When the bounding boxes of a path and its clip are disjoint (i.e. they
do not intersect) the result of their intersection is a negative
rectangle.
When calculating the intersection of the bboxes, the binning stage
ensures that the bbox is non-negative. It then normalizes the
coordinates to bin dimensions and rounds the top-left corner down
to the neareast integer and the bottom-right corner up.
However this rounding causes zero-area bounding boxes to have a non-zero
area and sends the bottom-right corner to the placed in the next bin.
This causes fully clipped out draw objects to be included in binning,
with an incorrect clip bounding box that causes them to be erroneously
drawn with partial clipping.
`binning` now takes care around this logic to make sure that a zero-area
intersected-bbox gets skipped and clipped out. `tile_alloc`, also takes
care in its logic.
Fixes#286 and #333
Just load the atomic bump counter directly instead of piping it through a shared variable, when workgroupUniformLoad is not available. The value is in fact dynamically uniform, but that depends on the stage not setting its own failure flag, a fairly subtle invariant.
I think there was a write-after-read hazard for the reuse of sh_part_count[0]. However, doing the experiment of just changing that doesn't fix the problem on mac. It's possible there's a shader compilation problem (possibly the same one as provoking the storageBarrier workaround in tile_alloc), or also possibly a logic error I'm not understanding.
In any case, this change does appear to fix the hangs on mac.
Fixes#267
A number of things were wrong:
* The args were missing to `run`
* The robust memory changes introduced uniformity errors
* `clear_buffer` is a todo for wgpu on wasm
* Some more time calls crept in
* Initializing both env_logger and console_logger fails
In addition, we conditionally opt the shaders into
`workgroupUniformLoad`, as that's available on wasm but not yet native.
Some of the things (args, uniformity errors) are important fixes. Other
things (clear_buffer, wUL being optional) are workarounds for wgpu
limitations and have TODO items to be removed when wgpu catches up.
* Add counts to offsets when comparing against buffer size limits
* Remove multiplication by 4 in blend buffer allocation (we use units of u32)
* Move buffer sizes from BumpAllocators to Config
* Add comments about early exit
* Move the vello crate to the root of the crate
* Add warning that README is work in progress
* Add newline in warning
* Move the unlicense into the shader folder
* Fixup wgsl-analyzer include paths
2023-01-05 09:32:09 +00:00
Renamed from vello/shader/tile_alloc.wgsl (Browse further)
