Closing a busy split or confirming a tab close could freeze GTK while
unrealizing the GLArea. Both reported GDB traces show the main thread
waiting for the CPU frame-state mutex while the renderer keeps rebuilding
dense text. GTK unrealizes the display before stopping the workers, so
continuous output can keep the competing renderer active indefinitely.
Use parking_lot fair mutexes for CPU frame state and GPU draw state. A
waiting lifecycle or draw callback receives ownership instead of losing
it to the next frame update. Keep the existing lock order and resource
cleanup; no output, scrollback, or frame-rate limits are introduced. The
fair-lock handoff adds scheduling overhead when the locks are contended.
Correct the threading documentation: the CPU state is also accessed by
apprt callbacks, and the Rust-only mutex is therefore contended.
Test plan:
- Add a mock GPU regression continuously rebuilding 200x150 dense cells
while another thread unrealizes and realizes the display. It failed
its three-second deadline with the old locks and passes with fair locks.
- All 235 renderer/core tests pass, including Mesa EGL rendering tests.
- Clippy for renderer/core/GTK, all targets, passes with -D warnings.
- Nightly formatting check and release binary build pass.
- GTK/Wayland replay with font size 9 and 1 GiB scrollback runs base64
floods in two splits, confirms split and tab closes, then successfully
executes and renders a command in the surviving terminal.
Docs: docs/rewrite/ARCHITECTURE.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)
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
Ports renderer/{generic,cell,row,link,State,Overlay,image,Thread}.zig:
- generic.rs builds GPU cell buffers from terminal RenderState each
frame: backgrounds, shaped text runs with glyph atlases and nerd font
constraints, all cursor styles, decorations via sprites, selection and
search colors, min-contrast, bold/faint/blink handling, preedit,
padding extension, background image, custom shader uniforms, link
hover underlines, scrollbar and health reporting.
- The renderer thread updates CPU-side state only and asks the host to
redraw; the app runtime calls draw_frame from the GLArea render signal
(the GL context lives on the GTK thread, as in Ghostty).
- ghostty_renderer::state::{State, SharedState} is the canonical shared
renderer state (termio's interim copy will switch to it).
Deviations: overlay uses a direct RGBA rasterizer instead of z2d; bg
images decode with png/jpeg-decoder instead of wuffs; zero-length link
matches advance by one char (Zig would loop forever).
Kitty image rendering is implemented in image::State but not yet called
from generic::update_kitty (raced with the terminal-side wiring).
Test Plan:
- cargo test -p ghostty-renderer (69 unit + 9 headless EGL tests that
render a Terminal through the full pipeline and check pixels)
Ports the terminal-independent half of ZIG/src/renderer (OpenGL only):
- opengl/*: buffers, frames, pipelines, render passes, samplers,
targets, textures and the OpenGL GraphicsAPI backend on top of glow;
the GTK GLArea glue is replaced by a get_proc_address loader closure
- the GLSL shaders, copied verbatim and embedded; uniform/vertex structs
as bytemuck Pod types with std140 offsets asserted in tests
- shadertoy custom shaders converted with naga (GLSL in -> validate ->
GLSL 430 out) instead of glslang + spirv-cross
- size (screen/grid/cell/padding math), cursor style logic, backend
health, options and message types
The crate opts into unsafe_code = "deny"; unsafe glow calls live only in
opengl/gl.rs. A headless EGL integration test builds every pipeline and
the converted shadertoy shaders on Mesa and reads back rendered pixels.
Note: Zig's shadertoy Uniforms order the selection background/foreground
colors opposite to the GLSL block (likely an upstream bug); kept as in
Zig for parity and recorded in the notes.
Deferred to the next renderer pass: generic, cell, image, link, row,
State, Thread, Overlay (need terminal render state).
Test Plan:
- cargo test -p ghostty-renderer (33 tests incl. tests/egl_headless.rs)
ddidderr