gghalftone - Halftone, Dither and Line-Screen Fills for 'ggplot2'

Halftone screens as ggplot2 layers. Dots are placed at draw time on a lattice with a physical pitch in millimetres, so a figure gets the same screen at any output size. Provides geom_halftone() for gridded fields, geom_spot() for per-point tone discs, with_halftone() to screen the fill of any layer (ribbons, areas, bars, polygons, sf), with_halo() and with_relief() for lines over a screen, a screen aesthetic for colour-free encodings, line screens, Bayer, blue-noise and Floyd-Steinberg dithering, overprinting of overlapping groups, with_press() for press artefacts, and a theme modifier with export helpers.