This focused integration keeps projection, spatial compute, and map rendering in their natural layers. The deck.gl MapView owns pan, zoom, picking, and the camera; MapLibre supplies a synchronized dark basemap; @luma.gl/experimental/luproj projects the source coordinates; and @luma.gl/experimental/geospatial indexes and queries the resident points.

The uniform grid stores position-row indices, keeping candidate addressing distinct from optional application IDs. Both the viewport and radius queries use the default row-index output and write it to GPU buffers. Their clamped counts alias DrawCommandBuffer.instanceCount, so the custom deck.gl layer consumes each result with an indirect draw and no CPU count synchronization in the render path. Click the map to move the radius query, choose a taxi-zone preset to recenter, and hover a point to inspect its source row and coordinates.

The one-million-point browser fixture is a deterministic expansion of the same public sample used by the Billion-Point Spatial Atlas. It remains the default and does not issue taxi-data network requests. The corpus counter preserves the 168,898,952-row target while the resident counter states what is actually allocated on the current GPU. Open the command-graph inspector in the control card to compare projection/index construction with the per-frame viewport and radius queries.

An opt-in packed source can be supplied with the taxi-manifest query parameter:

?taxi-manifest=https://data.example/taxi/manifest.json

The app streams only the leading row groups needed for its capacity-bounded resident window, which defaults to one million rows. The manifest must explicitly declare OGC:CRS84, CRS84, WGS84, or browser-style EPSG:4326 coordinates with X as longitude and Y as latitude. It rejects unknown and projected coordinate systems instead of placing them incorrectly on the basemap. Loading and GPU activation are atomic: a request, decode, CRS, or allocation failure leaves the deterministic fixture active and reports the failure in the source status. Cross-origin manifests and shards must permit browser CORS requests.