I realized there's a problem with encoding clip bboxes relative to the
current transform (see #36 for a more detailed explanation), so this is
changing it to absolute bboxes.
This more or less gets clips working. There are optimization
opportunities (all-clear and all-opaque mask tiles), and it doesn't deal
with overflow of the blend stack, but it seems to basically work.
Actually handle transforms in RenderCtx (was implemented in renderer but
not actually plumbed through). This also requires maintaining a state
stack, which will also be required for clipping.
This PR also starts work on encoding clipping, including tracking
bounding boxes.
WIP, none of this is tested yet.
The hub does a little better lifetime tracking of resources (so
Rust-side references can be dropped), and in the future will be used for
dynamic selection of backend.
The migration is still a bit half-baked, as there are a bunch of
Vulkan-specific types in the signatures, but it shouldn't be too much
work to sort that out. Perhaps it can wait until there is a second
backend though.
The main motivation for this is to create image objects with lifetime
tracking, one of the things required for #38.
Update to latest versions of all dependencies. Among other things, this
gets us on piet 0.2, though almost all of the changes were around text,
which is not yet implemented.
Path segments are unsorted, but other elements are using the same
sort-middle approach as before.
This is a checkpoint. At this point, there are unoptimized versions
of tile init and coarse path raster, but it isn't wired up into a
working pipeline. Also observing about a 3x performance regression in
element processing, which needs to be investigated.
Trying to fit it into the fancy monad doesn't really work, so use a
more straightforward approach to compute it from the aggregate.
Also add yEdge logic (basically copying piet-metal). With a fix to
ELEMENT_BINNING_RATIO (which I had simply gotten wrong), the example
renders almost correctly, with small bounding box artifacts.
Write the right_edge to the binning output.
More work on encoding the fill/stroke distinction and plumbing that
through the pipeline. This is a bit unsatisfying because of the code
duplication; having an extra fill/stroke bool might be better, but I
want to avoid making the structs bigger (this could be solved by
better packing in the struct encoding).
Fills are plumbed through to the last stage. Backdrop is WIP.
This should get the "right_edge" value for each segment plumbed through
to the binning phase. It also needs to be plumbed to coarse raster and
wired up there.
Also considering WIP because none of this logic has been tested yet.
As of this point, it mostly renders stroke outlines for tiger. Some
dropouts are because the scan in the elements pass doesn't do lookback
yet, others are probably a bug.
This version seems to work but the allocation of segments has low
utilization. Probably best to allocate in chunks rather than try to
make them contiguous.
This just adds the first step of polyline stroking, which is adding it
to the scene. Also just a bit of cleaning up of dimensions into one
header file.
