+ +

Coding Style

+ +

+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 +Some old parts use a style that's a bit out of date.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. +

+ +

+Basic formatting guidelines +

+ +

3-space indentation, no tabs. +
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. +
Opening braces go on the same line as the if/for/while statement. +For example: +
```
+   if (condition) {
+      foo;
+   } else {
+      bar;
+   }
+
```
+ +
Put a space before/after operators. For example, a = b + c; +and not a=b+c; + +
This GNU indent command generally does the right thing for formatting: +
```
+   indent -br -i3 -npcs --no-tabs infile.c -o outfile.c
+
```
+ +

Use comments wherever you think it would be helpful for other developers. +Several specific cases and style examples follow. Note that we roughly +follow Doxygen conventions. +
+
+Single-line comments: +

+   /* null-out pointer to prevent dangling reference below */
+   bufferObj = NULL;
+

+Or, +

+   bufferObj = NULL;  /* prevent dangling reference below */
+

+Multi-line comment: +

+   /* If this is a new buffer object id, or one which was generated but
+    * never used before, allocate a buffer object now.
+    */
+

+We try to quote the OpenGL specification where prudent: +

+   /* 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:
+    *
+    *     *  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.
+    */
+

+Function comment example: +

+   /**
+    * 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 */
+   }
+

+ +

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 +grep ^function_name dir/* to find function definitions. Also, +the opening brace goes on the next line by itself (see above.) + +

Function names follow various conventions depending on the type of 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
+

+ +

Constants, macros and enumerant names are ALL_UPPERCASE, with _ between +words. +
Mesa usually uses camel case for local variables (Ex: "localVarname") +while gallium typically uses underscores (Ex: "local_var_name"). +
Global variables are almost never used because Mesa should be thread-safe. + +
Booleans. Places that are not directly visible to the GL API +should prefer the use of bool, true, and +false over GLboolean, GL_TRUE, and +GL_FALSE. In C code, this may mean that +#include <stdbool.h> needs to be added. The +try_emit_* methods in src/mesa/program/ir_to_mesa.cpp and +src/mesa/state_tracker/st_glsl_to_tgsi.cpp can serve as examples. + +

+ +

Coding Style

-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. -

-Basic formatting guidelines -

3-space indentation, no tabs. -

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. -

Opening braces go on the same line as the if/for/while statement. -For example: -

-   if (condition) {
-      foo;
-   } else {
-      bar;
-   }
-

- -

Put a space before/after operators. For example, a = b + c; -and not a=b+c; - -

This GNU indent command generally does the right thing for formatting: -

-   indent -br -i3 -npcs --no-tabs infile.c -o outfile.c
-

- -

Use comments wherever you think it would be helpful for other developers. -Several specific cases and style examples follow. Note that we roughly -follow Doxygen conventions. -
-
-Single-line comments: -

-   /* null-out pointer to prevent dangling reference below */
-   bufferObj = NULL;
-

-Or, -

-   bufferObj = NULL;  /* prevent dangling reference below */
-

-Multi-line comment: -

-   /* If this is a new buffer object id, or one which was generated but
-    * never used before, allocate a buffer object now.
-    */
-

-We try to quote the OpenGL specification where prudent: -

-   /* 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:
-    *
-    *     *  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.
-    */
-

-Function comment example: -

-   /**
-    * 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 */
-   }
-

- -

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 -grep ^function_name dir/* to find function definitions. Also, -the opening brace goes on the next line by itself (see above.) - -

Function names follow various conventions depending on the type of 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
-

- -

Constants, macros and enumerant names are ALL_UPPERCASE, with _ between -words. -

Mesa usually uses camel case for local variables (Ex: "localVarname") -while gallium typically uses underscores (Ex: "local_var_name"). -

Global variables are almost never used because Mesa should be thread-safe. - -

Booleans. Places that are not directly visible to the GL API -should prefer the use of bool, true, and -false over GLboolean, GL_TRUE, and -GL_FALSE. In C code, this may mean that -#include <stdbool.h> needs to be added. The -try_emit_* methods in src/mesa/program/ir_to_mesa.cpp and -src/mesa/state_tracker/st_glsl_to_tgsi.cpp can serve as examples. - -

Submitting patches

@@ -156,7 +31,8 @@ The basic guidelines for submitting patches are:

Patches should be sufficiently tested before submitting. -

Code patches should follow Mesa coding conventions. +

Code patches should follow Mesa +coding conventions.

Whenever possible, patches should only effect individual Mesa/Gallium components.

Patches should never introduce build breaks and should be bisectable (see -- 2.30.2

The Mesa 3D Graphics Library

Coding Style

Coding Style

Submitting patches