker@foo.com&gt;
 225     Acked-by: Joe Hacker &lt;jhacker@foo.com&gt;
 226 </pre>
 227 </ul>
 228
 229
 230
 231 <h3>Testing Patches</h3>
 232
 233 <p>
 234 It should go without saying that patches must be tested.  In general,
 235 do whatever testing is prudent.
 236 </p>
 237
 238 <p>
 239 You should always run the Mesa test suite before submitting patches.
 240 The test suite can be run using the 'make check' command. All tests
 241 must pass before patches will be accepted, this may mean you have
 242 to update the tests themselves.
 243 </p>
 244
 245 <p>
 246 Whenever possible and applicable, test the patch with
 247 <a href="http://piglit.freedesktop.org">Piglit</a> to
 248 check for regressions.
 249 </p>
 250
 251
 252 <h3>Mailing Patches</h3>
 253
 254 <p>
 255 Patches should be sent to the mesa-dev mailing list for review:
 256 <a href="https://lists.freedesktop.org/mailman/listinfo/mesa-dev">
 257 mesa-dev@lists.freedesktop.org<a/>.
 258 When submitting a patch make sure to use
 259 <a href="https://git-scm.com/docs/git-send-email">git send-email</a>
 260 rather than attaching patches to emails. Sending patches as
 261 attachments prevents people from being able to provide in-line review
 262 comments.
 263 </p>
 264
 265 <p>
 266 When submitting follow-up patches you can use --in-reply-to to make v2, v3,
 267 etc patches show up as replies to the originals. This usually works well
 268 when you're sending out updates to individual patches (as opposed to
 269 re-sending the whole series). Using --in-reply-to makes
 270 it harder for reviewers to accidentally review old patches.
 271 </p>
 272
 273 <p>
 274 When submitting follow-up patches you should also login to
 275 <a href="https://patchwork.freedesktop.org">patchwork</a> and change the
 276 state of your old patches to Superseded.
 277 </p>
 278
 279 <h3>Reviewing Patches</h3>
 280
 281 <p>
 282 When you've reviewed a patch on the mailing list, please be unambiguous
 283 about your review.  That is, state either
 284 <pre>
 285     Reviewed-by: Joe Hacker &lt;jhacker@foo.com&gt;
 286 </pre>
 287 or
 288 <pre>
 289     Acked-by: Joe Hacker &lt;jhacker@foo.com&gt;
 290 </pre>
 291 Rather than saying just "LGTM" or "Seems OK".
 292 </p>
 293
 294 <p>
 295 If small changes are suggested, it's OK to say something like:
 296 <pre>
 297    With the above fixes, Reviewed-by: Joe Hacker &lt;jhacker@foo.com&gt;
 298 </pre>
 299 which tells the patch author that the patch can be committed, as long
 300 as the issues are resolved first.
 301 </p>
 302
 303
 304 <h3>Marking a commit as a candidate for a stable branch</h3>
 305
 306 <p>
 307 If you want a commit to be applied to a stable branch,
 308 you should add an appropriate note to the commit message.
 309 </p>
 310
 311 <p>
 312 Here are some examples of such a note:
 313 </p>
 314 <ul>
 315   <li>CC: &lt;mesa-stable@lists.freedesktop.org&gt;</li>
 316   <li>CC: "9.2 10.0" &lt;mesa-stable@lists.freedesktop.org&gt;</li>
 317   <li>CC: "10.0" &lt;mesa-stable@lists.freedesktop.org&gt;</li>
 318 </ul>
 319
 320 Simply adding the CC to the mesa-stable list address is adequate to nominate
 321 the commit for the most-recently-created stable branch. It is only necessary
 322 to specify a specific branch name, (such as "9.2 10.0" or "10.0" in the
 323 examples above), if you want to nominate the commit for an older stable
 324 branch. And, as in these examples, you can nominate the commit for the older
 325 branch in addition to the more recent branch, or nominate the commit
 326 exclusively for the older branch.
 327
 328 This "CC" syntax for patch nomination will cause patches to automatically be
 329 copied to the mesa-stable@ mailing list when you use "git send-email" to send
 330 patches to the mesa-dev@ mailing list. Also, if you realize that a commit
 331 should be nominated for the stable branch after it has already been committed,
 332 you can send a note directly to the mesa-stable@lists.freedesktop.org where
 333 the Mesa stable-branch maintainers will receive it. Be sure to mention the
 334 commit ID of the commit of interest (as it appears in the mesa master branch).
 335
 336 The latest set of patches that have been nominated, accepted, or rejected for
 337 the upcoming stable release can always be seen on the
 338 <a href="http://cworth.org/~cworth/mesa-stable-queue/">Mesa Stable Queue</a>
 339 page.
 340
 341 <h3>Criteria for accepting patches to the stable branch</h3>
 342
 343 Mesa has a designated release manager for each stable branch, and the release
 344 manager is the only developer that should be pushing changes to these
 345 branches. Everyone else should simply nominate patches using the mechanism
 346 described above.
 347
 348 The stable-release manager will work with the list of nominated patches, and
 349 for each patch that meets the crtieria below will cherry-pick the patch with:
 350 <code>git cherry-pick -x &lt;commit&gt;</code>. The <code>-x</code> option is
 351 important so that the picked patch references the comit ID of the original
 352 patch.
 353
 354 The stable-release manager may at times need to force-push changes to the
 355 stable branches, for example, to drop a previously-picked patch that was later
 356 identified as causing a regression). These force-pushes may cause changes to
 357 be lost from the stable branch if developers push things directly. Consider
 358 yourself warned.
 359
 360 The stable-release manager is also given broad discretion in rejecting patches
 361 that have been nominated for the stable branch. The most basic rule is that
 362 the stable branch is for bug fixes only, (no new features, no
 363 regressions). Here is a non-exhaustive list of some reasons that a patch may
 364 be rejected:
 365
 366 <ul>
 367   <li>Patch introduces a regression. Any reported build breakage or other
 368   regression caused by a particular patch, (game no longer work, piglit test
 369   changes from PASS to FAIL), is justification for rejecting a patch.</li>
 370
 371   <li>Patch is too large, (say, larger than 100 lines)</li>
 372
 373   <li>Patch is not a fix. For example, a commit that moves code around with no
 374   functional change should be rejected.</li>
 375
 376   <li>Patch fix is not clearly described. For example, a commit message
 377   of only a single line, no description of the bug, no mention of bugzilla,
 378   etc.</li>
 379
 380   <li>Patch has not obviously been reviewed, For example, the commit message
 381   has no Reviewed-by, Signed-off-by, nor Tested-by tags from anyone but the
 382   author.</li>
 383
 384   <li>Patch has not already been merged to the master branch. As a rule, bug
 385   fixes should never be applied first to a stable branch. Patches should land
 386   first on the master branch and then be cherry-picked to a stable
 387   branch. (This is to avoid future releases causing regressions if the patch
 388   is not also applied to master.) The only things that might look like
 389   exceptions would be backports of patches from master that happen to look
 390   significantly different.</li>
 391
 392   <li>Patch depends on too many other patches. Ideally, all stable-branch
 393   patches should be self-contained. It sometimes occurs that a single, logical
 394   bug-fix occurs as two separate patches on master, (such as an original
 395   patch, then a subsequent fix-up to that patch). In such a case, these two
 396   patches should be squashed into a single, self-contained patch for the
 397   stable branch. (Of course, if the squashing makes the patch too large, then
 398   that could be a reason to reject the patch.)</li>
 399
 400   <li>Patch includes new feature development, not bug fixes. New OpenGL
 401   features, extensions, etc. should be applied to Mesa master and included in
 402   the next major release. Stable releases are intended only for bug fixes.
 403
 404   Note: As an exception to this rule, the stable-release manager may accept
 405   hardware-enabling "features". For example, backports of new code to support
 406   a newly-developed hardware product can be accepted if they can be reasonably
 407   determined to not have effects on other hardware.</li>
 408
 409   <li>Patch is a performance optimization. As a rule, performance patches are
 410   not candidates for the stable branch. The only exception might be a case
 411   where an application's performance was recently severely impacted so as to
 412   become unusable. The fix for this performance regression could then be
 413   considered for a stable branch. The optimization must also be
 414   non-controversial and the patches still need to meet the other criteria of
 415   being simple and self-contained</li>
 416
 417   <li>Patch introduces a new failure mode (such as an assert). While the new
 418   assert might technically be correct, for example to make Mesa more
 419   conformant, this is not the kind of "bug fix" we want in a stable
 420   release. The potential problem here is that an OpenGL program that was
 421   previously working, (even if technically non-compliant with the
 422   specification), could stop working after this patch. So that would be a
 423   regression that is unaacceptable for the stable branch.</li>
 424 </ul>
 425
 426
 427 <h2 id="release">Making a New Mesa Release</h2>
 428
 429 <p>
 430 These are the instructions for making a new Mesa release.
 431 </p>
 432
 433 <h3>Get latest source files</h3>
 434 <p>
 435 Use git to get the latest Mesa files from the git repository, from whatever
 436 branch is relevant. This document uses the convention X.Y.Z for the release
 437 being created, which should be created from a branch named X.Y.
 438 </p>
 439
 440 <h3>Perform basic testing</h3>
 441 <p>
 442 The release manager should, at the very least, test the code by compiling it,
 443 installing it, and running the latest piglit to ensure that no piglit tests
 444 have regressed since the previous release.
 445 </p>
 446
 447 <p>
 448 The release manager should do this testing with at least one hardware driver,
 449 (say, whatever is contained in the local development machine), as well as on
 450 both Gallium and non-Gallium software drivers. The software testing can be
 451 performed by running piglit with the following environment-variable set:
 452 </p>
 453
 454 <pre>
 455 LIBGL_ALWAYS_SOFTWARE=1
 456 </pre>
 457
 458 And Gallium vs. non-Gallium software drivers can be obtained by using the
 459 following configure flags on separate builds:
 460
 461 <pre>
 462 --with-dri-drivers=swrast
 463 --with-gallium-drivers=swrast
 464 </pre>
 465
 466 <p>
 467 Note: If both options are given in one build, both swrast_dri.so drivers will
 468 be compiled, but only one will be installed. The following command can be used
 469 to ensure the correct driver is being tested:
 470 </p>
 471
 472 <pre>
 473 LIBGL_ALWAYS_SOFTWARE=1 glxinfo | grep "renderer string"
 474 </pre>
 475
 476 If any regressions are found in this testing with piglit, stop here, and do
 477 not perform a release until regressions are fixed.
 478
 479 <h3>Update version in file VERSION</h3>
 480
 481 <p>
 482 Increment the version contained in the file VERSION at Mesa's top-level, then
 483 commit this change.
 484 </p>
 485
 486 <h3>Create release notes for the new release</h3>
 487
 488 <p>
 489 Create a new file docs/relnotes/X.Y.Z.html, (follow the style of the previous
 490 release notes). Note that the sha256sums section of the release notes should
 491 be empty at this point.
 492 </p>
 493
 494 <p>
 495 Two scripts are available to help generate portions of the release notes:
 496
 497 <pre>
 498         ./bin/bugzilla_mesa.sh
 499         ./bin/shortlog_mesa.sh
 500 </pre>
 501
 502 <p>
 503 The first script identifies commits that reference bugzilla bugs and obtains
 504 the descriptions of those bugs from bugzilla. The second script generates a
 505 log of all commits. In both cases, HTML-formatted lists are printed to stdout
 506 to be included in the release notes.
 507 </p>
 508
 509 <p>
 510 Commit these changes
 511 </p>
 512
 513 <h3>Make the release archives, signatures, and the release tag</h3>
 514 <p>
 515 From inside the Mesa directory:
 516 <pre>
 517         ./autogen.sh
 518         make -j1 tarballs
 519 </pre>
 520
 521 <p>
 522 After the tarballs are created, the sha256 checksums for the files will
 523 be computed and printed. These will be used in a step below.
 524 </p>
 525
 526 <p>
 527 It's important at this point to also verify that the constructed tar file
 528 actually builds:
 529 </p>
 530
 531 <pre>
 532         tar xjf MesaLib-X.Y.Z.tar.bz2
 533         cd Mesa-X.Y.Z
 534         ./configure --enable-gallium-llvm
 535         make -j6
 536         make install
 537 </pre>
 538
 539 <p>
 540 Some touch testing should also be performed at this point, (run glxgears or
 541 more involved OpenGL programs against the installed Mesa).
 542 </p>
 543
 544 <p>
 545 Create detached GPG signatures for each of the archive files created above:
 546 </p>
 547
 548 <pre>
 549         gpg --sign --detach MesaLib-X.Y.Z.tar.gz
 550         gpg --sign --detach MesaLib-X.Y.Z.tar.bz2
 551         gpg --sign --detach MesaLib-X.Y.Z.zip
 552 </pre>
 553
 554 <p>
 555 Tag the commit used for the build:
 556 </p>
 557
 558 <pre>
 559         git tag -s mesa-X.Y.X -m "Mesa X.Y.Z release"
 560 </pre>
 561
 562 <p>
 563 Note: It would be nice to investigate and fix the issue that causes the
 564 tarballs target to fail with multiple build process, such as with "-j4". It
 565 would also be nice to incorporate all of the above commands into a single
 566 makefile target. And instead of a custom "tarballs" target, we should
 567 incorporate things into the standard "make dist" and "make distcheck" targets.
 568 </p>
 569
 570 <h3>Add the sha256sums to the release notes</h3>
 571
 572 <p>
 573 Edit docs/relnotes/X.Y.Z.html to add the sha256sums printed as part of "make
 574 tarballs" in the previous step. Commit this change.
 575 </p>
 576
 577 <h3>Push all commits and the tag created above</h3>
 578
 579 <p>
 580 This is the first step that cannot easily be undone. The release is going
 581 forward from this point:
 582 </p>
 583
 584 <pre>
 585         git push origin X.Y --tags
 586 </pre>
 587
 588 <h3>Install the release files and signatures on the distribution server</h3>
 589
 590 <p>
 591 The following commands can be used to copy the release archive files and
 592 signatures to the freedesktop.org server:
 593 </p>
 594
 595 <pre>
 596         scp MesaLib-X.Y.Z* people.freedesktop.org:
 597         ssh people.freedesktop.org
 598         cd /srv/ftp.freedesktop.org/pub/mesa
 599         mkdir X.Y.Z
 600         cd X.Y.Z
 601         mv ~/MesaLib-X.Y.Z* .
 602 </pre>
 603
 604 <h3>Back on mesa master, add the new release notes into the tree</h3>
 605
 606 <p>
 607 Something like the following steps will do the trick:
 608 </p>
 609
 610 <pre>
 611         cp docs/relnotes/X.Y.Z.html /tmp
 612         git checkout master
 613         cp /tmp/X.Y.Z.html docs/relnotes
 614         git add docs/relnotes/X.Y.Z.html
 615 </pre>
 616
 617 <p>
 618 Also, edit docs/relnotes.html to add a link to the new release notes, and edit
 619 docs/index.html to add a news entry. Then commit and push:
 620 </p>
 621
 622 <pre>
 623         git commit -a -m "docs: Import X.Y.Z release notes, add news item."
 624         git push origin
 625 </pre>
 626
 627 <h3>Update the mesa3d.org website</h3>
 628
 629 <p>
 630 NOTE: The recent release managers have not been performing this step
 631 themselves, but leaving this to Brian Paul, (who has access to the
 632 sourceforge.net hosting for mesa3d.org). Brian is more than willing to grant
 633 the permission necessary to future release managers to do this step on their
 634 own.
 635 </p>
 636
 637 <p>
 638 Update the web site by copying the docs/ directory's files to
 639 /home/users/b/br/brianp/mesa-www/htdocs/ with:
 640 <br>
 641 <code>
 642 sftp USERNAME,mesa3d@web.sourceforge.net
 643 </code>
 644 </p>
 645
 646
 647 <h3>Announce the release</h3>
 648 <p>
 649 Make an announcement on the mailing lists:
 650
 651 <em>mesa-dev@lists.freedesktop.org</em>,
 652 and
 653 <em>mesa-announce@lists.freedesktop.org</em>
 654
 655 Follow the template of previously-sent release announcements. The following
 656 command can be used to generate the log of changes to be included in the
 657 release announcement:
 658
 659 <pre>
 660         git shortlog mesa-X.Y.Z-1..mesa-X.Y.Z
 661 </pre>
 662 </p>
 663
 664
 665 <h2 id="extensions">Adding Extensions</h2>
 666
 667 <p>
 668 To add a new GL extension to Mesa you have to do at least the following.
 669
 670 <ul>
 671 <li>
 672    If glext.h doesn't define the extension, edit include/GL/gl.h and add
 673    code like this:
 674    <pre>
 675      #ifndef GL_EXT_the_extension_name
 676      #define GL_EXT_the_extension_name 1
 677      /* declare the new enum tokens */
 678      /* prototype the new functions */
 679      /* TYPEDEFS for the new functions */
 680      #endif
 681    </pre>
 682 </li>
 683 <li>
 684    In the src/mapi/glapi/gen/ directory, add the new extension functions and
 685    enums to the gl_API.xml file.
 686    Then, a bunch of source files must be regenerated by executing the
 687    corresponding Python scripts.
 688 </li>
 689 <li>
 690    Add a new entry to the <code>gl_extensions</code> struct in mtypes.h
 691    if the extension requires driver capabilities not already exposed by
 692    another extension.
 693 </li>
 694 <li>
 695    Add a new entry to the src/mesa/main/extensions_table.h file.
 696 </li>
 697 <li>
 698    From this point, the best way to proceed is to find another extension,
 699    similar to the new one, that's already implemented in Mesa and use it
 700    as an example.
 701 </li>
 702 <li>
 703    If the new extension adds new GL state, the functions in get.c, enable.c
 704    and attrib.c will most likely require new code.
 705 </li>
 706 <li>
 707    To determine if the new extension is active in the current context,
 708    use the auto-generated _mesa_has_##name_str() function defined in
 709    src/mesa/main/extensions.h.
 710 </li>
 711 <li>
 712    The dispatch tests check_table.cpp and dispatch_sanity.cpp
 713    should be updated with details about the new extensions functions. These
 714    tests are run using 'make check'
 715 </li>
 716 </ul>
 717 </p>
 718
 719
 720
 721
 722 </div>
 723 </body>
 724 </html>