A collection of drawable objects

sketch is a list of drawable objects that can be rendered together with a single call to draw(). Sketches can be built up incrementally using the + operator, e.g. sketch() + shape_circle() + shape_circle(x = 2).

Usage

sketch(shapes = list(), canvas = sketchpad::canvas())

Arguments

shapes

A list of drawable-classed objects. Default list().

canvas

A canvas object, giving the background/framing settings draw() applies to the sketch as a whole. Default canvas() (no background, axis limits computed from shapes).

Details

A sketch also supports list-like access to its shapes: length(s) counts them, s[[i]] returns the single drawable at position i, and s[i] returns a new sketch containing only the selected shapes (its canvas is preserved) – mirroring how [[/[ differ on a plain list.

See also

Other core structure: canvas(), draw(), drawable(), group(), style(), xy()

Examples

s <- sketch() + shape_circle(radius = 1) + shape_circle(x = 2, radius = 0.5)
draw(s)


s2 <- sketch(canvas = canvas(background = "grey95")) +
  shape_circle(radius = 1)
draw(s2)


length(s)
#> [1] 2
s[[1]]
#> <shape_circle>
#>   x = 0, y = 0, radius = 1, n = 100
#>   style: color = black, fill = black, linewidth = 1
#>   geometry: polygon, trans: identity
s[1]
#> <sketch: 1 shape>
#>   1: shape_circle
#>   canvas: background = NA, clip = FALSE

# a trans applied to a sketch composes onto every shape's own @trans
draw(s + trans_rotate(pi / 6))


# accumulate many shapes in a loop, e.g. a ring of circles
ring <- sketch()
for (angle in seq(0, 2 * pi, length.out = 9)[-9]) {
  ring <- ring + shape_circle(x = cos(angle), y = sin(angle), radius = 0.3)
}
draw(ring)