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Combine several drawables into one multi-sub-path shape

Source: R/shape_combine.R
shape_combine.Rd

shape_combine() merges the computed points of several polygon-geometry drawables into a single shape_raw, one sub-path per input (see xy's own id). This is the ergonomic entry point for the two motivating multi-sub-path use cases – a shape with a hole (one input nested inside another, under style()'s default rule = "evenodd"), or several disjoint shapes sharing one style – without computing id by hand the way shape_raw()'s own id argument requires.

Usage

shape_combine(..., style = NULL)

Arguments

...

Two or more polygon-geometry drawable objects (@geometry == "polygon", e.g. shape_circle(), shape_blob()).

style

A style object for the combined shape, or NULL (the default) to reuse the first input's own style. Every input's own style besides the one that's kept is discarded – a drawable has exactly one style; several independently-styled shapes should use a sketch instead.

Value

A shape_raw.

Details

Each input's own already-computed points (i.e. trans/noise-based distortion already applied, the same way convert() "bakes in" a drawable's transform) becomes one or more sub-paths in the combined output – an input that already has multiple sub-paths of its own (e.g. the output of an earlier shape_combine() call) keeps them all, renumbered to stay distinct from every other input's own sub-paths. Whether nested sub-paths render as a hole or a second solid region is purely a function of their geometric nesting and style@rule (see style()'s own docs) – not of argument order, and not of anything shape_combine() itself decides.

See also

Other 2D shapes: shape_bezier(), shape_blob(), shape_circle(), shape_ellipse(), shape_polygon(), shape_raw(), shape_rectangle(), shape_ribbon(), shape_star(), shape_stroke(), shape_strokepath(), shape_twist(), shape_wedge()

Examples

# a ring with a hole: a smaller circle nested inside a larger one
draw(shape_combine(
  shape_circle(radius = 2),
  shape_circle(radius = 1),
  style = style(fill = "steelblue")
))


# several disjoint blobs sharing one style
draw(shape_combine(
  shape_blob(x = 0, distortion = noise_field(seed = 1L)),
  shape_blob(x = 3, distortion = noise_field(seed = 2L)),
  shape_blob(x = 6, distortion = noise_field(seed = 3L)),
  style = style(fill = "goldenrod")
))


# combining a hole with a disjoint extra shape in one call
draw(shape_combine(
  shape_circle(x = 0, radius = 2),
  shape_circle(x = 0, radius = 1),
  shape_circle(x = 4, radius = 0.5)
))