Disappearing characters

Disappearing characters

[Duncan Hothersall]

Hello all.

I have a file test-fonts.tex which just combines Palatino and Helvetica
into one typescript:
----
\loadmapfile[context-base]
\usetypescriptfile[type-buy]
\starttypescript [TESTfonts]
  \definetypeface [TESTCombo] [rm] [serif] [palatino] [default]
[encoding=texnansi]
  \definetypeface [TESTCombo] [ss] [sans] [helvetica] [default]
[encoding=texnansi]
\stoptypescript
----

And I have a simple test file which tries that typescript out:
----
\usetypescriptfile[test-fonts.tex]
\usetypescript[TESTfonts][texnansi]
\setupbodyfont[TESTCombo,14pt]
\starttext
Palatino? Normal \Delta, Maths \mathematics\Delta, Greek \greekDelta\par
Palatino? Normal \delta, Maths \mathematics\delta, Greek \greekdelta\par

{\ss Helvetica? Normal \Delta, Maths \mathematics\Delta, Greek
\greekDelta\par
Helvetica? Normal \delta, Maths \mathematics\delta, Greek \greekdelta\par}
\stoptext
----

With the line
'\setupbodyfont[TESTCombo,14pt]'
everything works well, but when I change it to
'\setupbodyfont[TESTCombo,10pt]'
the Delta signs disappear! (The lowercase deltas remain - weird?)

I am really confused (and it took ages to understand what was happening,
since the disappearing Greek originally occurred in a 700 page book...).

When comparing the log files for each version, the broken one (10pt) has
the line:
----
Warning: pdfetex.exe (file
c:\tex\texmf/fonts/type1/urw/palatino/uplr8a.pfb): glyph `uni20AC' undefined
----
whereas the working one (14pt) doesn't, and instead has:
----
{c:\tex\texmf-local/fonts/enc/dvips/lm/cmrm.enc}<c:\tex\texmf/fonts/type1/public/lm/lmr10.pfb>
----

So, it seems to be something to do with a missing switch to the font
which contains the \Delta character, but why should it only happen at
smaller font sizes? Experimentation suggests that 12pt and below has
this problem, and over 12pt the problem disappears.

Thanks to anyone who can explain and help me to fix it.

Duncan

Re: Disappearing characters

[Duncan Hothersall]

I said:
> \starttypescript [TESTfonts]
>   \definetypeface [TESTCombo] [rm] [serif] [palatino] [default]
> [encoding=texnansi]
>   \definetypeface [TESTCombo] [ss] [sans] [helvetica] [default]
> [encoding=texnansi]
> \stoptypescript

I realise that by adding

----
  \definetypeface [TESTCombo] [tt] [mono]  [modern] [computer-modern]
[encoding=\typescripttwo]
  \definetypeface [TESTCombo] [mm] [math]  [modern] [computer-modern]
[encoding=\typescripttwo]
----

to that typescript, I can stop the Deltas disappearing; however, it
would be really helpful if someone can tell me why I only need to do
that for font sizes below 12pt?!

Thanks,

Duncan