Re: [Mesa3d-dev] dri2 st + tfp set tex buffer2

[Dave A. <ai...@gm...>]

On Mon, Apr 5, 2010 at 2:37 PM, Chia-I Wu <ol...@gm...> wrote:
> On Mon, Apr 5, 2010 at 12:00 PM, Dave Airlie <ai...@gm...> wrote:
>>> The attached patch fixes tfp test for me (with i915g).  Could you see if r300g
>>> passes the test with the patch?
>>> The teximage callback has an internal_format parameter that specifies how the
>>> pipe texture should be treated.  It can differ from the format of the texture.
>>> It seems to suffice for TFP.  I was lazy enough not to use it :(
>> That was my first attempt also, however it fails as the texture is
>> already created, and
>> in r300g we already have worked out the hw state assuming the texture
>> format won't
>> change. This seems to be what gallium expects. So in this case you end
>> up recreating
>> a new texture at finalise because the formats don't match and you lose
>> the pixmap.
> r300g does not see the texture before st_finalize_texture, right?  It seems to
> me that the patch should give the correct behavior but a (really bad)
> unnecessary texture copy in st_finalize_texture.  Could we avoid the copy by
> solely changing the sampler view?

It sees the texture via
dri_st_framebuffer_validate_att(drawable->stfb,
ST_ATTACHMENT_FRONT_LEFT)
which causes the texture to be creates from the dri2 buffer handle,

The thing is we need the exact buffer object we get from the X server,
we can't copy it to another texture later, as it destroys the shared texture
and just seems to create another private one.

Dave.