World map in globe-like view using R, sf, and ggplot2

world_map.R

library("sf")
library("ggplot2")
library("rnaturalearth")

world = ne_countries(scale = "medium", returnclass = "sf")
sel = "Poland"
country = world[world$name == sel, ]

# center the view on the selected country
ct = st_centroid(st_geometry(country))
coords = st_coordinates(ct)
lon_0 = coords[[1, "X"]]
lat_0 = coords[[1, "Y"]]

ortho_crs = paste0("+proj=ortho +lat_0=", lat_0, " +lon_0=", lon_0)

# visible hemisphere
horizon = st_buffer(ct, dist = 9900000)
world = st_intersection(world, horizon)
world_ortho = st_transform(world, crs = ortho_crs)
world_ortho = st_make_valid(world_ortho)
world_coast = st_union(world_ortho)

ocean = st_point(c(lon_0, lat_0))
ocean = st_sfc(ocean, crs = 4326)
ocean = st_transform(ocean, crs = ortho_crs)
ocean = st_buffer(ocean, dist = 6371000)

g = st_graticule(lat = seq(-90, 90, 20), lon = seq(-180, 180, 30))
g = st_transform(g, crs = ortho_crs)

ggplot() +
  geom_sf(data = ocean, fill = "aliceblue", color = NA) +
  geom_sf(data = world_ortho, fill = "lightgrey", color = "white") +
  geom_sf(data = world_coast, fill = NA, color = "aliceblue") +
  geom_sf(data = subset(world_ortho, name == sel), fill = "darkgreen", color = "black") +
  geom_sf(data = g, color = alpha("grey", 0.5)) +
  theme_void()