Makie.jl recipe example

recipe.jl

### Makie: define recipes

using Makie

@recipe(CircleShape, x, y, r) do scene
    Attributes(
        color = :red
    )
end

function Makie.plot!(chart::CircleShape{<:Tuple{<:Real,<:Real,<:Real}})
    x = chart[1]
    y = chart[2]
    r = chart[3]

    function get_points(x, y, r)
        N = 500
        θ = LinRange(0, 2*π, N)
        return (x .+ r .* cos.(θ), y .+ r .* sin.(θ))
    end

    XY = lift(get_points, x, y, r)
    pX = lift(x -> x[1], XY)
    pY = lift(x -> x[2], XY)

    lines!(chart, pX, pY, color=chart.color)
    chart
end