In this PR we moved global alpha handling using temporary layers to
mutation of paint in vello_cpu (we were already doing this in vello
classic). This + not using temporary layer for SrcOver (default and most
common composition operation) allows us to remove most temporary layers
from `with_composition`.
This slightly improves performance of vello backend, but drastically
improves performance of vello_cpu. We are now able to render bunnymark
(100 bunnies) with 60 FPS.
In the future we could cache current layer and change it when
compositing operation changes, although that would complicate clips, so
improvement is questionable.
Testing: Existing WPT tests for functionality, but we do not have any
performance tests.
Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>
According to my tests `OptimizeSpeed` slight improves performance and it
does NOT affect WPT results in negative way.
Testing: Tested by existing WPT tests.
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Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>
As noted in #38345, vello scenes only grow. While we can reset them when
clearing viewport (#38356) that is not enough. We need to reset scene on
each render (~each frame) and providing old frame as backdrop to new
scene. Be do this lazily so multiple rendering without any changes
should be cheaper, we still do GPUBuffer mapping, because that would
require more complex work.
Testing: Code functionality is covered by existing WPT tests, but we do
not have any performance test.
---------
Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>
Vello scene only ever grows, so we need to clear it as soon as it's
possible (in clear rect). This PR also adds ignore_clips to
vello_backend (already exists in vello_cpu_backend).
Testing: Behavior is verified by existing tests, as this is mainly a
change for performance. There are currently no performance tests. This
makes bunnymark actually playable (from 3 FPS to 20 FPS on vello_cpu).
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Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>
vello_cpu does not have any tests timeouts, because we do not need
download stuff from GPU as all work happens on CPU. So performance wise
it's better then classic vello at least for our usecase. There are some
vello bugs, but I think we will be able to sort them out within
upstream, eventually. Interestingly enough there are no new PASS like
they were with classic vello.
Difference with raqote can be observed here:
https://github.com/sagudev/servo/actions/runs/16549241085/attempts/1#summary-46802486798
## Known vello problems:
- https://github.com/linebender/vello/issues/1119
- https://github.com/linebender/vello/issues/1056
-
`/html/canvas/element/fill-and-stroke-styles/2d.gradient.interpolate.coloralpha.html`
- `kurbo::Cap::Butt` is defect (only visible with big lineWidth)
https://github.com/linebender/vello/issues/1063
- `/html/canvas/element/line-styles/2d.line.cross.html`
- `/html/canvas/element/line-styles/2d.line.miter.acute.html`
- other lack of strong correct problems
(https://github.com/linebender/vello/issues/1063#issuecomment-2998084736):
- `/html/canvas/element/path-objects/2d.path.rect.selfintersect.html`
- `putImageData(getImageData(...), ...)` is lossy (precision problems,
might be due to ImageData being unmultiplied)
-
`/html/canvas/element/pixel-manipulation/2d.imageData.put.unchanged.html`
Testing: Tested using vello_cpu_canvas subsuite
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Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>
