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| author | Emil Velikov <emil.velikov@collabora.com> | 2016-11-16 00:31:26 +0000 |
|---|---|---|
| committer | Emil Velikov <emil.l.velikov@gmail.com> | 2016-11-21 15:08:04 +0000 |
| commit | e561737c5208765ef450c70879837da059573249 (patch) | |
| tree | c57d8563f920108ec66d63d827afbd69d4030fc9 /docs/codingstyle.html | |
| parent | edbf3ebe1ffbed6456d333552609dd02e9969596 (diff) | |
docs: split Codying style into separate document
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Diffstat (limited to 'docs/codingstyle.html')
| -rw-r--r-- | docs/codingstyle.html | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/docs/codingstyle.html b/docs/codingstyle.html new file mode 100644 index 0000000000..4dfb0cc02f --- /dev/null +++ b/docs/codingstyle.html @@ -0,0 +1,142 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html lang="en"> +<head> + <meta http-equiv="content-type" content="text/html; charset=utf-8"> + <title>Coding Style</title> + <link rel="stylesheet" type="text/css" href="mesa.css"> +</head> +<body> + +<div class="header"> + <h1>The Mesa 3D Graphics Library</h1> +</div> + +<iframe src="contents.html"></iframe> +<div class="content"> + +<h1>Coding Style</h1> + +<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 +Some old parts use a style that's a bit out of date. + +Different sections of mesa can use different coding style as set in the local +EditorConfig (.editorconfig) and/or Emacs (.dir-locals.el) file. + +Alternatively the following is applicable. + +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> +</p> + +</div> +</body> +</html> |