On 2017-01-20 23:54, Alan Braslau wrote:
> On Fri, 20 Jan 2017 22:33:40 -0500
> Rik Kabel <context@rik.users.panix.com> wrote:
>
>> Can anyone suggest a better way to compose such symbols than using
>> the raw TeX commands used here? Is there a more ConTeXt-ish way to do
>> this? Is it possible to get options to center the glyphs from which
>> the symbol is assembled (separate horizontal and vertical, with the
>> ability to offset them)?
>>
>> Is there a ConTeXt way other than \definesymbol to create such
>> combined symbols?
> MetaPost (with textext())?

Thank you for that, Alan. I hadn’t ever used MetaPost before, thinking 
it was too complex for my needs. Now I see it may be quite useful.

So, how can I make the inner glyph (‘?’ in the example below) 
transparent, so that the background shows through along with anything 
else that lives on a lower layer? I’ve seen a method for constructed 
shapes, but nothing that I can apply to text glyphs. Undraw doesn’t do it.

       \setupbackgrounds
        [page]
        [background=color,backgroundcolor=yellow]
      \definefont
        [DVSrB]
        [file:DejaVuSerif-Bold.ttf]
      \startuseMPgraphic{HeartTest}
        picture h;
        h := "♥" infont "\truefontname{DejaVuSerif-Bold.ttf}" scaled 20;
        picture q;
        q := textext("{\DVSrB ?}") scaled 10;     % just a different way
        q := q shifted - (xpart center q, 12pt) ;
        draw h withcolor blue;
        undraw q;                                   % this doesn't do it
      \stopuseMPgraphic
      \starttext
        \useMPgraphic{HeartTest}
      \stoptext

-- 
Rik