golang.org/x/image/vector v0.47.0, patched for lys-lib

A copy of the vector package of golang.org/x/image v0.47.0 (BSD 3-Clause, LICENSE), without its tests, its generator or the generator's template, carried as a package of the lys-lib module and imported as github.com/stubbedev/lys-lib/third_party/vector. render and third_party/rasterx rasterize glyphs, clips and SVG paths through it.

Why it lives inside the module

As with third_party/oksvg: Go ignores a dependency's replace directives, so a patched copy wired in through go.mod would reach lys-lib's own builds and none of its consumers'.

Patches

Curve flattening rounds the same on every architecture

vector.go: upstream aims for bit-exact results across architectures and across Go and assembly, and raster_floating.go already converts its products for that reason, but QuadTo, CubeTo and lerp did not. On arm64 they fused into FMAs, so a curve's segments, and then its edge coverage, differed from amd64's. Each product that reaches an addition or a subtraction is now converted first. amd64's results are unchanged. Pinned by lys_test.go, which also holds the assembly accumulators to the portable ones on the architectures that have them, and by just no-fused.

Upstream status

Not offered upstream yet.