[PATCH dri3proto v2] Add modifier/multi-plane requests, bump to v1.1

[Michel Dänzer]

On 29/07/17 11:08 PM, Daniel Stone wrote:
> On 28 July 2017 at 16:44, Keith Packard <keithp at keithp.com> wrote:
>> Daniel Stone <daniel at fooishbar.org> writes:
> 
>   - the proposed DRI3 v1.1 spec replaced 'depth' as the determinant of
> format with an explicit FourCC enum to make things more explicit
>   - doing that seems to have just confused everyone, so we can make it
> a lot more clear by going back to using depth to determine the format
> (i.e. depth 24 == XRGB8888 storage), and only adding modifiers on top
> of that

[...]

> The reason I changed depth to a FourCC wasn't because I'm desperate to
> support XBGR as well as XRGB, but because a) drm_fourcc.h modifier
> tokens are usually paired with drm_fourcc.h format tokens, and b)
> currently with DRI3 v1.0, there is an implicit hardcoded mapping
> between depth and format, and being more explicit seemed better than
> being implicit. Those two are purely cosmetic though, so going back to
> the DRI3 v1.0 scheme of just using depth rather than a FourCC format
> would perhaps make the intent a bit more clear. Also, the
> XRGB8888/ARGB8888 format restrictions don't seem to be biting anyone:
> I haven't seen any demand for extended formats.

As explained in other posts, there is no fixed format
mapping/restriction with DRI3 v1.0 anyway. It can support all formats
that can be stored as integer values of n bits, where n matches (or is
even just <= ?) any supported pixmap depth.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer