github.com/srwiley/rasterx v0.0.0-20220730225603-2ab79fcdd4ef, patched for lys-lib

A copy of github.com/srwiley/rasterx at 2ab79fcdd4ef (BSD 3-Clause, LICENSE), its non-test sources only, carried as a package of the lys-lib module and imported as github.com/stubbedev/lys-lib/third_party/rasterx. render and third_party/oksvg stroke, dash and transform 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

Products round the same on every architecture

matrix.go, geomx.go, shapes.go, gradient.go, fill.go, stroke.go: the Go spec lets the compiler fuse x*y + z into one FMA instruction, which skips the rounding of the product. It does so on arm64 and not on amd64, so a symbolic icon's edge pixels differed between the two: 918 of 63296 in lys-ui's builtin icon grid and 12 of 480000 in lys-splash's frames. Each product that reaches an addition or a subtraction is now converted, float64(x*y) + z, which the spec defines to round first. That includes x/2, which the compiler turns into a product, and x*y*2, which it turns into x*y + x*y. amd64's results are unchanged. Pinned by the family's goldens, which hold exactly on amd64 and arm64, and by just no-fused.

Import path

scan.go imports third_party/vector in place of golang.org/x/image/vector.

Upstream status

Not offered upstream yet; the repository has had no commits since 2022.