inner poly rect box stroke Makie

inner_stroke.jl

r1 = Rect2f((10, 20), (5, 8))
r2 = Rect2f((20, 30), (5, 8))

f, ax, _ = poly(r1)

linewidth = Observable(20)

r2_pixel = lift(ax.scene.camera.projectionview, ax.scene.viewport, linewidth) do _, _, lw
    mi, ma = extrema(r2)
    _mi = Makie.project(ax.scene, mi) .+ 0.5lw
    _ma = Makie.project(ax.scene, ma) .- 0.5lw
    Rect2f(_mi, _ma - _mi)
end

lines!(ax, r2; linewidth)
lines!(ax, r2_pixel; linewidth, space = :pixel, alpha = 0.8)
f