[XeTeX] new 'size' feature of Opentype fonts

[Jonathan Kew]

On 19 Sep 2006, at 4:35 am, Michael Zedler wrote:

> Hello Jonathan,
>
> perhaps you followed the discussion on the opentype mailing list;
> Adobe's new AFDKO 2.0 creates 'size' info according to the specs now.

Hi Michael -

I'm afraid I don't keep up with the OT list, normally....

>
> I generated an otf version of MnSymbol (all the 14 fonts) that uses  
> the
> new size feature and put it on
> http://www.hft.ei.tum.de/mz/MnSymbolOTF.zip. Perhaps you may find it
> useful for testing when you add support for the new size feature.

Good to see that work is happening on this. However, it's not yet  
perfect.... see below. (XeTeX does support the 'size' feature, as  
implemented in several Adobe fonts. However, its implementation in  
MnSymbol doesn't seem to be quite right yet, and so it does not find  
the optical faces properly.)

Here's the result of examining the "regular" fonts with otfinfo -- 
query-optical-size:

MnSymbol10.otf:design size 0.8 pt, size range (0 pt, 10 pt],  
subfamily ID 6, subfamily name Design by Achim Blumensath, Conversion  
to pfb by Michael Zedler. This font is in the public domain.

MnSymbol12.otf:design size 0.8 pt, size range (0 pt, 12 pt],  
subfamily ID 6, subfamily name Design by Achim Blumensath, Conversion  
to pfb by Michael Zedler. This font is in the public domain.

MnSymbol5.otf:design size 0.8 pt, size range (0 pt, 5 pt], subfamily  
ID 6, subfamily name Design by Achim Blumensath, Conversion to pfb by  
Michael Zedler. This font is in the public domain.

MnSymbol6.otf:design size 0.8 pt, size range (0 pt, 6 pt], subfamily  
ID 6, subfamily name Design by Achim Blumensath, Conversion to pfb by  
Michael Zedler. This font is in the public domain.

MnSymbol7.otf:design size 0.8 pt, size range (0 pt, 7 pt], subfamily  
ID 6, subfamily name Design by Achim Blumensath, Conversion to pfb by  
Michael Zedler. This font is in the public domain.

MnSymbol8.otf:design size 0.8 pt, size range (0 pt, 8 pt], subfamily  
ID 6, subfamily name Design by Achim Blumensath, Conversion to pfb by  
Michael Zedler. This font is in the public domain.

MnSymbol9.otf:design size 0.8 pt, size range (0 pt, 9 pt], subfamily  
ID 6, subfamily name Design by Achim Blumensath, Conversion to pfb by  
Michael Zedler. This font is in the public domain.


Note:
(a) design size is always the same, and not the correct value
(b) size range always begins at zero, which is not correct (and means  
xetex will not find the right face); the size ranges should be  
distinct, non-overlapping.
(c) subfamily name string ID is not correct; it apparently points to  
the copyright string


Now the Bold fonts:

MnSymbol-Bold10.otf:design size 0.8 pt, size range (0 pt, 10 pt],  
subfamily ID 6, subfamily name Design by Achim Blumensath, Conversion  
to pfb by Michael Zedler. This font is in the public domain.

MnSymbol-Bold12.otf:design size 0.8 pt, size range (0 pt, 12 pt],  
subfamily ID 6, subfamily name Design by Achim Blumensath, Conversion  
to pfb by Michael Zedler. This font is in the public domain.

MnSymbol-Bold5.otf:design size 0.8 pt, size range (0 pt, 5 pt],  
subfamily ID 6, subfamily name Design by Achim Blumensath, Conversion  
to pfb by Michael Zedler. This font is in the public domain.

MnSymbol-Bold6.otf:design size 0.8 pt, size range (0 pt, 6 pt],  
subfamily ID 6, subfamily name Design by Achim Blumensath, Conversion  
to pfb by Michael Zedler. This font is in the public domain.

MnSymbol-Bold7.otf:design size 0.8 pt, size range (0 pt, 7 pt],  
subfamily ID 6, subfamily name Design by Achim Blumensath, Conversion  
to pfb by Michael Zedler. This font is in the public domain.

MnSymbol-Bold8.otf:design size 0.8 pt, size range (0 pt, 8 pt],  
subfamily ID 6, subfamily name Design by Achim Blumensath, Conversion  
to pfb by Michael Zedler. This font is in the public domain.

MnSymbol-Bold9.otf:design size 0.8 pt, size range (0 pt, 9 pt],  
subfamily ID 6, subfamily name Design by Achim Blumensath, Conversion  
to pfb by Michael Zedler. This font is in the public domain.


Note:
same problems as the regular fonts; in addition, the subfamily ID is  
the same for bold and regular, which is incorrect.


In addition, the font names seem odd, and somewhat inconsistent. I  
haven't done an exhaustive dump and comparison, but many (not all)  
seem to have a family name that is *only* a number, for example. A  
careful review and cleanup is needed, I think, before these are ready  
for use as an OpenType family.


JK