Logo

Played around with Luxor yesterday, thought this package is still missing some kind of logo.
Here's one idea, something like a "decoder ring". I thought about one being able to change between different units dynamically, "dialing them in", sort of.

Here's the Luxor code

```julia
using Luxor
using Luxor.Colors

image_width = 500

@drawsvg begin
circle_radius = 0.85 * image_width / 2
scale(circle_radius, circle_radius)

offsets_deg = [20, 160, -2.5]
colors = Base.splat(RGB).([Luxor.julia_green, Luxor.julia_red, Luxor.julia_purple])
inner_radius = 0.25
ring_thicknesses = [0.25, 0.25, 0.25]
ringgap = 0.02
sectorgap_deg = 5
sector_whiten = 0.25
casing_opacity = 0.8
casing_overhang = 0.05

prefixes = ["p", "n", "μ", "m", "", "k"]
units = ["g", "s", "m"]

whiten(c, fraction) = Colors.weighted_color_mean(fraction, c, colorant"white")

sector_width = 360 / length(prefixes)

for i in 1:3
color = colors[i]

r1 = inner_radius + (i-1) * ringgap + sum(ring_thicknesses[1:i-1], init = 0.0)
r2 = r1 + ring_thicknesses[i]

for (j, pref) in enumerate(prefixes)

ang = offsets_deg[i] + ((j - 1) / length(prefixes) * 360)

angstart = ang - 0.5 * sector_width
angstop = ang + 0.5 * sector_width

sethue(iseven(j) ? colors[i] : whiten(colors[i], 1 - sector_whiten))
sector(O, r1, r2, deg2rad(angstart), deg2rad(angstop), action = :fill)

radius = 0.5 * (r1 + r2)
center = Point(reverse(sincosd(ang))) * radius
sethue("white")
s = pref * units[i]
@show s

# textcurvecentered is buggy when scaling is active
@layer begin
scale(1/circle_radius, 1/circle_radius)
fs = 25
fontsize(fs)
fontface("Helvetica Bold")
textcurvecentered(s, deg2rad(ang), radius * circle_radius, O, letter_spacing = 0, baselineshift = -0.3 * fs)
end
end
end

r1 = inner_radius - casing_overhang
r2 = r1 + sum(ring_thicknesses) + ((length(ring_thicknesses) - 1) * ringgap) + (2 * casing_overhang)
sethue(Luxor.julia_blue)
setopacity(casing_opacity)
sector(O, r1, r2, deg2rad(270 + 0.5 * sector_width), deg2rad(270 - 0.5 * sector_width), action = :fill)
end image_width image_width
```