using Gnuplot
empty!(Gnuplot.options.init)
push!( Gnuplot.options.init, linetypes(:Set1_5, lw=1.5, ps=1.5))
function saveas(file; sx=550, sy=350, fs=0.8, term="svg")
    Gnuplot.save(term="$(term) size $(sx),$(sy) fontscale $(fs)", "$(file).svg")
end;

Interlocking Torus

@gsp "set multiplot title 'Interlocking Tori'"
U = LinRange(-pi, pi, 100)
V = LinRange(-pi, pi, 20)
@gsp :- "unset key" "unset xtics" "unset ytics" "unset ztics"
@gsp :- "set border 0" "set view 60, 30, 1.5, 0.9"
@gsp :- "set style fill transparent solid 0.7"

for loop in 1:2
    if loop == 1
        @gsp :- 1 title="PM3D surface\\nno depth sorting"
        @gsp :- "set origin -0.02,0.0"
        @gsp :- "set size 0.55, 0.9"
        @gsp :- palette(:dense)
        @gsp :- "set colorbox vertical user origin 0.005, 0.15 size 0.02, 0.50"
        @gsp :- "set pm3d scansforward" :-  ## scansbackward
    else
        @gsp :- 2 title="PM3D surface\\ndepth sorting"
        @gsp :- "set origin 0.40,0.0"
        @gsp :- "set size 0.55, 0.9"
        @gsp :- palette(:plasma)
        @gsp :- "set colorbox vertical user origin 0.9, 0.15 size 0.02, 0.50"
        @gsp :- "set pm3d depthorder"
    end
    x = [cos(u) + .5 * cos(u) * cos(v)      for u in U, v in V]
    y = [sin(u) + .5 * sin(u) * cos(v)      for u in U, v in V]
    z = [.5 * sin(v)                        for u in U, v in V]
    @gsp :-  x' y' z' "w pm3d"

    x = [1 + cos(u) + .5 * cos(u) * cos(v)  for u in U, v in V]
    y = [.5 * sin(v)                        for u in U, v in V]
    z = [sin(u) + .5 * sin(u) * cos(v)      for u in U, v in V]
    @gsp :- x' y' z' "w pm3d"
end
saveas("surface005");