veiland 0.3.1

A packaging-only patch release for Nix users. Nothing in veiland itself
changed since v0.3.0 -- no core, protocol, SDK or plugin code was touched.

Fixed

• NixOS: the Python plugins could not run. Every installed veiland-*
  Python widget died at startup with "cannot load libgbm". They now start
  normally. (8984950)

Full changelog: v0.3.0...v0.3.1

veiland 0.3.0

veiland 0.3.0

Veiland gains a GLSL shader tier: veiland-shader runs a
Shadertoy-convention fragment shader as a lock-screen layer. Seven
shaders ship in the binary, and a path to your own .frag runs that
instead, so a shader you like on Shadertoy usually drops in unchanged.

Upgrading from 0.2.0 is a straight upgrade: nothing was removed and no
configuration changed.

Added

The shader plugin

• veiland-shader compiles a Shadertoy-convention mainImage shader
  and renders it into its region every frame. You write only that
  function; the version directive, precision qualifiers, uniform
  declarations, and the main() that calls it are prepended for you.
  fragCoord arrives with Shadertoy's bottom-left origin.
• Seven embedded presets, needing nothing installed: nebula,
  deepfield, starfield, moon, meteor, warp, and plasma.
  Preset names are a stable interface, like a CLI flag.
• path runs a .frag file of your own, and wins over preset when
  both are set.
• The full single-pass Shadertoy uniform set is declared, so a shader
  mentioning one compiles even where the value is not meaningful here.
  iTime, iTimeDelta, iFrame, iFrameRate and iResolution are
  live; iChannel0 is a 256x256 tiling noise texture; iMouse is zero,
  since plugins receive no pointer events; iDate fills only its
  seconds-since-local-midnight component.
• opacity below 1.0 switches the layer to premultiplied transparency,
  so a shader written with alpha in mind composites over what sits under
  it. At the default 1.0 the layer is opaque and the shader's alpha is
  ignored, which is the right default because Shadertoy shaders write
  undefined alpha.
• render_scale and max_fps are the thermal knobs. max_fps defaults
  to 30 rather than the compositor rate, because a full-screen fragment
  shader runs your maths on every pixel of every frame.
• loop_seconds wraps iTime at a period you choose, for shaders with
  a natural cycle or for very long locks, where a float iTime loses
  precision as it climbs.
• veiland-shader --check [FILE] compiles a shader and prints the
  driver's own compile log, so a syntax error surfaces without locking
  the screen. It exits 0 when the shader compiles; with no argument it
  checks whatever your config selects.
• A bad shader never costs you the scene. An unknown preset, an
  unreadable or oversized file, or a compile error logs the reason with
  the compiler's full output and draws a dark fill, with the plugin
  still running.

Scenes, widgets, and the SDK

• A Deep Field astronomy example scene
  (docs/examples/deepfield-astronomy.toml): four shader layers, three
  of them transparent, under a markup clock and an ephemeris HUD.
  Entirely procedural, with no image asset.
• The markup widget gained a {jd} substitution, the Julian Day
  Number that astronomers count in.
• GbmEgl::new_es3 in veiland-plugin, for plugins whose shaders need
  a GLES 3 context to compile #version 300 es.

veiland 0.2.0

veiland 0.2.0

Veiland gains a Python plugin tier: a full SDK plus nine ready-made
widgets, so a scene can now show the weather, what's playing, or your
network state without writing Rust. Wallpapers can blur, plugins can be
anchored to a corner instead of pinned to pixel coordinates, and the
text tier moved to Pango markup.

Upgrading from 0.1.0: read Removed and Changed first. The
clock and label plugins are gone, and PAM no longer runs the account
phase.

Added

Python plugin tier

• veiland_plugin.py, a Python SDK mirroring the Rust one: wire codec,
  Connection, GBM buffer allocation, FramePacer, and BufferChain.
  Plugins are ordinary Python programs; the wire format was never tied
  to Rust, and this is the proof.
• Four companions: veiland_text (Pango text), veiland_svg (SVG icon
  rendering), veiland_dbus (D-Bus, no async runtime), and
  veiland_layout (content anchoring and debug borders).
• Nine widgets installed as veiland-* commands on every packaging
  target: markup, weather, now-playing, avatar, wifi,
  ethernet, bluetooth, battery, shape.
• markup is the new text tier: one block of Pango markup with ten
  substitutions: {user}, {name}, {host}, {time}, {date},
  {uptime}, {loadavg}, {kernel}, {distro}, {distro_version}.
  {time} and {date} take a strftime format; a bad one shows the text
  you typed instead of crashing.
• weather reads Open-Meteo by city name or latitude/longitude. No API
  key, and the fetch uses only the standard library, so it adds no
  dependency beyond the shared widget stack. Eleven CC0 icons included.
• now-playing shows the current MPRIS track, read-only.
• shape draws a rounded colored rectangle, a backdrop to group other
  widgets against.
• Python tooling in CI: ruff, mypy --strict, and pytest.

Core

• Anchored region placement: halign/valign with fraction-of-surface
  width, height, and margin (margin_x/margin_y per axis). A
  widget anchored to a corner lands in the same relative spot on 1080p
  and 4K, instead of at fixed pixel coordinates.
• --help and --version. Version carries the git revision on builds
  off master, so a bug report says which build it came from.
• VEILAND_GL_DEBUG=1 for GL diagnostics: the driver debug callback
  where available, with a glGetError fallback.

Plugins

• wallpaper gained blur, darken, and blur_regions: blur the
  whole surface, then tint rounded regions on top as frosted cards.
• particles gained an opt-in twinkle (with twinkle_speed and
  twinkle_depth) for a shimmering starfield.
• Optional labels beside the glyph on wifi, bluetooth, and
  battery; avatar gained a rounded-square shape.

Scenes and docs

• Four composed example scenes with screenshots: aurora-corners,
  aurora-card, aurora-dashboard, and deepfield.
• A documentation website (Zola), with per-plugin reference pages
  generated from a single source and checked in CI.
• docs/plugin-python.md, the Python SDK reference.
• Manual VM packaging tests (scripts/vmtest/) that boot real Debian,
  Fedora, and Arch guests, install the built package, and verify the
  widget dependency closure resolves.

Changed

• PAM now runs pam_authenticate only, not pam_acct_mgmt. A
  correct password was intermittently rejected right after a fast logout
  and login, because the account phase returned a transient error while
  logind tore down the previous session. A locker re-verifies an
  existing session; deciding whether an account may start one is a
  login manager's job, and applying it here could lock you out of your
  own live session with no way to change the password. Shipped PAM files
  drop the now-dead account line. Existing installs keep their current
  file, where the stale line is simply never evaluated. Trade-off: an
  account disabled while the screen is locked still unlocks with a
  correct password. The session is already open either way.
• Configure now carries the plugin's region dimensions rather than the
  full surface size, so a plugin assigned a region renders at that
  region's size instead of drawing full-surface and being squashed into
  it.
• Python widgets are referenced by bare veiland-* name in the example
  scenes, resolved on PATH like the Rust plugins.

Removed

• The clock and label plugins. markup replaces both, with
  Pango markup, live substitutions, and font matching that follows the
  system's configuration. Scenes using them need
  binary = "veiland-markup" and a text key; see
  docs/examples/ for worked configurations.

Fixed

• CPU-rendered plugins flickered because a single buffer was redrawn in
  place while the host was still sampling it. BufferChain double-buffers
  and fixes it.
• Dmabufs that a driver only accepts as external textures rendered black
  (NVIDIA marks linear and CPU-written buffers this way, so every CPU
  plugin was affected). The core now samples them via
  GL_TEXTURE_EXTERNAL_OES, and falls back cleanly on stacks without the
  extension.
• Glyphs bled into their neighbours in the text atlas; a 1px gutter fixes
  it.
• A glyph the rasterizer can't render is now reported once instead of
  silently vanishing. Hairline font weights drop digits on some fonts,
  which previously looked like a bug in the clock.

veiland 0.1.0

First release. Veiland is a GPU lock screen for Wayland that you compose
from layers, each one a separate program.

Added

Core locker

• ext-session-lock-v1 lock surface; works on any compositor implementing
  the protocol (tested on Hyprland and Sway). The compositor enforces the
  lock, so the session fails closed even if veiland crashes.
• PAM authentication against the veiland service (auth + account
  phases), run on a worker thread so a wrong password never freezes the
  animation.
• Configurable password indicator, always composited on top of all plugin
  output.
• Multi-monitor support with per-plugin output targeting, and HiDPI-aware
  text rendering via veiland-text (cosmic-text backend).
• Reliability across suspend/resume, DPMS off/on, and monitor
  unplug/replug — including unplugging every monitor at once and
  hot-plugging a display in while locked.
• Password-buffer hygiene: mlock'd, zeroed after the PAM call, and the
  core sets prctl(PR_SET_DUMPABLE, 0) at startup to deny same-UID
  ptrace/proc-mem reads and core dumps (VEILAND_ALLOW_DUMP=1 opts out).

Plugin system and protocol

• Process-isolated plugins: every layer is a separate program, spawned over
  a socketpair and speaking a versioned tagged-message protocol on an
  AF_UNIX SOCK_SEQPACKET socket. Plugins never receive keyboard input and
  have no unlock path — the API surface is absent by construction.
• Zero-copy GPU rendering: plugins allocate buffers via GBM, render with
  their own EGL/OpenGL context, and pass DMA-BUF file descriptors to the
  core via SCM_RIGHTS; the core imports them as EGLImage textures. No
  pixel data crosses CPU memory.
• Explicit sync: frames carry a sync-fence fd where the driver supports it,
  with a glFinish fallback negotiated automatically.
• Scene composition: plugins layer by z_index, can target specific
  monitors, and are configured through [[plugin]] tables in
  ~/.config/veiland/config.toml.
• A crashed or misbehaving plugin costs its own layer, never the locker:
  malformed messages close the plugin's socket and a fallback is drawn for
  its region.
• veiland-plugin, the Rust plugin SDK: imperative primitives
  (Connection, FramePacer, DmaBuffer, GbmEgl) the plugin author
  drives from their own main(). The wire format is documented and not
  tied to Rust.
• veiland-protocol, the wire-format implementation, with a cargo-fuzz
  harness for the codec.

Bundled plugins (14)

• wallpaper — image wallpaper.
• clock — time display.
• label — static text.
• vignette — darkened-edges overlay.
• particles, sakura, snow, rain, embers, fireflies — the
  particle family: drifting particles, falling petals, dendritic ice
  crystals, slanted rain streaks, rising sparks, wandering glow.
• gradient, parallax, blobs — ambient backgrounds: flowing color
  ramp, layered bokeh depth, lava-lamp metaballs.
• raymarcher — raymarched gyroid tunnel drift.

Packaging

• NixOS flake: package, dev shell, and checks, plus a NixOS module
  (services.veiland.enable = true) that installs the binary and reference
  plugins and registers the PAM service.
• Arch Linux PKGBUILD (AUR).
• Debian package for Debian testing (trixie), with the PAM service bundled.
• RPM spec for Fedora/RHEL, with the PAM service bundled; .deb and .rpm
  artifacts are built by CI and attached to releases.
• Reference PAM service files and an annotated example config under
  packaging/.

Documentation

• docs/architecture.md — full write-up: trust boundaries, module map,
  security model.
• docs/protocol.md — the wire-format specification (the spec is
  authoritative over the implementation).
• docs/plugin-api.md — plugin SDK reference.
• docs/plugin-authoring-claude.md — drop-in context file for writing
  plugins with an AI coding assistant.
• docs/config.md — configuration reference.
• Ready-made example scenes in docs/examples/, matching the README
  gallery (shinkai composes ten plugin instances across two monitors).
• SECURITY.md and CONTRIBUTING.md.