Tag

tiles

3 posts

rendering

7 min read Jul 15, 2026

The hemisphere that was never selected: a fast-path bbox that collapsed to a point

Half the globe rendered as background again — same symptom as the drape-suppression bug, opposite root cause. This time the trans-antimeridian tiles were never selected: the overzoom fast-path unprojects the viewport corners to a lon/lat box, but on a small globe disc the corners miss the sphere, the box collapses to the sub-camera point, and it emits the single tile column under the camera — which a contiguous longitude range can never wrap across the dateline. Told apart from the draw bug by seam location and persistence.

debugging globe tiles

performance

6 min read Jul 13, 2026

The map that downloaded the world

A static map view produced 10+ MB/s bursts and a warm phone. The render loop was innocent, our first probe fabricated a '93 duplicate requests' finding, and the real villain was the availability feature that keeps fast-pan from blanking — politely fetching an 85-tile, 33 MB world pyramid on every load and pinning it against eviction forever. Same view after the fix: 35.33 MB → 6.27 MB.

networking debugging tiles

testing

4 min read Jul 7, 2026

Offline tile mirrors for deterministic map e2e

Our CI container's browser can't reach the internet, but the final render gate needs a real 117-layer basemap. On mirroring styles, tiles, glyphs and sprites locally — and the traps: SPA fallback serving HTML as tiles, unencoded fontstacks, and settling on signals instead of sleeps.

e2e infrastructure tiles