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   5   <title>Development Notes</title>
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  10 <div class="header">
  11   <h1>The Mesa 3D Graphics Library</h1>
  12 </div>
  13
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  15 <div class="content">
  16
  17 <h1>Development Notes</h1>
  18
  19
  20 <h2>Adding Extensions</h2>
  21
  22 <p>
  23 To add a new GL extension to Mesa you have to do at least the following.
  24
  25 <ul>
  26 <li>
  27    If glext.h doesn't define the extension, edit include/GL/gl.h and add
  28    code like this:
  29    <pre>
  30      #ifndef GL_EXT_the_extension_name
  31      #define GL_EXT_the_extension_name 1
  32      /* declare the new enum tokens */
  33      /* prototype the new functions */
  34      /* TYPEDEFS for the new functions */
  35      #endif
  36    </pre>
  37 </li>
  38 <li>
  39    In the src/mapi/glapi/gen/ directory, add the new extension functions and
  40    enums to the gl_API.xml file.
  41    Then, a bunch of source files must be regenerated by executing the
  42    corresponding Python scripts.
  43 </li>
  44 <li>
  45    Add a new entry to the <code>gl_extensions</code> struct in mtypes.h
  46 </li>
  47 <li>
  48    Update the <code>extensions.c</code> file.
  49 </li>
  50 <li>
  51    From this point, the best way to proceed is to find another extension,
  52    similar to the new one, that's already implemented in Mesa and use it
  53    as an example.
  54 </li>
  55 <li>
  56    If the new extension adds new GL state, the functions in get.c, enable.c
  57    and attrib.c will most likely require new code.
  58 </li>
  59 <li>
  60    The dispatch tests check_table.cpp and dispatch_sanity.cpp
  61    should be updated with details about the new extensions functions. These
  62    tests are run using 'make check'
  63 </li>
  64 </ul>
  65
  66
  67
  68 <h2>Coding Style</h2>
  69
  70 <p>
  71 Mesa's code style has changed over the years.  Here's the latest.
  72 </p>
  73
  74 <p>
  75 Comment your code!  It's extremely important that open-source code be
  76 well documented.  Also, strive to write clean, easily understandable code.
  77 </p>
  78
  79 <p>
  80 3-space indentation
  81 </p>
  82
  83 <p>
  84 If you use tabs, set them to 8 columns
  85 </p>
  86
  87 <p>
  88 Line width: the preferred width to fill comments and code in Mesa is 78
  89 columns.  Exceptions are sometimes made for clarity (e.g. tabular data is
  90 sometimes filled to a much larger width so that extraneous carriage returns
  91 don't obscure the table).
  92 </p>
  93
  94 <p>
  95 Brace example:
  96 </p>
  97 <pre>
  98         if (condition) {
  99            foo;
 100         }
 101         else {
 102            bar;
 103         }
 104
 105         switch (condition) {
 106         case 0:
 107            foo();
 108            break;
 109
 110         case 1: {
 111            ...
 112            break;
 113         }
 114
 115         default:
 116            ...
 117            break;
 118         }
 119 </pre>
 120
 121 <p>
 122 Here's the GNU indent command which will best approximate my preferred style:
 123 (Note that it won't format switch statements in the preferred way)
 124 </p>
 125 <pre>
 126         indent -br -i3 -npcs --no-tabs infile.c -o outfile.c
 127 </pre>
 128
 129
 130 <p>
 131 Local variable name example:  localVarName (no underscores)
 132 </p>
 133
 134 <p>
 135 Constants and macros are ALL_UPPERCASE, with _ between words
 136 </p>
 137
 138 <p>
 139 Global variables are not allowed.
 140 </p>
 141
 142 <p>
 143 Function name examples:
 144 </p>
 145 <pre>
 146         glFooBar()       - a public GL entry point (in glapi_dispatch.c)
 147         _mesa_FooBar()   - the internal immediate mode function
 148         save_FooBar()    - retained mode (display list) function in dlist.c
 149         foo_bar()        - a static (private) function
 150         _mesa_foo_bar()  - an internal non-static Mesa function
 151 </pre>
 152
 153 <p>
 154 Places that are not directly visible to the GL API should prefer the use
 155 of <tt>bool</tt>, <tt>true</tt>, and
 156 <tt>false</tt> over <tt>GLboolean</tt>, <tt>GL_TRUE</tt>, and
 157 <tt>GL_FALSE</tt>.  In C code, this may mean that
 158 <tt>#include &lt;stdbool.h&gt;</tt> needs to be added.  The
 159 <tt>try_emit_</tt>* methods in src/mesa/program/ir_to_mesa.cpp and
 160 src/mesa/state_tracker/st_glsl_to_tgsi.cpp can serve as examples.
 161 </p>
 162
 163 <h2>Submitting patches</h2>
 164
 165 <p>
 166 You should always run the Mesa Testsuite before submitting patches.
 167 The Testsuite can be run using the 'make check' command. All tests
 168 must pass before patches will be accepted, this may mean you have
 169 to update the tests themselves.
 170 </p>
 171
 172 <p>
 173 Patches should be sent to the Mesa mailing list for review.
 174 When submitting a patch make sure to use git send-email rather than attaching
 175 patches to emails. Sending patches as attachments prevents people from being
 176 able to provide in-line review comments.
 177 </p>
 178
 179 <p>
 180 When submitting follow-up patches you can use --in-reply-to to make v2, v3,
 181 etc patches show up as replies to the originals. This usually works well
 182 when you're sending out updates to individual patches (as opposed to
 183 re-sending the whole series). Using --in-reply-to makes
 184 it harder for reviewers to accidentally review old patches.
 185 </p>
 186
 187 <h2>Marking a commit as a candidate for a stable branch</h2>
 188
 189 <p>
 190 If you want a commit to be applied to a stable branch,
 191 you should add an appropriate note to the commit message.
 192 </p>
 193
 194 <p>
 195 Here are some examples of such a note:
 196 </p>
 197 <ul>
 198   <li>CC: &lt;mesa-stable@lists.freedesktop.org&gt;</li>
 199   <li>CC: "9.2 10.0" &lt;mesa-stable@lists.freedesktop.org&gt;</li>
 200   <li>CC: "10.0" &lt;mesa-stable@lists.freedesktop.org&gt;</li>
 201 </ul>
 202
 203 Simply adding the CC to the mesa-stable list address is adequate to nominate
 204 the commit for the most-recently-created stable branch. It is only necessary
 205 to specify a specific branch name, (such as "9.2 10.0" or "10.0" in the
 206 examples above), if you want to nominate the commit for an older stable
 207 branch. And, as in these examples, you can nominate the commit for the older
 208 branch in addition to the more recent branch, or nominate the commit
 209 exclusively for the older branch.
 210
 211 This "CC" syntax for patch nomination will cause patches to automatically be
 212 copied to the mesa-stable@ mailing list when you use "git send-email" to send
 213 patches to the mesa-dev@ mailing list. Also, if you realize that a commit
 214 should be nominated for the stable branch after it has already been committed,
 215 you can send a note directly to the mesa-stable@lists.freedesktop.org where
 216 the Mesa stable-branch maintainers will receive it. Be sure to mention the
 217 commit ID of the commit of interest (as it appears in the mesa master branch).
 218
 219 The latest set of patches that have been nominated, accepted, or rejected for
 220 the upcoming stable release can always be seen on the
 221 <a href=http://cworth.org/~cworth/mesa-stable-queue/">Mesa Stable Queue</a>
 222 page.
 223
 224 <h2>Cherry-picking candidates for a stable branch</h2>
 225
 226 <p>
 227 Please use <code>git cherry-pick -x &lt;commit&gt;</code> for cherry-picking a commit
 228 from master to a stable branch.
 229 </p>
 230
 231 <h2>Making a New Mesa Release</h2>
 232
 233 <p>
 234 These are the instructions for making a new Mesa release.
 235 </p>
 236
 237 <h3>Get latest source files</h3>
 238 <p>
 239 Use git to get the latest Mesa files from the git repository, from whatever
 240 branch is relevant.
 241 </p>
 242
 243
 244 <h3>Verify and update version info in VERSION</h3>
 245
 246 <p>
 247 Create a docs/relnotes/x.y.z.html file.
 248 The bin/bugzilla_mesa.sh and bin/shortlog_mesa.sh scripts can be used to
 249 create the HTML-formatted lists of bugfixes and changes to include in the file.
 250 Link the new docs/relnotes/x.y.z.html file into the main <a href="relnotes.html">relnotes.html</a> file.
 251 </p>
 252
 253 <p>
 254 Update <a href="index.html">docs/index.html</a>.
 255 </p>
 256
 257 <p>
 258 Tag the files with the release name (in the form <b>mesa-x.y</b>)
 259 with: <code>git tag -s mesa-x.y -m "Mesa x.y Release"</code>
 260 Then: <code>git push origin mesa-x.y</code>
 261 </p>
 262
 263
 264 <h3>Make the tarballs</h3>
 265 <p>
 266 Make the distribution files.  From inside the Mesa directory:
 267 <pre>
 268         ./autogen.sh
 269         make tarballs
 270 </pre>
 271
 272 <p>
 273 After the tarballs are created, the md5 checksums for the files will
 274 be computed.
 275 Add them to the docs/relnotes/x.y.html file.
 276 </p>
 277
 278 <p>
 279 Copy the distribution files to a temporary directory, unpack them,
 280 compile everything, and run some demos to be sure everything works.
 281 </p>
 282
 283 <h3>Update the website and announce the release</h3>
 284 <p>
 285 Make a new directory for the release on annarchy.freedesktop.org with:
 286 <br>
 287 <code>
 288 mkdir /srv/ftp.freedesktop.org/pub/mesa/x.y
 289 </code>
 290 </p>
 291
 292 <p>
 293 Basically, to upload the tarball files with:
 294 <br>
 295 <code>
 296 rsync -avP -e ssh MesaLib-x.y.* USERNAME@annarchy.freedesktop.org:/srv/ftp.freedesktop.org/pub/mesa/x.y/
 297 </code>
 298 </p>
 299
 300 <p>
 301 Update the web site by copying the docs/ directory's files to
 302 /home/users/b/br/brianp/mesa-www/htdocs/ with:
 303 <br>
 304 <code>
 305 sftp USERNAME,mesa3d@web.sourceforge.net
 306 </code>
 307 </p>
 308
 309 <p>
 310 Make an announcement on the mailing lists:
 311
 312 <em>mesa-dev@lists.freedesktop.org</em>,
 313 <em>mesa-users@lists.freedesktop.org</em>
 314 and
 315 <em>mesa-announce@lists.freedesktop.org</em>
 316 </p>
 317
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