Am 18.04.2015 um 13:51 schrieb Hans Hagen <pragma@wxs.nl>:

On 4/18/2015 1:21 PM, Csikos Bela wrote:

Before answering I wanted to find out how to make this fallback: Using a given font
and fall back to only one (or a few) specific characters in another font. For example
using Tex Gyre Pagella and fall back to Dejavu's black diamond, but not to any other
characters.

To learn how to do this, in the last few days I read most of (if not all) the related pages on
the wiki site, and browsed the indicated pdf documents too. Unfortunately I find the wiki
pages confusing, and I couldn't find out how to solve the problem yet, but I did not want
to wait longer with the answer. I will study further the docs.

search for 'fallbacks' in the test suite

(you can have fallback ranges but also individual characters)

Fallbacks don’t work when you use \iffontchar to check if the character is in the font
even though it is available in the fallback font.

\definefallbackfamily [testfont] [rm] [DejaVu Serif] [range=0x25C6]
\definefontfamily     [testfont] [rm] [TeX Gyre Pagella]

\setupbodyfont[dejavu]

\starttext

◆ : \checkedtextchar{"25C6}{{\tttf ??}}

\switchtobodyfont[testfont]

◆ : \checkedtextchar{"25C6}{{\tttf ??}}

\stoptext

Wolfgang