BONEYARD · part · bay

Gate

src/41-gate.js · one module, no third-party code

Designed still Focus preview for keys

ParametersFactory

How it works

The camera travels through a dark four-sided canyon. Every point is authored in world space, bent along a shallow deterministic flight path, then projected through a near plane with x' = focal * x / z and y' = focal * y / z. Opaque wall, ceiling and floor cells are painted from far to near, so nearer geometry hides what is behind it. Four sunset-sampled ribbons run down those surfaces, bounded by thin phosphor tracks and crisp dark seams. Each ribbon is divided into stable world-depth color slices with a narrow hot core and a restrained outer shoulder. They are real longitudinal faces, not a screen gradient, and their colored cells grow and leave the viewport as the camera crosses each station.

A single shutter fin occupies each station, alternating left, ceiling, right and floor. No station closes into a ring. At the default glide, a fin passes the camera about once per second and the wrapped replacement appears at the far end. launch() only adds forward speed: spool, transit and settle all advance the same distance accumulator, then return to the living glide. Full emits one transit event and carries a short physical shake. Calm moves gently with no event, punch or shake. Still renders one selected travel frame synchronously; launch() selects a second stable frame and resize preserves that choice without starting a clock.

Provenance

technique: a full-viewport 1/z slit canyon with continuous source-lit ribbons, offset one-sided shutter fins, longitudinal phosphor tracks and a camera that always flies forward through wrapped depth stations
lineage: Douglas Trumbull's slit-scan for 2001: A Space Odyssey (1968), after John Whitney's slit-scan experiments (1950s and 1960s); vector arcade flight displays and practical backlit miniatures
original: the amber, coral and rose ribbons sample ONE column of Tim Gilbert's own 2025-03-01 Sonoran sunset photograph, resampled to 1 x 1024 (assets/sunset-strip.png, provenance in sunset-strip.json); the canyon, asymmetric shutters and cyan structural tracks are original code-built geometry
not: a film recreation, a video, a photo, or a texture-mapped tunnel. The photograph supplies bounded light colors while projected world geometry supplies motion and occlusion.
deps: none · high-resolution Canvas 2D perspective geometry · 2026-10
budget: target <4 ms mean for requestAnimationFrame-paced normal-rate tick calls at desktop DPR1; synchronous JavaScript and Canvas API cost only, with compositor, paint, GPU, network and thermal work excluded
api: mount(canvas, params, ctx) -> { tick, resize, still, deactivate, destroy, params, launch(), state }
license: MIT, Desert Data Labs LLC

Budget: target <4 ms mean for requestAnimationFrame-paced normal-rate tick calls at desktop DPR1; synchronous JavaScript and Canvas API cost only, with compositor, paint, GPU, network and thermal work excluded