Re: [Mesa3d-dev] Mesa (gallium-resources): gallium: fix comments for changed USAGE flags

[Keith W. <ke...@vm...>]

On Fri, 2010-04-09 at 08:45 -0700, Roland Scheidegger wrote:
> Module: Mesa
> Branch: gallium-resources
> Commit: faf53328d1154c51d8a59513f2bfcae62272b0bf
> URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=faf53328d1154c51d8a59513f2bfcae62272b0bf
> 
> Author: Roland Scheidegger <sr...@vm...>
> Date:   Fri Apr  9 17:44:24 2010 +0200
> 
> gallium: fix comments for changed USAGE flags
> 
> ---
> 
>  src/gallium/auxiliary/util/u_simple_screen.h  |    9 +++++----
>  src/gallium/drivers/svga/svga_winsys.h        |   10 ++++------
>  src/gallium/include/pipe/p_screen.h           |    2 +-
>  src/gallium/include/state_tracker/sw_winsys.h |    2 +-
>  4 files changed, 11 insertions(+), 12 deletions(-)
> 
> diff --git a/src/gallium/auxiliary/util/u_simple_screen.h b/src/gallium/auxiliary/util/u_simple_screen.h
> index 0042277..1ba59af 100644
> --- a/src/gallium/auxiliary/util/u_simple_screen.h
> +++ b/src/gallium/auxiliary/util/u_simple_screen.h
> @@ -73,9 +73,10 @@ struct pipe_winsys
>      * window systems must then implement that interface (rather than the
>      * other way around...).
>      *
> -    * usage is a bitmask of PIPE_BUFFER_USAGE_PIXEL/VERTEX/INDEX/CONSTANT. This
> -    * usage argument is only an optimization hint, not a guarantee, therefore
> -    * proper behavior must be observed in all circumstances.
> +    * usage is a bitmask of PIPE_BIND_*.
> +    * XXX is this true?
> +    * This usage argument is only an optimization hint, not a guarantee,
> +    * therefore proper behavior must be observed in all circumstances.

The new flags are no longer hints - they are supposed actually specify
which operations are permitted on a resource.  

Unfortunately I don't think this is very well enforced yet -- I intend
to add a "debug" layer to sit between state-tracker and driver, based on
the drivers/identity layer, which will check for violations of this &
other rules.

Keith