Open Street Map operates using a system of tiles whose value and bounds
are easily calculated from WGS84 longitude/latitude. These functions convert
between tile system coordinates and longitude/latitude.
Usage
osm_tile(pt, zoom)
osm_tile_quadkey(tile)
osm_tile_top_left(tile, crs = osm_crs_native())
osm_tile_envelope(tile, crs = osm_crs_native())
Value
- `osm_tile()`: A `data.frame()` with columns `x`, `y`, and `zoom`.
- `osm_tile_top_left()`: A [wk::xy()] of the top-left (northwest) corner
of the tile.
- `osm_tile_envelope()`: A [wk::rct()] of the tile bounds.
Arguments
pt
A vector of points as coerced by [wk::as_xy()]. The CRS for these
points is considered.
zoom
A zoom level, generally between 0 and 21, with higher values
representing a smaller (i.e., more detailed) tile.
tile
A `data.frame()` with columns `x`, `y`, and `zoom`.
crs
A target CRS. Either [wk::wk_crs_longlat()] or
[osm_crs_native()].