Add a tiled hexagon source from the H3 geospatial indexing system.

Wraps the h3t tile protocol, which registers a h3tiles:// MapLibre protocol and fetches H3J-formatted JSON tiles from a {z}/{x}/{y} endpoint. Unlike add_h3j_source(), which pulls a single H3J file, this source lets the map request only the cells visible in the current viewport — on pan/zoom the protocol handler fires a fresh request per tile.

Usage

add_h3t_source(
  map,
  id,
  tiles,
  sourcelayer = id,
  geometry_type = c("Polygon", "Point"),
  minzoom = 0,
  maxzoom = 14,
  promote_id = TRUE,
  debug = FALSE
)

Arguments

map: A map object created by maplibre() or a maplibre_proxy.
id: Unique source ID.
tiles: A character vector of tile URL templates, each using the h3tiles:// scheme. The tokens {z}, {x}, {y} are substituted by MapLibre on each tile request. Example: "h3tiles://h3t.example.com/{z}/{x}/{y}.h3t?q=...".
sourcelayer: Name of the source layer that downstream add_fill_layer() (or similar) calls reference via source_layer. Defaults to id.
geometry_type: Either "Polygon" (hex boundaries) or "Point" (cell centroids). Defaults to "Polygon".
minzoom, maxzoom: Zoom bounds for the source (MapLibre semantics).
promote_id: Whether to promote the h3id property to the feature ID.
debug: If TRUE, the protocol handler logs per-tile timing to the browser console.

References

https://github.com/INSPIDE/h3j-h3t

Examples

if (FALSE) { # interactive()
maplibre(center = c(-119, 34), zoom = 5) |>
  add_h3t_source(
    id = "sardine",
    tiles = "h3tiles://h3t.example.com/{z}/{x}/{y}.h3t?q=<base64-SELECT>"
  ) |>
  add_fill_layer(
    id           = "sardine",
    source       = "sardine",
    source_layer = "sardine",
    fill_color   = interpolate(
      column = "value", values = c(0, 100),
      stops = c("#ffffcc", "#e31a1c")
    ),
    fill_opacity = 0.7
  )
}