Add support for GeoPandas lines and points

This builds on PR #1285 to support rendering GeoPandas GeoSeries as lines and points as well as the existing polygons.

Canvas.line accepts LineString, MultiLineString, MultiPolygon and Polygon geometry types.
Canvas.points accepts MultiPoint and Point.
Canvas.polygons accepts MultiPolygon and Polygon.

There is no support for LinearRing yet as that is not supported by shapely.to_ragged_array.

Example:

import colorcet as cc
import datashader as ds
import geodatasets
import geopandas

df = geopandas.read_file(geodatasets.get_path("nybb"))
df["area"] = df.area

canvas = ds.Canvas(plot_height=600, plot_width=600)
agg = canvas.line(source=df, geometry="geometry", agg=ds.max("area"))
ds.transfer_functions.shade(agg, cmap=cc.bgy, how="linear")

generates this image: temp

Lines support antialiasing as usual. All GeoPandas tests moved to their own file test_geopandas.py which also includes equivalent SpatialPandas tests that are pixel identical.

Example notebook to follow in separate PR.

Pinging @jorisvandenbossche and @martinfleis for visibility.

holoviz / datashader

Add support for GeoPandas lines and points #1293

Codecov Report