Re: RTL PUA?

William_J_G Overington 於 2011年8月22日 下午12:36 寫道：

> On Monday 22 August 2011, John H. Jenkins <jenkins_at_apple.com> wrote:
>
>> Forgive my asking, but this reference to the "description section of the Macintosh Roman section of a TrueType font" has me puzzled, because I don't know what you're talking about. What table contains this string?
>
> When I use FontCreator, made by High-Logic, http://www.high-logic.com is the webspace: with a font file open, I can select Format from the menu bar and then select Naming... from the drop down menu.
>
> That leads to a dialogue panel.
>
> From that dialogue panel one may select, for an ordinary, basic Unicode font, either of two platforms, namely Macintosh Roman and Microsoft Unicode BMP only.
>
> Having selected a platform, one may view the text content of various fields for that platform, such as font family name and copyright notice, version string and postscript name. There is then a button that is labelled Advanced... that, if clicked, opens another dialogue panel with various other text fields, including Font Designer and Description, which are the two that I often use.
>
> Now, when the text values in the fields are stored in the font file, the values for the Macintosh Roman platform are stored in plain text and the values for the Microsoft Unicode BMP only platform are stored in some encoded format.
>
> So, if one opens a TrueType font file in WordPad and one searches for an item of plain text that is in one of the fields of the font, then the text that is in the Macintosh platform can be found, yet the text that is in the Microsoft Unicode BMP only platform cannot be found.
>
> So, I thought that if a manufacturer of a wordprocessing application or a desktop publishing application decided to make a "special researcher's edition" of the software, then that software could, when a font is selected, first scan the font for a PUA.RTL string and, if one is found, override the left-to-right nature of the identified characters to be a right-to-left nature, just while that font is selected.
>
> Whether such a software package ever becomes available is something that only time will tell, yet it seems to me that it is a method that could be used without needing any changes by any committee.
>

Ah. You're referring to an entry in the 'name' table, then. The intention of the 'name' table is to provide localizable strings for the UI. Using it to store data of any sort for the rendering engine would be very, very inappropriate.

In general, one should not be using a text editor to examine the contents of a TrueType font. It would be like using a text editor to examine the contents of an application. Even if you see some plain text, you really don't have any sense for how it's actually being used.

You may want to bone up on the structure of TrueType/OpenType fonts.

=====
John H. Jenkins
井作恆
𐐖𐐱𐑌 𐐐. 𐐖𐐩𐑍𐐿𐐮𐑌𐑆
jenkins_at_apple.com
Received on Mon Aug 22 2011 - 14:12:08 CDT