CairoMakie does not respect the alpha attribute in poly

[asinghvi17]

• what version of Makie are you running? (]st -m Makie) master
• can you reproduce the bug with a fresh environment ? (]activate --temp; add Makie) yes
• What platform + GPU are you on? irrelevant

MWE:

f, a, p = poly(Rect2f(Vec2f(0), Vec2f(1)); color = :gray, alpha = 0.5)
a.title = "Alpha by direct kwarg"

a2, p2 = poly(f[1, 2], Rect2f(Vec2f(0), Vec2f(1)); color = (:gray, 0.5))
a2.title = "Alpha in color"

f

This is likely an issue only in CairoMakie, since GLMakie works.

[SimonDanisch]

Didn't we have an issue and PR for this? :D

[asinghvi17]

I vaguely remembered that too, but couldn't find it...maybe it's the shared attributes PR? But that's not merged yet either.

[ffreyer]

#3735?

[asinghvi17]

Yeah, that looks like the same issue!

Makie.jl/CairoMakie/src/utils.jl

Lines 496 to 499 in 252d40e

	function to_cairo_color(color, plot_object)
	return to_color(color)
	end

could probably be changed to query for alpha and include it. Then we don't have to worry about alpha at all, in any plot recipe.

We'd probably have to remove some of the explicit alpha mentions, as in lines etc...