diff options
author | Dave Airlie <[email protected]> | 2009-02-13 01:11:25 +1000 |
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committer | Dave Airlie <[email protected]> | 2009-02-13 01:11:25 +1000 |
commit | 53116910b10e3b8a05f42970eff311c21808699f (patch) | |
tree | 6831e50a56a02fed324f8cb119e05d837e00d7cf /src/gallium/README.portability | |
parent | 7e104f9cde94279a902b408e8d1cf21779b393a8 (diff) | |
parent | 0ccbc3c905f0594a35d72887a1f115e148aaa596 (diff) |
Merge remote branch 'origin/master' into radeon-rewrite
Conflicts:
configure.ac
src/mesa/drivers/dri/r200/r200_context.c
src/mesa/drivers/dri/r300/r300_render.c
Diffstat (limited to 'src/gallium/README.portability')
-rw-r--r-- | src/gallium/README.portability | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/src/gallium/README.portability b/src/gallium/README.portability new file mode 100644 index 00000000000..adecf4bb798 --- /dev/null +++ b/src/gallium/README.portability @@ -0,0 +1,109 @@ + CROSS-PLATFORM PORTABILITY GUIDELINES FOR GALLIUM3D + + += General Considerations = + +The state tracker and winsys driver support a rather limited number of +platforms. However, the pipe drivers are meant to run in a wide number of +platforms. Hence the pipe drivers, the auxiliary modules, and all public +headers in general, should strictly follow these guidelines to ensure + + += Compiler Support = + +* Include the p_compiler.h. + +* Don't use the 'inline' keyword, use the INLINE macro in p_compiler.h instead. + +* Cast explicitly when converting to integer types of smaller sizes. + +* Cast explicitly when converting between float, double and integral types. + +* Don't use named struct initializers. + +* Don't use variable number of macro arguments. Use static inline functions +instead. + +* Don't use C99 features. + += Standard Library = + +* Avoid including standard library headers. Most standard library functions are +not available in Windows Kernel Mode. Use the appropriate p_*.h include. + +== Memory Allocation == + +* Use MALLOC, CALLOC, FREE instead of the malloc, calloc, free functions. + +* Use align_pointer() function defined in u_memory.h for aligning pointers + in a portable way. + +== Debugging == + +* Use the functions/macros in p_debug.h. + +* Don't include assert.h, call abort, printf, etc. + + += Code Style = + +== Inherantice in C == + +The main thing we do is mimic inheritance by structure containment. + +Here's a silly made-up example: + +/* base class */ +struct buffer +{ + int size; + void (*validate)(struct buffer *buf); +}; + +/* sub-class of bufffer */ +struct texture_buffer +{ + struct buffer base; /* the base class, MUST COME FIRST! */ + int format; + int width, height; +}; + + +Then, we'll typically have cast-wrapper functions to convert base-class +pointers to sub-class pointers where needed: + +static inline struct vertex_buffer *vertex_buffer(struct buffer *buf) +{ + return (struct vertex_buffer *) buf; +} + + +To create/init a sub-classed object: + +struct buffer *create_texture_buffer(int w, int h, int format) +{ + struct texture_buffer *t = malloc(sizeof(*t)); + t->format = format; + t->width = w; + t->height = h; + t->base.size = w * h; + t->base.validate = tex_validate; + return &t->base; +} + +Example sub-class method: + +void tex_validate(struct buffer *buf) +{ + struct texture_buffer *tb = texture_buffer(buf); + assert(tb->format); + assert(tb->width); + assert(tb->height); +} + + +Note that we typically do not use typedefs to make "class names"; we use +'struct whatever' everywhere. + +Gallium's pipe_context and the subclassed psb_context, etc are prime examples +of this. There's also many examples in Mesa and the Mesa state tracker. |