[Mesa-dev] [PATCH 1/2] dri: add backbuffer use flag

[Marek Olšák]

On Wed, Mar 2, 2016 at 12:01 AM, Ian Romanick <idr at freedesktop.org> wrote:
> On 03/01/2016 01:41 PM, Marek Olšák wrote:
>> From: Axel Davy <axel.davy at ens.fr>
>>
>> This will be used by the next commit.
>> ---
>>  include/GL/internal/dri_interface.h     | 1 +
>>  src/egl/drivers/dri2/platform_wayland.c | 8 +++++---
>>  src/loader/loader_dri3_helper.c         | 6 ++++--
>>  3 files changed, 10 insertions(+), 5 deletions(-)
>>
>> diff --git a/include/GL/internal/dri_interface.h b/include/GL/internal/dri_interface.h
>> index 6bbd3fa..9ff4e4b 100644
>> --- a/include/GL/internal/dri_interface.h
>> +++ b/include/GL/internal/dri_interface.h
>> @@ -1100,6 +1100,7 @@ struct __DRIdri2ExtensionRec {
>>  #define __DRI_IMAGE_USE_SCANOUT              0x0002
>>  #define __DRI_IMAGE_USE_CURSOR               0x0004 /* Depricated */
>>  #define __DRI_IMAGE_USE_LINEAR               0x0008
>> +#define __DRI_IMAGE_USE_BACKBUFFER     0x0010
>>
>>
>>  /**
>> diff --git a/src/egl/drivers/dri2/platform_wayland.c b/src/egl/drivers/dri2/platform_wayland.c
>> index 341acb7..ff0d5c8 100644
>> --- a/src/egl/drivers/dri2/platform_wayland.c
>> +++ b/src/egl/drivers/dri2/platform_wayland.c
>> @@ -305,7 +305,7 @@ get_back_bo(struct dri2_egl_surface *dri2_surf)
>>  {
>>     struct dri2_egl_display *dri2_dpy =
>>        dri2_egl_display(dri2_surf->base.Resource.Display);
>> -   int i;
>> +   int i, use_flags;
>>     unsigned int dri_image_format;
>>
>>     /* currently supports three WL DRM formats,
>> @@ -352,6 +352,8 @@ get_back_bo(struct dri2_egl_surface *dri2_surf)
>>     if (dri2_surf->back == NULL)
>>        return -1;
>>
>> +   use_flags = __DRI_IMAGE_USE_SHARE | __DRI_IMAGE_USE_BACKBUFFER;
>> +
>
> I think this needs some versioning, but I'm not that familiar with these
> flags.  What happens when you use this with a *_dri.so that doesn't know
> what __DRI_IMAGE_USE_BACKBUFFER is?

Nothing. Drivers only look at flags they know.

Marek