Resolves the 3 P3 items in docs/rewrite/notes/review-rv12-codex.md
(final-Z15.md):
- Sprite strokes: tiny-skia is replaced by a port of z2d 0.10's stroke
plotter (sprite/stroke.rs) plus z2d's arc segmentation and truncating
integer compositing, feeding the ported 4x4 multisample rasterizer.
All 36 reference sprite sheets now match Ghostty's byte for byte (test
tolerance 0), and `just visual-parity` with a production build shows
0 differing pixels (max delta 0) against the installed Ghostty 1.3.1
for the test page (block and bar cursor) and the tabs+splits scenario,
terminal area and chrome alike. tiny-skia dependency removed.
- zig_error maps errno values per target via libc (Linux, Darwin/BSD)
and Win32 codes the way Zig std does on Windows.
- theme=. / theme=.. report "it is a directory" via a port of
std.fs.path.basename, matching Ghostty.
Test Plan:
- cargo test --workspace --no-fail-fast (3498 passed, exit 0)
- cargo build --profile production && just visual-parity
- just check-macos (both), just check-windows, just check-wasm
Adds scripts/visual-parity.sh (`just visual-parity`): launches the
installed Ghostty 1.3.1 and the Rust build in an isolated headless
nested weston (GL renderer, Mesa forced, weston-screenshooter via
--debug), with identical isolated config, a deterministic test page
(ASCII, ligatures, all SGR styles and underline kinds, 16/256/truecolor,
box/block/braille/powerline/nerd icons, CJK, emoji, wide chars,
cursor) and a tabs+splits scenario driven through Xwayland, then diffs
the captures (terminal area and chrome separately, heatmaps).
Fixes found by comparing against the original:
- A pane stayed blank after a nested split: the GTK render path called
draw_frame(false) where Ghostty uses drawFrame(true) (a re-realized
GLArea has a new swap chain that nothing else redraws).
- Sprite glyph antialiasing now ports z2d's default 4x4 multisample
rasterizer instead of tiny-skia's analytic coverage (pixels differing
from Ghostty's reference sprite sheets: 5.76% -> 1.20%, none off by
more than 96 levels); the sheet test tolerance is tightened to 0.1%.
Result vs Ghostty 1.3.1: test page 0.020% of pixels differ (196 px at
curly-underline ends and diagonal box strokes, max delta 86 levels);
tabs+splits and headerbar/tab bar are bit-identical. Details in
docs/rewrite/notes/visual-parity-VP.md.
Test Plan:
- just visual-parity (needs weston, weston-screenshooter, xdotool)
- cargo test -p ghostty-font (sprite sheet comparison)
ddidderr