Interactive light cone

using AbstractPlotting

scene = linesegments([Point2f0(-5,0) => Point2f0(5,0), Point2f0(0,-1) => Point2f0(0,2)],scale_plot=false, show_axis=false)

function get_lightcone(pos)
    x,v = pos
    len = sqrt(x^2+2^2)
    return [
            Point2f0(x,v) => Point2f0(x + x/len, v + 2/len),
            Point2f0(x + x/len, v + 2/len) => Point2f0(x-1, v),
            Point2f0(x-1, v) => Point2f0(x,v)
        ]
end

visible = Node(false)
lift(scene.events.mousebuttons) do mb
    visible[] = ispressed(scene, Mouse.left)
end

coords = lift(scene.events.mouseposition) do mp
    pos = to_world(scene, Point2f0(mp))
    return get_lightcone(pos)
end

linesegments!(scene, coords; visible = visible)

# Do not execute beyond this point!

RecordEvents(scene, "output")