Fold alpha to the inner savelayer in savelayer-savelayer-restore
patterns such as this:
SaveLayer (non-opaque)
Save
ClipRect
SaveLayer
Restore
Restore
Restore
Current blink generates these for example for SVG content such as this:
<path style="opacity:0.5 filter:url(#blur_filter)"/>
The outer save layer is due to the opacity and the inner one is due to
blur filter being implemented with picture image filter.
Reduces layers in desk_carsvg.skp testcase from 115 to 78.
BUG=skia:3119
Review URL: https://codereview.chromium.org/835973005
Fold alpha of a save layer call to the subsequent draw call paint, even when
the draw call paint color is already non-opaque.
Comparing the difference of the unoptimized and the optimized call pattern
with all (layer alpha, draw alpha) combinations, this produces
off-by-one pixels ~50% of the time.
Reduces layers of current desk_carsvg.skp (recorded with cross-process
picture image filters allowed) from 122 to 115.
BUG=skia:3119
Review URL: https://codereview.chromium.org/840483005
They're only hints. We can ignore them in this optimization.
My only hesitation is that this pattern doesn't seem to happen in our .skps.
BUG=skia:
Review URL: https://codereview.chromium.org/849243002
I'm soon going to have SkRecorder start calling getTotalMatrix(), which
would be broken in write-only mode. That change is big and nebulous,
but it's clear kWriteOnly needs to go, so we might as well kill it now.
My notes in bench_playback about kWriteOnly mode being important were
probably overly cautious. I now think this is a fair enough comparison
even re-recording into a read-write canvas.
BUG=skia:2378
R=fmalita@chromium.org, mtklein@google.com
Author: mtklein@chromium.org
Review URL: https://codereview.chromium.org/290653004
git-svn-id: http://skia.googlecode.com/svn/trunk@14963 2bbb7eff-a529-9590-31e7-b0007b416f81
