Skip to contents

Hatch fill

Source: R/paint.R
vl_hatch.Rd

Fills a shape with ruled parallel lines. Unlike vl_pattern(), which rasterises a tile, a hatch is geometry: it stays crisp at any zoom, prints correctly, and survives being converted to greyscale.

Usage

vl_hatch(angle = 45, spacing = 3, width = 0.75, col = "black", bg = NA)

Arguments

angle

Direction of the rules, in degrees counter-clockwise from horizontal. Distinct angles (0, 45, 90, 135) read as distinct categories.

spacing

Distance between rules, in points.

width

Rule width, in points.

col

Rule colour.

bg

Optional background painted behind the rules. NA (default) leaves whatever is underneath showing through.

Value

A vellum_hatch object, usable anywhere a fill is.

Details

That last point is the reason to reach for it. A colour encoding that fails for a red/green-blind reader — which render()'s cvd argument will show you and vl_lint() will flag — is fixed by encoding with texture as well as hue. Hatching is the standard way to do that.

See also

vl_pattern() for a tiled grob, linear_gradient(), vl_lint()

Examples

vl_scene(3, 2) |>
  draw(rect_grob(width = 0.8, height = 0.8, gp = vl_gpar(
    fill = vl_hatch(angle = 45, spacing = 4), col = "grey30"
  )))