struct Vec {
mut:
    x f64
    y f64
    z f64
}

struct Plane {
    position Vec
    normal   Vec
}

struct Sphere {
    position Vec
    radius   f64
}

interface Object {
    position Vec
}

fn test_append_struct_to_interface_array() {
    mut scene := []Object{}

    scene << Plane{
        position: Vec{0, -10, 0}
        normal:   Vec{0, -1, 0}
    }
    scene << Sphere{
        position: Vec{0, 0, -20}
        radius:   7
    }

    println(scene)

    assert scene.len == 2
    assert scene[0].position.x == 0
    assert scene[0].position.y == -10
    assert scene[0].position.z == 0
    assert scene[1].position.x == 0
    assert scene[1].position.y == 0
    assert scene[1].position.z == -20
}