hexify 0.6.5

Fixed empty translation unit warning in vendored H3 h3Assert.c (clang 21 -Wempty-translation-unit)

hexify 0.6.4

Removed compiled object files (.o) from source tarball that caused installation failure on Linux (Debian) and NOTE on all platforms
Wrapped plot_globe() examples in \donttest{} to reduce check time (was 608s on win-builder)
Reworded DESCRIPTION to avoid “vendored” spelling flag

cell_to_sf() now applies sf::st_wrap_dateline() automatically, fixing horizontal streaks on flat map projections (Plate Carrée, Robinson, etc.) for hexagons crossing the ±180° antimeridian
as_sf(x, geometry = "polygon") now routes all grids (ISEA and H3) through cell_to_sf(), ensuring consistent antimeridian handling
hexify_cell_to_sf() gains antimeridian normalization matching cell_to_sf()
Vignettes no longer require manual st_wrap_dateline() calls

Native H3 backend — zero external dependencies

Vendored H3 v4.4.1 C source, replacing the h3o R package dependency
H3 is now always available — no optional install, no Suggests
Uses H3 experimental polygon fill for full spatial coverage in hexify()
New native C++ bindings: h3_lat_lng_to_cell, h3_cell_to_boundary, h3_cell_to_parent, h3_cell_to_children, h3_polygon_to_cells, h3_cell_area_km2, h3_cell_to_lat_lng

ISEA–H3 crosswalk and per-cell area

New h3_crosswalk(): bidirectional mapping between ISEA and H3 cell IDs, with automatic resolution matching and per-cell area comparison
New cell_area(): returns geodesic area (km²) for each cell — constant for ISEA (equal-area), location-dependent for H3, with session-scoped caching
HexData $cell_area_km2, [["cell_area_km2"]], and as.data.frame() now return per-cell areas for H3 grids instead of the grid-wide average
Internal: extracted closest_h3_resolution() helper shared by hex_grid() and h3_crosswalk()

H3 grid support

Added H3 (Uber) as a first-class grid type: hex_grid(resolution = 8, type = "h3")
All core functions work with H3 grids: hexify(), cell_to_sf(), grid_rect(), grid_global(), grid_clip(), get_parent(), get_children()
H3 support requires the h3o package (Suggests, not required for ISEA workflows)
New hexify_compare_resolutions(type = "h3") for H3 resolution table
dgearthstat() now accepts HexGridInfo objects directly
New grid_type slot on HexGridInfo: "isea" (default) or "h3"
HexData cell_id slot supports character (H3) and numeric (ISEA) cell IDs
Backward compatible: all existing ISEA workflows unchanged

Hotfix for geometry issues

Fixed invalid pentagon geometries that caused gaps in global grids
Fixed antimeridian-crossing polygons using st_wrap_dateline()
Added polar cap sampling to grid_global() to include cells above ±85° latitude

Reduced test suite runtime for CRAN by skipping detailed consistency tests (full tests still run locally via NOT_CRAN=true)
Fixed CRAN incoming check NOTE: “Overall checktime 15 min > 10 min”

Hotfix for CRAN UBSAN check failure

Fixed undefined behavior in Snyder ISEA projection causing NaN values (UBSAN error on M1 Mac CRAN check: “nan is outside the range of representable values of type ‘long long’” at coordinate_transforms.cpp:243-244)
Root cause: floating-point precision in face assignment could project points onto geometrically invalid triangle faces near icosahedron edges
Solution: added projection validation with face-retry logic - if validation fails (z > DH), automatically tries adjacent faces until valid