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I am using Apache FOP for PDF generation in Arabic text. I have understood that Apache FOP full supports Arabic text from their site documentation i.e. http://xmlgraphics.apache.org/fop/trunk/complexscripts.html

But I am bit little confuse because I don't know which font is better for arabic language. From documentation they have given Arabic language supported font list with their GPOS support.

Arabic Fonts

Font               Version  Glyphs  Comments
Arial Unicode MS    1.01    50377   limited GPOS support
Lateef              1.0     1147    language features for Kurdish (KUR), Sindhi (SND), Urdu (URD)
Scheherazade        1.0     1197    language features for Kurdish (KUR), Sindhi (SND), Urdu (URD)
Simplified Arabic   1.01        contains invalid, out of order coverage table entries
Simplified Arabic   5.00    414 lacks GPOS support
Simplified Arabic   5.92    473 includes GPOS for advanced position adjustment
Traditional Arabic  1.01    530 lacks GPOS support
Traditional Arabic  5.00    530 lacks GPOS support
Traditional Arabic  5.92    589 includes GPOS for advanced position adjustment

So my Question is what is meant by GPOS?.I know its full form Glyph Position.I want more information related to GPOS so that I can decide ttf font properly.

Oomph Fortuity
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1 Answers1

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Read the Official documentation from Adobe. As you can see, a GPOS table can define a lot of functionality:

The GPOS table supports eight types of actions for positioning and attaching glyphs ..

some "typical" for any font, such as kerning, some per decision of the font designer, such as superscripts and subscripts and niceties such as "all caps spacing", and some that perform advanced re-positioning for complex scripts and glyphs. The latter is not a design decision, but are actually required to have the font display as it should. (Hence, "lacks GPOS support", for an Arabic font, means it contains the plain character set, but all positioning is left to the font drawing engine.)

"Limited GPOS support" means exactly what it says; "full support" would indicate all features in a font should work as intended by the OpenType Specification. In this case, the programmers of FOP are aware they did not implement all possible features and/or GPOS functionality.

That means that fonts which only use the supported features will work "correctly" (i.e., as the font designer intended). Some fonts may be using not-implemented features and so they cannot guarantee your text will come out as intended.

Go through the list and try each of the fonts (if you have them) and see what the limitations actually mean. I would guess the latest versions of both "Simplified Arabic" and "Traditional Arabic" should work.

Jongware
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