panfrost: Rework fixed-function blending
The fixed-function blend logic uses the following equation: A + B x C.
A, B and C are configurable and can be complemented with negation (for
A and B) or inversion (for C) modifiers. Let's rework the blending
code to take that into account.
Note that we need to update the checksum of a few traces because the
equations we use have changed, leading to small deviations on the
final images. Indeed, there are several valid options for a given GL
blend equation, but the operand selection probably has an impact on the
rounding, leading to those mismatch.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6980>
10 files changed
