add Makie plotting

Project.toml

@@ -12,21 +12,25 @@ StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 
 [weakdeps]
 Accessors = "7d9f7c33-5ae7-4f3b-8dc6-eff91059b697"
+Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
 Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
 
 [extensions]
 AccessorsExt = "Accessors"
+MakieExt = "Makie"
 UnitfulExt = "Unitful"
 
 [compat]
 Accessors = "0.1"
 AstroAngles = "0.2"
 ConstructionBase = "1"
+Makie = "0.21.18"
 Rotations = "1"
 StaticArrays = "0.8, 0.9, 1"
 Unitful = "1.15"
 julia = "1.6"
 
 [extras]
 Accessors = "7d9f7c33-5ae7-4f3b-8dc6-eff91059b697"
+Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
 Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"

ext/MakieExt.jl

@@ -0,0 +1,11 @@
+module MakieExt
+
+using Makie
+using SkyCoords: AbstractSkyCoords, lonlat
+
+Makie.convert_arguments(ct::PointBased, c::AbstractSkyCoords) = convert_arguments(ct, [c])
+
+Makie.convert_arguments(ct::PointBased, cs::AbstractVector{<:AbstractSkyCoords}) =
+    convert_arguments(ct, map(c -> Point(lonlat(c)...), cs))
+
+end

ext/UnitfulExt.jl

@@ -11,6 +11,7 @@
 
 SkyCoords.lon(u::Unitful.Units, c) = SkyCoords.lon(c) * u"rad" |> u
 SkyCoords.lat(u::Unitful.Units, c) = SkyCoords.lat(c) * u"rad" |> u
+SkyCoords.lonlat(u::Unitful.Units, c) = SkyCoords.lonlat(c) .* u"rad" .|> u
 
 SkyCoords.separation(u::Unitful.Units, c1, c2) = SkyCoords.separation(c1, c2) * u"rad" |> u
 SkyCoords.position_angle(u::Unitful.Units, c1, c2) = SkyCoords.position_angle(c1, c2) * u"rad" |> u

src/SkyCoords.jl

@@ -121,6 +121,8 @@ lon(c::EclipticCoords) = c.lon
 lon(c::AbstractSkyCoords) = c.ra
 lat(c::AbstractSkyCoords) = c.dec
 
+lonlat(c::AbstractSkyCoords) = (lon(c), lat(c))
+
 # Abstract away specific field names (ra, dec vs l, b)
 coords2cart(c::AbstractSkyCoords) = coords2cart(lon(c), lat(c))
 

test/Project.toml

@@ -5,6 +5,7 @@ CondaPkg = "992eb4ea-22a4-4c89-a5bb-47a3300528ab"
 ConstructionBase = "187b0558-2788-49d3-abe0-74a17ed4e7c9"
 DelimitedFiles = "8bb1440f-4735-579b-a4ab-409b98df4dab"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
 PythonCall = "6099a3de-0909-46bc-b1f4-468b9a2dfc0d"
 StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"

test/runtests.jl

@@ -8,6 +8,7 @@ using SkyCoords
 using StableRNGs
 using Statistics
 using Test
+import Makie
 
 import SkyCoords: lat, lon
 
@@ -242,3 +243,12 @@ end
         @test coord_out == coord_in |> OUT_SYS
     end
 end
+
+VERSION >= v"1.9" && @testset "plotting with Makie" begin
+    coo = ICRSCoords(1, 2)
+
+    @test Makie.convert_arguments(Makie.Scatter, coo) == ([Makie.Point(1, 2)],)
+    @test Makie.convert_arguments(Makie.Scatter, [coo]) == ([Makie.Point(1, 2)],)
+    @test Makie.convert_arguments(Makie.Lines, [coo, coo]) == ([Makie.Point(1, 2), Makie.Point(1, 2)],)
+    @test Makie.convert_arguments(Makie.Lines, [coo][1:0]) == ([],)
+end