No clip paths?

[jkrumbiegel]

I can't find documentation on clipping paths, like making a half moon by subtracting a circle from another circle. Is this not possible in compose.jl?

[Mattriks]

There is basic clipping, not documented yet. For basic clipping, everything outside the clip() shape is clipped out:

set_default_graphic_size(7inch,3.5inch)

points(x::Compose.Form) = x.primitives[1].points

X = rand(10,2)
colv = HSVA.(range(0,stop=180,length=10), 1, 1, 0.5)

img = compose(context(units=UnitBox(0,0,2,1)), stroke("black"),
    (context(), rectangle(), fill(nothing)),
    (context(), ngon([0.5,1.5],[0.5], [0.4], [10]), fill(nothing), stroke("lightgray")),
    (context(), xgon(X[:,1],X[:,2],[0.2],[4]), fill(colv)),
    (context(), xgon(X[:,1].+1,X[:,2],[0.2],[4]), fill(colv),
        clip(points(ngon(1.5,0.5, 0.4, 10))) )
)

draw(PNG(), img)
# draw(SVG(), img)

Your hypothetical example of a crescent moon is interesting because that would involve inner clipping i.e. everything inside the inner circle (or shape) is clipped out. Pasting a white circle would have the same effect (but don't know if that's suitable):

img = compose(context(),
    (context(), circle([0.5,0.35], [0.5], [0.25,0.3]), fill(["gold","white"]))
)

[tlnagy]

It would be awesome to have this make it into the docs, looks great @Mattriks