In theory, this should be more cache efficient and allow us to trim the
operation to the width of row, shaving a few texel fetches. The cost is
that we cause pixman to evaluate the composite operation per-row. This
should only be a temporary solution until we can do something better
through pixman...
On a i5-2520m, ymmv,
firefox-fishtank 64585.38 -> 56823.41: 1.14x speedup
swfdec-fill-rate 1383.24 -> 1665.88: 1.20x slowdown
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reducing the number of passes has the usual change in the antialiasing
side-effects, as well as the boon of being faster (and theorectically more
accurate through reduced loss of dynamic range.)
On an i5-2520m:
swfdec-giant-steps-full 3240.43 -> 2651.36: 1.22x speedup
grads-heat-map 166.84 -> 136.79: 1.22x speedup
swfdec-giant-steps 940.19 -> 796.24: 1.18x speedup
ocitysmap 953.51 -> 831.96: 1.15x speedup
webkit-canvas-alpha 13924.01 -> 13115.70: 1.06x speedup
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
We suffer from the large overhead in calling pixman_image_composite32
per-span, but even will that overhead it is a net win with the usual
caveat about cache efficiency and function call overhead.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
The actual span rasterisers may be able to specialise if they know that
the spans will be pixel aligned.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
We were calling the antialias close function from the unantialiased
paths - a function that operates on a completely different structure to
the one passed in.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Having spent the last dev cycle looking at how we could specialize the
compositors for various backends, we once again look for the
commonalities in order to reduce the duplication. In part this is
motivated by the idea that spans is a good interface for both the
existent GL backend and pixman, and so they deserve a dedicated
compositor. xcb/xlib target an identical rendering system and so they
should be using the same compositor, and it should be possible to run
that same compositor locally against pixman to generate reference tests.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
P.S. This brings massive upheaval (read breakage) I've tried delaying in
order to fix as many things as possible but now this one patch does far,
far, far too much. Apologies in advance for breaking your favourite
backend, but trust me in that the end result will be much better. :)
