Gate Hound — workshop

34×24 pixel sprite — a checkpoint dog whose ears, hackles, and a badge reader's tick counter read a replayed credential, since the lamp itself still says valid.

A dog stationed at a badge reader. calm is a single scan: ears up, steady green lamp, one tick. alert is the same badge replayed: the lamp still reads valid — that’s the whole problem with a stolen session credential, it passes the check every time — but the reader’s tick counter climbs fast, the scan-rate gauge pegs high, and the dog’s ears pin back, hackles rise, and teeth show. Nothing here fails a badge. The dog reads the rhythm of the scans, because rhythm is the only tell a replayed credential leaves. Nods to a week of infostealer campaigns replaying stolen session cookies straight past password and MFA — the tell in those incidents was usage draining in ticks nobody was there to make, same shape as this reader’s counter.

Reuse

export/hound-sheet.png — 170×24 strip, five 34×24 frames in order: calm-0, calm-1, alert-0, alert-1, alert-2.
hound-{calm,alert}-*.png — the individual frames.
hound@8x.png — prescaled 8× hero shot for docs/previews.

Render at integer scales with nearest-neighbor filtering or the edges smear. calm plays at 1.5 fps, alert at 5 fps (ANIMATIONS in the module carries both).

Source

No .aseprite — the canonical source is source/gate-hound.mjs: a framework-free ES module. Edit the numbers and regenerate everything with:

node source/render.mjs

(needs site/node_modules installed — the script resolves Playwright from there.) That one command rewrites export/, media/, thumb.png, and the demo’s bundled copy of the module, so nothing drifts.

How the frames are built

Same trick as night-shift’s owl: the dog’s round body, ears, and hackle ruffle are rasterized from an ellipse formula and a handful of per-frame numbers instead of a hand-typed character grid, and the reader beside it is drawn from a literal readout — ticks stacks one short stroke per scan, gauge is a pixel-width fill bar for scan rate, and lampOn toggles the status light (including one deliberately-off flicker frame in alert). The “posture reads a metric” idea, applied twice in one sprite: once to the dog’s own silhouette, once to the prop beside it.

Gotchas

validateGrids() only checks that FRAME_ORDER/ANIMATIONS reference real frames — there’s no character grid to catch a ragged row, since there isn’t one. Sanity-check new frames by rendering and looking.
demo/gate-hound.js is generated. Edit source/gate-hound.mjs and re-render.
The hackle spikes are placed by a fixed dx list against the ellipse’s current top arc, so if DOG_RY or DOG_RX changes, recheck that the spikes still land on the silhouette rather than floating off it.
The demo draws the sprite by calling paintFrame at runtime, fine at this size. A game should blit hound-sheet.png instead.

Port notes

paintFrame is arithmetic plus fillRect calls with no DOM dependency beyond a 2D context — same shape as warehouse-duck’s and night-shift’s — so a DragonRuby port translates directly: reimplement the ellipse/gauge math against args.outputs.solids, or just consume hound-sheet.png as a spritesheet with source_x = frame * 34.