On Monday 22 August 2011, William_J_G Overington <[email protected]>
wrote:
> Would a third option work?
>
> In the Description section of the Macintosh Roman section of a TrueType font,
> include a line of text in a plain text format of which the following line of
> text is an example.
>
> PUA.RTL="$E000-$E1FF,$E440-$E447,$E541,$E549,$E57C,$EA00-$EA0F,$EC07";
>
> One could specify precisely which Private Use Area characters were to become
> RTL when using that particular font.
>
> One would need rendering software that looked for such a string of text in
> the font file, yet, as far as I am aware, no approval from any committee in
> order to put this solution into practical use.
Thinking further on this, I am putting forward the following suggestion for
discussion, in the hope that it might be of use.
Suppose that a a "special researcher's edition" of a wordprocessing
application or a desktop publishing application at start up looks in a
specified directory for a file with the following file name.
pua_major.txt
If pua_major.txt exists, then it is opened and it is searched for a PUA.RTL
assignment statement. If a PUA.RTL assignment statement is not found in the
file, it is taken as if the following had been included in the file.
PUA.RTL="";
If pua_major.txt is found, then that is an end of the searching process and no
search for PUA.RTL would take place in a font file.
If pua_major.txt is not found, then the application looks in a specified
directory for a file with the following file name.
pua_minor.txt
If pua_minor.txt exists, then it is opened and it is searched for a PUA.RTL
assignment statement. If a PUA.RTL assignment statement is not found in the
file, it is taken as if the following had been included in the file.
PUA.RTL="";
Also, if the file is not found, the PUA.RTL assignment statement is taken as
the following.
PUA.RTL="";
However, the value of PUA.RTL thus determined would be kept in reserve and only
used if there were no PUA.RTL assignment statement in the font that is being
used.
This method would allow the choice of where to specify right-to-left
directionality for some Private Use characters to be made either as being in a
font file or in a text file, with the choice of whether the text file is an
override or a backup of any such information within a font.
Would such a format solve the needs of those who want to use right-to-left
Private Use characters? If not, could people say what other features are needed
please in the hope that a suitable system can be specified by consensus within
this thread?
William Overington
23 August 2011
