update links, add example

README.md

@@ -8,7 +8,7 @@
 Karnak.jl is a small extension for the Luxor.jl package to
 help with constructing graph-style drawings.
 
-Karnak relies on [Graphs.jl](https://juliagraphs.org/Graphs.jl/) for graph construction, and
+Karnak relies on [Graphs.jl](https://github.com/JuliaGraphs/Graphs.jl) for graph construction, and
 on [NetworkLayout.jl](https://juliagraphs.org/NetworkLayout.jl/) for graph layout.
 
 The focus in Karnak, unlike other graph visualization

docs/src/index.md

@@ -6,7 +6,7 @@ Karnak.jl is a small extension for the Luxor.jl package to
 help with constructing graph-style drawings.
 
 Karnak relies on
-[Graphs.jl](https://juliagraphs.org/Graphs.jl/) for graph
+[Graphs.jl](https://github.com/JuliaGraphs/Graphs.jl) for graph
 construction, and on
 [NetworkLayout.jl](https://juliagraphs.org/NetworkLayout.jl/)
 for graph layout.

examples/julia-graphs-logo.jl

@@ -0,0 +1,57 @@
+using Graphs
+using Karnak
+using Colors
+
+function lighten(col::Colorant, f)
+    c = convert(RGB, col)
+    return RGB(f * c.r, f * c.g, f * c.b)
+end
+
+function julia_sphere(pt::Point, w, col::Colorant;
+        action = :none)
+    setmesh(mesh(
+        makebezierpath(box(pt, w * 1.5, w * 1.5)),
+        [lighten(col, .5),
+         lighten(col, 1.75),
+         lighten(col, 1.25),
+         lighten(col, .6)]))
+    circle(pt, w, action)
+end
+
+function draw_edge(pt1, pt2)
+    for k in 0:0.1:1
+        setline(rescale(k, 0, 1, 25, 1))
+        sethue(lighten(colorant"grey50", rescale(k, 0, 1, 0.5, 1.5)))
+        setopacity(rescale(k, 0, 1, 0.5, 0.75))
+        line(pt1, pt2, :stroke)
+    end
+end
+
+outerpts = ngonside(O, 450, 4, π/4, vertices=true)
+innerpts = ngonside(O, 150, 4, π/2, vertices=true)
+pts = vcat(outerpts, innerpts)
+colors = map(c -> RGB(c...), [Luxor.julia_blue, Luxor.julia_red, Luxor.julia_green, Luxor.julia_purple])
+
+Drawing(600, 600, "/tmp/julia-graphs.svg")
+    origin()
+    squircle(O, 294, 294, :clip, rt=0.2)
+    sethue("black")
+    paint()
+    g = SimpleGraph([
+        Edge(1,2), Edge(2,3), Edge(3,4), Edge(1,4),
+        Edge(5,6), Edge(6,7), Edge(7,8), Edge(5,8),
+        Edge(1,5), Edge(2,6), Edge(3,7), Edge(4,8),
+        ])
+
+    drawgraph(Graph(g),
+        layout=pts,
+        vertexfunction = (v, c) -> begin
+            d = distance(O, c[v])
+            d > 200 ? k = 0 : k = 1
+            julia_sphere(c[v], rescale(d, 0, 200, 52, 50), colors[mod1(v + k, 4)], action=:fill)
+        end,
+        edgefunction = (k, s, d, f, t) -> draw_edge(f, t)
+        )
+finish()
+preview()
+# run(`svgo -i /private/tmp/julia-graphs.svg -o /private/tmp/julia-graphs-opt.svg`)