[Mesa-dev] [PATCH 08/18] meta/blit: Don't pollute the sampler object namespace in _mesa_meta_setup_sampler

[Erik Faye-Lund]

On Tue, Jan 12, 2016 at 5:44 PM, Ian Romanick <idr at freedesktop.org> wrote:
> On 01/12/2016 01:36 AM, Erik Faye-Lund wrote:
>> On Sat, Jan 9, 2016 at 3:59 AM, Ian Romanick <idr at freedesktop.org> wrote:
>>> From: Ian Romanick <ian.d.romanick at intel.com>
>>>
>>> tl;dr: For many types of GL object, we can *NEVER* use the Gen function.
>>>
>>> In OpenGL ES (all versions!) and OpenGL compatibility profile,
>>> applications don't have to call Gen functions.  The GL spec is very
>>> clear about how you can mix-and-match generated names and non-generated
>>> names: you can use any name you want for a particular object type until
>>> you call the Gen function for that object type.
>>
>> Not that it affects this patch (except perhaps the commit message),
>> but at least in GLES2 you can even keep on using the old buffer,
>> texture, framebuffer or renderbuffer names even after calling the
>> Gen-function, because Gen{Buffers,Textures,Framebuffers,Renderbuffers}
>> are defined as "returns n previously unused
>> {buffer,texture,framebuffer,renderbuffer} object names in textures".
>> Since the object names needs to be previously unused, the
>> Gen-functions cannot generate names that has been previously bound. I
>> expect that the same goes for other specifications, but I haven't
>> verified that.
>
> Correct.  After you start calling GenFoo you just can't invent your own
> names for foo objects.  There are some cases where it can work, but,
> especially in the case of GLX indirect rendering, it may not work on
> some implementations even when you think it should.
>
> This commit message gets copy-and-pasted a *lot*.  If you think there
> are changes that should be made, I can do that on the future patches in
> this series.

I don't think it's important. This is accurate enough to justify the change.