This is one of the stages in the new element pipeline. It's a simple
one, just a prefix sum of a couple counts, and some of it will probably
get merged with a downstream stage, but we'll do it separately for now
for convenience.
This patch also contains an update to Vulkan tools 1.2.198, which
accounts for the large diff of translated shaders.
This patch contains the core of the path stream processing, though some
integration bits are missing. The core logic is tested, though
combinations of path types, transforms, and line widths are not (yet).
Progress towards #119
There's a bit of reorganizing as well. Shader stages are made available
from piet-gpu to the test rig, config is now a proper structure
(marshaled with bytemuck).
This commit just has the transform stage, which is a simple monoid scan
of affine transforms.
Progress toward #119
Separate out render context upload from renderer creation. Upload ramps
to GPU buffer. Encode gradients to scene description. Fix a number of
bugs in uploading and processing.
This renders gradients in a test image, but has some shortcomings. For
one, staging buffers need to be applied for a couple things (they're
just host mapped for now). Also, the interaction between sRGB and
premultiplied alpha isn't quite right. The size of the gradient ramp
buffer is fixed and should be dynamic.
And of course there's always more optimization to be done, including
making the upload of gradient ramps more incremental, and probably
hashing of the stops instead of the processed ramps.
WIP. Most of the GPU-side work should be done (though it's not tested
end-to-end and it's certainly possible I missed something), but still
needs work on encoding side.
