Resolves the parity items of docs/rewrite/notes/review-rv17-codex.md
(final-Z20.md):
- FreeType-only font backend is also available on Apple targets
(discovery-free, embedded emoji fonts); ghostty_surface_quicklook_font
returns null for every backend except plain CoreText like Zig.
- The +list-fonts test keys off the font crate's selected backend
(HAS_DISCOVERY), correct under feature unification and on Apple.
- Inspector font: 32 px rasterized with FreeType (dear-imgui freetype)
like Ghostty; a new `visual-parity.sh inspector` scenario shows 0.031%
differing pixels (hover highlight) vs the original on Linux. Windows,
Apple and wasm keep stb_truetype at 32 px (registered as a deliberate
deviation).
- Inspector DCS/APC descriptions follow Zig 0.15.2's formatting
(checked by running Zig), incl. the terminal.Parser.Action prefix.
- The ImGui demo window appears only in dev-profile builds, mirroring
Zig's .Debug-only gate.
Test Plan:
- cargo test --workspace --no-fail-fast (3582 passed)
- just check-macos (both, also with --features font-backend-freetype)
- scripts/visual-parity.sh inspector
Ghostty can be built with -Dfont-backend=freetype, which uses FreeType
without any font discovery. The Rust port only had fontconfig+freetype
(default on Linux) and the CoreText variants. The new cargo feature
`font-backend-freetype` on ghostty-font (forwarded by ghostty-cli and
the root crate; non-Apple, non-wasm targets) behaves like Zig's mode:
font-family discovery, fallback search and codepoint-map overrides are
skipped (embedded fonts only); +list-fonts and +show-face print Zig's
"built without a font discovery mechanism" message and exit 1; +version
reports `.freetype`. The default backend is unchanged.
Also registers the Rust-only benchmark tooling extensions (--time,
--handler=full, ghostty-synthetic +sgr) in DEVIANT_FIXES.md.
Note: `--all-features` now selects this backend for the workspace.
Test Plan:
- cargo test -p ghostty-font --features font-backend-freetype (198)
- cargo build --features font-backend-freetype && ghostty +list-fonts
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)
Resolves the 6 differential gap groups in docs/rewrite/notes/review-
rv9-codex.md (details in final-Z11.md):
- ghostty_os::zig_fmt ports std.fmt.parseInt/parseUnsigned/parseFloat
(underscores, 0x/0o/0b prefixes, hex floats, inf/nan) with the Zig std
tests and replaces every int/float parse in config, keybind
parameters, ssh-cache and desktop detection.
- Interior NUL no longer panics in font names and ends C strings like
Zig's backing bytes (fontconfig, C config getters, title actions,
clipboard callback, relative paths, config-file, shaders, background
image, GTK CSS).
- GTK new-window arguments are trimmed of ASCII whitespace only.
- Command tokenization uses a port of std.process.ArgIteratorGeneral
(incl. CR/LF separators) with its std tests.
- UTF-8 validation happens where Zig's field parsers do it, so error
kinds match (metric modifiers, quick-terminal size, link, ...).
A scripted differential run of 202 fields x ~220 hostile/valid values
against /usr/bin/ghostty (+validate-config and +show-config: exit code,
stdout, stderr) now has zero mismatches besides build-specific defaults
(theme resources path, auto-update-channel, gtk-opengl-debug); it also
surfaced and fixed background-blur failure state, NaN formatting and
NaN/-0 finalize clamps. Regression tests: ghostty-config/tests/
zig_parity.rs.
Test Plan:
- cargo test --workspace --no-fail-fast (3456 passed, exit 0)
- just check-macos (both), just check-windows, just check-wasm
Zig parses config values (cli/args.zig, Config.zig field parsers,
config/string.zig) from raw byte slices, and each field type decides
whether it requires UTF-8 (InvalidValue otherwise) or stores bytes. The
port escape-encoded raw bytes into Strings at the line reader and let
fields parse the escaped text, so fields could observe encoding
artifacts; successive audits kept finding such leaks (RV5-RV8).
Field parsers now receive the original bytes: text fields validate UTF-8
where Zig does, byte/path fields store bytes (EncodedOs/OsString). This
resolves all 9 RV8 findings (docs/rewrite/notes/review-rv8-codex.md),
each with a regression test: Windows path conversion fails with
BadPathName instead of substituting U+FFFD; Windows process launch uses
strict UTF-8 like Zig's Command; the WTF-8 decoder accepts paired-
surrogate encodings like Zig; literal U+FDD0 Unicode key triggers;
selection-word-chars and clipboard-codepoint-map reject invalid UTF-8;
font style / codepoint-map family names use original bytes; C title
actions forward bytes; D-Bus new-window/Flatpak conversions match Zig.
Design, sweep and validation: docs/rewrite/notes/final-bytes-refactor.md.
Also moves the bundled iTerm2-Color-Schemes license out of
resources/themes/ so +list-themes no longer lists it as a theme
(output is now byte-identical to Ghostty 1.3.1).
Done by Codex (gpt-6-astra), reviewed and verified by the orchestrator.
Test Plan:
- cargo test --workspace --no-fail-fast (3428 passed, exit 0)
- just check-macos (both), just check-windows, just check-wasm
- +show-config --default --docs, +list-keybinds, +list-actions --docs,
+list-themes --plain compared with /usr/bin/ghostty
Resolves the 9 gap groups in docs/rewrite/notes/review-rv7-codex.md and
audits every string-typed config field against its consumers
(field -> consumers -> decode status table in final-Z9.md):
- Windows EnvMap keys use a port of Zig's nls.zig uppercase table
(upcaseW); Windows locale init follows Zig's chain (setlocale +
_putenv_s); malformed WTF-8 now fails process launch conversions like
Zig instead of substituting U+FFFD; kitty file paths convert WTF-8.
- bash --rcfile/--init-file, configured TERM and inherited GTK LANG
keep their original bytes.
- C API clipboard completion and ghostty_surface_binding_action take
bytes; complete_clipboard_request is byte-typed through the core.
- text:/csi:/esc: bindings, enquiry-response, input = path:, embedded
initial_input, search needles, titles, link regexes, clipboard
codepoint map, command palette text and GTK font/namespace values
decode the escape encoding before use.
Remaining by design: D-Bus a{ss} values and +new-window arguments are
UTF-8 by D-Bus type. C API key/preedit text follows separately.
Test Plan:
- cargo test --workspace
- just check-macos (both), just check-windows, just check-wasm
Escaped config strings (ghostty_os::osbytes) kept reaching OS
boundaries undecoded, and decoding was occasionally applied to plain
text. The root cause was that both were plain `String`s. Now:
- `EncodedOs` is a newtype (no Display/AsRef<Path>) that decodes only
via to_os/to_path/to_bytes/to_wide; plain text enters via
from_plain_text. OS helpers (env, home, xdg, passwd, resources dir,
path expansion), config::Path, WorkingDirectory, theme/file_load/edit
paths, terminal pwd, OpenUrl/Pwd actions and termio cwd use it, so the
compiler forces decoding at every boundary. os::open takes &OsStr.
Config output is unchanged.
Fixes all rows of docs/rewrite/notes/review-rv5-codex.md (final-Z7.md):
screen-file copy; regex/OSC 8 URLs no longer decoded (regression);
lossless Windows WTF-8/WTF-16 for args, env and CreateProcessW; Windows
resources dir/TERMINFO; color OSC request lists and X11 color lookup no
longer allocate globally (C zero-allocation test extended); macOS Mach
handler resumes all threads before KERN_FAILURE (hang regression) and
SIGABRT minidumps go through the exception thread; plus open-config,
background images, crash dir, ssh cache, exe dir/PATH, fontconfig
filenames, file links, kitty TMPDIR, .hushlogin and benchmark paths.
The typing also surfaced and fixed gtk-custom-css, bell audio, bash
HISTFILE, OSC 52 writes and the C config getters.
Test Plan:
- cargo test --workspace (3376 passed)
- just check-macos (both), just check-windows, just check-wasm
- diff <(ghostty-rs +show-config --default --docs) \
<(ghostty +show-config --default --docs)
Ports apprt/embedded.zig, main_c.zig and config/CApi.zig + c_get.zig as
crates/ghostty-lib (cdylib/staticlib/rlib `libghostty`), exporting every
function of the unchanged include/ghostty.h - the ABI Ghostty's Swift
macOS/iOS app links against. The embedded runtime implements the
runtime traits over the host's C callbacks, so the real core drives it.
- ghostty-core selects the renderer per target: Metal on Apple (surface
NSView/UIView via RtSurface::platform_view), OpenGL elsewhere.
- ghostty_config_get follows Zig's c_get rules via a CValue type (143
supported keys, checked against the Zig field types).
- The inspector C API is complete; its Metal backend replaces ImGui's
Metal renderer and has not run.
Verification: generated C ABI probe (sizeof/alignof/offsetof of every
struct/union, 755 enum values, every function linked, nm exports, headers
byte-identical to upstream); a C host on Linux covering init, CLI
actions, config, app, keys, focus and color scheme; an opt-in
test-platform feature creating real surfaces on Linux with headless EGL
and a pty (13 tests). Apple targets are clippy-clean but not run; the
Swift app has not been built against it.
Test Plan:
- cargo test -p ghostty-lib (and --features test-platform)
- cargo clippy --target aarch64-apple-darwin -p ghostty-lib (cross env
in docs/rewrite/notes/macos-M1.md)
Ports the macOS-specific Zig code behind cfg(target_os = "macos"):
- renderer: a GraphicsApi trait with generic::Renderer<G>; Metal backend
(all renderer/metal/* files, shaders.metal verbatim, runtime library
compile, IOSurface layer, CVDisplayLink), shadertoy -> MSL via naga;
OpenGL remains the backend elsewhere.
- font: CoreText face, shaper and discovery with build.rs backend
selection (coretext default; coretext-freetype / coretext-harfbuzz /
coretext-noshape features), no fontconfig/freetype/harfbuzz on Apple.
- input: KeymapDarwin via UCKeyTranslate, option-as-alt, mac keycodes.
- os: macos, mach, cf_release_thread, NSProcessInfo args and macOS
branches; config: macOS defaults, keybinds, Application Support paths.
- termio/core: login(1) wrapping, openpty/execvpe, Darwin child exit
handling, os_log logging.
Compile-checked for aarch64/x86_64-apple-darwin (clippy -D warnings
clean) using the cross setup in docs/rewrite/notes/macos-M1.md; cannot
run here. The embedded runtime/C API (embedded.zig) is the next step.
Also includes the cross-platform integration edits shared by the crash,
verification, Windows and macOS work (Cargo target-gating, thread
crash-context hooks, apprt-gtk surface/IME refactor, termio/os cfg
gates), a cfg fix so ghostty-config builds on wasm32, and an allow for
the intentional recursion in the crash overflow test.
Test Plan:
- cargo test --workspace (3224 passed)
- cargo clippy --workspace --all-targets -- -D warnings
- cargo check --target aarch64-apple-darwin -p ghostty-renderer (with
the documented cross env)
Ghostty's wasm code talks to JavaScript through the zig-js library
(mitchellh/zig-js, pinned in build.zig.zon). The first port invented its
own import ABI because the dependency wasn't available; now:
- ghostty-os/src/wasm/js.rs is a Rust port of zig-js's Zig side (Ref,
Value, Object get/set/call/new, global, runtime, string) using its
"zig-js" import module, function names and NaN-boxed value refs.
- web_canvas face and the atlas debug canvas make the same JS calls as
Ghostty's Zig code.
- zig-js's unmodified JS host (+ LICENSE) is vendored under
crates/ghostty-wasm/js/zig-js and drives the node test.
Test Plan:
- cargo test -p ghostty-wasm (node >= 24; asserts zig-js imports and no
leaked host values)
Ports main_wasm.zig as crates/ghostty-wasm (cdylib exporting the Zig
names: atlas_*, face_*, deferred_face_*, shaper_*, config_*), the
web_canvas font face and shaper (backend selected on wasm32), os/wasm
(logging, target, JS interop) and config/Wasm.zig.
C-library dependencies (freetype, harfbuzz, fontconfig, onig, gettext,
D-Bus, rustix) are target-gated. Like Zig's wasm build, link regex
search (StringMap::search_iterator) is unavailable without Oniguruma;
Collection/SharedGrid/harfbuzz are compiled out on wasm32. ghostty-os
switches from forbid to deny unsafe_code for the JS import blocks.
The JS import ABI is currently a documented handle-based interface with
a reference host (js/ghostty_host.js); aligning it with zig-js's exact
import names follows separately.
Test Plan:
- cargo build --target wasm32-unknown-unknown -p ghostty-font \
-p ghostty-config -p ghostty-terminal -p ghostty-vt -p ghostty-wasm
- cargo test -p ghostty-wasm (node runs the module against a fake canvas)
rustfmt.toml sets group_imports, imports_granularity and imports_layout,
which are nightly-only; agents formatted with stable rustfmt, which
ignored them. This is a formatting-only pass with `cargo +nightly fmt`.
Test Plan:
- cargo clippy --workspace --all-targets -- -D warnings
- cargo test --workspace
Completes the font engine port:
- shaper/run.rs ports run.zig: the RunIterator over terminal rows that
splits text runs at style/face boundaries, selection and cursor,
handles graphemes and ligatures; Shaper::shape_run shapes a run.
- shared_grid_set.rs ports SharedGridSet.zig: grids keyed by a config
derived key, handed out as Arc<SharedGrid>.
- Font-related types now have one canonical definition in ghostty-config
(Variation, Descriptor, CodepointMap, metric modifiers, freetype load
flags, synthetic style, shaping break) which the font crate re-exports.
MetricModifier::apply_i32 now saturates to -i32::MAX like Zig.
- The 23 terminal-driven harfbuzz shaper tests are ported, printing via
Screen until Terminal lands.
Test Plan:
- cargo test -p ghostty-font (157 passed, 3 ignored - also skipped in
Zig); Devanagari/Chakma/Bengali tests return early without system fonts
- cargo test -p ghostty-config (255 passed)
Ports the rest of ZIG/src/font for the freetype/fontconfig/harfbuzz
backend: face loading and rasterization (synthetic bold/italic, color
emoji bitmaps, glyph constraints for nerd font icons), fontconfig
discovery, DeferredFace, Collection, CodepointResolver, CodepointMap,
SharedGrid, opentype table parsers, the nerd font attribute table, and
the harfbuzz shaper with feature parsing and shaping cache.
Embedded fonts (JetBrains Mono 2.304 variable, Symbols Nerd Font 3.4.0,
Noto emoji) and the test fonts from Ghostty live in res/ with their OFL/
MIT licenses.
The crate opts into unsafe_code = "deny"; FFI is confined to ft.rs,
fontconfig.rs and hb.rs with SAFETY comments. Glyph resampling uses an
stb-style resampler that is not bit-identical to stb.
Deferred to the next font pass (needs ghostty-terminal/config):
shaper/run.zig, SharedGridSet.zig and the 23 terminal-driven shaper
tests. Config-facing types are mirrored locally in config_types.rs.
Test Plan:
- cargo test -p ghostty-font (139 tests)
Ports ZIG/src/font/{Metrics,Atlas,Glyph}.zig and the whole sprite font
(font/sprite/**): box drawing, block elements, braille, branch/git
graph symbols, geometric shapes, powerline, and the symbols for legacy
computing (+ supplement, incl. the octants table).
Ghostty draws sprites with z2d; we use tiny-skia for path coverage,
composited onto an alpha8 canvas, while following the Zig geometry
(positions, thickness, rounding). Comptime discovery of draw functions
is replaced by explicit, overlap-checked codepoint range tables.
Upstream reference sheets are vendored in testdata/ and compared with a
tolerance: braille and U+1CD00 are pixel-identical; other sheets differ
only in antialiasing on thin diagonals/curves. Review renders are written
to target/sprite_sheets/.
The crate temporarily drops its config/unicode/terminal deps until the
rest of the font engine is ported (Phase 3).
Test Plan:
- cargo test -p ghostty-font (49 tests incl. reference sheet comparison)
- inspect target/sprite_sheets/review-all-18x36.png
Start of the full Rust rewrite of Ghostty 1.3.1 (reference source in
../ghostty). Sets up a workspace whose crates mirror Ghostty's Zig modules
(vt, unicode, datastruct, os, input, config, terminal, font, renderer,
termio, core, apprt-gtk) so porting work can proceed in parallel per crate.
Also adds:
- docs/rewrite/{ARCHITECTURE,PLAN,STATUS,AGENT_GUIDE}.md: crate map, core
design decisions (safe Rust, slab-based PageList, logical capacity
accounting), phased plan, progress tracker, and porting rules.
- Workspace clippy config relaxing pedantic lints that are pure noise for
low-level terminal code (casts, long functions).
- Shared vt types needed by several work packages up front: kitty
keyboard flags (kitty/key.rs) and the CSI separator bitset (SepList).
Test Plan:
- cargo test -p ghostty-vt (3 tests pass)
- cargo clippy -p ghostty-vt --all-targets -- -D warnings
ddidderr