[PATCH 1/2] Fix clipping when windows are used as sources

[Alex Deucher]

On Tue, Jun 16, 2009 at 1:02 AM, Maarten Maathuis<madman2003 at gmail.com> wrote:
> On Mon, Jun 15, 2009 at 11:23 AM, Soeren Sandmann<sandmann at daimi.au.dk> wrote:
>> Maarten Maathuis <madman2003 at gmail.com> writes:
>>
>>> Does this make transformed composite (XRGB source) with no extending
>>> ok again with regards to the black pixels that a lot of hw sample
>>> outside the texture?
>>
>> It doesn't change that.
>>
>>> Previously it switched from being ok to being bad, i'm just curious if
>>> it changed again?
>>
>> The RENDER spec says that for REPEAT_NONE, pixels outside the texture
>> are 0, which is what pixman has always done for transformed images and
>> in 0.16.0 will also do in the non-transformed case. Previously it
>> would clip those pixels away and not do any compositing for them.
>>
>> For operators like SRC, this is the difference between leaving the
>> destination in place and painting it transparent black.
>
> I'm still curious how a texture without alpha channel is supposed to
> have transparent pixels.

This makes it hard to accelerate on most hardware as well.

Alex