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Again, with a more detailed explanation added as comments.<br>
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On 20.04.2011 17:33, Christoph Bumiller wrote:
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<pre wrap="">On 04/19/2011 04:00 AM, Christoph Bumiller wrote:
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<pre wrap=""> On 16.04.2011 18:50, Christoph Bumiller wrote:
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<pre wrap="">I hope the new version is correct, the commit message describes why I
did the first change, and the second change is described in a comment.
Note that the MAD for inversion uses Height - 1 instead of Height.
With this, piglit glsl-arb-fragment-coord-conventions and
fbo-depth-sample-compare pass on nvc0.
I was assuming that integer pixel centers for size 100 range from 0 to
99 and half-integer pixel centers from 0.5 to 99.5.
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<pre wrap="">Attached a better version of the patch, potentially saving an
instruction and avoiding precision issues with NEAREST filtering that
made piglit's blending-in-shader fail.
The only other location I found STATE_FB_WPOS_Y_TRANSFORM used was
r600 classic, which should also work more correctly now since (at
least according to gallium caps) it uses half-integer pixel center,
and for H=100, 0.5 * -1 + 99 obviously isn't the desired 99.5.
Please review.
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<pre wrap="">Unfortunately I found another small error making a more precise piglit
test that draws to a float buffer instead of mangling the coordinate
like the original test does, which conceals errors.
Now there's a dependency again on whether inversion is actually done or
not, so I added a check on the inversion constant in the shader, but
maybe adding additional uniforms or even adjusting
STATE_FB_WPOS_Y_TRANSFORM dependent on the coordinat convention might be
nicer ?
Sorry for not noticing right away,
Christoph
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