srdusr
aboutsummaryrefslogtreecommitdiffstats
path: root/crates/wayland/src/decoration.rs
AgeCommit message (Collapse)AuthorFilesLines
2026-04-20Confirm Nemo's popup works; fix the two bugs that hid it, and shadow bleed ↵srdusr1-1/+1
across a monitor seam Nemo's right-click context menu was the last open punch-list item, parked twice as untestable. It works: verified end to end in a throwaway nested compositor, menu and submenu both, at the correct position and stacking. The popup path itself needed no fix, so the POPUP-GEOM-DIAG/POPUP-GRAB-DIAG diagnostics are removed. Two real bugs turned up in the way of testing it. zwlr_virtual_pointer was a silent no-op on the winit backend. Every Motion/MotionAbsolute handler read UdevState::bounds() behind an early return when state.udev was None, and that field is Some only for the DRM backend. The protocol advertised its global, accepted create_virtual_pointer and accepted every request, then discarded all motion with no error and no log. That is the backend a nested instance runs on, so the only safe way to drive a throwaway compositor - a Wayland client of that compositor, which cannot reach any other session, unlike ydotool's /dev/uinput writes - did not work at all. Bounds now come from WindowManager::monitors() when udev is absent; both backends fill that list from Platform::monitors(). The winit backend's screencopy pass rendered no popups and no shadows. It re-renders the scene offscreen, and that second scene was missing tiers, so grim on a nested instance reported the opposite of the truth: a menu drawing perfectly on screen photographed as absent. The DRM backend never had this, since it serves screencopy from the on-screen frame it just drew. Border strips are still missing from that pass, called out in the code rather than left silent. Also fixed, from the "windows show a bit in the other monitor" report: shadow_rect expanded by SHADOW_SIZE on every side with no monitor-boundary awareness, so a window flush against a seam put its 24px shadow strip on the neighbouring screen. shadow_rect_clipped clips to the bounding box of the monitors the window's geometry actually touches - not just its assigned one, since a window straddling a seam really does occupy both and clipping there would cut its shadow off mid-body. The bitmap's own extent stays unclipped, because the src rectangle indexes into it; only the fragment list is clipped. Six tests on the incident's own numbers. Not confirmed on screen: the nested backend cannot produce a second monitor. New tool: tools/virtual-pointer-click, a scriptable virtual-pointer driver that acknowledges each command after its round-trip, so a test script can put a screenshot between a move and the click that follows it. 489 tests pass, clippy clean.
2026-01-30Fix a real regression: dynamic-mode windows lost their shadow via ↵srdusr1-1/+1
toggle_floating The tiled-shadow-tint fix earlier today gated the shadow on Window::floating alone. arrange_workspace only reads floating under the "tiling" layout, so every window on this project's own default "dynamic" layout starts, and stays, floating: false - the gate misread that as "tiled, no shadow" regardless of which layout was actually running, so shadows silently vanished under dynamic mode entirely, recoverable only by pressing Super+S (toggle_floating), which then looked like that key toggles a tint rather than floating. Fixed by checking the workspace's own layout name first: a window is only "currently tiled" when its workspace runs "tiling" AND it hasn't opted out via floating. DecorationSignature's floating field is now currently_tiled, since a layout switch changes this for every window on a workspace without touching any of their own floating fields. Also disabled general.shadows in the user's own config per direct request - never asked for, on by default, and a real problem for color-accuracy work regardless of how correctly it renders otherwise. Also fixed both context menus (titlebar and desktop) silently truncating labels past a fixed 170px width with no indication - widened dynamically to each menu's own real widest label via a new measure_text_width helper.
2026-01-28Redesign the titlebar right-click menu: real separators/headers, live ↵srdusr1-34/+76
customization Reported live: "looks very ugly currently and some of it doesn't make sense." Both were real. Every row, including a bare divider, took one full TITLEBAR_HEIGHT slot, so a separator was a 1px hairline in the middle of 32px of empty space; "Move to Workspace" faked a section caption by embedding box-drawing characters directly in an ordinary item's label, which rendered - and behaved, until the click-dispatch site's own special case - exactly like a clickable row that did nothing. Separately, "Floating" was always offered even though Window::floating only affects the "tiling" layout: toggling it under this project's own default "dynamic" layout visibly changes nothing, reading as a broken control rather than an inapplicable one. ContextMenu (crates/core/src/context_menu.rs) gained real Separator (9px) and Header (22px, non-interactive, dimmed) row kinds with their own small heights, replacing the label-hack outright. Both backends' rendering now sum each row's own real height instead of assuming one uniform value, so hit-testing and pixels can't disagree about where a row is. Floating is omitted entirely outside the tiling layout. New, in direct response to "allow customizing from there as well": a Customize section with live Button Style / Button Side toggles. Each flips the matching ThemeConfig field and immediately redraws every open window's titlebar - not routed through srd set's own path, which is scoped to windows created after the call for lack of a redraw hook it can reach; a menu action that didn't visibly change the titlebar you clicked would be its own "doesn't make sense" bug. Full workspace build/test/clippy clean (242 core tests, +8; 152 wayland, net-even after rewriting the old label-hack tests).
2025-11-20Redesign the native lock screen: clock/avatar header, on-screen keyboard, ↵srdusr1-3/+3
wrong-password shake The native lock UI was a flat bordered rectangle with three left-aligned text lines and no shadow, clock, or identity marker - reported directly as looking unfinished. Splits the redesign across a new transparent-canvas header (time, date, circular avatar, username) above a redesigned, centered password box with a real drop shadow and a dimmed placeholder prompt, plus a genuine on-screen QWERTY-shaped keyboard with working Shift/Backspace/Return/Space and real click hit-testing shared with the render path via one `lock_stack_layout` function, and a damped-sine shake on a failed attempt. LockConfig gains show_clock/show_keyboard/avatar_bg, each independently srd.set-able and documented in a new theme.lock.* section in DEFAULTS.md. native_lock_render_elements now takes one NativeLockFrame struct instead of positional buffer arguments now that it composites five optional layers instead of two. Full workspace build/test/clippy clean (152 wayland tests, +6 new).
2025-09-28Context/desktop menu polish: real hover tint, real separator line, Select Allsrdusr1-5/+37
Reported live: "looks weird and unpolished... need a lot more items". Compared directly against the exact AGS reference this project's own menu rebuild already targets rather than guessing: - Highlighted rows used a flat, fully-saturated fill instead of the reference's subtle 22%-accent-into-background wash. New decoration:: color::mix_rgb (channel-wise linear blend, generalizing brighten/ darken's fixed-target blends to an arbitrary second colour/ratio) lets render_context_menu reproduce that same ratio. - Every separator row was a label string of Unicode box-drawing characters rendered as text glyphs, which render inconsistently at small sizes - a label that's entirely U+2500 now draws a real 1px hairline instead; a label that mixes it with real text ("--- Move to Workspace ---", a deliberate section-header convention) still renders as text, unchanged. - "Select All" added to the bare-desktop menu, the one action every mainstream desktop's own menu offers that this one lacked. New tests needed real care: the panel's own rounded-corner distance field softens alpha within its radius of any canvas edge, not just the visible corners, so a naive full-row pixel scan against bg picked that up as a false positive on the first attempt - fixed by scanning only rows/columns confirmed (via a throwaway debug dump) to sit inside the panel's genuinely flat interior. Full workspace build/test/clippy clean, built and installed. Real submenus and per-row icons remain real, separate scope - this project's floating-menu UI has no nested-panel concept yet.
2025-09-10Wayland backend: desktop icons v2, menu rebuild, layer-shell/scale fixes,srdusr1-47/+170
XWayland stability, GPU rendering, and multi-cursor Phase 2 The bulk of a multi-session shift's real work landed in crates/wayland. Full root-cause/verification narrative for every item below lives in docs/TODO.md (each has its own dated entry); this is the summary: Desktop shell: - Real desktop icons v2 (state/desktop_icons.rs, desktop_icons.rs): fixed origin-baked-before-the-bar-connects, fixed-icon sort order, and a proper Rename/Delete-to-Trash menu (window_memory.rs backs the rename-persistence side). Rubber-band marquee multi-select. - icon_theme.rs: real freedesktop icon-theme lookup (inherits chain, hicolor fallback) rendering actual theme SVGs via resvg/tiny-skia, replacing the hand-drawn placeholder glyphs. - Context/desktop menus (decoration.rs, desktop_menu.rs, state/menu.rs) rebuilt to match the project's own AGS panel styling: rounded floating panel, tinted-fill row highlight, real separators, a much fuller titlebar window-menu action set. Layer-shell / multi-monitor: - Layer-shell hit-testing and render positioning (input/pointer.rs, udev/render.rs's element placement) now correctly convert LayerMap's logical geometry into physical pixels on a fractionally-scaled output - root cause of a bottom-anchored dock being unclickable and unpainted while a top-anchored bar on the same output worked. udev/outputs.rs's relayout_outputs gained the same physical/logical split for cross-output positioning, now backed by a real unit test (next_logical_x) built from the original measured incident numbers. - state/geometry.rs: a window's border/decoration no longer briefly clips when moved between differently-scaled monitors mid-drag. XWayland / stability: - xwayland.rs, udev/session.rs, udev/platform.rs: fixed a 100%- reproducible cold-start XKEYBOARD crash-loop (XWayland's own stdin inherited a real, already-owned VT; env passthrough and idle-callback spawn timing were both real, independent gaps) that had silently taken down all X11-app support and the global-menu registrar every session. - state/toplevel.rs, state/lifecycle.rs: XWayland dialog detection via WM_TRANSIENT_FOR, not just a native xdg_toplevel parent. Rendering: - udev/render.rs, decoration.rs: real GPU (GBM+EGL+DrmCompositor) window-content and cursor rendering on the udev backend, falling back to the untouched Pixman path automatically on any init failure. - decoration/tests.rs, state/mod.rs: rounded-corner/border fixes for interactive resize lag and cross-monitor moves. Multi-cursor Phase 2 (virtual_pointer.rs, new; state/mod.rs, udev/ platform.rs, winit/nested_platform.rs): pins a zwlr_virtual_pointer_ unstable_v1 object to a specific window, bypassing the shared seat/ focus/pointer_pos path entirely via hand-rolled wl_pointer.enter/motion/ button/frame/leave against every WlPointer the target client has bound (PointerHandle::client_pointers). Lets an agent operate one window while a human uses another, genuinely simultaneously, with zero client cooperation and no second wl_seat (confirmed a dead end: real clients only ever bind the first seat advertised). Full workspace build/test/clippy clean.
2025-08-19Polish the hand-drawn desktop icon glyphs: rounded corners, gradient, bluesrdusr1-24/+74
Requested directly: default icons "look very rudimentary... make slightly blue as well, polished look". Two changes to decoration::render_desktop_icon and its five draw_*_glyph helpers: - New fill_rounded_rect primitive: softly rounded corners (the same clamp-then-distance smoothstep construction rounded_corners_pixman:: apply_corner_mask already established for content masking, not a new technique) plus a vertical top-to-bottom gradient instead of one flat fill - the same light-source cue buttons.rs's own glossy_shade uses for the titlebar dots, as a plain linear gradient here. Applied to each glyph's main body shape; small details (folder tab edge, computer stand, trash ridges, home roof) stay flat/sharp. - A dedicated ICON_COLOR constant (a clean mid-blue) instead of reading theme.titlebar_fg_focused - that field is whatever the user's own titlebar accent happens to be configured to, which could be any colour; these glyphs want a consistent, recognisable blue palette of their own, independent of theme. Build/test/clippy already verified clean as part of the layer-shell scale fix commit just before this one (same source tree, installed together).
2025-08-15Add real desktop icons plus right-click desktop/icon context menussrdusr1-0/+183
Closes "right-click on bare desktop" - previously a true no-op, nothing rendered above the wallpaper at all. Requested directly: a real desktop "just like windows does" - Home/Computer/Trash plus one icon per real ~/Desktop entry, individually draggable with persisted grid positions, double-click to open, right-click menus (per-icon "Open" plus "Set as Wallpaper" for image files when general.wallpaper_command is set; bare desktop "New Folder"/"Refresh"). Architecture mirrors the existing context_menu.rs/snap_flyout.rs "compositor-owned floating UI" pattern: desktop_icons.rs (data model, grid layout, filesystem scan, hit-test), desktop_icons_state.rs (JSON persistence, same shape as monitor_layout.rs), desktop_menu.rs (the new right-click menu, reusing decoration::render_context_menu's existing rasterizer), state/desktop_icons.rs (CompState glue: rescan/select/drag/ open/persist), and a new decoration::render_desktop_icon rasterizer -- hand-drawn glyphs, since no PNG/SVG decoding capability exists anywhere in this workspace. Wired into both render loops (udev and winit) above the wallpaper and below every window, and into input/pointer.rs's button/ motion handlers for selection, drag, double-click, and both menus. Four new config keys: general.desktop_icons (default true - a directly requested, purely visual feature, unlike the opt-in-while-experimental general.gpu), general.file_manager, general.desktop_icon_single_click, general.wallpaper_command (all default off/empty). Deliberately out of scope for this pass, stated up front: move-to-trash and "Empty Trash" (destructive, no confirmation-dialog primitive to gate them on yet), filesystem watching, multi-select, per-mimetype icon art, icons on any monitor but the primary one. 124 wayland-crate tests (up from 106), full workspace build and clippy clean.
2025-02-15Checkpoint: preserve all uncommitted rust-rewrite worktree worksrdusr1-791/+67
Safety commit before reconciling this worktree with main, which has diverged with its own separate fixes today. Nothing here is reviewed or curated yet - this exists purely so none of this work can be lost to a git operation, disk issue, or worktree cleanup while that reconciliation happens.
2024-12-24Accumulate wayland-crate additions: capture rendering, focus/Space sync, VT ↵srdusr1-36/+167
resume, plumbing Bundles the remaining wayland-crate changes built up here, touching both backends (udev and winit) and the shared input/rendering code: - udev/capture.rs: off-screen Pixman render of an arbitrary (not necessarily on-screen) workspace's window content to a PPM file -- what crates/core's capture-request queue drives, for a workspace switcher's thumbnail previews. wlr-screencopy structurally can't do this (it can only see what an output is presenting), which is why this exists as a separate render path rather than reusing it. - input::focus_window now also raises the window in smithay's own Space, not just core's stacking order - Space is what actually renders on top and what pointer hit-testing reads, so any focus path that skipped this (an IPC "focus" dispatch, concretely) left a window genuinely focused while still rendering, and receiving clicks, underneath whatever was already topmost. Both backends' poll loops now re-sync this after any IPC mutation. - udev/session.rs's VT-switch resume fix (drains a stale pending page flip before reasserting CRTCs) already has its own earlier, cleanly isolated commit - not duplicated here. - Assorted decoration/cursor/rounded-corners/output-management/ screencopy/XWayland changes and their cross-backend wiring. Coarser than the repo's usual one-purpose-per-commit convention, deliberately - see the core-crate sweep commit's own message for why.
2024-08-23Round the bottom border strip's corners to match the topsrdusr1-3/+72
MISSING.md listed the border frame's bottom/left/right strips as staying square while the top one (and the titlebar above it) rounds -- "unrelated to client content rounding... not attempted." The left/ right strips genuinely can't participate (border_strips' geometry has them span only the height between the top and bottom strips, no corner to round), but the bottom strip is exactly the same shape as the top one and had no reason left to stay square. decoration::render_border_bottom mirrors render_border_top exactly (round_bottom_corners mirrors round_top_corners), cached the same way in a new border_bottom_decorations map, and drawn in both render loops via the same all-or-nothing occlusion check the top strip already uses - pulled out of the left/right strips' per-fragment occlusion splitting into its own dedicated bitmap path, matching top's existing trade-off (cropping a rounded bitmap's source rect per fragment is real extra work for a strip this thin) rather than inventing a new one. One real bug caught before it shipped: round_bottom_corners' corner- centre math (height - r - 1) panics on unsigned underflow whenever the radius clamp lands on the strip's own full height (a real, common case - a 2px-thick test strip hits it immediately). Fixed by computing the centre as a signed offset instead, mirroring how the existing dx/dy distance math already avoids the same class of issue.
2024-07-10Fix three pre-existing clippy warningssrdusr1-9/+10
- ipc.rs: drop a u64 -> u64 no-op cast (WindowId is a plain u64 alias). - decoration.rs: draw_line took 8 args; bundle the two endpoints into (i32, i32) tuples instead of four loose coordinates. - output_management.rs: collapse a WEnum::Value if-let directly into the outer SetTransform match arm's pattern.
2024-06-24Real rounded corners on client content (GLES/winit backend), via a custom shadersrdusr1-1/+8
decoration.rs's round_top_corners only ever clipped the compositor's own titlebar/border bitmap - its own doc comment already said why nothing more had been done: clipping arbitrary client content needs a real per-pixel mask, "a much bigger change than this cosmetic pass". That's this change, for the one backend that can do it cheaply: the udev backend's PixmanRenderer is software-only with no shader stage at all, but GlesRenderer (winit) has a real custom-shader path (`compile_custom_texture_shader`, `TextureShaderElement`) that a first look at smithay's higher-level convenience APIs missed entirely. crates/wayland/src/rounded_corners.rs: a GLSL fragment shader masking a window's texture against a rounded-rect signed-distance field while sampling it (the same technique cosmic-comp/niri use for GPU-side rounded corners) - built by hand from the surface's own committed texture/view/ damage state (`RendererSurfaceState`'s public accessors), since no smithay convenience wrapper builds a masked element at all (`CropRenderElement` only crops to a rectangle). A decorated window rounds only its bottom two corners - the top two are already rounded, on the titlebar's own CPU bitmap, by decoration.rs, at the exact same `CORNER_RADIUS` (now `pub(crate)`, shared between the two so the curve reads as one continuous radius, not two different ones meeting at a seam) - an undecorated/CSD window rounds all four, since its content is the window's whole visible extent. Falls back to plain unrounded content on any failure (shader didn't compile, no committed buffer yet, a single-pixel-buffer surface), same "always show something over a prettier maybe-nothing" reasoning cursor.rs's built-in-arrow fallback already uses. Deliberately scoped to a window's *main* surface only, not subsurfaces - documented as a real, if narrow, follow-up rather than attempted here. `TextureShaderElement` only implements `RenderElement<GlesRenderer>`, not the generic `RenderElement<R>` every `OverlayElement<R>` variant needs, so it can't be added to that shared enum without breaking `OverlayElement< PixmanRenderer>` (used identically by udev.rs) the moment a GLES-only variant showed up in it. `WinitElement<=GlesRenderer>` (new, winit.rs-only) wraps the existing enum as one variant instead of touching it - this is the same lesson as the fullscreen-hiding investigation earlier this session, just resolved cleanly this time: nesting a *foreign* generic type inside your own hits real bound-resolution walls; wrapping your own already-working type inside a new concrete-renderer enum doesn't, because smithay's own `render_elements!` macro documents exactly this `<=ConcreteRenderer>` form. Config: `general.rounded_corners` (default `true`), `srd.window` unaffected - this is a `general.*` compositor-behavior knob, not a per-window rule action like `opacity`. Verified live: shader compiles without error on this machine's real Mesa/ llvmpipe GL driver, and a decorated wezterm window's bottom-left and bottom-right corners both show a real, smoothly anti-aliased curve on the actual client-rendered pixels (not a compositor bitmap) in a host-session screenshot - qualitatively sharper than `round_top_corners`' deliberate hard cutoff, since a GPU shader can afford a ~2px smoothstep a CPU bitmap pass isn't worth adding for. cargo build --workspace (all 9 crates), cargo clippy --workspace (0 new warnings), cargo test --workspace (197 tests, 0 failed).
2024-06-20Add drop shadows and shrink the resize grab margin that was eating content ↵srdusr1-1/+129
clicks Two independent daily-driving gaps closed in one pass, both from MISSING.md and live user feedback: Drop shadows (general.shadows, default true). Reuses the exact "bitmap drawn outside geometry, cached like the border" technique border_strips/ render_border_top already established - decoration::shadow_bitmap rasterizes a linear alpha falloff (Chebyshev/square-ring distance, not a true blur -- no blur primitive exists without a GPU shader, and the udev backend's PixmanRenderer is software-only) from SHADOW_MAX_ALPHA (90/255, deliberately subtle) at the window's own edge down to fully transparent SHADOW_SIZE (12px) out. Cached in CompState::shadow_buffers, rebuilt at the same trigger points as border_top_decorations (redraw_decoration_buffer), for the identical damage-tracking reason: a fresh Id every frame means OutputDamageTracker never finds a previous-frame match. No shadow for a maximized or fullscreen window, matching the Hyprland/GNOME convention MISSING.md measures against. Resize grab margin: 10px -> 6px (general.resize_margin, now configurable, same call-site-count-preserving change as threading a new parameter through one indirection point: ResizeEdge::hit_test's only production caller is WindowManager::hit_test, so this didn't need touching every backend despite hit_test being shared verbatim across X11/Wayland/Windows/macOS). Reported live: ordinary clicks near any window edge - a link near a browser's edge, a button near a panel's edge - regularly registered as a resize-edge grab instead of reaching the client, not just an occasional near-miss, because the 10px band was measured inward from the client's own content rect. 6px stays comfortably grabbable while giving content back most of its edge. Verified: cargo build --workspace (all 9 crates including the windows/macos stub backends), cargo clippy --workspace (0 new warnings), cargo test across core/wayland/config/x11 (188 tests, 0 failed). Shadow rendering verified at the render-element level live in a nested session (correct geometry, alpha, buffer contents) - grim/screencopy itself turned out to route through winit.rs's separate capture_offscreen path, which only ever drew `decorations` (titlebars), never borders or shadows, so screenshots taken this way have never shown either; a real gap, not fixed in this pass.
2024-05-30Fix decoration drift during animated transitions; checkpoint ↵srdusr1-21/+416
IPC/global-menu/output-management work Border/titlebar decoration was built from Window.geometry (the animation's final target) in both wayland backends' render loops, while sync_geometry already draws a window's actual content at window_anims' interpolated rect during any maximize/fullscreen/open-slide tween. Border and content read two different rectangles for the whole transition, so the border visibly detached from the window it was outlining - reported as "borders aren't flush." Both udev.rs and winit.rs now read the same animated rect for titlebar placement, border-strip placement, and the occlusion test against later windows in stacking order. Verified: cargo build --workspace, cargo clippy (0 new warnings), cargo test -p srdwm-core (111/111). Also checkpoints substantial protocol/IPC work from prior sessions that had accumulated uncommitted: gtk-shell1 support (gtk_shell.rs, the vendored gtk-shell.xml, xwayland.rs's X11-side mirror) backing the global app menu; zwlr_foreign_toplevel_manager_v1 (foreign_toplevel.rs) broadcasting distinct maximized/minimized/fullscreen/activated state per window; output_management (ext-output-management + layer-shell exclusive-zone reservation tracking); workspace.rs and context_menu.rs; a Unix-socket IPC crate (platform/src/ ipc.rs) and a `srd` control-CLI crate (crates/ctl); xkb_config.rs; and a theme module (core/src/theme.rs). A peer session working the AGS shell concurrently verified several of these live against a running srdwm: the global menu rendering a real app's File/Edit menu over gtk-shell1, and foreign-toplevel correctly reporting maximized and fullscreen as independent, non-simultaneous states with the geometry each implies (maximize stops at a reserved top bar and past a dock; fullscreen reaches the true monitor edge).
2024-04-02Add window rules, real config validation, and a Wayland DRM/udev backendsrdusr1-0/+191
- srd.rule(): match windows by title/class, apply floating/maximized/ workspace/geometry/decoration actions on creation (crates/core/src/rules.rs) - srd.validate_config()/srd.debug.*: real range/format checks and status/profiling helpers, replacing the always-true stub - Wayland titlebar text rendering via fontdue, unit-tested without a display (crates/wayland/src/decoration.rs) - Wayland precise keybinding matching, replacing the "any Super-held key" heuristic, sharing the keysym table with X11 (moved to crates/core/src/keysyms.rs) - Wayland DRM/udev backend (crates/wayland/src/udev.rs): runs as the real compositor on a bare TTY via libseat/libinput/KMS, software rendering via Pixman + dumb buffers (no GBM/EGL required) - srdwm_platform::detect() fix, found via VM testing: a bare TTY with no DISPLAY/WAYLAND_DISPLAY now correctly resolves to Wayland instead of an X11 backend that can never work there - XWayland integration groundwork (crates/wayland/src/xwayland.rs): spawn, X11Wm, and full XwmHandler event routing into the same WindowManager/ Space pipeline as native clients. Windows don't render yet - a real glamor-vs-software-renderer conflict in XWayland's own fallback path, root-caused via WAYLAND_DEBUG tracing and documented in docs/IMPLEMENTATION_STATUS.md rather than worked around blind. All verified live in an isolated QEMU VM: X11 backend shows two decorated, correctly-tiled xterms with real title text; the DRM/udev Wayland backend opens the GPU, initializes input, and scans out a rendered frame via KMS page-flip.