paciolis.typ

// Example by @samuelireson
#import "@preview/cetz:0.3.2": canvas, draw, tree

#set page(width: auto, height: auto, margin: .5cm)

#canvas(length: 2cm, {
  import draw: *
  let phi = (1 + calc.sqrt(5)) / 2

  ortho({
    hide({
      line(
        (-phi, -1, 0), (-phi, 1, 0), (phi, 1, 0), (phi, -1, 0), close: true, name: "xy",
      )
      line(
        (-1, 0, -phi), (1, 0, -phi), (1, 0, phi), (-1, 0, phi), close: true, name: "xz",
      )
      line(
        (0, -phi, -1), (0, -phi, 1), (0, phi, 1), (0, phi, -1), close: true, name: "yz",
      )
    })

    intersections("a", "yz", "xy")
    intersections("b", "xz", "yz")
    intersections("c", "xy", "xz")

    set-style(stroke: (thickness: 0.5pt, cap: "round", join: "round"))
    line((0, 0, 0), "c.1", (phi, 1, 0), (phi, -1, 0), "c.3")
    line("c.0", (-phi, 1, 0), "a.2")
    line((0, 0, 0), "b.1", (1, 0, phi), (-1, 0, phi), "b.3")
    line("b.0", (1, 0, -phi), "c.2")
    line((0, 0, 0), "a.1", (0, phi, 1), (0, phi, -1), "a.3")
    line("a.0", (0, -phi, 1), "b.2")

    anchor("A", (0, phi, 1))
    content("A", [$A$], anchor: "north", padding: .1)
    anchor("B", (-1, 0, phi))
    content("B", [$B$], anchor: "south", padding: .1)
    anchor("C", (1, 0, phi))
    content("C", [$C$], anchor: "south", padding: .1)
    line("A", "B", stroke: (dash: "dashed"))
    line("A", "C", stroke: (dash: "dashed"))
  })
})