geom_area()
geom_bar()
geom_line()
geom_point()
geom_polygon()
geom_histogram()
geom_rect()
geom_tile()
geom_raster()
geom_text()
sf
tbl_graph
&
geom_sf()
stat_...()
...
plot()
ggplot
The Position class is slightly simpler than the other ggproto classes.
Look at FacetWrap or FacetGrid, and simply provide new compute_layout(), and map_data() methods
compute_layout()
map_data()
What is a ggproto?
ggproto
The answer is back in chapter20 ggplot2 internals