[Mesa-dev] Gallium API questions
mostawesomedude at gmail.com
Thu Jun 24 07:59:32 PDT 2010
On Thu, Jun 24, 2010 at 6:03 AM, Brian Paul <brianp at vmware.com> wrote:
> Keith Whitwell wrote:
>>> We currently allow partial specification of position, requiring only
>>> (x, y) and filling in z as 0 and w as 1 if missing. Is that still
>>> valid? Similarly, colors may be specified as (r, g, b) triplets with
>>> no alpha, and alpha defaults to 1. Is that still valid, or are there
>>> changes further up the API that make this not needed?
>> I don't think either of those statements are true, except for the
>> special case that in the fragment shader *only* position.z is writeable
>> - ie the x,y coordinates are already fixed, and there is no meaning to
>> writing the position.w coordinate once you're inside the fragment
> I believe Corbin was referring to incoming vertex data in the case of
> glVertex2f and glColor3f, for example.
> I need to update the docs with fragment shader z-write...
Yep. I went ahead and noted the lop rules (and added a small galahad
test) and also filled out the vertex element page with some simple
rules on vertex data formats.
More work remains, but I have things on my plate for the day.
When the facts change, I change my mind. What do you do, sir? ~ Keynes
<MostAwesomeDude at gmail.com>
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