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diff --git a/docs/devinfo.html b/docs/devinfo.html index e068d87da13..f5113b0bd72 100644 --- a/docs/devinfo.html +++ b/docs/devinfo.html @@ -28,97 +28,118 @@ <h2 id="style">Coding Style</h2> <p> -Mesa's code style has changed over the years. Here's the latest. +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 +Some old parts use a style that's a bit out of date.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> -Comment your code! It's extremely important that open-source code be -well documented. Also, strive to write clean, easily understandable code. +Basic formatting guidelines </p> -<p> -3-space indentation -</p> - -<p> -If you use tabs, set them to 8 columns -</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> -<p> -Line width: the preferred width to fill comments and code in Mesa is 78 -columns. Exceptions are sometimes made for clarity (e.g. tabular data is -sometimes filled to a much larger width so that extraneous carriage returns -don't obscure the table). -</p> +<li>Put a space before/after operators. For example, <tt>a = b + c;</tt> +and not <tt>a=b+c;</tt> -<p> -Brace example: -</p> +<li>This GNU indent command generally does the right thing for formatting: <pre> - if (condition) { - foo; - } - else { - bar; - } - - switch (condition) { - case 0: - foo(); - break; - - case 1: { - ... - break; - } - - default: - ... - break; - } + indent -br -i3 -npcs --no-tabs infile.c -o outfile.c </pre> -<p> -Here's the GNU indent command which will best approximate my preferred style: -(Note that it won't format switch statements in the preferred way) -</p> +<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> - indent -br -i3 -npcs --no-tabs infile.c -o outfile.c + /* 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.) -<p> -Local variable name example: localVarName (no underscores) -</p> - -<p> -Constants and macros are ALL_UPPERCASE, with _ between words -</p> - -<p> -Global variables are not allowed. -</p> - -<p> -Function name examples: -</p> +<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 + 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> -<p> -Places that are not directly visible to the GL API should prefer the use -of <tt>bool</tt>, <tt>true</tt>, and +<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. -</p> + +</ul> <h2 id="submitting">Submitting patches</h2> |