Incorrect LaTeX rendering about luxor.jl

[GiggleLiu]

I also notice that YaoPlots.jl does not render correctly in today's presentation:

It is not related to MathTexEngine, all utf-8 code does not render (at least on Mac) I think.

I'd love to see a full latex support! It will be amazing.

[cormullion]

Hi! The first thing is to get the MathTeXEngine fonts installed correctly - then at least some of the characters will appear in the right font. I’ll try your example later today to see if it’s a Luxor or MathTeXEngine issue.

[bmxam]

I see. How do you check that the MathTeXEngine fonts are correctly installed? I ran the Luxor LaTeX documentation example (see below). Everything seems at the right place but, indeed, the font seems a little bit "bad" to me.

[bmxam]

On a linux machine, where the fonts of MathTeXEngine have been copied to ~/.local/share/fonts, I obtain the following result:

[cormullion]

That's the first step. :) Now, I wonder whether MathTeXEngine is going to do a large integral anyway. To debug it:

using MathTeXEngine
generate_tex_elements(L"\int_{\Gamma} \nabla f dA")
6-element Vector{Any}:
 (TeXChar '∫' [index 5930 in NewComputerModern Math - Regular], [0.0, 0.0], 1.0)
 (TeXChar 'Γ' [index 374 in NewComputerModern Math - Regular], [-0.014700007624924183, -1.36899995803833], 0.6)
 (TeXChar '∇' [index 842 in NewComputerModern Math - Regular], [0.9990000128746033, 0.0], 1.0)
 (TeXChar 'f' [index 71 in NewComputerModern - 10 Italic], [1.8320000171661377, 0.0], 1.0)
 (TeXChar 'd' [index 69 in NewComputerModern - 10 Italic], [2.1389999389648438, 0.0], 1.0)
 (TeXChar 'A' [index 34 in NewComputerModern - 10 Italic], [2.6500000953674316, 0.0], 1.0)

and it looks like that "∫" glyph is scaled at 1.0... :( But I might be wrong.

Is that expected behaviour?

Well, yes... Support for LaTeX is not really very good, partly because text handling in Luxor/Cairo generally isn't very good, and partly because Cairo.jl doesn't really have maintainers any more (eg JuliaGraphics/Cairo.jl#357).

To be honest, I'd suggest either:

• saving LaTex as an SVG image and importing it

• fiddling with textplace() (which is painful but sometimes it gets the job done):

d = @png begin
    textplace(
        "∫abΓ∇fda",
        O - (200, 0),
        [
            (size=120, face="NewCMMath-Regular", advance=false), # ∫
            (size=40, face="NewComputerModern10-Regular", shift = -70, kern=20), # a
            (size=40, shift = 100, kern = 25), # b
            (size=50, kern = 5), # Γ
            (size=50, face="NewCMMath-Regular", kern=5), # ∇
            (size=50, face="NewComputerModern10-Regular", ), # f
            (size=50, ), # d
            (size=50, ), # a
        ])
end 600 600 "mwe.png"

display(d)

[bmxam]

Thank you for your answer. I chose the LaTeX svg in the present case. It would be nice to have a "fallback" extension where the LaTeX would be compiled on-the-fly (it would require a proper install) and rendered. I might take a look at it some day.

[cormullion]

Yes - would be good.

But full LaTeX support is probably out of scope for this “simple drawing package” 😂. Makie.jl is a possibility.